Xenomonitoring

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 American Samoa 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.  Xenomonitoring work to assess Aedes mosquitoes is underway.

The results from this study will be combined into a multi-country analysis and are expected to help inform WHO guidance on stopping and surveillance for LF. 

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 Haiti 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.  Xenomonitoring work to assess Culex mosquitoes will be conducted in the same sites as the human sampling. 

The results from this study will be combined into a multi-country analysis and are expected to help inform WHO guidance on stopping and surveillance for LF. 

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.

The results from this study will be combined into a multi-country analysis and are expected to help inform WHO guidance on stopping and surveillance for LF. 

After two decades of onchocerciasis control activities in Bioko island, transmission is expected to be interrupted. This study aims to demonstrate that WHO criteria to verify transmission interruption have been met. It also aims to standardize the reading of RDTs, particularly the FTS and Ov16, and reduce the potential for human error.

To evaluate the utility of ongoing surveillance of adults in a post-treatment setting.

To determine if post-treatment surveillance of adults represents a more effective surveillance strategy than TAS or xenomonitoring.

Cotonou and Porto-Novo are the two main urban locations of Benin where the LF status is undetermined. A study will be conducted to evaluate the prevalence of LF using antigenemia and antibody testing (FTS and Wb123). An entomological survey will be implemented to understand the dynamic of LF transmission and potential barriers to LF MDA in urban settings. 

To determine the feasibility of the use of entomological traps by community members for onchocerciasis and lymphatic filariasis entomological assessments.

To determine the feasibility of the use of entomological traps by community members for onchocerciasis and lymphatic filariasis entomological assessments.

Mass drug administration (MDA) programs have dramatically reduced lymphatic filariasis (LF) incidence in many areas around the globe, including Bangladesh. Post-treatment surveillance activities as recommended by WHO include repeated transmission assessment surveys (TAS) among children and ongoing surveillance to detect new foci of transmission and collect data on infection trends in the general population. The contribution of molecular xenomonitoring (MX, or detection of filarial DNA in mosquitoes) to confirm the interruption of transmission during the post-treatment surveillance phase has not been well defined. There is also a need to better understand the relationship between the prevalence of W. bancrofti DNA in mosquitoes and infection in humans.

Determine the utility of xenomonitoring and serological assessments for the detection of residual transmission