To assess the programmatic feasibility of and determine the most appropriate age group and sampling strategy for an oncho mapping survey for ivermectin-naïve areas
To analyze the relationships between the currently used indicator for impact assessments - prevalence of the clincial sign TF - and the prevalence of infection and antibody among 1-9 year old children in hyperendemic districts prior to mass drug administration
Currently MDA is stopped when TF in children aged 1-9 years is below 5%. However, the relationship between TF, presence of infection and antibody has not been studied in a sufficient number of settings to enable predictions of outcome to be confidently made based on baseline prevalence, intervention coverage, and the prevalence of disease and infection at the time of impact survey. There are several districts in Malawi with TF prevalence between 5 and 9.9% which are eligible for one year of interventions, including a single round of MDA. This study will add important data to be used to model outcomes of interventions conducted by trachoma elimination programs, and in particular, help develop operational guidelines for stopping MDA.
To test alternative rapid diagnostic test (RDT) formats for the Wb123 rapid test. In field trials, the current test format was less sensitive that FTS in post-MDA settings whereas alternative Wb123 test formats (ELISA, multiplex) were more sensitive. Our group uses new detection systems, based on nanoshells, to improve RDT performance.
To define a cost-effective strategy to map Ivermectin-naïve districts for Onchocerciasis, Lymphatic Filariasis, and Loiasis in the context of elimination of these NTDs
Estimating Population Denominators and Coverage of Mass Drug Administration Using Polio’s Vaccination Tracking System
To determine the viability of utilizing the polio program’s Vaccination Tracking System (VTS) to generate more accurate population, drug requirement and coverage estimates in NTD programs
Serological indicators to measure the impact of the NTD control program on onchocerciasis in 3 distinct settings in Tanzania
To compare Ov16 ELISA and Ov16 rapid diagnostic test results, and better understand the significance of Ov16 serology in hypo-, meso- and hyper-endemic settings post-treatment.
The primary objective for this request is to evaluate the performance of the Biplex RDT in a cohort of 500 people previously tested for oncho and LF in 2014 (3-year follow up). The evaluation of the Biplex is an add-on to a study that will conduct a longitudinal follow up on a cohort of 500 people from the Tshopo Province. The primary outcomes are serology and clinical manifestations of onchocerciasis, This study also evaluates serology, parasitology and clinical manifestations for other filarial infections, mainly LF, Loa and Mansonella.
Preliminary Findings and Lessons Learned
This study built on an existing onchocerciasis longitudinal follow-up study in Banalia community, Tshopo province, DRC. The location is co-endemic for Oncho, LF, Loa loa and Mansonella perstans. 500 people previously tested in 2014 have been followed up and were retested in 2017. A total of 239, out of 500, agreed to participate in the follow-up activity and provided a blood specimen. Thirty percent were positive by skin snip, 3% were positive by FTS, 15% were found to have loa (thick blood film) and 41% had M. perstans. Ov16 ELISA testing found 67% positive, while the Biplex found 38% Ov16 positive. The sensitivity of the Ov16 biplex compared to the ELISA was 53%.
Through funding from the Wellcome Trust to develop a global atlas of podoconiosis. We aim to advance new knowledge on the geographical distribution and spatial epidemiology of the disease.
i. Conduct national cross-sectional surveys in selected countries to validate the environmental predictive model developed using the mapping data in Ethiopia.
ii. Create evidence consensus maps, develop risk maps and ground-truthing work and delineate the spatial distribution and geographical limits of podoconiosis globally.
iii. Estimate the global burden of podoconiosis by quantifying the number affected, the population at risk and DALYs attributable.
iv. Estimate how much it will cost to control or eliminate podoconiosis globally.