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Mbugi NO, Laizer H, Chacha M, Mbega E. Prevalence of human schistosomiasis in various regions of Tanzania Mainland and Zanzibar: A systematic review and meta-analysis of studies conducted for the past ten years (2013-2023). PLoS Negl Trop Dis 2024; 18:e0012462. [PMID: 39250468 DOI: 10.1371/journal.pntd.0012462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 08/17/2024] [Indexed: 09/11/2024] Open
Abstract
Schistosomiasis is a significant public health problem in Tanzania, particularly for the people living in the marginalized settings. We have conducted a systematic review with meta-analysis on the prevalence of schistosomiasis to add knowledge towards the development of effective approaches to control the disease in Tanzania. Online databases namely, Pub Med, SCOPUS and AJOL, were systematically searched and a random effect model was used to calculate the pooled prevalence of the disease. Heterogeneity and the between studies variances were determined using Cochran (Q) and Higgins (I2) tests, respectively. A total of 55 articles met the inclusion criterion for this review and all have satisfactory quality scores. The pooled prevalence of the disease in Tanzania was 26.40%. Tanzania mainland had the highest schistosomiasis prevalence (28.89%) than Zanzibar (8.95%). Sub-group analyses based on the year of publication revealed the going up of the pooled prevalence, whereby for (2013-2018) and (2018-2023) the prevalence was 23.41% and 30.06%, respectively. The prevalence of the Schistosoma mansoni and Schistosoma hematobium were 37.91% and 8.86% respectively. Mara, Simuyu, and Mwanza were the most prevalent regions, with a pooled prevalence of 77.39%, 72.26%, and 51.19%, respectively. The pooled prevalence based on the diagnostic method was 64.11% for PCR and 56.46% for POC-CCA, which is relatively high compared to other tests. Cochrans and Higgins (I2) test has shown significant heterogeneity (p-value = 0.001 and I2 = 99.6). Factors including age, region, diagnostic method and sample size have shown significant contribution to the displayed heterogeneity. The pronounced and increasing prevalence of the disease suggests potential low coverage and possibly lack of involvement of some regions in the control of the disease. This, therefore, calls for an intensive implementation of control interventions in all endemic regions, preferably using an integrated approach that targets several stages of the disease lifecycle.
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Affiliation(s)
- Nicolaus Omari Mbugi
- The Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha, Tanzania
- Mbeya University of Science and Technology, College of Science and Technical Education, Mbeya, Tanzania
| | - Hudson Laizer
- Mbeya University of Science and Technology, College of Science and Technical Education, Mbeya, Tanzania
| | | | - Ernest Mbega
- The Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha, Tanzania
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Zacharia A, Makene T, Haule S, Lukumay G, Omary H, Shabani M, Ngasala B. Urogenital schistosomiasis among adult male population in an endemic area of southern Tanzania: a descriptive cross-sectional study. BMJ Open 2024; 14:e079690. [PMID: 38889945 PMCID: PMC11191765 DOI: 10.1136/bmjopen-2023-079690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 04/26/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND Urogenital schistosomiasis (UGS) caused by Schistosoma haematobium is endemic in Southern Tanzania. The disease has significant implications for both socioeconomic and public health. Because infections with S. haematobium usually peak in childhood, the majority of studies have concentrated on school-aged children leaving other groups such as males which might be continuous reservoir of infection transmission. However, despite its chronic consequences in the male population, the disease has received insufficient attention, especially in sub-Saharan Africa. This study was conducted to describe the previous and current schistosomiasis status among adult males living in high-endemic areas of southern Tanzania DESIGN, SETTING AND PARTICIPANTS: A descriptive cross-sectional study was employed to gather data on the prevalence of UGS among adult men residing at schistosomiasis endemic in the Mtama District Council. Quantitative methods of data collection which included questionnaire and laboratory procedures were used. RESULTS Out of 245 participants, macrohaematuria and microhaematuria were found in 12 (4.9%, 95% CI 2.4% to 7.8%) and 66 (26.9%, 95% CI 21.6% to 32.7%) participants, respectively. S. haematobium ova were recovered from the urine samples of 54 (22.0%, 95% CI 16.7% to 27.3%) participants. The median intensity of infection was 20 eggs per 10 mL of urine ranging from 1 to 201 eggs per 10 mL of urine (IQR) 60.5). Out of 245 participants 33 (13.5% 95% CI 9.0% to 17.6%) had light intensity of infection and 21 (38.9%, 95% CI; 25.0% to 52.5%) had heavy intensity of infection. Overall, the prevalence of heavy intensity of infection was 8.6% (95% CI 4.9% to 12.6%). The prevalence and intensity of UGS varied significantly by age, marital status and village of residence. CONCLUSION This study sheds light on the prevalence of UGS among adult males in endemic areas of southern Tanzania. The results highlight the urgent need for comprehensive intervention strategies to address the burden of the disease.
