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Kajeguka DC, Mponela FM, Mkumbo E, Kaaya AN, Lasway D, Kaaya RD, Alifrangis M, Elanga-Ndille E, Mmbaga BT, Kavishe R. Prevalence and Associated Factors of Dengue Virus Circulation in the Rural Community, Handeni District in Tanga, Tanzania. J Trop Med 2023; 2023:5576300. [PMID: 38028027 PMCID: PMC10651340 DOI: 10.1155/2023/5576300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 10/23/2023] [Accepted: 10/31/2023] [Indexed: 12/01/2023] Open
Abstract
Dengue virus is among the most important re-emerging arbovirus that causes global public health attention. Dengue has historically been thought of as an urban disease that frequently occurs in rapidly urbanized settings. However, dengue has become more widespread in rural regions in recent years. Understanding the changing dengue epidemiology in different geographical settings is important for targeted intervention. In Tanzania, dengue fever is not frequently reported because of the poor surveillance infrastructure, underestimation, and a lack of consideration of dengue as a priority. Therefore, the true burden as well as the risk factors for increased transmission has not been fully ascertained, particularly in rural areas. A cross-sectional community-based study was conducted in June 2021, involving a total of 362 participants of all age groups. We investigated the prevalence of acute dengue infection, seroprevalence, and associated factors among the community in three villages of the rural Handeni district. The prevalence of acute dengue infection (based on PCR) was 2.2% (8/362). Dengue-specific IgM and IgG antibodies were detected in 3.3% (12/362) and 5.2% (19/362) of the participants, respectively. Adult participants who were having vegetation around their houses were more likely to be DENV seropositive (AOR = 2.4, CI = 1.88-4.18, p value = 0.05). Children living in houses with garbage pit around their households were less likely to be DENV seropositive (AOR = 0.13, CI = 0.03-0.56, p value <0.01). DENV continues to circulate in rural Tanzania, causes an alarming situation, and necessitates prompt public health action to enhance vector surveillance and control in rural communities.
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Affiliation(s)
| | | | - Emmanuel Mkumbo
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Anna N. Kaaya
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Daniel Lasway
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Robert D. Kaaya
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
- Pan-African Malaria Vector Control Consortium, Moshi, Tanzania
| | - Michael Alifrangis
- Centre for Medical Parasitology, Department Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | | | - Blandina T. Mmbaga
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - Reginald Kavishe
- Kilimanjaro Christian Medical University College, Moshi, Tanzania
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Pascoe L, Clemen T, Bradshaw K, Nyambo D. Review of Importance of Weather and Environmental Variables in Agent-Based Arbovirus Models. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15578. [PMID: 36497652 PMCID: PMC9740748 DOI: 10.3390/ijerph192315578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
The study sought to review the works of literature on agent-based modeling and the influence of climatic and environmental factors on disease outbreak, transmission, and surveillance. Thus, drawing the influence of environmental variables such as vegetation index, households, mosquito habitats, breeding sites, and climatic variables including precipitation or rainfall, temperature, wind speed, and relative humidity on dengue disease modeling using the agent-based model in an African context and globally was the aim of the study. A search strategy was developed and used to search for relevant articles from four databases, namely, PubMed, Scopus, Research4Life, and Google Scholar. Inclusion criteria were developed, and 20 articles met the criteria and have been included in the review. From the reviewed works of literature, the study observed that climatic and environmental factors may influence the arbovirus disease outbreak, transmission, and surveillance. Thus, there is a call for further research on the area. To benefit from arbovirus modeling, it is crucial to consider the influence of climatic and environmental factors, especially in Africa, where there are limited studies exploring this phenomenon.
