Mwanza National Institute of Medical Research - Tanzania (NIMR)
To evaluate strategies to improve the sensitivity of the TAS for detecting evidence of recent lymphatic filariasis transmission in an evaluation unit (EU). The TAS Strengthening Study in Tanzania is designed to assess additional indicators that may be added to the current TAS platform in order to strengthen the resulting stopping or surveillance decisions. A comprehensive analysis will be conducted to understand the correlation between antigen and antibody in adults and children with the mosquito data. A spatial analysis looking at microfoci of infection will also be conducted. Because the EU is also endemic for onchocerciasis, the new Ov16 monoplex RDT was used in the field. The Wb123 and Ov16 antibodies were assessed via ELISA in the NIMR lab in Tanga and the results will soon be compiled. Xenomonitoring work to assess Culex and Anopheles mosquitoes, as well as black flies, is underway.
Preliminary Findings and Lessons Learned
The ultimate goal of this study is to strengthen the existing TAS platform so that the programs can be more confident with their stopping and surveillance decisions. In order to strengthen the existing TAS platform we need to better understand which target population(s) and diagnostic indicator(s) are best-suited for identifying areas with persistent transmission that is not expected to cease on its own, knowing that the answer may vary according the primary vector and stage of the program. In the selected sites a community-based TAS was conducted using the standard sampling of 6-7 year olds while a community TAS (individuals >8 years) was conducted concurrently. All samples were tested via FTS and DBS (for Wb123 ELISA). In these same communities a molecular xenomonitoring study will take place and the mosquitoes will be tested for filarial DNA to relate back to the human specimens. To date human sampling has been completed in all sites and laboratory analysis of the specimens is complete. Mosquito collection has been completed in Haiti and Tanzania and the PCR analysis has been completed in Haiti and is planned for Tanzania (pending the arrival of a new PCR machine). In American Samoa xenomonitoring has been delayed due to weather conditions and arbovirus outbreaks; work is expected to commence spring 2018.
Monitor STH in PSAC and WCBA following cessation of LF MDA (Tanzania)
Monitor recrudescence of STH after TAS to improve planning of STH programs and more effective use of STH drugs.
Gaining schistosomiasis control in Kenya, Mozambique, and Tanzania
Gaining Control: >25% Prevalence MDA strategies; and subtle morbidity of Cohort; Population genetics, and snail monitoring
Impact of Malaria Vector Control & Status of Lymphatic Filariasis Transmission in the Lake Zone of Tanzania
Sample Size: 6,024 DBS and 2,854 anopheline mosquitoes
Towards sustainability of Schistosomiasis Control: improving health of lake shore communities and engaging civil society structures, educational and health facilities in the hyper-endemic area of Mwanza, Tanzania
Schistosomiasis is among the neglected tropical diseases which are highly endemic in Tanzania, especially along and on the Island of Lake Victoria, in northwestern region. After Nigeria, Tanzania is second country in sub-Saharan Africa for having the highest prevalence of schistosomiasis infection and it is estimated that 52% of approximately 50 million people are living with the disease. Current control strategies in Tanzania focus on mass drug administration (MDA) of Praziquantel (PZQ) mainly in school children. Despite of these efforts, the burden of disease remains high, showing local infection rates of up to 97% among school children. School- based MDA alone is unlikely to have a lasting effect on transmission. Awareness creation and engagement across sectors and of civil society (cooperatives, community councils) structures will help to achieve more sustainable results. The objective of this project is to engage affected communities and civil society structures representing risk population (cooperatives, beach management units) to create awareness through e.g. CHAST (children’s hygiene and sanitation training), participation in control activities and improved health seeking behaviors. Secondarily, the study aims to institutionalize measures for early diagnosis and treatment in health facilities of Nyamagana and Ilemela district, along the Lake Victoria, northwestern Tanzania.
Follow-up LF TAS and comparison of ICT and Filariasis Strip Test in a post-MDA surveillance setting.
The multi-country studies on the same topic led to the endorsement by WHO for the FTS as an approved diagnostic tool.
Impact of Malaria Vector Control & Status of Lymphatic Filariasis Transmission in the Lake Zone of Tanzania
Sample Size: 6,024 DBS and 2,854 anopheline mosquitoes
Development and validation of dried urine spot method for detection of Schistosoma circulating antigens from a resource limited archetype in Tanzania
1. What are the optimal conditions for developing a simple and efficient DUS collection method that yields reliable results in diagnosing schistosomiasis using the Schistosoma CCA cassette test in resource-limited settings?
2. What are the optimal conditions for developing a simple and efficient DUS-based Schistosoma circulating antigens extraction method for detection in the Schistosoma CCA cassette test method?
3. Does the DUS-based Schistosoma CCA cassette test method give reproducible results?
4. Is the DUS-based Schistosoma CCA cassette test method produce clinically valid result?
5. What are the optimal storage conditions for DUS for maximum Schistosoma circulating antigen stability in resource-limited environments?