Multi-lab comparison for STH PCR methods
To pilot a rapid coverage supervision tool (now known as the Supervisor's Coverage Tool) that can be used to determine if the supervision areas under investigation are likely to have exceeded the WHO threshold for coverage and to serve as an in-process monitoring tool for supervising the MDA distribution. Report to WHO M&E working group; potential for inclusion in future WHO program assessment guidelines.
The Supervisor’s Coverage Tool (SCT) is a quick, simple, and inexpensive monitoring tool that can be used to assess preventive chemotherapy coverage of a mass drug administration (MDA). During the development and optimization process of the tool, the SCT was piloted in communities in Nigeria and Ethiopia. The pilot study in Cross River State, Nigeria, included seven first-level Supervision Areas (SA), which corresponded to villages in four Local Government Areas (LGAs). Drug coverage was assessed for ivermectin and albendazole in four SAs and only Ivermectin in three SAs.
Findings and lessons learned:
- The main reasons for not swallowing medicines were community drug distributor (CDD) not showing up, respondent being away at time of drug distribution or not collecting drug from a fixed point of distribution, fear of side effects, drug supply running out, recent migration, and lack of awareness about drug distribution.
- The SCT permitted LGA coordinators to supervise the drug distribution systematically, which allowed them to find out that in most parts of one LGA treatment was suspended despite the CDD claiming the completion of treatment in the area.
- Some treatment registers did not include all people living in the SA, therefore some households were not included in the CDDs treatment boundaries. On the other hand, some LGAs had very good treatment registers, proper documentation of treatment from CDDs, and their community also commended them during village gatherings expressing their gratitude.
- All CDDs were making remarkable effort with little or no reward. Unlike previous monitoring visits where supervisors have to field numerous complaints around incentives, because the SCT gave supervisors an objective evaluation of their work, many CDDs did not feel justified in complaining about incentives.
- Overall, the SCT was deemed feasible to implement at the supervisory area and the information generated led to programmatic action to improve treatment coverage.
Comparison of FTS antigen and Wb123 ELISA in a co-endemic LF and Loiasis area (Or Integrated lymphatic filariasis and Loiasis mapping)
Compare lymphatic filariasis FTS antigen prevalence to the Wb123 antibody prevalence in an area co-endemic with Loa-loa. Refine LF prevalence with FTS and provide evidence for MDA intervention by excluding areas where prevalence of ICT card is due to Loa loa cross reaction; 2) Provide additional data to address the influence of Loa loa cross-reaction and the specificity of antigen rapid test positive result alone to identify ongoing LF transmission in areas co-endemic for LF and Loiasis.
Community implementation and comparison of Human landing and Non human landing collection methods for vectors of Wuchereria bancrofti and Onchocerca volvulus for entomological monitoring of transmission (Burkina Faso)
To determine the feasibility of the use of entomological traps by community members for onchocerciasis and lymphatic filariasis entomological assessments.
To determine the current status of LF using a combination of seroepidemiological tools to determine prevalence of circulating filarial antigen (CFA) and antifilarial antibodies.
Preliminary study findings:
- 2,976 individuals (age: 2 to 100 years) were tested for circulating filariail antigen using the immunochromatographic (ICT) test during daytime visits. Night-time blood samples to detect microfilariae (MF) were requested from those who tested positive via the ICT test.
- Out of the 38 persons found to be positive for LF infection by ICT test, 33 provided a night-time blood sample for examination of MF. Overall, nine individuals were found to be MF positive, with the highest prevalence in Ndau Island.
- The current study suggests that LF transmission may be absent in Taita-Taveta and Tana River counties in coastal Kenya and therefore transmission assessment surveys (TAS) should be considered with a view to stopping MDA. By contrast, evidence for ongoing transmission in Kwale, Kilifi and Lamu counties indicates the need for further MDA rounds in these counties.
- Additionally, the study demonstrated the feasibility of conducting integrated serosurveillance of several infectious diseases of public health interest, as well as levels of seroprotection against vaccine preventable diseases. The findings of the current study underscore the added value of using multiplex antibody measurements to guide and monitor LF elimination efforts.
Community-wide Surveys for Evaluation of LF transmission Interruption, Oncho Transmission Assessment and Comparison of Diagnostic Tools in LF-Onchocerciasis Areas
Assess the performance of LF and Oncho diagnostic tools after stopping LF MDA but continuing Oncho MDA.
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.
To compare coverage evaluation methods to identify a method that is statistically rigorous and feasible for programs. This study will focus on assessing MDA coverage for lymphatic filariasis by comparing the cost, time and feasibility of 3 different methods: the EPI approach (n=1768), LQAS design (n=95) and probability sampling alternatives (n=1768).
Primary Findings and Lessons Learned
Coverage surveys are an important tool for programs to evaluate their reporting systems and to determine whether effective MDA coverage has been achieved. However, for various reasons coverage surveys are seldom implemented. Some key challenges are: perceived technical difficulty, lack of resources, and lack of standardized guidance on how to conduct coverage surveys. This protocol seeks to address the 1st and 3rd points by comparing the feasibility of three different coverage survey methods (EPI approach, LQAS, and segmentation). This study was completed in 3 districts in Burkina Faso. All 3 districts found that their survey coverage was above the WHO target threshold (65% for LF). Furthermore, in all 3 cases the survey coverage validated (or nearly validated) the reported coverage. Taken together this suggests that the Burkina Faso program is working well. The feasibility results found all 3 methods to be very similar with regards to time, cost and perceived difficulty. Because only the segmentation approach results in a probability sample, this method was recommended by the M&E Working Group and ultimately approved by the STAG. Since the approval, significant work has been underway to create guidelines for conducting coverage surveys for preventive chemotherapy. An excel tool was created to improve the usability of the tool and online learning modules are currently in the works.