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Dee DP, Lam G, Edielu A, Anguajibi V, Webb EL, Wamboko A, Mawa PA, Friedman JF, Simpson H, Bustinduy AL. A cross-sectional pilot household study of Schistosoma mansoni burden and associated morbidities in Lake Albert, Uganda. Trop Med Int Health 2024; 29:334-342. [PMID: 38356464 PMCID: PMC10984764 DOI: 10.1111/tmi.13978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
OBJECTIVES Schistosomiasis is persistent in Lake Albert, Uganda, but local data are limited. This study aims to describe the local burden of moderate-to-heavy infection and associated morbidity in all ages and identify factors associated with these outcomes to guide further research. METHODS This cross-sectional pilot study was conducted in July-August, 2022 in four village sites (Walukuba, Rwentale, Kyabarangwa and Runga) of the Praziquantel in Preschoolers (PIP) trial. Residents (approximately four per household) of any age of households of PIP participants were eligible, but individuals <10 years were only enrolled if no older individuals were available. Socio-demographic information, household location, single stool Kato-Katz and hepatic ultrasound results were obtained for a convenience sampled subset of trial households. The primary outcome, moderate-to-heavy infection (≥100 eggs per gram of faeces), was analysed using mixed-effects logistic regression, with a household random effect. Univariate analyses were used for the secondary outcome, periportal fibrosis (Niamey protocol ultrasound image pattern C-F). RESULTS Of 243 participants with a median age of 22 (interquartile range 12-33) years from 66 households, 49.8% (103/207 with a Kato-Katz result) had moderate-to-heavy infection and 11.2% (25/224 with ultrasound data) had periportal fibrosis. Moderate-to-heavy infection clustered by household (intraclass correlation coefficient = 0.11) and, in multivariable analysis, varied by village (Walukuba vs. Kyabarangwa adjusted odds ratio [aOR] 0.11, 95% CI 0.02-0.71), was highest in participants aged 10-15 years (vs. 5-9 years aOR 6.14, 95% CI 1.61-23.38) and lower in those reporting praziquantel treatment in the past year (aOR 0.39, 95% CI 0.18-0.88). CONCLUSIONS In this setting, schistosome infection and morbidity are pervasive in all age groups. More intensive interventions are needed, for example more frequent praziquantel treatment, under investigation in the PIP trial and improved water and sanitation. More research is needed to understand local treatment barriers and optimal control strategies.
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Affiliation(s)
- Dominic P Dee
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, United Kingdom
| | - Germain Lam
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andrew Edielu
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | | | - Emily L Webb
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Patrice A Mawa
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | - Jennifer F Friedman
- Center for International Health Research, Rhode Island Hospital, Providence, Rhode Island, United States
- Alpert Medical School of Brown University, Providence, Rhode Island, United States
| | - Hope Simpson
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Centre for Global Health Research, Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Amaya L Bustinduy
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Tabo Z, Breuer L, Fabia C, Samuel G, Albrecht C. A machine learning approach for modeling the occurrence of the major intermediate hosts for schistosomiasis in East Africa. Sci Rep 2024; 14:4274. [PMID: 38383705 PMCID: PMC10881506 DOI: 10.1038/s41598-024-54699-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/15/2024] [Indexed: 02/23/2024] Open
Abstract
Schistosomiasis, a prevalent water-borne disease second only to malaria, significantly impacts impoverished rural communities, primarily in Sub-Saharan Africa where over 90% of the severely affected population resides. The disease, majorly caused by Schistosoma mansoni and S. haematobium parasites, relies on freshwater snails, specifically Biomphalaria and Bulinus species, as crucial intermediate host (IH) snails. Targeted snail control is advisable, however, there is still limited knowledge about the community structure of the two genera especially in East Africa. Utilizing a machine learning approach, we employed random forest to identify key features influencing the distribution of both IH snails in this region. Our results reveal geography and climate as primary factors for Biomphalaria, while Bulinus occurrence is additionally influenced by soil clay content and nitrogen concentration. Favorable climate conditions indicate a high prevalence of IHs in East Africa, while the intricate connection with geography might signify either dispersal limitations or environmental filtering. Predicted probabilities demonstrate non-linear patterns, with Bulinus being more likely to occur than Biomphalaria in the region. This study provides foundational framework insights for targeted schistosomiasis prevention and control strategies in the region, assisting health workers and policymakers in their efforts.
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Affiliation(s)
- Zadoki Tabo
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26 (iFZ), 35392, Giessen, Germany.
- Institute for Landscape Ecology and Resource Management, Justus Liebig University Giessen, Heinrich-Buff-Ring 26 (iFZ), 35392, Giessen, Germany.
| | - Lutz Breuer
- Institute for Landscape Ecology and Resource Management, Justus Liebig University Giessen, Heinrich-Buff-Ring 26 (iFZ), 35392, Giessen, Germany
- Centre for International Development and Environmental Research (ZEU), Justus Liebig University Giessen, Senckenbergstrasse 3, 35390, Giessen, Germany
| | - Codalli Fabia
- Institute for Landscape Ecology and Resource Management, Justus Liebig University Giessen, Heinrich-Buff-Ring 26 (iFZ), 35392, Giessen, Germany
| | - Gorata Samuel
- Institute for Landscape Ecology and Resource Management, Justus Liebig University Giessen, Heinrich-Buff-Ring 26 (iFZ), 35392, Giessen, Germany
- Department of Environmental Science, Faculty of Science, University of Botswana, P/Bag UB00704, Gaborone, Botswana
| | - Christian Albrecht
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26 (iFZ), 35392, Giessen, Germany
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Starkloff NC, Angelo T, Mahalila MP, Charles J, Kinung'hi S, Civitello DJ. Spatio-temporal variability in transmission risk of human schistosomes and animal trematodes in a seasonally desiccating East African landscape. Proc Biol Sci 2024; 291:20231766. [PMID: 38196367 PMCID: PMC10777146 DOI: 10.1098/rspb.2023.1766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 12/05/2023] [Indexed: 01/11/2024] Open
Abstract
Different populations of hosts and parasites experience distinct seasonality in environmental factors, depending on local-scale biotic and abiotic factors. This can lead to highly heterogeneous disease outcomes across host ranges. Variable seasonality characterizes urogenital schistosomiasis, a neglected tropical disease caused by parasitic trematodes (Schistosoma haematobium). Their intermediate hosts are aquatic Bulinus snails that are highly adapted to extreme rainfall seasonality, undergoing prolonged dormancy yearly. While Bulinus snails have a remarkable capacity for rebounding following dormancy, we investigated the extent to which parasite survival within snails is diminished. We conducted an investigation of seasonal snail schistosome dynamics in 109 ponds of variable ephemerality in Tanzania from August 2021 to July 2022. First, we found that ponds have two synchronized peaks of schistosome infection prevalence and observed cercariae, though of lower magnitude in the fully desiccating than non-desiccating ponds. Second, we evaluated total yearly schistosome prevalence across an ephemerality gradient, finding ponds with intermediate ephemerality to have the highest infection rates. We also investigated dynamics of non-schistosome trematodes, which lacked synonymity with schistosome patterns. We found peak schistosome transmission risk at intermediate pond ephemerality, thus the impacts of anticipated increases in landscape desiccation could result in increases or decreases in transmission risk with global change.
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Affiliation(s)
| | - Teckla Angelo
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
- Nelson Mandela African Institute of Science and Technology, Arusha, Tanzania
| | - Moses P. Mahalila
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
| | - Jenitha Charles
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
| | - Safari Kinung'hi
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
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Pach S, Webb EL, Edielu A, Nagawa R, Anguajibi V, Mpooya S, Wu H, Colt S, Mawa P, Richter J, Friedman JF, Bustinduy AL. Baseline Liver Ultrasound Findings in Preschool Children From the Praziquantel in Preschoolers Trial in Lake Albert, Uganda. Pediatr Infect Dis J 2024; 43:14-20. [PMID: 37922490 PMCID: PMC10842963 DOI: 10.1097/inf.0000000000004119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2023]
Abstract
BACKGROUND Periportal fibrosis is a late-stage manifestation of chronic infection with Schistosoma mansoni . Praziquantel (PZQ), the only drug available for the treatment of schistosomiasis, has limited effect in treating established morbidity. Preschool-age children (PSAC) are not considered to be an at-risk population for severe morbidity. However, the prevalence of periportal fibrosis in PSAC in S. mansoni endemic settings is unknown. METHODS As part of a phase II clinical trial comparing different dosing regimens of PZQ in children age 12-47 months infected with S. mansoni in Uganda ("praziquantel in preschoolers" trial), we present baseline results assessing liver ultrasound (US) findings as per the WHO Niamey Protocol. RESULTS A total of 7/347 (2%) PSAC had Image Pattern C with pipe stems and echogenic rings suggestive of periportal fibrosis, 29/347 (8%) had Image Pattern B and 58 (17%) had evidence of periportal thickening There were higher adjusted odds of periportal thickening with older age [odds ratio (OR): 1.04; 95% confidence interval (CI): 1.00-1.07], primary maternal education (OR: 1.04; 95% CI: 1.00-1.07) and being taken to the lake weekly (OR: 3.02; 95% CI: 1.19-7.63). A further 44/347 children (13%) had a rounded caudal liver edge which was associated with high S. mansoni infection intensity (adjusted OR: 3.31; 95% CI: 1.46-7.51). CONCLUSIONS Incipient schistosomiasis-related liver morbidity was detected in young children enrolled in the praziquantel in preschoolers trial. Adequate age-adjusted reference measurements for liver ultrasound findings in very small children are lacking but urgently needed. Schistosomiasis-related fibrosis may be delayed or averted with early and repeated PZQ treatment.
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Affiliation(s)
| | - Emily L Webb
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Andrew Edielu
- From the Department of Clinical Research
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | - Roy Nagawa
- J.B International Medical Centre, Kampala, Uganda
| | | | | | - Hannah Wu
- Center for International Health Research, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island
| | - Susannah Colt
- Center for International Health Research, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island
| | - Patrice Mawa
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Joachim Richter
- Global Health Center, Institute of International Health, Charite Universitätsmedizin, Corporate Member of Free and Humboldt University, Berlin, Germany
- Swiss Tropical and Public Health Institute, Basle, Switzerland
| | - Jennifer F Friedman
- Center for International Health Research, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island
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Andrus PS, Stothard JR, Wade CM. Seasonal patterns of Schistosoma mansoni infection within Biomphalaria snails at the Ugandan shorelines of Lake Albert and Lake Victoria. PLoS Negl Trop Dis 2023; 17:e0011506. [PMID: 37578945 PMCID: PMC10424865 DOI: 10.1371/journal.pntd.0011506] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/06/2023] [Indexed: 08/16/2023] Open
Abstract
Intestinal schistosomiasis is hyperendemic in many sub-Saharan African countries. In Uganda, it is endemic at both Lake Albert (LA) and Lake Victoria (LV) and caused by S. mansoni that uses Biomphalaria snails as obligatory intermediate snail hosts. To shed light on local patterns of infection, we utilised two PCR-based methods to detect S. mansoni within Biomphalaria spp. as collected at the Ugandan shorelines of Lake Albert and Lake Victoria from 2009-2010. Overall, at our Lake Albert sites, the mean infection prevalence was 12.5% (15 of 120 snails), while at our Lake Victoria sites the prevalence was 5% (3 of 60 snails). At our Lake Albert sites, the highest infection prevalence of 13.3% (8 of 60 snails) was at Walukuba, while at our Lake Victoria sites, the highest infection prevalence of 10% (2 of 20 snails) was at Lwanika. Three species of Biomphalaria, B. pfeifferi, B. stanleyi and B. sudanica, were identified at our Lake Albert collection sites, while only a single species, B. choanomphala, was identified at our Lake Victoria collection sites. Biomphalaria stanleyi (2 of 20 snails; 15%) had the highest infection prevalence, followed by B. sudanica (5 of 60 snails; 13.3%), B. pfeifferi (4 of 40 snails; 10%) and B. choanomphala (3 of 60 snails; 5%). Of the Biomphalaria species identified, B. choanomphala had the highest haplotype (gene) diversity score, followed by B. stanleyi, B. sudanica and B. pfeifferi. Sites with a higher mean prevalence of S. mansoni infection had higher intra-species haplotype diversity scores than sites with a lower mean prevalence. The wet seasons (LA: 13.3%; LV: 8.7%) had a consistently higher mean infection prevalence of S. mansoni than the dry seasons (LA: 9.5%; LV: 5%) for all species and all sites tested at both Lake Albert (n = 480) and Lake Victoria (n = 320), though the difference was not statistically significant.
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Affiliation(s)
- Peter S. Andrus
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - J. Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Christopher M. Wade
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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6
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Starkloff NC, Angelo T, Mahalila MP, Charles J, Kinung’hi S, Civitello DJ. Spatiotemporal variability in transmission risk of human schistosomes and animal trematodes in a seasonally desiccating East African landscape. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542103. [PMID: 37292923 PMCID: PMC10245890 DOI: 10.1101/2023.05.25.542103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Different populations of hosts and parasites experience distinct seasonality in environmental factors, depending on local-scale biotic and abiotic factors. This can lead to highly heterogenous disease outcomes across host ranges. Variable seasonality characterizes urogenital schistosomiasis, a neglected tropical disease caused by parasitic trematodes (Schistosoma haematobium). Their intermediate hosts are aquatic Bulinus snails that are highly adapted to extreme rainfall seasonality, undergoing dormancy for up to seven months yearly. While Bulinus snails have a remarkable capacity for rebounding following dormancy, parasite survival within snails is greatly diminished. We conducted a year-round investigation of seasonal snail-schistosome dynamics in 109 ponds of variable ephemerality in Tanzania. First, we found that ponds have two synchronized peaks of schistosome infection prevalence and cercariae release, though of lower magnitude in the fully desiccating ponds than non-desiccating ponds. Second, we evaluated total yearly prevalence across a gradient of an ephemerality, finding ponds with intermediate ephemerality to have the highest infection rates. We also investigated dynamics of non-schistosome trematodes, which lacked synonymity with schistosome patterns. We found peak schistosome transmission risk at intermediate pond ephemerality, thus the impacts of anticipated increases in landscape desiccation could result in increases or decreases in transmission risk with global change.
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Affiliation(s)
| | - Teckla Angelo
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
| | - Moses P. Mahalila
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
| | - Jenitha Charles
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
| | - Safari Kinung’hi
- National Institute of Medical Research Mwanza Center, Mwanza, Tanzania
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Oso OG, Sunday JO, Odaibo AB. Temporal modelling of Lymnaea natalensis (Krauss, 1848) in tropical aquatic habitats. Onderstepoort J Vet Res 2023; 90:e1-e13. [PMID: 37265142 DOI: 10.4102/ojvr.v90i1.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/06/2022] [Accepted: 06/28/2022] [Indexed: 06/03/2023] Open
Abstract
Lymnaea natalensis is the only snail intermediate host of Fasciola gigantica, the causative agent of fascioliasis, in Nigeria. The species also serves as intermediate host for many other African trematode species of medical and veterinary importance, and it is found throughout the country. However, there is no detailed information on the factors that influence its distribution and seasonal abundance in the tropical aquatic habitats in Nigeria. This study used the geographic information system and remotely sensed data to develop models for predicting the distribution of L. natalensis in South-Western Nigeria. Both land surface temperature (LST) and normalised difference vegetation index (NDVI) were extracted from Landsat satellite imagery; other variables (slope and elevation) were extracted from a digital elevation model (DEM) while rainfall data were retrieved from the European Meteorology Research Programme (EMRP). These environmental variables were integrated into a geographic information system (GIS) to predict suitable habitats of L. natalensis using exploratory regression. A total of 1410 L. natalensis snails were collected vis-à-vis 22 sampling sites. Built-up areas recorded more L. natalensis compared with farmlands. There was no significant difference in the abundance of snails with season (p 0.05). The regression models showed that rainfall, NDVI, and slope were predictors of L. natalensis distribution. The habitats suitable for L. natalensis were central areas, while areas to the north and south were not suitable for L. natalensis.Contribution: The predictive risk models of L. natalensis in the study will be useful in mapping other areas where the snail sampling could not be conducted.
