The question of how to conduct post-elimination surveillance is a high priority for the NTD community, given that most NTD programs scale back or shut down completely once elimination as a public health problem is achieved. Few solutions exist and this proposal provides an interesting and useful case study for surveillance moving forward. The study team plans to target 1708 pregnant women as a proxy for measuring LF resurgence in a post-elimination context. As a comparison group, they plan to conduct a prevalence survey of 427 households (1708 participants) in the same community to compare LF prevalence found in each methodology. Each participant at the health facility’s residence will be geo-referenced to understand the coverage area. They also plan to conduct interviews with patients and health workers, a time-motion study, and a cost analysis to assess the additional burden on health care workers and the health system. The study will occur in 14 facilities in one district of Malawi where LF was highly endemic prior to the launch of the program.
Urban dwellers have frequently been included as "hard to reach" when examining MDA coverage and uptake. Poor coverage in urban settings is a key factor that prevents programs in some settings from achieving success. This research study proposes a community-based participatory action research (CBPAR) strategy to better understand the reasons why this population isn’t reached and/or their decision not to participate in onchocerciasis and lymphatic filariasis MDAs. The results will help identify last mile strategies for urban populations and will generate a technical toolkit for how to conduct rapid participatory research in areas that require novel outreach methods amongst hard-to-reach populations. This form of social science methodology has not been used frequently within the NTD community and this proposal offers an opportunity to build the evidence base for these methods within the context of hard to reach populations.
The researchers plan to conduct a number of activities in order to determine the effectiveness of the participatory approach in targeting urban populations as compared to the standard mobilization and delivery approach.
Rapid ethnographic interviews, a new technique aimed at rapidly collecting and analyzing qualitative data, to gather community feedback regarding barriers in accessing treatment
An intervention development workshop with community leaders, health workers, researchers, and the ministry of health
Deliver the newly designed strategy in Za-Kpota district and compare coverage in urban settings to Ouinhi district
Finalize a rapid participatory approach toolkit and conduct a time-motion study of the approach to improve the business case to the MoH for uptake 5. Surveys and individual interviews with key stakeholders to determine acceptability, appropriateness, and feasibility of the proposed approach and toolkit
The researchers propose taking a novel approach to increase coverage and reach previously neglected populations by engaging non-compliant individuals in devising a more effective strategy through a technique called knowledge co-production. The researchers plan to address the following questions:
Can an intervention package co-produced with systematically non-compliant individuals result in increased MDA coverage between the 2019 and 2020 LF MDA rounds?
Who and where are the systematic non-compliers in Leogane and Gressier?
What are the reasons motivating systematic non-compliance?
Is MDA non-compliance associated with hotspots of LF transmission?
The researchers plan the following activities:
A household cluster survey with 1300 individuals of all ages. This will define coverage in the past MDA and identify non-compliant individuals. In addition, ‘hidden’ non-compliers (NCs) will be located by a networking approach (respondent-driven sampling [RDS]).
All NCs will then be eligible to be selected into groups of 10 by age (18-25; 26-50; >50), sex (M, F) and demography (urban/rural). These 12 groups will each work with the national health team to devise new approaches to the non-compliance issue. These will be put into place for the 2020 MDA and then assessed by the co-production strategy groups. After the 2020 MDA a second survey will occur to assess impact.
The relationship between non-compliance and hotspots will be assessed using spatial analysis and defined serologically (FTS and DBS for antibodies) in collaboration with CDC.
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.
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.
The overall goal of this research proposal is to prioritize the five novel Bancroftian antigen candidates with respect to their ease-of-use and practicability within the frame of a future Wb123/WbAgx biplex test, based on their biophysical properties, stability data and behavior in our lateral flow assay setup. Along with the concurrent biochemical/clinical validation by the Nutman group. This will allow an informed choice as to which candidate antigen(s) should be used for the biplex assay development.
1. Development of spatio-temporal models and associated statistical methods to enable forward projections of the geographical distribution of prevalence, and hence the risk of resurgence, by combining model-based geostatistical analysis with mechanistic predictive modelling of disease transmission dynamics, using the most recent available data on disease prevalence and environmental risk-factors.
2. To use the results from aim 1 to derive statistically efficient and affordable designs for networks of sentinel sites to enable continued monitoring of prevalence in areas at high risk of resurgence."