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Affiliation(s)
- Abdallah Zacharia
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Twilumba Makene
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Stanley Haule
- Pathology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Gift Lukumay
- Community Health Nursing, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of
| | - Huda Omary
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of
| | - Monica Shabani
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Billy Ngasala
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
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Ayob N, Burger RP, Belelie MD, Nkosi NC, Havenga H, de Necker L, Cilliers DP. Modelling the historical distribution of schistosomiasis-transmitting snails in South Africa using ecological niche models. PLoS One 2023; 18:e0295149. [PMID: 38033142 PMCID: PMC10688899 DOI: 10.1371/journal.pone.0295149] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/14/2023] [Indexed: 12/02/2023] Open
Abstract
Schistosomiasis is a vector-borne disease transmitted by freshwater snails and is prevalent in rural areas with poor sanitation and no access to tap water. Three snail species are known to transmit schistosomiasis in South Africa (SA), namely Biomphalaria pfeifferi, Bulinus globosus and Bulinus africanus. In 2003, a predicted prevalence of 70% was reported in tropical climates in SA. Temperature and rainfall variability can alter schistosomiasis-transmitting snails' development by increasing or decreasing their abundance and geographical distribution. This study aimed to map the historical distribution of schistosomiasis from 1950 to 2006 in SA. The snail sampling data were obtained from the historical National Snail Freshwater Collection (NFSC). Bioclimatic variables were extracted using ERA 5 reanalysis data provided by the Copernicus Climate Change Service. In this study, we used 19 bioclimatic and four soil variables. The temporal aggregation was the mean climatological period pre-calculated over the 40-year reference period with a spatial resolution of 0.5° x 0.5°. Multicollinearity was reduced by calculating the Variance Inflation Factor Core (VIF), and highly correlated variables (> 0.85) were excluded. To obtain an "ensemble" and avoid the integration of weak models, we averaged predictions using the True Skill Statistical (TSS) method. Results showed that the ensemble model achieved the highest Area Under the Curve (AUC) scores (0.99). For B. africanus, precipitation-related variables contributed to determining the suitability for schistosomiasis. Temperature and precipitation-related variables influenced the distribution of B. globosus in all three models. Biomphalaria pfeifferi showed that Temperature Seasonality (bio4) contributed the most (47%) in all three models. According to the models, suitable areas for transmitting schistosomiasis were in the eastern regions of South Africa. Temperature and rainfall can impact the transmission and distribution of schistosomiasis in SA. The results will enable us to develop future projections for Schistosoma in SA based on climate scenarios.