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Affiliation(s)
- Opeyemi G Oso
- Department of Zoology, Faculty of Science, University of Ibadan, Ibadan.
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Mulindwa J, Namulondo J, Kitibwa A, Nassuuna J, Nyangiri OA, Kimuda MP, Boobo A, Nerima B, Busingye F, Candia R, Namukuta A, Ssenyonga R, Ukumu N, Ajal P, Adriko M, Noyes H, de Dood CJ, Corstjens PLAM, van Dam GJ, Elliott AM, Matovu E. High prevalence of Schistosoma mansoni infection and stunting among school age children in communities along the Albert-Nile, Northern Uganda: A cross sectional study. PLoS Negl Trop Dis 2022; 16:e0010570. [PMID: 35895705 PMCID: PMC9359559 DOI: 10.1371/journal.pntd.0010570] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/08/2022] [Accepted: 06/08/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Knowing the prevalence of schistosomiasis is key to informing programmes to control and eliminate the disease as a public health problem. It is also important to understand the impact of infection on child growth and development in order to allocate appropriate resources and effort to the control of the disease. METHODS We conducted a survey to estimate the prevalence of schistosomiasis among school aged children in villages along the Albert-Nile shore line in the district of Pakwach, North Western Uganda. A total of 914 children aged between 10-15 years were screened for Schistosoma mansoni using the POC-CCA and Kato Katz (KK) techniques. The infection intensities were assessed by POC-CCA and KK as well as CAA tests. The KK intensities were also correlated with POC-CCA and with CAA intensity. Anthropometric measurements were also taken and multivariate analysis was carried out to investigate their association with infection status. RESULTS The prevalence of schistosomiasis using the POC-CCA diagnostic test was estimated at 85% (95% CI: 83-87), being highest amongst children living closer to the Albert-Nile shoreline. Visual scoring of the POC-CCA results was more sensitive than the Kato Katz test and was positively correlated with the quantified infection intensities by the CAA test. The majority of the children were underweight (BMI<18.5), and most notably, boys had significantly lower height for age (stunting) than girls in the same age range (p < 0.0001), but this was not directly associated with S. mansoni infection. CONCLUSION High prevalence of S. mansoni infection in the region calls for more frequent mass drug administration with praziquantel. We observed high levels of stunting which was not associated with schistosomiasis. There is a need for improved nutrition among the children in the area.
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Affiliation(s)
- Julius Mulindwa
- Department of Biochemistry and Sports Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Joyce Namulondo
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Anna Kitibwa
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Jacent Nassuuna
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Oscar Asanya Nyangiri
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Magambo Phillip Kimuda
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Alex Boobo
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Barbara Nerima
- Department of Biochemistry and Sports Sciences, College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Fred Busingye
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Rowel Candia
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Annet Namukuta
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Ronald Ssenyonga
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University, Kampala, Uganda
| | - Noah Ukumu
- Pakwach District Local Government, District Health Office, Pakwach, Uganda
| | - Paul Ajal
- Pakwach District Local Government, District Health Office, Pakwach, Uganda
| | - Moses Adriko
- Vector Borne & NTD Control Division, Ministry of Health, Kampala, Uganda
| | - Harry Noyes
- Centre for Genomic Research, University of Liverpool, Liverpool, United Kingdom
| | - Claudia J. de Dood
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Paul L. A. M. Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alison M. Elliott
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Enock Matovu
- Department of Biotechnical and Diagnostic Sciences, College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
- * E-mail:
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Molla G, Tintagu T, Yasin A, Alemu B, Assen AA, Tadesse K. Bovine schistosomiasis in some selected areas of South Wollo and Oromia Zones of Amhara Region, North-East Ethiopia. PLoS One 2022; 17:e0259787. [PMID: 35714123 PMCID: PMC9205502 DOI: 10.1371/journal.pone.0259787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 05/31/2022] [Indexed: 11/29/2022] Open
Abstract
A cross-sectional coprological and pathological study was conducted in five districts of South Wollo and Oromia Administrative Zones, Amhara regional state, Ethiopia from November 2020 to June 2021 to determine the prevalence and associated risk factors of Bovine Schistosomiasis and to characterize pathological lesions induced by the adult worm of Schistosoma bovis. For coprological examination, a total of 768 fecal samples were collected both from the field (384) and the abattoirs (384). An abattoir survey was carried out on 384 cattle to evaluate the performance of the sedimentation method. The risk factors were identified using multivariable mixed-effect logistic regression analyses. The diagnostic efficacy of the sedimentation technique was determined by calculating sensitivity and specificity considering postmortem examination as a reference test. The overall prevalence of bovine shistosomiasis using coprological examination was found to be 16.7% (95% CI = 14.10–19.49). The prevalence of shistosomiasis based on post-mortem examination was found to be 17.19% (95% CI = 13.55–21.34). Local cattle breed (OR = 2.44, 95%CI = 1.34–4.43), poor body condition (OR = 4.09, 95% CI = 2.45–6.83) and adult (OR = 1.78, 95% CI = 1.21–3.28) cattle are more likely to acquire shistosomiasis than crossbreed, good body condition, and young cattle. The sensitivity and specificity of sedimentation techniques, keeping postmortem examination as a reference test were 74.24% (95%CI = 61.99–84.22) and 98.11% (95%CI = 95.94–99.30), respectively. The major gross lesions were observed in the liver and intestinal tracts. In conclusion, adult local cattle with medium and poor body conditions should be prioritized for deworming and future surveillance.
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Affiliation(s)
- Gashaw Molla
- Dessie Zuria Livestock Development Office, Dessie, Ethiopia
| | - Tarekegn Tintagu
- School of Veterinary Medicine, Wollo University, Dessie, Ethiopia
- * E-mail:
| | - Ahmed Yasin
- School of Veterinary Medicine, Wollo University, Dessie, Ethiopia
| | - Bethelehem Alemu
- School of Veterinary Medicine, Wollo University, Dessie, Ethiopia
| | | | - Kassahun Tadesse
- School of Veterinary Medicine, Wollo University, Dessie, Ethiopia
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Oso OG, Sunday JO, Odaibo AB. Models for predicting bulinids species habitats in southwestern Nigeria. Parasite Epidemiol Control 2022; 18:e00256. [PMID: 35712128 PMCID: PMC9194844 DOI: 10.1016/j.parepi.2022.e00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/27/2021] [Accepted: 05/25/2022] [Indexed: 11/04/2022] Open
Abstract
Background Schistosomiasis prevalence is high in southwestern Nigeria and planorbids of the genus Bulinus had been implicated in the transmission of the disease in the area. The knowledge of species distribution in relation to environmental variables will be auspicious in planning control strategies. Methods Satellite imagery and geographic information system (GIS) were used to develop models for predicting the habitats suitable for bulinid species. Monthly snail sample collection was done in twenty-three randomly selected water contact sites using the standard method for a period of two years. Remotely sensed variables such as Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI) were extracted from Landsat TM, ETM+; Slope and Elevation were obtained from digital elevation model (DEM) while Rainfall was retrieved from European Meteorology Research Program. These environmental factors and snail species were integrated into QGIS to predict the potential habitats of different bulinid species using an exploratory regression model. Results The following environmental variables: flat-moderate slope (0.01–15.83), LST (21.1 °C-23.4 °C), NDVI (0.19–0.52), rainfall (> 1569.34 mm) and elevation (1–278 m) contributed to the model used in predicting habitat suitable for bulinids snail intermediate hosts. Exploratory regression models showed that LST, NDVI and slope were predictors of Bulinus globosus and Bulinus jousseaumei; elevation, LST, rainfall and slope were predictors of Bulinus camerunensis; rainfall, NDVI and slope were predictors of B. senegalensis while NDVI and slope were predictors of Bulinus forskalii in the area. Bulinids in the forskalii group showed clustering in middle belt and south. The predictive risk map of B. jousseaumei was similar to the pattern described for B. globosus, but with a high R-square value of 81%. Conclusion The predictive risk models of bulinid species in this study provided a robust output for the study area which could be used as base-line for other areas in that ecological zone. It will be useful in appropriate allocation of scarces resources in the control of schistosomiasis in that environment.
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Prevalence of Schistosoma mansoni and Associated Risk Factors in Human and Biomphalaria Snails in Ethiopia: A Systematic Review and Meta-analysis. Acta Parasitol 2022; 67:31-48. [PMID: 34259986 DOI: 10.1007/s11686-021-00449-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/28/2021] [Indexed: 01/27/2023]
Abstract
PURPOSE Schistosomiasis is one of the leading chronic parasitic diseases in Ethiopia. We aimed to summarize the prevalence of S. mansoni in human and Biomphalaria snails as well as risk factors in Ethiopia. METHODS Literature search was carried out from Scopus, Google Scholar, Science Direct and PubMed which reported Schistosoma mansoni infection in human and Biomphalaria snails in Ethiopia. The overall prevalence was estimated by a random-effect model and heterogeneities among studies were assessed by I2 test. RESULTS A total of 178,251 participants and 1,097 snails were tested for the presence of S. mansoni in the eligible studies. The pooled prevalence of S. mansoni was 32.5% (95% CI 28.0-37.0) and 15.9% (95% CI - 5.6-37.5) in human and Biomphalaria snails in Ethiopia, respectively. The highest pooled prevalence was 43.2% (95% CI 27.3-59.1) in South Nations and National Peoples region while the lowest pooled prevalence was 25% (95% CI 19.3-30.7) observed in the Afar region. Interestingly, the pooled prevalence of S. mansoni declined from 40.7% (95% CI 33-48.4) to 22.4% (95% CI 18.5-26.3) after the launching of mass drug administration (MDA). The analysis of risk factors showed that swimming habit (OR, 2.78; 95% CI 2.35-3.21) and participation in irrigation (OR, 2.69; 95% CI 1.45-3.73) were independent predictors for S. mansoni infection. CONCLUSION This study revealed that about one-third of human and nearly 16% of Biomphalaria snails were infected with S. mansoni in Ethiopia. This review indicated that the prevalence of S. mansoni declined after the implementation of MDA. This study highlights the importance of further integrated approaches for better control of schistosomiasis in Ethiopia.
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Nigo MM, Odermatt P, Salieb–Beugelaar GB, Morozov O, Battegay M, Hunziker PR. Epidemiology of Schistosoma mansoni infection in Ituri Province, north-eastern Democratic Republic of the Congo. PLoS Negl Trop Dis 2021; 15:e0009486. [PMID: 34855748 PMCID: PMC8638996 DOI: 10.1371/journal.pntd.0009486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 05/14/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Schistosomiasis, caused by Schistosoma mansoni, is of great significance to public health in sub-Saharan Africa. In the Democratic Republic of Congo (DRC), information on the burden of S. mansoni infection is scarce, which hinders the implementation of adequate control measures. We assessed the geographical distribution of S. mansoni infection across Ituri province in north-eastern DRC and determined the prevailing risk factors. METHODS/PRINCIPAL FINDINGS Two province-wide, community-based studies were conducted. In 2016, a geographical distribution study was carried out in 46 randomly selected villages across Ituri. In 2017, an in-depth study was conducted in 12 purposively-selected villages, across the province. Households were randomly selected, and members were enrolled. In 2016, one stool sample was collected per participant, while in 2017, several samples were collected per participant. S. mansoni eggs were detected using the Kato-Katz technique. In 2017, a point-of-care circulating cathodic S. mansoni antigen (POC-CCA) urine test was the second used diagnostic approach. Household and individual questionnaires were used to collect data on demographic, socioeconomic, environmental, behavioural and knowledge risk factors. Of the 2,131 participants in 2016, 40.0% were positive of S. mansoni infection. Infection prevalence in the villages ranged from 0 to 90.2%. Of the 707 participants in 2017, 73.1% were tested positive for S. mansoni. Prevalence ranged from 52.8 to 95.0% across the health districts visited. Infection prevalence increased from north to south and from west to east. Exposure to the waters of Lake Albert and the villages' altitude above sea level were associated with the distribution. Infection prevalence and intensity peaked in the age groups between 10 and 29 years. Preschool children were highly infected (62.3%). Key risk factors were poor housing structure (odds ratio [OR] 2.1, 95% 95% confidence interval [CI] 1.02-4.35), close proximity to water bodies (OR 1.72, 95% CI 1.1-2.49), long-term residence in a community (OR 1.41, 95% CI 1.11-1.79), lack of latrine in the household (OR 2.00, 95% CI 1.11-3.60), and swimming (OR 2.53, 95% CI 1.20-5.32) and washing (OR 1.75, 95% CI 1.10-2.78) in local water bodies. CONCLUSIONS/SIGNIFICANCE Our results show that S. mansoni is highly endemic and a major health concern in Ituri province, DRC. Infection prevalence and intensity, and the prevailing socioeconomic, environmental, and behavioural risk factors in Ituri reflect intense exposure and alarming transmission rates. A robust plan of action is urgently needed in the province.
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Affiliation(s)
- Maurice M. Nigo
- Nanomedicine Translation Group, Intensive Care Unit, University Hospital Basel, University of Basel, Basel, Switzerland
- CLINAM–European Foundation for Clinical Nanomedicine, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Institut Supérieur des Techniques Médicales (ISTM) Nyankunde, Bunia, Democratic Republic of Congo
| | - Peter Odermatt
- University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Georgette B. Salieb–Beugelaar
- Nanomedicine Translation Group, Intensive Care Unit, University Hospital Basel, University of Basel, Basel, Switzerland
- CLINAM–European Foundation for Clinical Nanomedicine, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Oleksii Morozov
- Nanomedicine Translation Group, Intensive Care Unit, University Hospital Basel, University of Basel, Basel, Switzerland
- CLINAM–European Foundation for Clinical Nanomedicine, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Manuel Battegay
- University of Basel, Basel, Switzerland
- Department of Infectiology & Hospital Hygiene, University Hospital Basel, Basel, Switzerland
| | - Patrick R. Hunziker
- Nanomedicine Translation Group, Intensive Care Unit, University Hospital Basel, University of Basel, Basel, Switzerland
- CLINAM–European Foundation for Clinical Nanomedicine, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Gender-related differences in prevalence, intensity and associated risk factors of Schistosoma infections in Africa: A systematic review and meta-analysis. PLoS Negl Trop Dis 2021; 15:e0009083. [PMID: 34788280 PMCID: PMC8635327 DOI: 10.1371/journal.pntd.0009083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 12/01/2021] [Accepted: 09/29/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Schistosomiasis remains a global-health problem with over 90% of its burden concentrated in Africa. Field studies reflect the complex ways in which socio-cultural and socio-economic variables, affect the distribution of Schistosoma infections across different populations. This review set out to systematically investigate and quantify the differences in Schistosoma infection burdens between males and females in Africa for two of the most prevalent Schistosoma species-Schistosoma mansoni and Schistosoma haematobium. METHODOLOGY We searched (from inception to 11th March 2020) Embase, MEDLINE, PubMed, and Web of Science for relevant studies on schistosomiasis. We included studies that report S. mansoni and/or S. haematobium prevalence and/or intensity data distributed between males and females. We conducted meta-analyses on the male to female (M:F) prevalence of infection ratios. Subgroup analyses were performed according to study baseline prevalence, sample size and the lower and upper age limit of study participants. We also present a descriptive analysis of differential risk and intensity of infection across males and females. Evidence for differences in the prevalence of schistosomiasis infection between males and females is presented, stratified by Schistosoma species. RESULT We identified 128 relevant studies, with over 200,000 participants across 23 countries. Of all the reported differences in the prevalence of infection between males and females, only 41% and 34% were statistically significant for S. mansoni and S. haematobium, respectively. Similar proportions of studies (27% and 34% for for S. haematobium and S. mansoni, respectively) of the reported differences in intensity of infection between males and females were statistically significant. The meta-analyses summarized a higher prevalence of infection in males; pooled random-effects weighted M:F prevalence of infection ratios were 1.20 (95% CI 1.11-1.29) for S. haematobium and 1.15 (95% CI 1.08-1.22) for S. mansoni. However, females are underrespresented in some of the studies. Additionally, there was significant heterogeneity across studies (Higgins I2 statistic (p-values < 0.001, I2values>95%)). Results of the subgroup analysis showed that the baseline prevalence influenced the M:F prevalence ratios for S. haematobium and S. mansoni, with higher M:F prevalence of infection ratios in settings with a lower baseline prevalence of infection. Across the studies, we identified four major risk factors associated with infection rates: occupational and recreational water contact, knowledge, socio-economic factors and demographic factors. The effect of these risk factors on the burden of infection in males and females varied across studies. CONCLUSIONS We find evidence of differences in prevalence of infection between males and females which may reflect differences in gender norms and water contact activities, suggesting that policy changes at the regional level may help ameliorate gender-related disparities in schistosomiasis infection burden. Collecting, robustly analysing, and reporting, sex-disaggregated epidemiological data, is currently lacking, but would be highly informative for planning effective treatment programmes and establishing those most at risk of schistosomiasis infections.