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Affiliation(s)
- Luba Pascoe
- Nelson Mandela African Institution of Science and Technology, Arusha P.O Box 447, Tanzania
| | - Thomas Clemen
- Nelson Mandela African Institution of Science and Technology, Arusha P.O Box 447, Tanzania
- Department of Computer Science, Hamburg University of Applied Sciences, Berliner Tor 7, 20099 Hamburg, Germany
| | - Karen Bradshaw
- Nelson Mandela African Institution of Science and Technology, Arusha P.O Box 447, Tanzania
- Department of Computer Science, Rhodes University, Grahamstown 6139, South Africa
| | - Devotha Nyambo
- Nelson Mandela African Institution of Science and Technology, Arusha P.O Box 447, Tanzania
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Uncovering the Burden of Dengue in Africa: Considerations on Magnitude, Misdiagnosis, and Ancestry. Viruses 2022; 14:v14020233. [PMID: 35215827 PMCID: PMC8877195 DOI: 10.3390/v14020233] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 01/27/2023] Open
Abstract
Dengue is a re-emerging neglected disease of major public health importance. This review highlights important considerations for dengue disease in Africa, including epidemiology and underestimation of disease burden in African countries, issues with malaria misdiagnosis and co-infections, and potential evidence of genetic protection from severe dengue disease in populations of African descent. The findings indicate that dengue virus prevalence in African countries and populations may be more widespread than reported data suggests, and that the Aedes mosquito vectors appear to be increasing in dissemination and number. Changes in climate, population, and plastic pollution are expected to worsen the dengue situation in Africa. Dengue misdiagnosis is also a problem in Africa, especially due to the typical non-specific clinical presentation of dengue leading to misdiagnosis as malaria. Finally, research suggests that a protective genetic component against severe dengue exists in African descent populations, but further studies should be conducted to strengthen this association in various populations, taking into consideration socioeconomic factors that may contribute to these findings. The main takeaway is that Africa should not be overlooked when it comes to dengue, and more attention and resources should be devoted to this disease in Africa.
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Ngingo BL, Mboera LEG, Chengula A, Machelle I, Makange MR, Msolla M, Mwanyika GO, Rugarabamu S, Misinzo G. Aedes aegypti abundance, larval indices and risk for dengue virus transmission in Kinondoni district, Tanzania. Trop Med Health 2022; 50:1. [PMID: 34980286 PMCID: PMC8725502 DOI: 10.1186/s41182-021-00395-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/27/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Tanzania has experienced periodic dengue outbreaks with increased incidence since 2010. However, there is limited information on vector dynamics and transmission risk in most parts of the country. This study was conducted to determine Aedes mosquito abundance, larval indices and dengue virus infection rate as risk indicators for DENV transmission in Kinondoni district, Dar es Salaam, Tanzania. METHODS A cross-sectional study was conducted in three wards of Kinondoni district in Tanzania between December 2019 and January 2020. In each ward, three streets were randomly selected for adult and immature mosquito sampling. The adult mosquitoes were collected using Mosquito Magnet traps, while mosquito larvae and pupae were inspected in water-holding containers in the selected household compounds. The detection of dengue virus (DENV) in female Aedes mosquitoes was done using a one-step reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS Of the 1416 adult female mosquitoes collected, Ae. aegypti accounted for 16.8% (n = 238). A total of 333 water-holding containers were inspected and 201 (60.4%) had at least an Aedes larvae or pupae. Water-holding containers supporting the breeding of Aedes larvae and pupae included discarded car tires, flowerpots and small and large plastic containers. The overall House Index, Container Index and Breteau Index were 55.1%, 60.4% and 114.2, respectively. None of the 763 female Aedes mosquitoes tested by RT-PCR was found to be infected with DENV. CONCLUSION The presence and abundance Ae. aegypti mosquitoes and the large proportion of water-holding containers infested with the mosquito larvae and pupae put residents of Kinondoni district at high risk of DENV transmission. Our findings emphasize the need for continuous mosquito vector surveillance and control to prevent the possibility of future DENV outbreaks in Tanzania.
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Affiliation(s)
- Baraka L Ngingo
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania.
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania.