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Affiliation(s)
- Nisa Ayob
- Unit for Environmental Sciences and Management, North-West University, Mafikeng Campus, Mafikeng, South Africa
| | - Roelof P. Burger
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Potchefstroom, South Africa
| | - Monray D. Belelie
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Potchefstroom, South Africa
| | - Ncobile C. Nkosi
- Unit for Environmental Sciences and Management, North-West University, Mafikeng Campus, Mafikeng, South Africa
| | - Henno Havenga
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Potchefstroom, South Africa
| | - Lizaan de Necker
- South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda, South Africa
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Dirk P. Cilliers
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Potchefstroom, South Africa
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Malibiche D, Mushi V, Justine NC, Silvestri V, Mhamilawa LE, Tarimo D. Prevalence and factors associated with ongoing transmission of Schistosoma haematobium after 12 rounds of Praziquantel Mass Drug Administration among school age children in Southern Tanzania. Parasite Epidemiol Control 2023; 23:e00323. [PMID: 37692460 PMCID: PMC10485624 DOI: 10.1016/j.parepi.2023.e00323] [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: 05/17/2023] [Revised: 07/21/2023] [Accepted: 08/27/2023] [Indexed: 09/12/2023] Open
Abstract
Background World Health Organization (WHO) recommends periodic praziquantel Mass Drug Administration (MDA) to vulnerable populations, especially school-aged children, to reduce the risk of transmission. In the S. haematobium endemic Lindi region, on the southeastern coast of Tanzania, praziquantel has been distributed for more than a decade (12 rounds) in schools. However, there is a paucity of data on the current burden and factors perpetuating ongoing urogenital schistosomiasis among SAC. The study investigated the prevalence and factors associated with the ongoing transmission of S. haematobium among school-age children (SAC) after 12 rounds of praziquantel in Nachingwea, Southern Tanzania. Material and methods A quantitative cross-sectional study was conducted between May and June 2022 among 483 SAC in the Nachingwea district. Macrohematuria, microhaematuria, and S. haematobium eggs were assessed in the collected urine sample for each participant, using macroscopic observation, urine dipstick, and urine filtration techniques, respectively. Infection intensity was quantified for positive S. haematobium urine samples. Knowledge and attitudes towards schistosomiasis were assessed among participants through an interview-administered questionnaire, and water contact practices were registered through an observation checklist. Data were summarized using descriptive statistics, the Chi-square test, and logistic regression. Results The prevalence of S. haematobium infection was 10.6%, with 0.6% (3/51) prevalence of heavy infection. The factors associated with S. haematobium persistence transmission were a habit of visiting the water bodies (AOR = 1.62, 95% CI: 0.40-1.96), swimming in the visited water bodies (AOR = 4.58, 95% CI: 1.72-12.19), using water from the river source (AOR = 3.79, 95% CI: 1.51-9.51) and attending Mkumba Primary School (17.4%; AOR = 6.12, 95% CI: 1.64-22.85). Conclusions Findings suggest ongoing transmission of urogenital schistosomiasis in the Nachingwea District despite 12 rounds of praziquantel treatment, with a low prevalence of heavy infection (0.6%). Praziquantel distribution should be complemented with health education, especially on the cause and transmission of urogenital schistosomiasis to increase knowledge that will improve a good attitude towards schistosomiasis prevention. An adequate water supply is to be considered to reduce infections due to the visit to water sources for daily use.
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Affiliation(s)
- Ditrick Malibiche
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Vivian Mushi
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Department of Zoology and Wildlife Conservation, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Nyanda C. Justine
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Department of Medical Parasitology and Entomology, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Valeria Silvestri
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Lwidiko E. Mhamilawa
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Donath Tarimo
- Department of Parasitology and Medical Entomology, School of Public Health and Social Sciences, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
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Hong ST. Review of Recent Prevalence of Urogenital Schistosomiasis in Sub-Saharan Africa and Diagnostic Challenges in the Field Setting. Life (Basel) 2023; 13:1670. [PMID: 37629527 PMCID: PMC10456001 DOI: 10.3390/life13081670] [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: 06/06/2023] [Revised: 07/18/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