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Schistosoma mansoni infection risk for school-aged children clusters within households and is modified by distance to freshwater bodies. PLoS One 2021; 16:e0258915. [PMID: 34735487 PMCID: PMC8568121 DOI: 10.1371/journal.pone.0258915] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/07/2021] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The interaction of socio-demographic and ecological factors with Schistosoma mansoni (S. mansoni) infection risk by age and the household clustering of infections between individuals are poorly understood. METHODS This study examined 1,832 individuals aged 5-90 years across 916 households in Mayuge District, Uganda. S. mansoni infection status and intensity were measured using Kato-Katz microscopy. Socio-demographic and ecological factors were examined as predictors of infection status and intensity using logistic and negative binomial regression models, respectively, with standard errors clustered by household. A subgroup analysis of children was conducted to examine the correlation of infection status between children and their caretakers. FINDINGS Infection varied within age groups based on the distance to Lake Victoria. Children aged 9-17 years and young adults aged 18-29 years who lived ≤0.50km from Lake Victoria were more likely to be infected compared to individuals of the same age who lived further away from the lake. Infections clustered within households. Children whose caretakers were heavily infected were 2.67 times more likely to be infected. CONCLUSION These findings demonstrate the focality of schistosome transmission and its dependence on socio-demographic, ecological and household factors. Future research should investigate the sampling of households within communities as a means of progressing towards precision mapping of S. mansoni infections.
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Aula OP, McManus DP, Jones MK, Gordon CA. Schistosomiasis with a Focus on Africa. Trop Med Infect Dis 2021; 6:109. [PMID: 34206495 PMCID: PMC8293433 DOI: 10.3390/tropicalmed6030109] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 12/19/2022] Open
Abstract
Schistosomiasis is a common neglected tropical disease of impoverished people and livestock in many developing countries in tropical Africa, the Middle East, Asia, and Latin America. Substantial progress has been made in controlling schistosomiasis in some African countries, but the disease still prevails in most parts of sub-Saharan Africa with an estimated 800 million people at risk of infection. Current control strategies rely primarily on treatment with praziquantel, as no vaccine is available; however, treatment alone does not prevent reinfection. There has been emphasis on the use of integrated approaches in the control and elimination of the disease in recent years with the development of health infrastructure and health education. However, there is a need to evaluate the present status of African schistosomiasis, primarily caused by Schistosoma mansoni and S. haematobium, and the factors affecting the disease as the basis for developing more effective control and elimination strategies in the future. This review provides an historical perspective of schistosomiasis in Africa and discusses the current status of control efforts in those countries where the disease is endemic.
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Affiliation(s)
- Oyime Poise Aula
- School of Public Health, Faculty of Medicine, University of Queensland, Brisbane 4006, Australia;
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
| | - Donald P. McManus
- School of Public Health, Faculty of Medicine, University of Queensland, Brisbane 4006, Australia;
| | - Malcolm K. Jones
- School of Veterinary Sciences, University of Queensland, Gatton 4343, Australia;
| | - Catherine A. Gordon
- School of Public Health, Faculty of Medicine, University of Queensland, Brisbane 4006, Australia;
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Nyandwi E, Osei FB, Veldkamp T, Amer S. Modeling schistosomiasis spatial risk dynamics over time in Rwanda using zero-inflated Poisson regression. Sci Rep 2020; 10:19276. [PMID: 33159143 PMCID: PMC7648759 DOI: 10.1038/s41598-020-76288-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/20/2020] [Indexed: 11/16/2022] Open
Abstract
The recorded clinical cases of S. mansoni at primary health facility level contain an excessive number of zero records. This could mean that no S. mansoni infection occurred (a true zero) in the health facility service area but it could also that at least one infection occurred but none were reported or diagnosed (a false zero). Standard statistical analysis, using exploratory or confirmatory spatial regression, fail to account for this type of data insufficiency. This study developed a zero-inflated Poisson model to explore the spatiotemporal variation in schistosomiasis risk at a fine spatial scale. We used environmental data generated at primary health facility service area level as explanatory variables affecting transmission risk. Identified risk factors were subsequently used to project the spatial variability of S. mansoni infection risk for 2050. The zero-inflated Poisson model shows a considerable increase of relative risk of the schistosomiasis over one decade. Furthermore, the changes between the risk in 2009 and forecasted risk by 2050 indicated both persistent and emerging areas with high relative risk of schistosomiasis infection. The risk of schistosomiasis transmission is 69%, 29%, and 50% higher in areas with rice cultivation, proximity to rice farms, and proximity to a water body respectively. The prediction and forecasting maps provide a valuable tool for monitoring schistosomiasis risk in Rwanda and planning future disease control initiatives in wetland ecosystem development context.
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Affiliation(s)
- Elias Nyandwi
- Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands.,Geographic Information Systems and Remote Sensing Centre, University of Rwanda, Kigali, Rwanda
| | - Frank Badu Osei
- Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands.
| | - Tom Veldkamp
- Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands
| | - Sherif Amer
- Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, The Netherlands
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Leta GT, Mekete K, Wuletaw Y, Gebretsadik A, Sime H, Mekasha S, Woyessa A, Shafi O, Vercruysse J, Grimes JET, Gardiner I, French M, Levecke B, Drake L, Harrison W, Fenwick A. National mapping of soil-transmitted helminth and schistosome infections in Ethiopia. Parasit Vectors 2020; 13:437. [PMID: 32873333 PMCID: PMC7466696 DOI: 10.1186/s13071-020-04317-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 08/25/2020] [Indexed: 11/10/2022] Open
Abstract
Background An accurate understanding of the geographical distributions of both soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and the hookworms Necator americanus and Ancylostoma duodenale) and schistosomes (SCH; Schistosoma mansoni and S. haematobium) is pivotal to be able to effectively design and implement mass drug administration (MDA) programmes. The objective of this study was to provide up-to-date data on the distribution of both STH and SCH in Ethiopia to inform the design of the national control program and to be able to efficiently achieve the 75% MDA coverage target set by the WHO. Methods Between 2013 and 2015, we assessed the distributions of STH and SCH infections in a nationwide survey covering 153,238 school-aged children (aged 5–15 years), from 625 woredas (districts), representing all nine Regional States and two City Administrations of Ethiopia. Nationwide disease maps were developed at the woreda level to enable recommendations on the design of the national MDA programme. Results The prevalence of any STH infection across the study population was 21.7%, with A. lumbricoides (12.8%) being the most prevalent STH, followed by hookworms (7.6%) and T. trichiura (5.9%). The prevalence for any SCH was 4.0% in areas where both SCH species were evaluated. Schistosoma mansoni was the most prevalent SCH (3.5 vs 0.3%). STHs were more prevalent in southwest Ethiopia, whereas SCH was found mostly in the west and northeast of the country. The prevalence of moderate-to-heavy intensity infections was 2.0% for STHs and 1.6% for SCH. For STH, a total of 251 woredas were classified as moderately (n = 178) or highly endemic (n = 73), and therefore qualify for an annual and biannual MDA program, respectively. For SCH, 67 woredas were classified as endemic and 8 as highly endemic, and hence they require every two years and annual MDA programme, respectively. Conclusions The results confirm that Ethiopia is endemic for both STHs and SCH, posing a significant public health problem. Following the WHO recommendations on mass drug administration, 18 and 14 million school-aged children are in need of MDA for STHs and SCH, respectively, based on the number of SACs that live on the eligible geographical areas.![]()
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Affiliation(s)
- Gemechu Tadesse Leta
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia. .,Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Kalkidan Mekete
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia
| | - Yonas Wuletaw
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia
| | - Abeba Gebretsadik
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia
| | - Heven Sime
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia
| | - Sindew Mekasha
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia
| | - Adugna Woyessa
- Ethiopian Public Health Institute, PO Box 1242/5654, Addis Ababa, Ethiopia
| | - Oumer Shafi
- Federal Ministry of Health, PO Box 1234, Addis Ababa, Ethiopia
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Jack E T Grimes
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London, SW7 2AZ, UK
| | - Iain Gardiner
- Partnership for Child Development, Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - Michael French
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, W2 1PG, UK.,RTI International, Washington D.C, USA
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Lesley Drake
- Partnership for Child Development, Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - Wendy Harrison
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, W2 1PG, UK
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Fine-scale heterogeneity in Schistosoma mansoni force of infection measured through antibody response. Proc Natl Acad Sci U S A 2020; 117:23174-23181. [PMID: 32868437 PMCID: PMC7502727 DOI: 10.1073/pnas.2008951117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Schistosomiasis is one of the most common parasitic diseases in the world, and most infected people (90%) live in Africa. Global control efforts use measures of population-level transmission to target programs and assess progress toward elimination. Monitoring Schistosoma mansoni transmission has traditionally relied on examining stool with microscopy, which is difficult to scale in large programs and has low sensitivity as infection burdens decline. Our results show that antibody-based measures of transmission align well with stool-based measures, provide higher sensitivity at lower levels of transmission, and enable fine-scale estimates of force of infection by geography and age. The findings represent a major step toward use of serosurveillance to guide schistosomiasis control efforts in Africa. Schistosomiasis is among the most common parasitic diseases in the world, with over 142 million people infected in low- and middle-income countries. Measuring population-level transmission is centrally important in guiding schistosomiasis control programs. Traditionally, human Schistosoma mansoni infections have been detected using stool microscopy, which is logistically difficult at program scale and has low sensitivity when people have low infection burdens. We compared serological measures of transmission based on antibody response to S. mansoni soluble egg antigen (SEA) with stool-based measures of infection among 3,663 preschool-age children in an area endemic for S. mansoni in western Kenya. We estimated force of infection among children using the seroconversion rate and examined how it varied geographically and by age. At the community level, serological measures of transmission aligned with stool-based measures of infection (ρ = 0.94), and serological measures provided more resolution for between-community differences at lower levels of infection. Force of infection showed a clear gradient of transmission with distance from Lake Victoria, with 94% of infections and 93% of seropositive children in communities <1.5 km from the lake. Force of infection increased through age 3 y, by which time 65% (95% CI: 53%, 75%) of children were SEA positive in high-transmission communities—2 y before they would be reached by school-based deworming programs. Our results show that serologic surveillance platforms represent an important opportunity to guide and monitor schistosomiasis control programs, and that in high-transmission settings preschool-age children represent a key population missed by school-based deworming programs.
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Galukande M, Were LF, Kigozi J, Kahendeke C, Muganzi A, Kambugu A. Closing the Gap toward Zero Tetanus Infection for Voluntary Medical Male Circumcision: Seven Case Reports and a Review of the Literature. Surg Infect (Larchmt) 2020; 21:599-607. [PMID: 32609063 DOI: 10.1089/sur.2020.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Voluntary medical male circumcision (VMMC) is important for HIV prevention, providing up to 60% protection. Although VMMC is usually a safe procedure, it is not free of associated serious adverse events. In the Uganda VMMC program, which is available to males 10 years of age and older, 11 individuals were reported with tetanus infection out of almost 3.5 million circumcisions over an eight-year period (2009-2018). The majority had received tetanus vaccination prior to VMMC. Disproportionately and statistically significantly, the elastic collar compression method accounted for half the tetanus infection cases, despite contributing to only less than 10% of circumcisions done. This article describes gaps in presumed tetanus vaccination (TTV) protection along with relevant discussions and recommendations. Case Presentations: We present seven tetanus case reports and a review of the literature. We were guided by a pre-determined thematic approach, focusing on immune response to TTV in the context of common infections and infestations in a tropical environment that may impair immune response to TTV. It is apparent in the available literature that the following (mostly tropical neglected infections) sufficiently impair antibody response to TTV: human immunodefiency virus (HIV), pulmonary tuberculosis, nematode infections, and schistosomiasis. Conclusions: One of seven patients died (14% case fatality). Individuals with prior exposure to certain infection(s) may not mount adequate antibody response to TTV sufficient to protect against acquiring tetanus. Therefore, TTV may not confer absolute protection against tetanus infection in these individuals. More needs to be done to ensure everyone is fully protected against tetanus, especially in the regions where risk of tetanus is heightened. We need to characterize the high-risk individuals (poor responders to TTV) and design targeted protective measures.
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Affiliation(s)
- Moses Galukande
- Department of Surgery, School of Medicine, Makerere College of Health Sciences, Kampala, Uganda.,Education and Research Unit, Makerere College of Health Sciences, Kampala, Uganda
| | - Leonard Francis Were
- Infectious Disease Institution, Makerere College of Health Sciences, Kampala, Uganda
| | - Joanita Kigozi
- Infectious Disease Institution, Makerere College of Health Sciences, Kampala, Uganda
| | | | - Alex Muganzi
- Infectious Disease Institution, Makerere College of Health Sciences, Kampala, Uganda
| | - Andrew Kambugu
- Infectious Disease Institution, Makerere College of Health Sciences, Kampala, Uganda
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Sinkala E, Vinikoor M, Zyambo K, Besa E, Nsokolo B, Kelly P. Propranolol Reduces Portal Vein Diameter in Schistosomal Liver Disease with Portal Hypertension: A Prospective Cohort Study. Am J Trop Med Hyg 2020; 102:832-837. [PMID: 32067625 PMCID: PMC7124927 DOI: 10.4269/ajtmh.19-0452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Hepatosplenic schistosomiasis (HSS) complicates portal hypertension, leading to life-threatening variceal bleeding. Variceal bleeding is associated with increased portal vein diameter (PVD). Beta-blockers prevent variceal bleeding. It is unclear whether beta-blockers such as propranolol can reduce PVD in HSS. We aimed to explore the effect of propranolol on PVD in HSS. A longitudinal study was conducted at the University Teaching Hospital, Zambia, as an extension of a clinical trial of rifaximin undertaken to test the hypothesis that rifaximin could reduce bacterial translocation in HSS. We randomized 85 adults to either rifaximin and standard care, or propranolol-based standard care only for 42 days. We then followed up all the patients on propranolol up to day 180. We used ultrasound to measure PVD at baseline and day 180. The primary outcome was reduction in PVD. Beta-blockade and splenic size reduction were secondary outcomes. Portal vein diameter reduced after 180 days of propranolol therapy from median 12 mm (interquartile range (IQR): 11–14) to median 10 mm (IQR: 9–13) (P < 0.001). The pulse rate reduced from baseline median 70 beats/minute (IQR: 66–80) to 65 beats/minute (IQR: 60–70) by day 180 (P = 0.006). Hemoglobin levels improved from baseline median 8 g/dL (IQR: 6–11) to 12 g/dL (10–14) (P < 0.001). Splenic size remained unchanged. Propranolol led to the reduction in PVD over 180 days. This suggests that ultrasound could be useful in monitoring response and compliance to beta-blockers, especially in resource-constraint areas where portal hypertension measurement facilities are unavailable.