- Faculty of Natural and Applied Sciences, St John's University of Tanzania, Dodoma, Tanzania.
| | - Leonard E G Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Augustino Chengula
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Ines Machelle
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Mariam R Makange
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Michael Msolla
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Gaspary O Mwanyika
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Medical Sciences and Technology, Mbeya University of Science and Technology, Mbeya, Tanzania
| | - Sima Rugarabamu
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Gerald Misinzo
- Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
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Mboera LEG, Sindato C, Mremi IR, Rumisha SF, George J, Ngolongolo R, Misinzo G, Karimuribo ED, Rweyemamu MM, Haider N, Hamid MA, Kock R. Socio-Ecological Systems Analysis and Health System Readiness in Responding to Dengue Epidemics in Ilala and Kinondoni Districts, Tanzania. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.738758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
IntroductionSince 2010, Tanzania has been experiencing frequent outbreaks of dengue. The objectives of this study were to carry out a socio-ecological systems (SES) analysis to identify risk factors and interventions and assess the readiness of the district in the prevention and control of dengue.MethodsThe study utilized a cross-sectional purposive selection of key stakeholders responsible for disease surveillance and response in human and animal sectors in Ilala and Kinondoni districts in Tanzania. A SES framework was used to identify drivers and construct perceived thematic causal explanations of the dengue outbreaks in the study districts. A mapping exercise was carried out to analyse the performance of the disease surveillance system at district and facility levels. A semi-structured questionnaire was used to assess the districts’ readiness in the response to dengue outbreak.ResultsThe two districts were characterized by both urban and peri-urban ecosystems, with a mixture of planned and unplanned settlements which support breeding and proliferation of Aedes mosquitoes. The results indicate inadequate levels of readiness in the management and control of dengue outbreaks, in terms of clinical competence, diagnostic capacities, surveillance system and control/prevention measures. Mosquito breeding sites, especially discarded automobile tyres, were reported to be scattered in the districts. Constraining factors in implementing disease surveillance included both intrapersonal and interpersonal factors, lack of case management guidelines, difficult language used in standard case definitions, inadequate laboratory capacity, lack of appropriate rapid response teams, inadequate knowledge on outbreak investigation and inadequate capacities in data management.ConclusionThe two districts had limited readiness in the management and control of dengue, in terms of clinical competence, diagnostic capacities, surveillance system and prevention and control measures. These challenges require the immediate attention by the authorities, as they compromise the effectiveness of the national strategy for community health support.
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Saleh F, Kitau J, Konradsen F, Mboera LEG, Schiøler KL. Emerging epidemics: is the Zanzibar healthcare system ready to detect and respond to mosquito-borne viral diseases? BMC Health Serv Res 2021; 21:866. [PMID: 34429111 PMCID: PMC8386054 DOI: 10.1186/s12913-021-06867-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 08/09/2021] [Indexed: 11/10/2022] Open
Abstract
Background Effective control of emerging mosquito-borne viral diseases such as dengue, chikungunya, and Zika requires, amongst other things, a functional healthcare system, ready and capable of timely detection and prompt response to incipient epidemics. We assessed the readiness of Zanzibar health facilities and districts for early detection and management of mosquito-borne viral disease outbreaks. Methods A cross-sectional study involving all 10 District Health Management Teams and 45 randomly selected public and private health facilities in Zanzibar was conducted using a mixed-methods approach including observations, document review, and structured interviews with health facility in-charges and District Health Management Team members. Results The readiness of the Zanzibar healthcare system for timely detection, management, and control of dengue and other mosquito-borne viral disease outbreaks was critically low. The majority of health facilities and districts lacked the necessary requirements including standard guidelines, trained staff, real-time data capture, analysis and reporting systems, as well as laboratory diagnostic capacity. In addition, health education programmes for creating public awareness and Aedes mosquito surveillance and control activities were non-existent. Conclusions The Zanzibar healthcare system has limited readiness for management, and control of mosquito-borne viral diseases. In light of impending epidemics, the critical shortage of skilled human resource, lack of guidelines, lack of effective disease and vector surveillance and control measures as well as lack of laboratory capacity at all levels of health facilities require urgent attention across the Zanzibar archipelago.