Human schistosomiasis is one of neglected tropical diseases that remain highly prevalent in sub-Saharan Africa (SSA). Human schistosomiasis is mainly caused by two species, Schistosoma haematobium and S. mansoni, leading to urogenital and intestinal schistosomiasis, respectively. The World Health Organization (WHO) recommends mass drug administration (MDA) with praziquantel as the primary method of global intervention. Currently, MDA with praziquantel covers over half of the target population in endemic SSA countries. However, an accurate diagnosis is crucial for monitoring and evaluating the effectiveness of MDA. The standard diagnosis of both urogenital and intestinal schistosomiasis relies on the microscopic identification of eggs. However, the diagnostic sensitivity of this approach is low, especially for light or ultra-light infections. This is because Schistosoma eggs are laid inside of the venous plexus of the urinary bladder or mesenteric vein, where the adult flukes live. Approximately half of the eggs circulate in the blood vessels or are packed in neighboring tissues, while the remaining half are expelled into the lumen of the urinary bladder or intestine intermittently when the blood vessels are ruptured. In the field setting, the accuracy of any diagnostic method is critical for proper management of the intervention. The present article reviews the recent prevalence of urogenital schistosomiasis in SSA and highlights the practical limitations of diagnostic methods such as urine microscopy, urine reagent strips, molecular diagnosis, and ultrasound scanning in the field setting. Despite continuous global efforts to eliminate schistosomiasis over the past 20 years, many areas still remain endemic in SSA. No single diagnostic approach achieves acceptable sensitivity and specificity in the field setting. Therefore, any field survey should employ a combination of these methods based on the purpose of the study to accurately monitor and evaluate urogenital schistosomiasis. Based on diagnostic values and a cost-benefit analysis, a urine reagent strip test can replace urine microscopy in the field setting. The WHO criteria by ultrasound diagnosis should be updated including the echogenic snow sign and contour distortion.
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Affiliation(s)
- Sung-Tae Hong
- Graduate School of International Development, Handong Global University, Pohang 37554, Republic of Korea;
- Department of Tropical Medicine and Parasitology, Institute of Endemic Diseases Medical Research Center, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
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Adolescents and young adults excluded from preventive chemotherapy for schistosomiasis control in Northern Tanzania: are they at risk and reservoirs of infection? Prevalence and determinants of transmission in Northern Tanzania. IJID REGIONS 2022; 4:111-119. [PMID: 35898620 PMCID: PMC9310109 DOI: 10.1016/j.ijregi.2022.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/05/2022]
Abstract
Urogenital schistosomiasis is endemic in Northern Tanzania. The overall prevalence of urogenital schistosomiasis was moderate. Infected adolescents and young adults are the S. haematobium reservoirs. The majority of the infected participants had light-intensity infection. Extension of preventive chemotherapy among adolescents and young adults is crucial.
Objective To investigate the magnitude of urogenital schistosomiasis and determinants of transmission among adolescents and young adults in Itilima district, Simiyu region, Northern Tanzania. Methods A quantitative cross-sectional study was carried out using probability sampling strategies to select 433 secondary school students from five schools among the five wards of Itilima district, an area endemic for urogenital schistosomiasis. A self-administered structured questionnaire was used to gather data on determinants, and urine samples were examined for macrohaematuria and the presence of Schistosoma haematobium using the standard urine filtration technique. Data analysis was performed using descriptive statistics, Chi-squared test and logistic regression. Results The overall prevalence rates of S. haematobium infection and macrohaematuria among adolescents and young adults were 15.9% and 3%, respectively, with the majority of individuals being lightly infected (85.5%). The determinants for urogenital schistosomiasis among the adolescents and young adults in Itilima district were: being in Form I [adjusted odds ratio (aOR) 2.42, 95% confidence interval (CI) 1.16–11.8; P=0.018]; being resident in Sasago ward (aOR 5.57, 95% CI 1.98–15.67; P=0.001) or Budalabujiga ward (aOR 2.99, 95% CI 1.04–8.56; P=0.042); having positive attitudes towards urogenital schistosomiasis (aOR 3.14, 95% CI 1.27–7.72; P=0.013); swimming in rivers (aOR 1.92, 95% CI 1.06–3.50; P=0.032); and urinating in water bodies (aOR 1.68, 95% CI 1.05–2.69; P=0.032). Conclusions Urogenital schistosomiasis is prevalent among adolescents and young adults, and serves as a reservoir for transmission of S. haematobium. Preventive chemotherapy campaigns should be extended to adolescents and young adults, and integrated with regular screening, health education and an adequate water supply.
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