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Affiliation(s)
- Edford Sinkala
- Department of Internal Medicine, University Teaching Hospital, Lusaka, Zambia.,Department of Internal Medicine, Tropical Gastroenterology and Nutritional Group, University of Zambia, Lusaka, Zambia
| | - Michael Vinikoor
- Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.,Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kanekwa Zyambo
- Department of Internal Medicine, Tropical Gastroenterology and Nutritional Group, University of Zambia, Lusaka, Zambia
| | - Ellen Besa
- Department of Internal Medicine, Tropical Gastroenterology and Nutritional Group, University of Zambia, Lusaka, Zambia
| | - Bright Nsokolo
- Department of Internal Medicine, Tropical Gastroenterology and Nutritional Group, University of Zambia, Lusaka, Zambia.,Department of Internal Medicine, University Teaching Hospital, Lusaka, Zambia
| | - Paul Kelly
- Blizard Institute, Barts and The London School of Medicine, Queen Mary University of London, London, United Kingdom.,Department of Internal Medicine, Tropical Gastroenterology and Nutritional Group, University of Zambia, Lusaka, Zambia.,Department of Internal Medicine, University Teaching Hospital, Lusaka, Zambia
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21
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Faust CL, Osakunor DNM, Downs JA, Kayuni S, Stothard JR, Lamberton PHL, Reinhard-Rupp J, Rollinson D. Schistosomiasis Control: Leave No Age Group Behind. Trends Parasitol 2020; 36:582-591. [PMID: 32430274 DOI: 10.1016/j.pt.2020.04.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 01/11/2023]
Abstract
Despite accelerating progress towards schistosomiasis control in sub-Saharan Africa, several age groups have been eclipsed by current treatment and monitoring strategies that mainly focus on school-aged children. As schistosomiasis poses a threat to people of all ages, unfortunate gaps exist in current treatment coverage and associated monitoring efforts, preventing subsequent health benefits to preschool-aged children as well as certain adolescents and adults. Expanding access to younger ages through the forthcoming pediatric praziquantel formulation and improving treatment coverage in older ages is essential. This should occur alongside formal inclusion of these groups in large-scale monitoring and evaluation activities. Current omission of these age groups from treatment and monitoring exacerbates health inequities and has long-term consequences for sustainable schistosomiasis control.
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Affiliation(s)
- Christina L Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Derick N M Osakunor
- Institute of Immunology and Infection Research, University of Edinburgh, Ashworth Laboratories, King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Jennifer A Downs
- Center for Global Health, Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Sekeleghe Kayuni
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; MASM Medi Clinics Limited, Medical Aid Society of Malawi (MASM), Blantyre, Malawi
| | - J Russell Stothard
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Poppy H L Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | | | - David Rollinson
- Global Schistosomiasis Alliance, Natural History Museum, London SW7 5BD, UK
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22
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Walker JW, Kittur N, Binder S, Castleman JD, Drake JM, Campbell CH, King CH, Colley DG. Environmental Predictors of Schistosomiasis Persistent Hotspots following Mass Treatment with Praziquantel. Am J Trop Med Hyg 2020; 102:328-338. [PMID: 31889506 PMCID: PMC7008331 DOI: 10.4269/ajtmh.19-0658] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Schistosomiasis control programs rely heavily on mass drug administration (MDA) campaigns with praziquantel for preventative chemotherapy. Areas where the prevalence and/or intensity of schistosomiasis infection remains high even after several rounds of treatment, termed "persistent hotspots" (PHSs), have been identified in trials of MDA effectiveness conducted by the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) in Kenya, Mozambique, Tanzania, and Côte d'Ivoire. In this analysis, we apply a previously developed set of criteria to classify the PHS status of 531 study villages from five SCORE trials. We then fit logistic regression models to data from SCORE and publically available georeferenced datasets to evaluate the influence of local environmental and population features, pre-intervention infection burden, and treatment scheduling on PHS status in each trial. The frequency of PHS in individual trials ranged from 35.3% to 71.6% in study villages. Significant relationships between PHS status and MDA frequency, distance to freshwater, rainfall, baseline schistosomiasis burden, elevation, land cover type, and village remoteness were each observed in at least one trial, although the strength and direction of these relationships was not always consistent among study sites. These findings suggest that PHSs are driven in part by environmental conditions that modify the risk and frequency of reinfection.
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Affiliation(s)
- Joseph W Walker
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, Georgia.,University of Georgia College of Public Health, Athens, Georgia
| | - Nupur Kittur
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Sue Binder
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Jennifer D Castleman
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - John M Drake
- Odum School of Ecology, University of Georgia, Athens, Georgia.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, Georgia
| | - Carl H Campbell
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio.,Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
| | - Daniel G Colley
- Department of Microbiology, University of Georgia, Athens, Georgia.,Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
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23
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Heat shock protein 70 (Hsp70) in Schistosoma mansoni and its role in decreased adult worm sensitivity to praziquantel. Parasitology 2020; 147:634-642. [PMID: 32127065 DOI: 10.1017/s0031182020000347] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Schistosoma mansoni is the most common species causing schistosomiasis. It has a complex life cycle involving a vertebrate definitive host and a snail intermediate host of the genus Biomphalaria. Each stage encounters a plethora of environmental stresses specially heat stress. Another sort of stress arises from repeated exposure of the parasite to praziquantel (PZQ), the only drug used for treatment, which leads to the development of resistance in the fields and the labs. Heat shock protein 70 (Hsp70) is found in different developmental stages of S. mansoni. It is immunogenic and regulate cercarial invasion besides its chaperone function. In the Biomphalaria/S. mansoni interaction, epigenetic modulations of the Hsp70 gene underscore the susceptibility phenotype of the snail. Hsp70 is up-regulated in adult S. mansoni with decreased sensitivity to PZQ. This could be due to the induction of oxidative and endoplasmic reticulum stress, induction of apoptosis, exposure to the stressful drug pressure and increase influx of calcium ions. Up-regulation of Hsp70 might help the worm to survive the schistosomicidal effect of the drug mainly by dealing with misfolded proteins, inhibition of apoptosis, induction of autophagy, up-regulation of the P-glycoprotein transporter and attenuation of the signalling from G protein coupled receptors.
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24
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Tefera A, Belay T, Bajiro M. Epidemiology of Schistosoma mansoni infection and associated risk factors among school children attending primary schools nearby rivers in Jimma town, an urban setting, Southwest Ethiopia. PLoS One 2020; 15:e0228007. [PMID: 32107485 PMCID: PMC7046261 DOI: 10.1371/journal.pone.0228007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 01/05/2020] [Indexed: 01/27/2023] Open
Abstract
Background Schistosomiasis is one of the most neglected tropical parasitic disease which is common in Ethiopia. It is disease of rural areas for decades but now days there are reports of schistosomiasis from urban settings. Therefore, this study aimed to determine epidemiology of Schistosoma mansoni (S. mansoni) infection and associated determinant factors among school children attending primary schools nearby rivers in Jimma town, an urban setting, southwest Ethiopia. Methodology A cross sectional study was conducted among 328 school children aged between 7–17 years in selected primary schools nearby rivers in Jimma town from March to April 2017. For the diagnosis of S. mansoni, a single stool sample was obtained from each child and processed using double Kato Katz thick smear for quantification of S. mansoni ova examined using light microscope. A questionnaire was used to collect socio demographic data and associated determinant factors for S. mansoni infection. Data were analyzed using SPSS version 20.0. Variables with P-value < 0.05 were significantly associated with S. mansoni infection. Results The overall prevalence of S. mansoni infection was found to be 28.7%. Majority of infection intensities were categorized as light with maximum egg per gram of stool (epg) was 1728. The geometric mean of infection intensity was 102.3epg. Schools distance from river (p = 0.001), swimming habit in rivers (p = 0.001) and crossing river on bare foot (p = 0.001) were independent risk factors for S. mansoni infection. Conclusions The study revealed S. mansoni infection is prevalent in Jimma town. The school children were at moderate risk of morbidity caused by S. mansoni (prevalence ≥ 10% and < 50% according to WHO threshold), hence a biannual mass drug administration with praziquantel is required once every two years in the study area and promote health information on prevention, control, transmission and risk factors for S. mansoni infection.
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Affiliation(s)
| | - Tariku Belay
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University Institute of Health, Jimma, Ethiopia
| | - Mitiku Bajiro
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University Institute of Health, Jimma, Ethiopia
- * E-mail:
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25
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Verjee MA. Schistosomiasis: Still a Cause of Significant Morbidity and Mortality. Res Rep Trop Med 2019; 10:153-163. [PMID: 32099508 PMCID: PMC6997417 DOI: 10.2147/rrtm.s204345] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 10/24/2019] [Indexed: 11/23/2022] Open
Abstract
Tropical diseases remain severe threats to global health with acute or chronic debility. Public health issues are regularly monitored and reported by the WHO. Conditions with high prevalence and virulence such as Schistosomiasis or Malaria still need active treatment. Advances over the decades in the treatment and management of Schistosomiasis have reduced morbidity and mortality in patients. However, poverty, adverse environments, lack of education and awareness, with parasites and vectors that can thrive if uncontrolled, remain issues for the successful global eradication of Schistosomiasis. From the disease's discovery in 1850, the author relates historical details to its current status. Several countries previously affected, including Japan and Tunisia, have eliminated the disease while others seek the same goal. Africa remains the most severely affected continent with vulnerable women and children, although the infection persists in South America and the Far East of Asia as well. Realistic improvements for continuing health conditions are vogue and emphasized for those at risk or afflicted by the infection, illustrating success models of concerted efforts of extirpation. Constant proximity to infected water, with a parasite host, are hurdles in reducing exposure. Effective medication for acute treatment is available, and prophylaxis by vaccination is promising. Where endemic Schistosomiasis is prevalent, significant morbidity and mortality have far-reaching complications in multiple human organ systems, including irreversible pulmonary hypertension, renal, genitourinary, central nervous system conditions, and neoplasia. Two hundred and thirty million people are estimated to have contracted Schistosomiasis globally, with up to 700 million still at risk of infection, and 200,000 deaths occur annually. The disease may be more prevalent than thought after newer tests have shown increased sensitivity to pathological antigens. The author discusses infectivity risks, investigations, prognosis, treatment, and management, as well as morbidity and mortality.
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Affiliation(s)
- Mohamud A Verjee
- Weill Cornell Medicine – Qatar, Qatar Foundation – Education City, Doha, Qatar
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26
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Tumwebaze I, Clewing C, Dusabe MC, Tumusiime J, Kagoro-Rugunda G, Hammoud C, Albrecht C. Molecular identification of Bulinus spp. intermediate host snails of Schistosoma spp. in crater lakes of western Uganda with implications for the transmission of the Schistosoma haematobium group parasites. Parasit Vectors 2019; 12:565. [PMID: 31775865 PMCID: PMC6882369 DOI: 10.1186/s13071-019-3811-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 11/15/2019] [Indexed: 12/05/2022] Open
Abstract
Background Human schistosomiasis is the second most important tropical disease and occurs in two forms in Africa (intestinal and urogenital) caused by the digenetic trematodes Schistosoma mansoni and Schistosoma haematobium, respectively. A proposed recent shift of schistosomiasis above a previously established altitudinal threshold of 1400 m above sea level in western Ugandan crater lakes has triggered more research interest there. Methods Based on extensive field sampling in western Uganda and beyond and employing an approach using sequences of the mitochondrial barcoding gene cytochrome c oxidase subunit 1 (cox1) this study aims were: (i) identification and establishment of the phylogenetic affinities of Bulinus species as potential hosts for Schistosoma spp.; (ii) determining diversity, frequency and distribution patterns of Bulinus spp.; and (iii) establishing genetic variability and phylogeographical patterns using Bayesian inference and parsimony network analyses. Results Out of the 58 crater lakes surveyed, three species of Bulinus snails were found in 34 crater lakes. Bulinus tropicus was dominating, Bulinus forskalii was found in two lakes and Bulinus truncatus in one. The latter two species are unconfirmed potential hosts for S. haematobium in this region. However, Bulinus tropicus is an important species for schistosomiasis transmission in ruminants. Bulinus tropicus comprised 31 haplotypes while both B. forskalii and B. truncatus exhibited only a single haplotype in the crater lakes. All species clustered with most of the haplotypes from surrounding lake systems forming source regions for the colonization of the crater lakes. Conclusions This first detailed malacological study of the crater lakes systems in western Uganda revealed presence of Bulinus species that are either not known or not regionally known to be hosts for S. haematobium, the causing agent of human urogenital schistosomiasis. Though this disease risk is almost negligible, the observed dominance of B. tropicus in the crater lakes shows that there is a likelihood of a high risk of infections with Schistosoma bovis. Thus, extra attention should be accorded to safeguard wild and domestic ruminants in this region as the population benefits from these animals.
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Affiliation(s)
- Immaculate Tumwebaze
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.
| | - Catharina Clewing
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany
| | | | - Julius Tumusiime
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Grace Kagoro-Rugunda
- Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Cyril Hammoud
- Department of Biology, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080, Tervuren, Belgium.,Limnology Research Unit, Ghent University, K. L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Christian Albrecht
- Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.,Department of Biology, Mbarara University of Science and Technology, Mbarara, Uganda
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27
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Exum NG, Kibira SPS, Ssenyonga R, Nobili J, Shannon AK, Ssempebwa JC, Tukahebwa EM, Radloff S, Schwab KJ, Makumbi FE. The prevalence of schistosomiasis in Uganda: A nationally representative population estimate to inform control programs and water and sanitation interventions. PLoS Negl Trop Dis 2019; 13:e0007617. [PMID: 31412023 PMCID: PMC6709927 DOI: 10.1371/journal.pntd.0007617] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 08/26/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022] Open
Abstract
Background To improve schistosomiasis control programs in Uganda, where intestinal schistosomiasis is a widespread public health problem, a country-wide assessment of the disease prevalence among all age ranges is needed. Few studies have aimed to quantify the relationships between disease prevalence and water and sanitation characteristics across Uganda to understand the potential to interrupt disease transmission with an integrated package of interventions. Methodology/Principal findings A nationally representative survey was undertaken that included a household and individual questionnaire followed by disease testing based on detection of worm antigens (circulating cathodic antigen–CCA), diagnosis and treatment. A comprehensive set of questions was asked of randomly sampled individuals, two years of age and above, to understand their water and sanitation infrastructure, open defecation behaviors, exposure to surface water bodies, and knowledge of schistosomiasis. From a set of 170 randomly sampled, geographically diverse enumeration areas, a total of 9,183 study participants were included. After adjustment with sample weights, the national prevalence of schistosomiasis was 25.6% (95% confidence interval (CI): 22.3, 29.0) with children ages two to four most at risk for the disease with 36.1% infected (95% CI: 30.1, 42.2). The defecation behaviors of an individual were more strongly associated with infection status than the household water and sanitation infrastructure, indicating the importance of incorporating behavior change into community-led total sanitation coverage. Conclusions/Significance Our results highlight the importance of incorporating monitoring and evaluation data into control programs in Uganda to understand the geographic distribution of schistosomiasis prevalence outside of communities where endemicity is known to be high. The high prevalence of schistosomiasis among the youngest age group, ineligible to receive drug treatment, shows the imperative to develop a child-appropriate drug protocol that can be safely administered to preschool-aged children. Water and sanitation interventions should be considered an essential investment for elimination alongside drug treatment. Schistosomiasis is a neglected tropical disease in sub-Saharan Africa that has remained intractable despite efforts to eliminate it through mass drug administration. The transmission cycle is perpetuated when sanitation infrastructure does not adequately capture infected urine or feces and local water bodies, with snail vectors, are contaminated. Schistosomiasis has been linked with stunting and cognitive deficits and there is particular concern for the most vulnerable age group under five years old who are undergoing critical intestinal development but are ineligible to receive drug treatment. Efforts to reduce the disease have focused on children and young adolescents in endemic areas, near water bodies where transmission is known to be high. In Uganda, where fresh water bodies are abundant and intestinal schistosomiasis is endemic, very little is understood about the disease prevalence at a national level. We conducted a large, nationally representative survey and found a national prevalence of 25.6% where the 2–4 year old children had the highest prevalence for schistosomiasis with 36.1% infected. The most significant risk-factor for the disease was an individual’s open defecation behaviors in surface waters. This emphasizes the need to include water and sanitation investments alongside drug treatment and behavior change to control schistosomiasis in Uganda.