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Affiliation(s)
- Fatma Saleh
- Department of Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania. .,Department of Allied Health Sciences, School of Health and Medical Sciences, The State University of Zanzibar, Zanzibar, Tanzania.
| | - Jovin Kitau
- Department of Parasitology and Entomology, Kilimanjaro Christian Medical University College, Moshi, Tanzania.,World Health Organization, Country office, Dar es Salaam, Tanzania
| | - Flemming Konradsen
- Global Health Section, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Leonard E G Mboera
- SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Karin L Schiøler
- Global Health Section, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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Affara M, Lagu HI, Achol E, Karamagi R, Omari N, Ochido G, Kezakarayagwa E, Kabatesi F, Nkeshimana A, Roba A, Ndia MN, Abudo MU, Kabanda A, Mpabuka E, Mwikarago EI, Kutjok PE, Samson DD, Deng LL, Moremi N, Kelly ME, Mkama PBM, Magesa A, Balinandi SK, Pimundu G, Nabadda SN, Puradiredja DI, Hinzmann J, Duraffour S, Gabriel M, Ruge G, Loag W, Ayiko R, Sonoiya SS, May J, Katende MJ, Gehre F. The East African Community (EAC) mobile laboratory networks in Kenya, Burundi, Tanzania, Rwanda, Uganda, and South Sudan-from project implementation to outbreak response against Dengue, Ebola, COVID-19, and epidemic-prone diseases. BMC Med 2021; 19:160. [PMID: 34238298 PMCID: PMC8266482 DOI: 10.1186/s12916-021-02028-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/09/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND East Africa is home to 170 million people and prone to frequent outbreaks of viral haemorrhagic fevers and various bacterial diseases. A major challenge is that epidemics mostly happen in remote areas, where infrastructure for Biosecurity Level (BSL) 3/4 laboratory capacity is not available. As samples have to be transported from the outbreak area to the National Public Health Laboratories (NPHL) in the capitals or even flown to international reference centres, diagnosis is significantly delayed and epidemics emerge. MAIN TEXT The East African Community (EAC), an intergovernmental body of Burundi, Rwanda, Tanzania, Kenya, Uganda, and South Sudan, received 10 million € funding from the German Development Bank (KfW) to establish BSL3/4 capacity in the region. Between 2017 and 2020, the EAC in collaboration with the Bernhard-Nocht-Institute for Tropical Medicine (Germany) and the Partner Countries' Ministries of Health and their respective NPHLs, established a regional network of nine mobile BSL3/4 laboratories. These rapidly deployable laboratories allowed the region to reduce sample turn-around-time (from days to an average of 8h) at the centre of the outbreak and rapidly respond to epidemics. In the present article, the approach for implementing such a regional project is outlined and five major aspects (including recommendations) are described: (i) the overall project coordination activities through the EAC Secretariat and the Partner States, (ii) procurement of equipment, (iii) the established laboratory setup and diagnostic panels, (iv) regional training activities and capacity building of various stakeholders and (v) completed and ongoing field missions. The latter includes an EAC/WHO field simulation exercise that was conducted on the border between Tanzania and Kenya in June 2019, the support in molecular diagnosis during the Tanzanian Dengue outbreak in 2019, the participation in the Ugandan National Ebola response activities in Kisoro district along the Uganda/DRC border in Oct/Nov 2019 and the deployments of the laboratories to assist in SARS-CoV-2 diagnostics throughout the region since early 2020. CONCLUSIONS The established EAC mobile laboratory network allows accurate and timely diagnosis of BSL3/4 pathogens in all East African countries, important for individual patient management and to effectively contain the spread of epidemic-prone diseases.
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Affiliation(s)
- Muna Affara
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,East African Community (EAC), Arusha, Tanzania
| | | | | | | | - Neema Omari
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,East African Community (EAC), Arusha, Tanzania
| | - Grace Ochido
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,East African Community (EAC), Arusha, Tanzania
| | - Eric Kezakarayagwa
- National Institute of Public Health, Ministry of Health and Fight Against AIDS, Bujumbura, Burundi
| | - Francine Kabatesi
- National Institute of Public Health, Ministry of Health and Fight Against AIDS, Bujumbura, Burundi
| | - Anatole Nkeshimana
- National Institute of Public Health, Ministry of Health and Fight Against AIDS, Bujumbura, Burundi
| | - Abdi Roba
- National Public Health Laboratories, Ministry of Health, Nairobi, Kenya
| | | | - Mamo U Abudo
- National Public Health Laboratories, Ministry of Health, Nairobi, Kenya
| | - Alice Kabanda
- National Reference Laboratory Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda
| | - Etienne Mpabuka
- National Reference Laboratory Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda
| | - Emil Ivan Mwikarago
- National Reference Laboratory Division, Rwanda Biomedical Centre, Ministry of Health, Kigali, Rwanda
| | - Philip Ezekiel Kutjok
- Public Health Laboratory and National Blood Transfusion Centre, Ministry of Health, Juba, South Sudan
| | - Donald Duku Samson
- Public Health Laboratory and National Blood Transfusion Centre, Ministry of Health, Juba, South Sudan
| | - Lul Lojok Deng
- Public Health Laboratory and National Blood Transfusion Centre, Ministry of Health, Juba, South Sudan
| | - Nyambura Moremi
- Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania.,National Health Laboratory, Quality Assurance and Training Centre, Dar es Salaam, Tanzania
| | - Maria Ezekiely Kelly
- Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania.,National Health Laboratory, Quality Assurance and Training Centre, Dar es Salaam, Tanzania
| | - Peter Bernard Mtesigwa Mkama
- Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania.,National Health Laboratory, Quality Assurance and Training Centre, Dar es Salaam, Tanzania
| | - Alex Magesa
- Ministry of Health, Community Development, Gender, Elderly and Children, Dodoma, Tanzania.,National Health Laboratory, Quality Assurance and Training Centre, Dar es Salaam, Tanzania
| | | | - Godfrey Pimundu
- National Health Laboratory and Diagnostic Services (NHLDS), Ministry of Health, Kampala, Uganda
| | - Susan Ndidde Nabadda
- National Health Laboratory and Diagnostic Services (NHLDS), Ministry of Health, Kampala, Uganda
| | - Dewi Ismajani Puradiredja
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Julia Hinzmann
- Virology Department, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,German Center for Infection Research (DZIF), partner site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Sophie Duraffour
- Virology Department, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,German Center for Infection Research (DZIF), partner site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Martin Gabriel
- Virology Department, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,German Center for Infection Research (DZIF), partner site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Gerd Ruge
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | - Wibke Loag
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany
| | | | | | - Juergen May
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany.,German Center for Infection Research (DZIF), partner site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany.,Tropical Medicine II, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | | | - Florian Gehre
- Department for Infectious Disease Epidemiology, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany. .,East African Community (EAC), Arusha, Tanzania.
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Evolution, heterogeneity and global dispersal of cosmopolitan genotype of Dengue virus type 2. Sci Rep 2021; 11:13496. [PMID: 34188091 PMCID: PMC8241877 DOI: 10.1038/s41598-021-92783-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
Dengue virus type 2 (DENV-2) contributes substantially to the dengue burden and dengue-related mortality in the tropics and sub-tropics. DENV-2 includes six genotypes, among which cosmopolitan genotype is the most widespread. The present study investigated the evolution, intra-genotype heterogeneity and dispersal of cosmopolitan genotype to understand unique genetic characteristics that have shaped the molecular epidemiology and distribution of cosmopolitan lineages. The spatial analysis demonstrated a wide geo-distribution of cosmopolitan genotype through an extensive inter-continental network, anchored in Southeast Asia and Indian sub-continent. Intra-genotype analyses using 3367 envelope gene sequences revealed six distinct lineages within the cosmopolitan genotype, namely the Indian sub-continent lineage and five other lineages. Indian sub-continent lineage was the most diverged among six lineages and has almost reached the nucleotide divergence threshold of 6% within E gene to qualify as a separate genotype. Genome wide amino acid signatures and selection pressure analyses further suggested differences in evolutionary characteristics between the Indian sub-continent lineage and other lineages. The present study narrates a comprehensive genomic analysis of cosmopolitan genotype and presents notable genetic characteristics that occurred during its evolution and global expansion. Whether those characteristics conferred a fitness advantage to cosmopolitan genotype in different geographies warrant further investigations.