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Affiliation(s)
- Natalie G. Exum
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail:
| | - Simon P. S. Kibira
- Department of Community Health and Behavioral Sciences, School of Public Health, Makerere University, Kampala, Uganda
| | - Ronald Ssenyonga
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University, Kampala, Uganda
| | - Julien Nobili
- Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Alexandra K. Shannon
- Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - John C. Ssempebwa
- Department of Disease Control and Environmental Health, School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Scott Radloff
- Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Kellogg J. Schwab
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States of America
| | - Fredrick E. Makumbi
- Department of Epidemiology and Biostatistics, School of Public Health, Makerere University, Kampala, Uganda
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28
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Wrable M, Kulinkina AV, Liss A, Koch M, Cruz MS, Biritwum NK, Ofosu A, Gute DM, Kosinski KC, Naumova EN. The use of remotely sensed environmental parameters for spatial and temporal schistosomiasis prediction across climate zones in Ghana. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:301. [PMID: 31254149 DOI: 10.1007/s10661-019-7411-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
Schistosomiasis control in sub-Saharan Africa is enacted primarily through preventive chemotherapy. Predictive models can play an important role in filling knowledge gaps in the distribution of the disease and help guide the allocation of limited resources. Previous modeling approaches have used localized cross-sectional survey data and environmental data typically collected at a discrete point in time. In this analysis, 8 years (2008-2015) of monthly schistosomiasis cases reported into Ghana's national surveillance system were used to assess temporal and spatial relationships between disease rates and three remotely sensed environmental variables: land surface temperature (LST), normalized difference vegetation index (NDVI), and accumulated precipitation (AP). Furthermore, the analysis was stratified by three major and nine minor climate zones, defined using a new climate classification method. Results showed a downward trend in reported disease rates (~ 1% per month) for all climate zones. Seasonality was present in the north with two peaks (March and September), and in the middle of the country with a single peak (July). Lowest disease rates were observed in December/January across climate zones. Seasonal patterns in the environmental variables and their associations with reported schistosomiasis infection rates varied across climate zones. Precipitation consistently demonstrated a positive association with disease outcome, with a 1-cm increase in rainfall contributing a 0.3-1.6% increase in monthly reported schistosomiasis infection rates. Generally, surveillance of neglected tropical diseases (NTDs) in low-income countries continues to suffer from data quality issues. However, with systematic improvements, our approach demonstrates a way for health departments to use routine surveillance data in combination with publicly available remote sensing data to analyze disease patterns with wide geographic coverage and varying levels of spatial and temporal aggregation.
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Affiliation(s)
| | | | - Alexander Liss
- School of Engineering, Tufts University, Medford, MA, USA
| | - Magaly Koch
- Center for Remote Sensing, Boston University, Boston, MA, USA
| | - Melissa S Cruz
- Friedman School of Nutrition Science and Policy, Tufts University, 150 Harrison Avenue, Boston, MA, 02111, USA
| | | | - Anthony Ofosu
- Ghana Health Service, Policy, Planning, Monitoring, and Evaluation Division, Accra, Ghana
| | - David M Gute
- School of Engineering, Tufts University, Medford, MA, USA
| | | | - Elena N Naumova
- School of Engineering, Tufts University, Medford, MA, USA.
- Friedman School of Nutrition Science and Policy, Tufts University, 150 Harrison Avenue, Boston, MA, 02111, USA.
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29
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Smith C, McLachlan G, Al Shehri H, Adriko M, Arinaitwe M, Atuhaire A, Muheki Tukahebwa E, LaCourse EJ, Stanton M, Stothard JR, Bustinduy AL. Schistosoma mansoni Infection as a Predictor of Low Aerobic Capacity in Ugandan Children. Am J Trop Med Hyg 2019; 100:1498-1506. [PMID: 30994097 PMCID: PMC6553905 DOI: 10.4269/ajtmh.18-0922] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/19/2019] [Indexed: 12/20/2022] Open
Abstract
Using the 20-meter shuttle run test (20mSRT) as a morbidity metric, we assessed whether Schistosoma mansoni infection was associated with decreased aerobic capacity in Ugandan children across a range of altitudes, either at low (∼600 m) or high (∼1,000 m) altitudes. A total of 305 children were recruited from six schools within the Buliisa District, Lake Albert, Uganda. A subset (n = 96) of these had been previously assessed and treated for schistosomiasis ± malaria 2 weeks prior. Fitness scores on the 20mSRT were translated into VO2max using a standardized equation. Unadjusted and multivariable-adjusted analyses were performed using VO2max as the primary outcome. Analysis of fitness scores from 304 children, inclusive of the subset follow-up cohort, revealed a median VO2max of 45.4 mL kg-1 min-1 (interquartile range: 42.9-48.0 mL kg-1 min-1). Children residing at high altitudes demonstrated increased aerobic capacities (46.3 versus 44.8 mL kg-1 min-1, P = 0.031). The prevalence of stunting, wasting, S. mansoni egg patent infection, malaria, giardiasis, anemia, and fecal occult blood were 36.7%, 16.1%, 44.3%, 65.2%, 21.4%, 50.6%, and 41.2%, respectively. Median VO2max was elevated in those previously treated, compared with those newly recruited (46.3 versus 44 mL kg-1 min-1, P < 0.001). Multivariable-adjusted analysis revealed a strong negative association between S. mansoni egg patent infection and VO2max at low altitude (beta coefficient: -3.96, 95% CI: -6.56 to -137, P = 0.004). This is the first study to document a negative association between S. mansoni infection and aerobic capacity at low altitudes using the 20mSRT.
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Affiliation(s)
- Courtney Smith
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Georgia McLachlan
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Hajri Al Shehri
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Arinaitwe
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aaron Atuhaire
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | | | - E. James LaCourse
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Michelle Stanton
- Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Amaya L. Bustinduy
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Sanya RE, Nkurunungi G, Hoek Spaans R, Nampijja M, O’Hara G, Kizindo R, Oduru G, Kabuubi Nakawungu P, Niwagaba E, Abayo E, Kabagenyi J, Zziwa C, Tumusiime J, Nakazibwe E, Kaweesa J, Muwonge Kakooza F, Akello M, Lubyayi L, Verweij J, Nash S, van Ree R, Mpairwe H, Tukahebwa E, Webb EL, Elliott AM. The Impact of Intensive Versus Standard Anthelminthic Treatment on Allergy-related Outcomes, Helminth Infection Intensity, and Helminth-related Morbidity in Lake Victoria Fishing Communities, Uganda: Results From the LaVIISWA Cluster-randomized Trial. Clin Infect Dis 2019; 68:1665-1674. [PMID: 30202872 PMCID: PMC6495012 DOI: 10.1093/cid/ciy761] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/03/2018] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The prevalence of allergy-related diseases is increasing in low-income countries. Parasitic helminths, common in these settings, may be protective. We hypothesized that intensive, community-wide, anthelminthic mass drug administration (MDA) would increase allergy-related diseases, while reducing helminth-related morbidity. METHODS In an open, cluster-randomized trial (ISRCTN47196031), we randomized 26 high-schistosomiasis-transmission fishing villages in Lake Victoria, Uganda, in a 1:1 ratio to receive community-wide intensive (quarterly single-dose praziquantel plus albendazole daily for 3 days) or standard (annual praziquantel plus 6 monthly single-dose albendazole) MDA. Primary outcomes were recent wheezing, skin prick test positivity (SPT), and allergen-specific immunoglobulin E (asIgE) after 3 years of intervention. Secondary outcomes included helminths, haemoglobin, and hepatosplenomegaly. RESULTS The outcome survey comprised 3350 individuals. Intensive MDA had no effect on wheezing (risk ratio [RR] 1.11, 95% confidence interval [CI] 0.64-1.93), SPT (RR 1.10, 95% CI 0.85-1.42), or asIgE (RR 0.96, 95% CI 0.82-1.12). Intensive MDA reduced Schistosoma mansoni infection intensity: the prevalence from Kato Katz examinations of single stool samples from each patient was 23% versus 39% (RR 0.70, 95% CI 0.55-0.88), but the urine circulating cathodic antigen test remained positive in 85% participants in both trial arms. Hookworm prevalence was 8% versus 11% (RR 0.55, 95% CI 0.31-1.00). There were no differences in anemia or hepatospenomegaly between trial arms. CONCLUSIONS Despite reductions in S. mansoni intensity and hookworm prevalence, intensive MDA had no effect on atopy, allergy-related diseases, or helminth-related pathology. This could be due to sustained low-intensity infections; thus, a causal link between helminths and allergy outcomes cannot be discounted. Intensive community-based MDA has a limited impact in high-schistosomiasis-transmission fishing communities, in the absence of other interventions. CLINICAL TRIALS REGISTRATION ISRCTN47196031.
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Affiliation(s)
- Richard E Sanya
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
- Department of Internal Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Gyaviira Nkurunungi
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Remy Hoek Spaans
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Margaret Nampijja
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Geraldine O’Hara
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Robert Kizindo
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Gloria Oduru
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Prossy Kabuubi Nakawungu
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Emmanuel Niwagaba
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Elson Abayo
- Entebbe Hospital, Wakiso District Local Government, Uganda
| | - Joyce Kabagenyi
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Christopher Zziwa
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | | | | | - James Kaweesa
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | | | - Mirriam Akello
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Lawrence Lubyayi
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | - Jaco Verweij
- Laboratory for Medical Microbiology and Immunology, St Elisabeth Hospital, Tilburg, The Netherlands
| | - Stephen Nash
- Medical Research Council Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Ronald van Ree
- Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Harriet Mpairwe
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
| | | | - Emily L Webb
- Medical Research Council Tropical Epidemiology Group, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Alison M Elliott
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, United Kingdom
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Yegorov S, Galiwango RM, Good SV, Mpendo J, Tannich E, Boggild AK, Kiwanuka N, Bagaya BS, Kaul R. Schistosoma mansoni infection and socio-behavioural predictors of HIV risk: a cross-sectional study in women from Uganda. BMC Infect Dis 2018; 18:586. [PMID: 30453907 PMCID: PMC6245923 DOI: 10.1186/s12879-018-3481-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 10/31/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosoma mansoni infection has been associated with increased risk of HIV transmission in African women. This association might be causal or mediated through shared socio-behavioural factors and associated co-infections. We tested the latter hypothesis in a cross-sectional pilot study in a cohort of women from a S. mansoni endemic region of Uganda. To validate the immunological effects of S. mansoni in this cohort, we additionally assessed known schistosomiasis biomarkers. METHODS HIV-uninfected non-pregnant adult women using public health services were tested for schistosomiasis using the urine circulating cathodic antigen test, followed by serology and Schistosoma spp.-specific PCR. Blood was obtained for herpes simplex virus (HSV)-2 serology, eosinophil counts and cytokine analysis. Samples collected from the genitourinary tract were used to test for classical sexually transmitted infections (STI), for bacterial vaginosis and to assess recent sexual activity via prostate-specific antigen testing. Questionnaires were used to capture a range of socio-economic and behavioral characteristics. RESULTS Among 58 participants, 33 (57%) had schistosomiasis, which was associated with elevated levels of interleukin (IL)-10 (0.32 vs. 0.19 pg/ml; p = 0.038) and a trend toward increased tumour necrosis factor (TNF) (1.73 vs. 1.42 pg/ml; p = 0.081). Eosinophil counts correlated with levels of both cytokines (r = 0.53, p = 0.001 and r = 0.38, p = 0.019, for IL-10 and TNF, respectively); the association of eosinophilia with schistosomiasis was not significant (OR = 2.538, p = 0.282). Further, schistosomiasis was associated with lower age (per-year OR = 0.910, p = 0.047), being unmarried (OR = 0.263, p = 0.030), less frequent hormonal contraceptive (HC) use (OR = 0.121, p = 0.002, dominated by long acting injectable contraceptives) and a trend to longer time since penile-vaginal sex (OR = 0.350, p = 0.064). All women infected by Chlamydia trachomatis (n = 5), were also positive for schistosomiasis (Fisher's exact p = 0.064). CONCLUSIONS Intestinal schistosomiasis in adult women was associated with systemic immune alterations, suggesting that associations with immunological correlates of HIV susceptibility warrant further investigation. S. mansoni associations with socio-behavioral parameters and C. trachomatis, which may alter both genital immunity and HIV exposure and/or acquisition risk, means that future studies should carefully control for potential confounders. These findings have implications for the design and interpretation of clinical studies on the effects of schistosomiasis on HIV acquisition.
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Affiliation(s)
- Sergey Yegorov
- Department of Immunology, University of Toronto, Toronto, Canada. .,Present address: Faculty of Education and Humanities, Suleyman Demirel University, Almaty, Kazakhstan.
| | | | - Sara V Good
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, Canada.,Community Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Juliet Mpendo
- Uganda Virus Research Institute -International AIDS Vaccine Initiative HIV Vaccine Program, Entebbe, Uganda
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Andrea K Boggild
- Department of Medicine, University of Toronto, Toronto, Canada.,Public Health Ontario Laboratories, Toronto, Canada
| | - Noah Kiwanuka
- Uganda Virus Research Institute -International AIDS Vaccine Initiative HIV Vaccine Program, Entebbe, Uganda.,Department of Epidemiology and Biostatistics, School of Public Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Bernard S Bagaya
- Uganda Virus Research Institute -International AIDS Vaccine Initiative HIV Vaccine Program, Entebbe, Uganda.,Department of Immunology and Molecular Biology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Rupert Kaul
- Department of Immunology, University of Toronto, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada
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Mintsa Nguema R, Mavoungou JF, Mengue Me Ngou-Milama K, Mabicka Mamfoumbi M, Koumba AA, Sani Lamine M, Diarra A, Nkone Asseko G, Mourou JR, Bouyou Akotet MK, Moné H, Mouahid G, Atsame J. Baseline Mapping of Schistosomiasis and Soil Transmitted Helminthiasis in the Northern and Eastern Health Regions of Gabon, Central Africa: Recommendations for Preventive Chemotherapy. Trop Med Infect Dis 2018; 3:tropicalmed3040119. [PMID: 30423901 PMCID: PMC6306699 DOI: 10.3390/tropicalmed3040119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 12/22/2022] Open
Abstract
In order to follow the Preventive Chemotherapy (PC) for the transmission control as recommended by WHO, Gabon initiated in 2014 the mapping of Schistosomiasis and Soil Transmitted Helminthiasis (STH). Here, we report the results of the Northern and Eastern health regions, representing a third of the land area and 12% of its total population. All nine departments of the two regions were surveyed and from each, five schools were examined with 50 schoolchildren per school. The parasitological examinations were realized using the filtration method for urine and the Kato-Katz technique for stool samples. Overall 2245 schoolchildren (1116 girls and 1129 boys), mean aged 11.28 ± 0.04 years, were examined. Combined schistosomiasis and STH affected 1270 (56.6%) with variation between regions, departments, and schools. For schistosomiasis, prevalence were 1.7% across the two regions, with no significant difference (p > 0.05) between the Northern (1.5%) and the Eastern (1.9%). Schistosomiasis is mainly caused by Schistosoma haematobium with the exception of one respective case of S. mansoni and S. guineensis. STH are more common than schistosomiasis, with an overall prevalence of 56.1% significantly different between the Northern (58.1%) and Eastern (53.6%) regions (p = 0.034). Trichuris trichiura is the most abundant infection with a prevalence of 43.7% followed by Ascaris lumbricoides 35.6% and hookworms 1.4%. According to these results, an appropriate PC strategy is given. In particular, because of the low efficacy of a single recommended drug on T. trichiura and hookworms, it is important to include two drugs for the treatment of STH in Gabon, due to the high prevalence and intensities of Trichuris infections.