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Mwanyika GO, Mboera LEG, Rugarabamu S, Makange M, Sindato C, Lutwama JJ, Paweska JT, Misinzo G. Circulation of dengue serotype 1 viruses during the 2019 outbreak in Dar es Salaam, Tanzania. Pathog Glob Health 2021; 115:467-475. [PMID: 33797341 DOI: 10.1080/20477724.2021.1905302] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Dengue is an important mosquito-borne viral disease in humans in tropical and subtropical countries. In 2019, a total of 6917 dengue cases were reported in Tanzania based on serological analysis. The aim of this study was to confirm the presence of dengue virus (DENV) and conduct its genetic characterization. A total of 191 serum samples were collected from the outpatients seeking care from health facilities in Kinondoni and Ilala districts between March and May 2019. All the samples were initially tested for the presence of non-structural protein 1 and anti-DENV immunoglobulin G (IgG) and IgM using a commercial OnSite Duo Dengue Ag-IgG/IgM rapid test. Of the 191 sera, 110 (57.6%) were DENV seropositive. The presence of DENV ribonucleic acid was confirmed in 18.2% of the seropositive sera by reverse transcription polymerase chain reaction (RT-PCR). The RT-PCR products were cleaned and partial sequences of DENV polyprotein gene determined using dideoxynucleotide cycle sequencing followed by phylogenetic analysis. We present the occurrence of DENV serotype 1 (DENV-1) during the 2019 outbreak in Tanzania. The DENV-1 strains reported in the present study are highly identical and cluster with Asian DENV-1 strains indicating the possibility of intercontinental spread of DENV through globalization. We advocate for the need for molecular surveillance of dengue viruses during outbreaks to provide rapid evidence of the disease to guide public health interventions.
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Affiliation(s)
- Gaspary O Mwanyika
- SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Health Science and Technology, Mbeya University of Science and Technology, Mbeya, Tanzania
| | - Leonard E G Mboera
- SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Sima Rugarabamu
- SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar Es Salaam, Tanzania
| | - Mariam Makange
- SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Calvin Sindato
- SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania.,National Institute for Medical Research, Tabora Research Centre, Tabora, Tanzania
| | - Julius J Lutwama
- Department of Arbovirology, Emerging and Re-emerging Infectious Diseases, Uganda Virus Research Institute, Entebbe, Uganda
| | - Janusz T Paweska
- National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
| | - Gerald Misinzo
- SACIDS Africa Centre of Excellence for Infectious Diseases, Sokoine University of Agriculture, Morogoro, Tanzania.,Department of Veterinary Microbiology, Parasitology and Biotechnology, Sokoine University of Agriculture, Morogoro, Tanzania
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Chipwaza B, Sumaye RD, Weisser M, Gingo W, Yeo NKW, Amrun SN, Okumu FO, Ng LFP. Occurrence of 4 Dengue Virus Serotypes and Chikungunya Virus in Kilombero Valley, Tanzania, During the Dengue Outbreak in 2018. Open Forum Infect Dis 2020; 8:ofaa626. [PMID: 33511240 PMCID: PMC7814382 DOI: 10.1093/ofid/ofaa626] [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] [Received: 09/09/2020] [Accepted: 12/21/2020] [Indexed: 12/23/2022] Open
Abstract
Background Dengue and Chikungunya viruses can cause large-scale epidemics, with attack rates of up to 80%. In Tanzania, there have been repeated outbreaks of dengue fever, the most recent in 2018 and 2019, mostly affecting the coastal areas. Despite the importance of these viruses, there is limited knowledge on the epidemiology of dengue (DENV) and Chikungunya (CHIKV) in Tanzania. This study was conducted to investigate the prevalence of DENV and CHIKV in Kilombero Valley, Tanzania. Methods A cross-sectional study was conducted at Kibaoni Health Center in Kilombero Valley, Southeastern Tanzania, in the rainy and dry seasons of 2018. Febrile patients of any age and gender were enrolled from the outpatient department. Blood samples were taken and screened for DENV and CHIKV viral RNA by real-time reverse transcription polymerase chain reaction assays. Results Overall, 294 patients were recruited. Most were females (65%), and one-third of patients were aged 14-25 years. DENV and CHIKV were detected in 29 (9.9%) and 3 (1.0%) patients, respectively. DENV was detected across all age groups during both the dry and rainy seasons. Although all 4 DENV serotypes were detected, serotypes 1 and 3 dominated and were present in 14 patients (42.4%) each. Additionally, the study showed DENV-1 and DENV-3 co-infections. Conclusions This study reveals the co-circulation of all 4 DENV serotypes and CHIKV in Kilombero. Importantly, we report the first occurrence of DENV-4 in Tanzania. Unlike previous DENV outbreaks caused by DENV-2, the 2018 outbreak was dominated by DENV-1 and DENV-3. The occurrence of all serotypes suggests the possibility of severe clinical outcomes in future DENV epidemics in Tanzania.
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Affiliation(s)
- Beatrice Chipwaza
- St. Francis University College of Health and Allied Sciences (SFUCHAS), Ifakara, Tanzania.,Ifakara Health Institute, Ifakara, Tanzania
| | | | - Maja Weisser
- Ifakara Health Institute, Ifakara, Tanzania.,Division of Infectious Diseases & Hospital Epidemiology, University Hospital Basel, Basel, Switzerland
| | - Winfrid Gingo
- St. Francis Referral Hospital (SFRH), Ifakara, Tanzania
| | - Nicholas Kim-Wah Yeo
- ASTAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Immunos, Biopolis, Singapore, Singapore.,Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Immunos, Biopolis, Singapore, Singapore
| | - Siti Naqiah Amrun
- ASTAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Immunos, Biopolis, Singapore, Singapore.,Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Immunos, Biopolis, Singapore, Singapore
| | - Fredros O Okumu
- Ifakara Health Institute, Ifakara, Tanzania.,Faculty of Health Science, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,School of Life Science and Biotechnology, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Lisa F P Ng
- ASTAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Immunos, Biopolis, Singapore, Singapore.,Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Immunos, Biopolis, Singapore, Singapore.,National Institute of Health Research, Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool, United Kingdom.,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
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Epidemic risk of arboviral diseases: Determining the habitats, spatial-temporal distribution, and abundance of immature Aedes aegypti in the Urban and Rural areas of Zanzibar, Tanzania. PLoS Negl Trop Dis 2020; 14:e0008949. [PMID: 33284806 PMCID: PMC7746278 DOI: 10.1371/journal.pntd.0008949] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 12/17/2020] [Accepted: 11/04/2020] [Indexed: 12/30/2022] Open
Abstract
Background In Zanzibar, little is known about the arboviral disease vector Aedes aegypti in terms of abundance, spatio-temporal distribution of its larval habitats or factors associated with its proliferation. Effective control of the vector requires knowledge on ecology and habitat characteristics and is currently the only available option for reducing the risk of arboviral epidemics in the island nation of Zanzibar. Methodology We conducted entomological surveys in households and surrounding compounds from February to May 2018 in the urban (Mwembemakumbi and Chumbuni) and rural (Chuini and Kama) Shehias (lowest government administrative unit) situated in the Urban-West region of Unguja island, Zanzibar. Larvae and pupae were collected, transported to the insectary, reared to adult, and identified to species level. Characteristics and types of water containers were also recorded on site. Generalized linear mixed models with binomial and negative binomial distributions were applied to determine factors associated with presence of Ae. aegypti immatures (i.e. both larvae and pupae) or pupae, alone and significant predictors of the abundance of immature Ae. aegypti or pupae, respectively. Results The survey provided evidence of widespread presence and abundance of Ae. aegypti mosquitoes in both urban and rural settings of Unguja Island. Interestingly, rural setting had higher numbers of infested containers, all immatures, and pupae than urban setting. Likewise, higher House and Breteau indices were recorded in rural compared to the