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Affiliation(s)
- Rodrigue Mintsa Nguema
- Research Institute in Tropical Ecology, National Center for Scientific and Technological Research, Libreville BP 13354, Gabon.
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
- Control Program of Parasitic Diseases, Libreville BP 2434, Gabon.
| | - Jacques F Mavoungou
- Research Institute in Tropical Ecology, National Center for Scientific and Technological Research, Libreville BP 13354, Gabon.
| | - Krystina Mengue Me Ngou-Milama
- Control Program of Parasitic Diseases, Libreville BP 2434, Gabon.
- National Laboratory of Public Health, Libreville BP 10736, Gabon.
| | - Modeste Mabicka Mamfoumbi
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
| | - Aubin A Koumba
- Research Institute in Tropical Ecology, National Center for Scientific and Technological Research, Libreville BP 13354, Gabon.
| | | | - Abdoulaye Diarra
- Word Health Organization Country Office Gabon, Libreville BP 820, Gabon.
| | | | - Jean R Mourou
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
| | - Marielle K Bouyou Akotet
- Department of Parasitology-Mycology, Faculty of Medicine, University of Health Sciences of Libreville, Libreville BP 4009, Gabon.
| | - Hélène Moné
- IHPE, Univ Montpellier, CNRS, UM, IFREMER, Univ Perpignan Via Domitia, Perpignan F-66860, France.
| | - Gabriel Mouahid
- IHPE, Univ Montpellier, CNRS, UM, IFREMER, Univ Perpignan Via Domitia, Perpignan F-66860, France.
| | - Julienne Atsame
- Control Program of Parasitic Diseases, Libreville BP 2434, Gabon.
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Toor J, Turner HC, Truscott JE, Werkman M, Phillips AE, Alsallaq R, Medley GF, King CH, Anderson RM. The design of schistosomiasis monitoring and evaluation programmes: The importance of collecting adult data to inform treatment strategies for Schistosoma mansoni. PLoS Negl Trop Dis 2018; 12:e0006717. [PMID: 30296257 PMCID: PMC6175503 DOI: 10.1371/journal.pntd.0006717] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/24/2018] [Indexed: 12/02/2022] Open
Abstract
Monitoring and evaluation (M&E) programmes are used to collect data which are required to assess the impact of current interventions on their progress towards achieving the World Health Organization (WHO) goals of morbidity control and elimination as a public health problem for schistosomiasis. Prevalence and intensity of infection data are typically collected from school-aged children (SAC) as they are relatively easy to sample and are thought to be most likely to be infected by schistosome parasites. However, adults are also likely to be infected. We use three different age-intensity profiles of infection for Schistosoma mansoni with low, moderate and high burdens of infection in adults to investigate how the age distribution of infection impacts the mathematical model generated recommendations of the preventive chemotherapy coverage levels required to achieve the WHO goals. We find that for moderate prevalence regions, regardless of the burden of infection in adults, treating SAC only may achieve the WHO goals. However, for high prevalence regions with a high burden of infection in adults, adult treatment is required to meet the WHO goals. Hence, we show that the optimal treatment strategy for a defined region requires consideration of the burden of infection in adults as it cannot be based solely on the prevalence of infection in SAC. Although past epidemiological data have informed mathematical models for the transmission and control of schistosome infections, more accurate and detailed data are required from M&E programmes to accurately determine the optimal treatment strategy for a defined region. We highlight the importance of collecting prevalence and intensity of infection data from a broader age-range, specifically the inclusion of adult data at baseline (prior to treatment) and throughout the treatment programme if possible, rather than SAC only, to accurately determine the treatment strategy for a defined region. Furthermore, we discuss additional epidemiological data, such as individual longitudinal adherence to treatment, that should ideally be collected in M&E programmes. Schistosomiasis remains an endemic parasitic disease affecting millions of people around the world. The World Health Organization (WHO) has set goals of morbidity control and elimination as a public health problem for schistosomiasis defined by reaching ≤5% and ≤1% prevalence of heavy-intensity infections in school-aged children, respectively. Monitoring and evaluation (M&E) programmes are used to collect data which can inform treatment strategies required in a defined area and can also aid in assessing the progress of implemented treatment strategies. Due to programmatic and financial constraints, M&E data are typically collected from school-aged children as they are thought to be most likely to be infected. We highlight that adults should be included within M&E programmes by showing how the burden of infection in adults impacts our mathematical model recommendations of the treatment coverage levels required to reach the WHO goals for schistosomiasis. Our results highlight the importance of collecting data from a broader age-range, specifically the inclusion of adult data at baseline (prior to treatment) and throughout the treatment programme if possible. Improving M&E programmes to incorporate collection of such data will allow for more accurate determination of the optimal treatment strategy for a defined region.
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Affiliation(s)
- Jaspreet Toor
- London Centre for Neglected Tropical Disease Research and Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary’s Campus, Imperial College London, London, United Kingdom
- * E-mail:
| | - Hugo C. Turner
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - James E. Truscott
- London Centre for Neglected Tropical Disease Research and Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - Marleen Werkman
- London Centre for Neglected Tropical Disease Research and Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
| | - Anna E. Phillips
- London Centre for Neglected Tropical Disease Research and Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary’s Campus, Imperial College London, London, United Kingdom
| | - Ramzi Alsallaq
- Center for Global Health and Diseases and Department of Mathematics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Graham F. Medley
- Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Charles H. King
- Center for Global Health and Diseases and Department of Mathematics, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Roy M. Anderson
- London Centre for Neglected Tropical Disease Research and Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Mary’s Campus, Imperial College London, London, United Kingdom
- The DeWorm3 Project, The Natural History Museum of London, London, United Kingdom
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Adriko M, Tinkitina B, Tukahebw EM, Standley CJ, Stothard JR, Kabatereine NB. The epidemiology of schistosomiasis in Lango region Uganda 60 years after Schwetz 1951: Can schistosomiasis be eliminated through mass drug administration without other supportive control measures? Acta Trop 2018; 185:412-418. [PMID: 29935144 DOI: 10.1016/j.actatropica.2018.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 05/31/2018] [Accepted: 06/11/2018] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Lango region is the only known endemic region for urinary and intestinal schistosomiasis in Uganda. Although there has been no significant improvement in sanitation and safe water supply in the region over years, the endemicity and prevalence of Schistosoma haematobium, in particular, have declined, perhaps due to yearly mass treatment campaigns implemented since 2003. METHODS We report the epidemiology of Urinary and Intestinal schistosomiasis in Lango since 1951-2011 determined through Microscopic examinations for S. mansoni and S. haematobium respectively. A retrospective data review from 195 to 2011 was done to establish the prevalence over the years in the region. We performed Poisson regression analysis to observe trends in epidemiology before and after control was initiated in 2002. In addition, malacological surveys were undertaken in 2007 to assess local transmission potential. FINDINGS Contrary to earlier records, S. haematobium was low and confined to a few putative foci, with declined in infections from 28.2% in 1951 to 2.48% by 2011. Although this decline can be attributed to control, this was already much lower in 1967 than 1951, long before control interventions began suggesting that environmental changes may have made the habitat less suitable for the transmission of S. haematobium. Compared to the historical records S. mansoni prevalence first increased up immediately before control interventions in 2003, significantly declined (p=<0.001) until 2007. However, in 2007 and 2011 declined insignificant, (p = 0.656). No snail has ever been isolated shedding S. haematobium cercariae but many Bulinus snail spp. were found shedding S. bovis cercariae. CONCLUSION This suggests that a combination of environmental and mass treatment has had a significant impact on transmission in Lango region.
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Affiliation(s)
- M Adriko
- Vector Control Division, Ministry of Health, P.O. Box 1661, Plot 15 Bombo Road, Kampala, Uganda; Uganda Institute of Allied Health & Management Science (UIAHMS), School of Medical Entomology and Parasitology, P.O. Box 1661, Kampala, Uganda.
| | - B Tinkitina
- Vector Control Division, Ministry of Health, P.O. Box 1661, Plot 15 Bombo Road, Kampala, Uganda
| | - E M Tukahebw
- Vector Control Division, Ministry of Health, P.O. Box 1661, Plot 15 Bombo Road, Kampala, Uganda
| | - C J Standley
- Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - J R Stothard
- Parasitology Department, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - N B Kabatereine
- Uganda Institute of Allied Health & Management Science (UIAHMS), School of Medical Entomology and Parasitology, P.O. Box 1661, Kampala, Uganda; Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, St Mary's Campus, Norfolk Place, London W2 1PG, UK
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35
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Araujo Navas AL, Soares Magalhães RJ, Osei F, Fornillos RJC, Leonardo LR, Stein A. Modelling local areas of exposure to Schistosoma japonicum in a limited survey data environment. Parasit Vectors 2018; 11:465. [PMID: 30103810 PMCID: PMC6090730 DOI: 10.1186/s13071-018-3039-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/27/2018] [Indexed: 01/14/2023] Open
Abstract
Background Spatial modelling studies of schistosomiasis (SCH) are now commonplace. Covariate values are commonly extracted at survey locations, where infection does not always take place, resulting in an unknown positional exposure mismatch. The present research aims to: (i) describe the nature of the positional exposure mismatch in modelling SCH helminth infections; (ii) delineate exposure areas to correct for such positional mismatch; and (iii) validate exposure areas using human positive cases. Methods To delineate exposure areas to Schistosoma japonicum, a spatial Bayesian network (sBN) was constructed. It uses data on exposure risk factors such as: potential sites for snails’ accessibility, geographical distribution of snail infection rate, and cost of the community to access nearby water bodies. Prior and conditional probabilities were obtained from the literature and inserted as weights based on their relative contribution to exposure; these probabilities were then used to calculate joint probabilities of exposure within the sBN. Results High values of probability of S. japonicum exposure correspond to polygons where snails could potentially be present, for instance in wet soils and areas with low slopes, but also where people can easily access water bodies. Low correlation (R2 = 0.3) was found between the percentage of human cases and the delineated probabilities of exposure when validation buffers are generated over the human cases. Conclusions The utility of a probabilistic method for the identification of exposure areas for S. japonicum, with wider application for other water-borne infections, was demonstrated. From a public health perspective, the schistosomiasis exposure sBN developed in this study could be used to guide local schistosomiasis control teams to specific potential areas of exposure, and improve efficiency of mass drug administration campaigns in places where people are likely to be exposed to the infection. Electronic supplementary material The online version of this article (10.1186/s13071-018-3039-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrea L Araujo Navas
- Faculty of Geo-information Science and Earth Observation (ITC), University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands.
| | - Ricardo J Soares Magalhães
- UQ Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, QLD, Gatton, 4343, Australia.,Child Health and Environment Program, Child Health Research Centre, The University of Queensland, QLD, South Brisbane, 4101, Australia
| | - Frank Osei
- Faculty of Geo-information Science and Earth Observation (ITC), University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands
| | - Raffy Jay C Fornillos
- Institute of Biology, College of Science, University of the Philippines Diliman, 1101, Quezon, Philippines
| | - Lydia R Leonardo
- Department of Parasitology, College of Public Health, University of the Philippines Manila, 1000, Manila, Philippines
| | - Alfred Stein
- Faculty of Geo-information Science and Earth Observation (ITC), University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands
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Elliott AM, Roestenberg M, Wajja A, Opio C, Angumya F, Adriko M, Egesa M, Gitome S, Mfutso-Bengo J, Bejon P, Kapulu M, Seager Z, Lutalo T, Nazziwa WB, Muwumuza A, Yazdanbakhsh M, Kaleebu P, Kabatereine N, Tukahebwa E. Ethical and scientific considerations on the establishment of a controlled human infection model for schistosomiasis in Uganda: report of a stakeholders' meeting held in Entebbe, Uganda. AAS Open Res 2018; 1:2. [PMID: 30714021 PMCID: PMC6358001 DOI: 10.12688/aasopenres.12841.2] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2018] [Indexed: 02/02/2023] Open
Abstract
Controlled human infection (CHI) models are gaining recognition as an approach to accelerating vaccine development, for use in both non-endemic and endemic populations: they can facilitate identification of the most promising candidate vaccines for further trials and advance understanding of protective immunity. Helminths present a continuing health burden in sub-Saharan Africa. Vaccine development for these complex organisms is particularly challenging, partly because protective responses are akin to mechanisms of allergy. A CHI model for Schistosoma mansoni (CHI-S) has been developed at Leiden University Medical Centre, the Netherlands. However, responses to schistosome infections, and candidate vaccines, are likely to be different among people from endemic settings compared to schistosome-naïve Dutch volunteers. Furthermore, among volunteers from endemic regions who have acquired immune responses through prior exposure, schistosome challenge can be used to define responses associated with clinical protection, and thus to guide vaccine development. To explore the possibility of establishing the CHI-S in Uganda, a Stakeholders' Meeting was held in Entebbe in 2017. Regulators, community members, researchers and policy-makers discussed implementation challenges and recommended preparatory steps: risk assessment; development of infrastructure and technical capacity to produce the infectious challenge material in Uganda; community engagement from Parliamentary to grass-roots level; pilot studies to establish approaches to assuring fully informed consent and true voluntariness, and strategies for selection of volunteers who can avoid natural infection during the 12-week CHI-S; the building of regulatory capacity; and the development of study protocols and a product dossier in close consultation with ethical and regulatory partners. It was recommended that, on completion, the protocol and product dossier be reviewed for approval in a joint meeting combining ethical, regulatory and environment management authorities. Most importantly, representatives of schistosomiasis-affected communities emphasised the urgent need for an effective vaccine and urged the research community not to delay in the development process.