urban setting. There was no statistically significant difference in Stegomyia indices between seasons across settings. Plastics, metal containers and car tires were identified as the most productive habitats which collectively produced over 90% of all Ae. aegypti pupae. Water storage, sun exposure, vegetation, and organic matter were significant predictors of the abundance of immature Ae. aegypti. Conclusions Widespread presence and abundance of Ae. aegypti were found in rural and urban areas of Unguja, the main island of Zanzibar. Information on productive habitats and predictors of colonization of water containers are important for the development of a routine Aedes surveillance system and targeted control interventions in Zanzibar and similar settings. Dengue is considered the most important mosquito-borne viral disease and a global public health threat. In recent decades, large scale epidemics of dengue have occurred across sub-Saharan Africa including mainland Tanzania. Aedes aegypti is identified as the principal vector for dengue transmission in most affected countries. In the absence of antiviral treatment and as a dengue vaccine is not readily available; dengue prevention depends largely on vector control. As mosquitoes develop resistance towards commonly applied chemical insecticides, environmental management targeting the destruction of larval habitats is recommended. In Zanzibar, little is known about Ae. aegypti in terms of type, magnitude, or distribution of its larval habitats. In this study, we identified the main larval habitats of Ae. aegypti, their seasonal variations and factors contributing to Ae. aegypti abundance across urban and rural settings of Unguja Island in Zanzibar. We found widespread presence and abundance of the vector with plastic and metal containers as well as car tires identified as the most important larval habitats. Season, location of water container, water storage, sun exposure, presence of vegetation and organic matter were among the factors associated with high Ae. aegypti abundance. This study is the first to document widespread occurrence and distribution of Ae. aegypti in Zanzibar and highlights the need for the establishment of a nation-wide Aedes surveillance program to guide the development and monitoring of targeted, context specific vector control interventions for prevention of dengue and other arboviral epidemics. Aedes surveillance involves periodic inspection of households and surrounding environments for presence of larvae/pupae in water-holding containers which are then targeted for larval source reduction, as well as monitoring of adult mosquito populations.
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Kazaura M. Knowledge, attitude and practices about dengue fever among adults living in Pwani Region, Tanzania in 2019. Afr Health Sci 2020; 20:1601-1609. [PMID: 34394220 PMCID: PMC8351831 DOI: 10.4314/ahs.v20i4.12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Dengue fever (DF) is currently widespread in tropical and sub-tropical countries. Among the triggers of epidemic include urbanization and internal migrations. Within the past few years, there have been DF outbreaks in Tanzania. Although Pwani region is among the predicted risk areas for the DF, there is insufficient data about people's knowledge, attitude and practices towards prevention of DF in their settings. Therefore, the aim of this study was to assess knowledge, attitude and practices about DF among adults in Pwani region in Tanzania. METHODS The cross-sectional study conducted in Mkuranga District, Pwani region in Tanzania. We used face-to-face interviews to collect data. The main analytical procedure was descriptive using frequencies. RESULTS The majority, 97.7%, were aware of DF. Nevertheless, almost 80% had a low knowledge on symptoms, transmission and vector control measures. Furthermore, less than 20% had positive attitude towards dengue fever prevention, severity of the illness and health seeking behavior. CONCLUSION Lack of enough knowledge and positive attitude about disease transmission, symptoms and preventive measures put the population at high risk of contracting the disease. There is need to create and improve friendly, correct and simple information, education and education messages for the rural populations.
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