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Affiliation(s)
- Alison M. Elliott
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine (MRC/UVRI and LSHTM) Uganda Research Unit, Entebbe, P.O. Box 49, Uganda,
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Anne Wajja
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine (MRC/UVRI and LSHTM) Uganda Research Unit, Entebbe, P.O. Box 49, Uganda
| | - Christopher Opio
- Department of Medicine, College of Health Sciences, Makerere University, Kampala, P.O. Box 7072, Uganda
| | - Francis Angumya
- Department of Medicine, College of Health Sciences, Makerere University, Kampala, P.O. Box 7072, Uganda
| | - Moses Adriko
- Vector Control Division, Ministry of Health of Uganda, Kampala, Uganda
| | - Moses Egesa
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine (MRC/UVRI and LSHTM) Uganda Research Unit, Entebbe, P.O. Box 49, Uganda,Department of Medical Microbiology, School of Biomedical Sciences, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Serah Gitome
- Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Joseph Mfutso-Bengo
- Centre for Bioethics for Eastern and Southern Africa, School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - Tom Lutalo
- Uganda Virus Research Institute, Entebbe, Uganda
| | | | | | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Pontiano Kaleebu
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine (MRC/UVRI and LSHTM) Uganda Research Unit, Entebbe, P.O. Box 49, Uganda,Uganda Virus Research Institute, Entebbe, Uganda
| | - Narcis Kabatereine
- Vector Control Division, Ministry of Health of Uganda, Kampala, Uganda,Schistosomiasis Control Initiative, Faculty of Medicine, School of Public Health, Imperial College London, London, UK
| | - Edridah Tukahebwa
- Vector Control Division, Ministry of Health of Uganda, Kampala, Uganda
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Hajjar WM, Alsheikh AM, Alhumaid AY, Alkreedees NA, Abdulwahed NB, Hajjar AW. Pulmonary schistosomiasis in a young male: A case report and review of the literature. Ann Thorac Med 2018; 13:190-192. [PMID: 30123339 PMCID: PMC6073789 DOI: 10.4103/atm.atm_300_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/25/2017] [Indexed: 11/16/2022] Open
Abstract
Schistosoma is a parasitic infection that affects many people worldwide. However, pulmonary Schistosomiasis is very rare entity which defined as pulmonary involvement develops in persons living or travelling in endemic areas. We report a rare case of 23-year-old Yamani patient admitted as an emergency with a 1-week history of productive cough, hemoptysis, and chest pain. Chest X-ray and computed tomography scan showed right upper lobe peripheral abscess cavity. All routine blood investigations and interventions such as bronchoscopy and bronchoalveolar lavage failed to confirm the diagnosis. However, he underwent right thoracoscopy and excision of this abscess, which unexpectedly showed in the histopathology of the resected specimen Schistosoma parasite infection.
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Affiliation(s)
- Waseem M. Hajjar
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Abdulmalik M. Alsheikh
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Alanoud Y. Alhumaid
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Noura A. Alkreedees
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Nouf B. Abdulwahed
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Adnan W. Hajjar
- Department of Surgery, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia
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Schistosomiasis in Zambia: a systematic review of past and present experiences. Infect Dis Poverty 2018; 7:41. [PMID: 29706131 PMCID: PMC5925830 DOI: 10.1186/s40249-018-0424-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 04/10/2018] [Indexed: 02/04/2023] Open
Abstract
Background The speedy rate of change in the environmental and socio-economics factors may increase the incidence, prevalence and risk of schistosomiasis infections in Zambia. However, available information does not provide a comprehensive understanding of the biogeography and distribution of the disease, ecology and population dynamics of intermediate host snails. The current study used an information-theoretical approach to understand the biogeography and prevalence schistosomiasis and identified knowledge gaps that would be useful to improve policy towards surveillance and eradication of intermediate hosts snails in Zambia. Methods To summarise the existing knowledge and build on past and present experiences of schistosomiasis epidemiology for effective disease control in Zambia, a systematic search of literature for the period 2000–2017 was done on PubMed, Google Scholar and EBSCOhost. Using the key words: ‘Schistosomiasis’, ‘Biomphalaria’, ‘Bulinus’, ‘Schistosoma mansoni’, ‘Schistosoma haematobium’, and ‘Zambia’, in combination with Booleans terms ‘AND’ and ‘OR’, published reports/papers were obtained and reviewed independently for inclusion. Results Thirteen papers published in English that fulfilled the inclusion criteria were selected for the final review. The papers suggest that the risk of infection has increased over the years and this has been attributed to environmental, socio-economic and demographic factors. Furthermore, schistosomiasis is endemic in many parts of the country with infection due to Schistosoma haematobium being more prevalent than that due to S. mansoni. This review also found that S. haematobium was linked to genital lesions, thus increasing risks of contracting other diseases such as HIV and cervical cancer. Conclusions For both S. haematobium and S. mansoni, environmental, socio-economic, and demographic factors were influential in the transmission and prevalence of the disease and highlight the need for detailed knowledge on ecological modelling and mapping the distribution of the disease and intermediate host snails for effective implementation of control strategies. Electronic supplementary material The online version of this article (10.1186/s40249-018-0424-5) contains supplementary material, which is available to authorized users.
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Standley CJ, Graeden E, Kerr J, Sorrell EM, Katz R. Decision support for evidence-based integration of disease control: A proof of concept for malaria and schistosomiasis. PLoS Negl Trop Dis 2018; 12:e0006328. [PMID: 29649260 PMCID: PMC5896906 DOI: 10.1371/journal.pntd.0006328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 02/19/2018] [Indexed: 11/19/2022] Open
Abstract
AUTHOR SUMMARY Designing and implementing effective programs for infectious disease control requires complex decision-making, informed by an understanding of the diseases, the types of disease interventions and control measures available, and the disease-relevant characteristics of the local community. Though disease modeling frameworks have been developed to address these questions and support decision-making, the complexity of current models presents a significant barrier to on-the-ground end users. The picture is further complicated when considering approaches for integration of different disease control programs, where co-infection dynamics, treatment interactions, and other variables must also be taken into account. Here, we describe the development of an application available on the internet with a simple user interface, to support on-the-ground decision-making for integrating disease control, given local conditions and practical constraints. The model upon which the tool is built provides predictive analysis for the effectiveness of integration of schistosomiasis and malaria control, two diseases with extensive geographical and epidemiological overlap. This proof-of-concept method and tool demonstrate significant progress in effectively translating the best available scientific models to support pragmatic decision-making on the ground, with the potential to significantly increase the impact and cost-effectiveness of disease control.
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Affiliation(s)
- Claire J. Standley
- Center for Global Health Science and Security, Georgetown University, Washington, DC, United States of America
- * E-mail:
| | - Ellie Graeden
- Talus Analytics, LLC, Lyons, CO, United States of America
| | - Justin Kerr
- Talus Analytics, LLC, Lyons, CO, United States of America
| | - Erin M. Sorrell
- Center for Global Health Science and Security, Georgetown University, Washington, DC, United States of America
| | - Rebecca Katz
- Center for Global Health Science and Security, Georgetown University, Washington, DC, United States of America
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Chala B, Torben W. An Epidemiological Trend of Urogenital Schistosomiasis in Ethiopia. Front Public Health 2018; 6:60. [PMID: 29556490 PMCID: PMC5844936 DOI: 10.3389/fpubh.2018.00060] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/15/2018] [Indexed: 11/18/2022] Open
Abstract
Schistosomiasis is a major public health problem in Ethiopia. Currently, the prevalence of the disease can possibly be heightened due to man-made ecological transformations particularly related to the recent development programs involving irrigation and construction of dams. The expansion of some of the water resource development projects has been cited enhancing the upsurge of urogenital schistosomiasis mainly in the lower altitude areas of the country. In connection to the extensive initiation of development projects in low altitude areas of the country, simultaneous and adequate attentions have never been given to address a pre-assessment of health impacts of the development programs prior to launching the projects. Helpful appraisals focusing on evaluation of epidemiology of urogenital schistosomiasis in Ethiopia have not been explored. Therefore, the current review attempts to trace an overall picture of the epidemiological status of urogenital schistosomiasis in the country; the past and existing trends of urogenital schistosomiasis surveys and control programs of the country are reviewed. Essential recommendations are highlighted for possible inputs in future control design strategies of national control program of schistosomiasis.
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Affiliation(s)
- Bayissa Chala
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia.,Department of Parasitology and Tropical Medicine, College of Medicine, Seoul National University, Seoul, South Korea
| | - Workineh Torben
- Division of Pathology, Tulane National Primate Research Center, Covington, LA, United States
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Sokolow SH, Wood CL, Jones IJ, Lafferty KD, Kuris AM, Hsieh MH, De Leo GA. To Reduce the Global Burden of Human Schistosomiasis, Use 'Old Fashioned' Snail Control. Trends Parasitol 2018; 34:23-40. [PMID: 29126819 PMCID: PMC5819334 DOI: 10.1016/j.pt.2017.10.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/30/2017] [Accepted: 10/16/2017] [Indexed: 12/27/2022]
Abstract
Control strategies to reduce human schistosomiasis have evolved from 'snail picking' campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and 'outside the box' strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly's stated goal to eliminate schistosomiasis, it is time to give snail control another look.
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Affiliation(s)
- Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA; Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195-5020, USA
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Kevin D Lafferty
- U.S. Geological Survey, Western Ecological Research Center, c/o Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Armand M Kuris
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Michael H Hsieh
- Children's National Health System, Washington DC, 20010, USA; The George Washington University, Washington DC, 20037, USA; Biomedical Research Institute, Rockville, MD 20850, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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Donohue RE, Mashoto KO, Mubyazi GM, Madon S, Malecela MN, Michael E. Biosocial Determinants of Persistent Schistosomiasis among Schoolchildren in Tanzania despite Repeated Treatment. Trop Med Infect Dis 2017; 2:E61. [PMID: 30270918 PMCID: PMC6082061 DOI: 10.3390/tropicalmed2040061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 01/19/2023] Open
Abstract
Schistosomiasis is a parasitic disease endemic to Tanzania and other countries of the global south, which is currently being addressed through preventive chemotherapy campaigns. However, there is growing recognition that chemotherapy strategies will need to be supplemented to sustainably control and eventually eliminate the disease. There remains a need to understand the factors contributing to continued transmission in order to ensure the effective configuration and implementation of supplemented programs. We conducted a cross-sectional questionnaire, to evaluate the biosocial determinants facilitating the persistence of schistosomiasis, among 1704 Tanzanian schoolchildren residing in two districts undergoing a preventive chemotherapeutic program: Rufiji and Mkuranga. A meta-analysis was carried out to select the diagnostic questions that provided a likelihood for predicting infection status. We found that self-reported schistosomiasis continues to persist among the schoolchildren, despite multiple rounds of drug administration.Using mixed effects logistic regression modeling, we found biosocial factors, including gender, socio-economic status, and water, sanitation, and hygiene (WASH)-related variables, were associated with this continued schistosomiasis presence. These findings highlight the significant role that social factors may play in the persistence of disease transmission despite multiple treatments, and support the need not only for including integrated technical measures, such as WASH, but also addressing issues of poverty and gender when designing effective and sustainable schistosomiasis control programs.
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Affiliation(s)
- Rose E Donohue
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Kijakazi O Mashoto
- National Institute for Medical Research, P.O. Box 9653, 3 Barack Obama Drive, 11101 Dar es Salaam, Tanzania.
| | - Godfrey M Mubyazi
- National Institute for Medical Research, P.O. Box 9653, 3 Barack Obama Drive, 11101 Dar es Salaam, Tanzania.
| | - Shirin Madon
- Department of International Development, London School of Economics & Political Science, Houghton Street, London WC2A 2AE, UK.
- Department of Management, London School of Economics & Political Science, Houghton Street, London WC2A 2AE, UK.
| | - Mwele N Malecela
- Tanzania Commission for Science and Technology (COSTECH), P.O. Box 4302, Ali Hassan Mwinyi Road, Kijitonyama, 14113 Dar es Salaam, Tanzania.
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
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Beechler BR, Jolles AE, Budischak SA, Corstjens PLAM, Ezenwa VO, Smith M, Spaan RS, van Dam GJ, Steinauer ML. Host immunity, nutrition and coinfection alter longitudinal infection patterns of schistosomes in a free ranging African buffalo population. PLoS Negl Trop Dis 2017; 11:e0006122. [PMID: 29253882 PMCID: PMC5755937 DOI: 10.1371/journal.pntd.0006122] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 01/05/2018] [Accepted: 11/20/2017] [Indexed: 11/19/2022] Open
Abstract
Schistosomes are trematode parasites of global importance, causing infections in millions of people, livestock, and wildlife. Most studies on schistosomiasis, involve human subjects; as such, there is a paucity of longitudinal studies investigating parasite dynamics in the absence of intervention. As a consequence, despite decades of research on schistosomiasis, our understanding of its ecology in natural host populations is centered around how environmental exposure and acquired immunity influence acquisition of parasites, while very little is known about the influence of host physiology, coinfection and clearance in the absence of drug treatment. We used a 4-year study in free-ranging African buffalo to investigate natural schistosome dynamics. We asked (i) what are the spatial and temporal patterns of schistosome infections; (ii) how do parasite burdens vary over time within individual hosts; and (iii) what host factors (immunological, physiological, co-infection) and environmental factors (season, location) explain patterns of schistosome acquisition and loss in buffalo? Schistosome infections were common among buffalo. Microgeographic structure explained some variation in parasite burdens among hosts, indicating transmission hotspots. Overall, parasite burdens ratcheted up over time; however, gains in schistosome abundance in the dry season were partially offset by losses in the wet season, with some hosts demonstrating complete clearance of infection. Variation among buffalo in schistosome loss was associated with immunologic and nutritional factors, as well as co-infection by the gastrointestinal helminth Cooperia fuelleborni. Our results demonstrate that schistosome infections are surprisingly dynamic in a free-living mammalian host population, and point to a role for host factors in driving variation in parasite clearance, but not parasite acquisition which is driven by seasonal changes and spatial habitat utilization. Our study illustrates the power of longitudinal studies for discovering mechanisms underlying parasite dynamics in individual animals and populations.
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Affiliation(s)
- Brianna R. Beechler
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
| | - Anna E. Jolles
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States of America
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States of America
| | - Sarah A. Budischak
- Odum School of Ecology, University of Georgia, Athens, GA, United States of America
| | - Paul L. A. M. Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Vanessa O. Ezenwa
- Odum School of Ecology, University of Georgia, Athens, GA, United States of America
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States of America
| | - Mireya Smith
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States of America
| | - Robert S. Spaan
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, United States of America
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michelle L. Steinauer
- College of Osteopathic Medicine of the PNW, Western University of Health Sciences, Lebanon, OR, United States of America
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Kabwama SN, Mafigiri R, Balinandi S, Kagirita A, Riolexus AA, Zhu BP. Risk factors for hematemesis in Hoima and Buliisa Districts, Western Uganda, September-October 2015. Pan Afr Med J 2017; 28:215. [PMID: 29610653 PMCID: PMC5878846 DOI: 10.11604/pamj.2017.28.215.12395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 10/28/2017] [Indexed: 12/12/2022] Open
Abstract
Introduction On 17 September 2015, Buliisa District Health Office reported multiple deaths due to haemorrhage to the Uganda Ministry of Health. We conducted an investigation to verify the existence of an outbreak and to identify the disease nature, mode of transmission and risk factors. Methods We defined a suspected case as onset of hematemesis between 1 June 2015 and 15 October 2015 in a resident of Hoima, Buliisa or neighbouring districts. We identified cases by reviewing medical records and actively searching in the community. We interviewed case-patients and health-care workers and performed descriptive epidemiology to generate hypotheses on possible exposures. In a case-control study we compared exposures between 21 cases and 81 controls, matched by age (± 10 years), sex and village of residence. We collected 22 biological specimens from 19 case-patients to test for Viral Haemorrhagic Fevers (VHF). We analysed the data using the Mantel-Haenszel method to account for the matched study design. Results We identified 56 cases with onset from June to October (attack rate 15/100,000 in Buliisa District and 5.2/100,000 in Hoima District). The age-specific attack rate was highest in persons aged 31-60 years (15/100,000 in Hoima and 47/100,000 in Buliisa); no persons below 15 years of age had the illness. In the case-control study, 42% (5/12) of cases vs. 0.0% (0/77) of controls had liver disease (ORM-H = ∞; 95%CI = 3.7-∞); 71% (10/14) of cases vs. 35% (28/81) of controls had ulcer disease (ORM-H = 13; 95% CI = 1.6-98); 27% (3/11) of cases vs. 14% (11/81) of controls used indomethacin prior to disease onset (ORM-H = 6.0; 95% CI = 1.0-36). None of the blood samples were positive for any of the VHFs. Conclusion This reported cluster of hematemesis illness was due to predisposing conditions and use of Non-Steroidal Anti-inflammatory Drugs (NSAID). Health education should be conducted on the danger of NSAIDs misuse, especially in persons with pre-disposing conditions.
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Affiliation(s)
- Steven Ndugwa Kabwama
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Richardson Mafigiri
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | | | - Atek Kagirita
- Central Public Health Laboratories, Ministry of Health, Kampala, Uganda
| | - Alex Ario Riolexus
- Uganda Public Health Fellowship Program, Field Epidemiology Track, Ministry of Health, Kampala, Uganda
| | - Bao-Ping Zhu
- US Centers for Disease Control and Prevention, Kampala, Uganda
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Chami GF, Kontoleon AA, Bulte E, Fenwick A, Kabatereine NB, Tukahebwa EM, Dunne DW. Community-directed mass drug administration is undermined by status seeking in friendship networks and inadequate trust in health advice networks. Soc Sci Med 2017; 183:37-47. [PMID: 28458073 PMCID: PMC5446315 DOI: 10.1016/j.socscimed.2017.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/28/2017] [Accepted: 04/07/2017] [Indexed: 12/01/2022]
Abstract
Over 1.9 billion individuals require preventive chemotherapy through mass drug administration (MDA). Community-directed MDA relies on volunteer community medicine distributors (CMDs) and their achievement of high coverage and compliance. Yet, it is unknown if village social networks influence effective MDA implementation by CMDs. In Mayuge District, Uganda, census-style surveys were conducted for 16,357 individuals from 3,491 households in 17 villages. Praziquantel, albendazole, and ivermectin were administered for one month in community-directed MDA to treat Schistosoma mansoni, hookworm, and lymphatic filariasis. Self-reported treatment outcomes, socioeconomic characteristics, friendship networks, and health advice networks were collected. We investigated systematically missed coverage and noncompliance. Coverage was defined as an eligible person being offered at least one drug by CMDs; compliance included ingesting at least one of the offered drugs. These outcomes were analyzed as a two-stage process using a Heckman selection model. To further assess if MDA through CMDs was working as intended, we examined the probability of accurate drug administration of 1) praziquantel, 2) both albendazole and ivermectin, and 3) all drugs. This analysis was conducted using bivariate Probit regression. Four indicators from each social network were examined: degree, betweenness centrality, closeness centrality, and the presence of a direct connection to CMDs. All models accounted for nested household and village standard errors. CMDs were more likely to offer medicines, and to accurately administer the drugs as trained by the national control programme, to individuals with high friendship degree (many connections) and high friendship closeness centrality (households that were only a short number of steps away from all other households in the network). Though high (88.59%), additional compliance was associated with directly trusting CMDs for health advice. Effective treatment provision requires addressing CMD biases towards influential, well-embedded individuals in friendship networks and utilizing health advice networks to increase village trust in CMDs. Evaluation of mass drug administration implementation using social networks. Evidence of social biases and status-seeking from community medicine distributors. Coverage and compliance with mass drug administration for 16,357 individuals. Impact of friendship and health advice networks on treatment probability. Overlap of network status and formal social status in rural villages.
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Affiliation(s)
- Goylette F Chami
- Department of Land Economy, University of Cambridge, Cambridge CB3 9EP, United Kingdom; Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom.
| | - Andreas A Kontoleon
- Department of Land Economy, University of Cambridge, Cambridge CB3 9EP, United Kingdom
| | - Erwin Bulte
- Department of Land Economy, University of Cambridge, Cambridge CB3 9EP, United Kingdom; Development Economics Group, Wageningen University, Wageningen 6706 KN, The Netherlands
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College London, London, W2 1PG, United Kingdom
| | - Narcis B Kabatereine
- Schistosomiasis Control Initiative, Imperial College London, London, W2 1PG, United Kingdom; Uganda Ministry of Health, Vector Control Division, Bilharzia and Worm Control Programme, Kampala, Uganda
| | - Edridah M Tukahebwa
- Uganda Ministry of Health, Vector Control Division, Bilharzia and Worm Control Programme, Kampala, Uganda
| | - David W Dunne
- Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom
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Rujeni N, Morona D, Ruberanziza E, Mazigo HD. Schistosomiasis and soil-transmitted helminthiasis in Rwanda: an update on their epidemiology and control. Infect Dis Poverty 2017; 6:8. [PMID: 28245883 PMCID: PMC5331630 DOI: 10.1186/s40249-016-0212-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 12/08/2016] [Indexed: 11/17/2022] Open
Abstract
Even though Rwanda lies within a region that has a high prevalence of schistosomiasis and soil-transmitted helminth (STH) infections, epidemiological information regarding these infections in the country remains scarce. The present review attempts to compile the available data on schistosomiasis and STHs, from 1940 to 2014, to provide an insight on the epidemiological profile of these infections. This information will, in turn, support the design and implementation of sustainable control measures. The available records indicate that only Schistosoma mansoni and all the major species of STHs are endemic in Rwanda. In 2008, the national prevalence of S. mansoni was reported to be 2.7%, ranging from 0 to 69.5%, and that of STH infections was 65.8% (diagnosed using the Kato-Katz technique). The prevalence of these infections varies from one district to another, with schoolchildren remaining a highly affected group. The main control approach is mass drug administration using albendazole and praziquantel, mostly targeting school-aged children in school environments. In 2008, adult individuals living in areas with a prevalence of S. mansoni ≥30% were also included in the mass drug administration programme. However, despite Rwanda achieving an almost 100% coverage of this programme in 2008–2010, the transmission of S. mansoni and STHs continues to take place, as illustrated by the most recent surveys. If Rwanda is to achieve sustainable control and elimination of schistosomiasis and STHs, there is a need to revise the country’s control strategy and adopt an integrated control approach that involves a combination of measures.
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Affiliation(s)
- Nadine Rujeni
- Department of Biomedical Laboratory Sciences, School of Health Sciences, College of Medicine and Health Sciences, University of Rwanda, P.O. Box 3286, Nyarugenge, Rwanda
| | - Domenica Morona
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania.
| | - Eugene Ruberanziza
- Rwanda Biomedical Center, Institute of HIV, Disease Prevention and Control, Malaria and Other Parasitic Diseases Division, Neglected Tropical Diseases and Other Parasitic Diseases Unit, Kigali, Rwanda
| | - Humphrey D Mazigo
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania
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Stanton MC, Adriko M, Arinaitwe M, Howell A, Davies J, Allison G, LaCourse EJ, Muheki E, Kabatereine NB, Stothard JR. Intestinal schistosomiasis in Uganda at high altitude (>1400 m): malacological and epidemiological surveys on Mount Elgon and in Fort Portal crater lakes reveal extra preventive chemotherapy needs. Infect Dis Poverty 2017; 6:34. [PMID: 28162096 PMCID: PMC5292801 DOI: 10.1186/s40249-017-0248-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/19/2017] [Indexed: 01/24/2023] Open
Abstract
Background Intestinal schistosomiasis is of public health importance in Uganda but communities living above 1400 m are not targeted for control as natural transmission is thought unlikely. To assess altitudinal boundaries and at-risk populations, conjoint malacological and epidemiological surveys were undertaken on Mount Elgon (1139 m–3937 m), in Fort Portal crater lakes and in the Rwenzori Mountains (1123 m–4050 m). Methods Seventy freshwater habitats [Mount Elgon (37), Fort Portal crater lakes (23), Rwenzori Mountains (8) and Lake Albert (2)] were inspected for Biomphalaria species. Water temperature, pH and conductivity were recorded. A parasitological examination of 756 schoolchildren [Mount Elgon (300), Fort Portal crater lakes (456)] by faecal microscopy of duplicate Kato-Katz smears from two consecutive stool samples was bolstered by antigen (urine-CCA dipstick) and antibody (SEA-ELISA) diagnostic assays. Results Biomphalaria spp. was found up to 1951 m on Mount Elgon and 1567 m in the Fort Portal crater lakes. Although no snail from Mount Elgon shed cercariae, molecular analysis judged 7.1% of snails sampled at altitudes above 1400 m as having DNA of Schistosoma mansoni; in Fort Portal crater lakes three snails shed schistosome cercariae. Prevalence of intestinal schistosomiasis as measured in schoolchildren by Kato-Katz (Mount Elgon = 5.3% v. Fort Portal crater lakes = 10.7%), CCA urine-dipsticks (18.3% v. 34.4%) and SEA-ELISA (42.3% v. 63.7%) showed negative associations with increasing altitude with some evidence of infection up to 2000 m. Conclusions Contrary to expectations, these surveys clearly show that natural transmission of intestinal schistosomiasis occurs above 1400 m, possibly extending up to 2000 m. Using spatial epidemiological predictions, this now places some extra six million people at-risk, denoting an expansion of preventive chemotherapy needs in Uganda. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0248-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michelle C Stanton
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda
| | - Moses Arinaitwe
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda
| | - Alison Howell
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Juliet Davies
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Gillian Allison
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - E James LaCourse
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Edridah Muheki
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda
| | - Narcis B Kabatereine
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda.,Schistosomiasis Control Initiative, Imperial College London, London, W2 1PG, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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Kalinda C, Chimbari M, Mukaratirwa S. Implications of Changing Temperatures on the Growth, Fecundity and Survival of Intermediate Host Snails of Schistosomiasis: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14010080. [PMID: 28098789 PMCID: PMC5295331 DOI: 10.3390/ijerph14010080] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/04/2017] [Accepted: 01/09/2017] [Indexed: 12/27/2022]
Abstract
Climate change has been predicted to increase the global mean temperature and to alter the ecological interactions among organisms. These changes may play critical roles in influencing the life history traits of the intermediate hosts (IHs). This review focused on studies and disease models that evaluate the potential effect of temperature rise on the ecology of IH snails and the development of parasites within them. The main focus was on IH snails of schistosome parasites that cause schistosomiasis in humans. A literature search was conducted on Google Scholar, EBSCOhost and PubMed databases using predefined medical subject heading terms, Boolean operators and truncation symbols in combinations with direct key words. The final synthesis included nineteen published articles. The studies reviewed indicated that temperature rise may alter the distribution, optimal conditions for breeding, growth and survival of IH snails which may eventually increase the spread and/or transmission of schistosomiasis. The literature also confirmed that the life history traits of IH snails and their interaction with the schistosome parasites are affected by temperature and hence a change in climate may have profound outcomes on the population size of snails, parasite density and disease epidemiology. We concluded that understanding the impact of temperature on the growth, fecundity and survival of IH snails may broaden the knowledge on the possible effects of climate change and hence inform schistosomiasis control programmes.
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Affiliation(s)
- Chester Kalinda
- School of Nursing and Public Health, College of Health Sciences, Howard College Campus, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - Moses Chimbari
- School of Nursing and Public Health, College of Health Sciences, Howard College Campus, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - Samson Mukaratirwa
- School of Life Sciences, College of Agriculture, Engineering and Science, Westville Campus, University of KwaZulu-Natal, Durban 4001, South Africa.
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49
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Al-Shehri H, Stanton MC, LaCourse JE, Atuhaire A, Arinaitwe M, Wamboko A, Adriko M, Kabatereine NB, Stothard JR. An extensive burden of giardiasis associated with intestinal schistosomiasis and anaemia in school children on the shoreline of Lake Albert, Uganda. Trans R Soc Trop Med Hyg 2016; 110:597-603. [PMID: 27864517 DOI: 10.1093/trstmh/trw072] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 10/24/2016] [Accepted: 11/14/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Water-borne parasitic diseases associated with poverty still blight the lives of African school children. In Uganda, intestinal schistosomiasis is still common along the shoreline of Lake Albert, despite ongoing control, and co-infection with giardiasis and malaria is poorly described. To shed light on putative interactions between diseases, a prospective cross-sectional parasitological survey was undertaken in five primary schools. METHODS Stool samples from 254 school children, aged 5-10 years, were examined by microscopy and rapid diagnostic tests (RDTs), with additional real-time PCR assays for detection of Giardia DNA. A finger-prick blood sample was also taken from each child and tested for malaria, and haemoblobin levels measured. Assocations between diseases and anaemia were assessed. RESULTS Intestinal schistosomiasis (46.5%), giardiasis (41.6%) and malaria (56.2%) were common, and a quarter of children were anaemic (<115 g/L). Up to 87.0% of children were excreting Giardia DNA and the prevalence of heavy infection by real-time PCR (Ct≤19) was 19.5%, being positively associated with light, moderate and heavy egg-patent schistosomiasis, as well as with anaemia. CONCLUSIONS In this setting, an extensive burden of giardiasis was revealed with heavy intensity infections associated with egg-patent intestinal schistosomiasis and anaemia. To improve child health, greater attention on giardiasis is needed along with exploring joined-up actions across diseases that promote better water hygiene and sanitation measures.
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Affiliation(s)
- Hajri Al-Shehri
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.,Ministry of Health, Asir District, Kingdom of Saudi Arabia
| | | | | | - Aaron Atuhaire
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Arinaitwe
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aida Wamboko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Narcis B Kabatereine
- Vector Control Division, Ministry of Health, Kampala, Uganda.,Schistosomiasis Control Initiative, School of Public Health, Imperial College London, London W2 1PG, UK
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50
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Blanquart F, Grabowski MK, Herbeck J, Nalugoda F, Serwadda D, Eller MA, Robb ML, Gray R, Kigozi G, Laeyendecker O, Lythgoe KA, Nakigozi G, Quinn TC, Reynolds SJ, Wawer MJ, Fraser C. A transmission-virulence evolutionary trade-off explains attenuation of HIV-1 in Uganda. eLife 2016; 5:e20492. [PMID: 27815945 PMCID: PMC5115872 DOI: 10.7554/elife.20492] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/01/2016] [Indexed: 01/25/2023] Open
Abstract
Evolutionary theory hypothesizes that intermediate virulence maximizes pathogen fitness as a result of a trade-off between virulence and transmission, but empirical evidence remains scarce. We bridge this gap using data from a large and long-standing HIV-1 prospective cohort, in Uganda. We use an epidemiological-evolutionary model parameterised with this data to derive evolutionary predictions based on analysis and detailed individual-based simulations. We robustly predict stabilising selection towards a low level of virulence, and rapid attenuation of the virus. Accordingly, set-point viral load, the most common measure of virulence, has declined in the last 20 years. Our model also predicts that subtype A is slowly outcompeting subtype D, with both subtypes becoming less virulent, as observed in the data. Reduction of set-point viral loads should have resulted in a 20% reduction in incidence, and a three years extension of untreated asymptomatic infection, increasing opportunities for timely treatment of infected individuals.
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Affiliation(s)
- François Blanquart
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, United Kingdom
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- School of Public Health, Imperial College London, London, United Kingdom
| | - Mary Kate Grabowski
- Department of Epidemiology, Johns Hopkins University, Baltimore, United States
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
| | - Joshua Herbeck
- International Clinical Research Center, University of Washington, Seattle, United States
- Department of Global Health, University of Washington, Seattle, United States
| | | | - David Serwadda
- Rakai Health Sciences Program, Entebbe, Uganda
- School of Public Health, Makerere University, Kampala, Uganda
| | - Michael A Eller
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, United States
| | - Merlin L Robb
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, United States
| | - Ronald Gray
- Department of Epidemiology, Johns Hopkins University, Baltimore, United States
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
- Rakai Health Sciences Program, Entebbe, Uganda
| | | | - Oliver Laeyendecker
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
| | - Katrina A Lythgoe
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, United Kingdom
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- School of Public Health, Imperial College London, London, United Kingdom
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Thomas C Quinn
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
| | - Steven J Reynolds
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, United States
| | - Maria J Wawer
- Department of Epidemiology, Johns Hopkins University, Baltimore, United States
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
| | - Christophe Fraser
- MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, United Kingdom
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- School of Public Health, Imperial College London, London, United Kingdom
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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