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TAS Strengthening in Haiti

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. 

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.

Countries: Haiti

TAS Strengthening in Tanzania

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.

Countries: Tanzania

Triple Drug Therapy (India)

To determine the frequency, type and severity of adverse events following triple-drug therapy (IVM+DEC+ALB, IDA) compared to the standard two-drug treatment (DEC+ALB, DA) in infected and uninfected individuals in a community.

To compare the efficacy of IDA vs. DA administered in communities for clearance of Mf and filarial antigenemia (Ag) in cohort and effectiveness (prevalence) in community settings. To assess the presence and intensity of filarial infection on the frequency and severity of adverse events. To compare community acceptance of MDA with IDA vs. DA.

Countries: India

LFTAS + Biplex + DBS in Oncho endemic areas in Cameroon

To assess if transmission assessment surveys (TAS) for lymphatic filariasis (LF) are a feasible platform to integrate transmission assessment for onchocerciasis, using the same age group (6-7 years old) and the same prevalence threshold (<2%) that the LF programs utilize.

1. To perform the TAS for stopping LF MDA and use it as platform for Oncho impact assessment.
2. To assess the level of endemicity of Oncho following at least five rounds of MDA in hypo, meso and hyper endemic districts.
3. To study the performance of the Wb123/Ov16 Biplex rapid diagnostic test (RDT) to assess Oncho and LF transmission interruption.

 

Preliminary study findings:

  • This study involved an integrated impact assessment of onchocerciasis and lymphatic filariasis using the LF TAS platform and the serologic rapid text Biplex in the Northern area of Cameroon.
  • The study sites covered 31 health districts in the Far-North and North regions, constituting nine evaluation units, for which TAS1 was planned.
  • Community-based cluster surveys were conducted collecting GPS and demographic information, lymphedema symptoms, and testing by FTS, by Wb123/Ov16 Biplex, and by Night Blood Smear of 6 and 7 year old children.
  • In total, 13,957 children were recruited from 267 enumeration units (villages).
  • Ten children showed evidence of LF exposure or infection: 4 were positive by FTS and 6 were positive by Wb123 (via biplex).  No children tested positive for both FTS and Wb123. 
  • Night blood smears - conducted in children who were positive by FTS and by Wb123/Ov16 Biplex - were all negative.
  • For onchocerciasis, one individual was Ov16 positive (by Biplex).

In conclusion, all nine evaluation units passed the TAS1 assessment. As for onchocerciasis, study results are consistent with the previous hypo-endemic status of the area.

Countries: Cameroon

Develop epidemiological and entomological methods to assess verification of transmission interruption of Onchocerciasis in Equatorial Guinea- Africa

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.

Preliminary Study Findings:

A cross-sectional study was conducted from September 2016 to January 2017. Participants were 5- to 9-year-old school children. Onchocerciasis/lymphatic Filariasis (LF, only in endemic districts) rapid diagnostic tests (RDTs) were performed. Blood spots were collected from RDT positive children and 10 percent of the RDT negatives to determine Ov16 and Wb123 IgG4 antibodies through enzyme-linked immunosorbent assay (ELISA). Skin snips were collected from RDT positives. Filarial detection was performed by PCR in positives and indeterminate sera. Black fly collection was carried out in traditional breeding sites. A total of 7,052 children, ranging from 5 to 9 years of age, were included in the study. Four children (0.06%) were Ov16 IgG4 RDT positives, but negative by ELISA Ov16, while 6 RDT negative children tested positive by ELISA. A total of 1,230 children from the Riaba and Baney districts were tested for LF. One child was Wb123 RDT positive (0.08%), but ELISA negative, while 3 RDT negative children were positive by Wb123 ELISA. All positive samples were negative by PCR for onchocerciasis and LF (in blood spot and skin snip). All fly collections and larval prospections in the traditional catching and prospection sites were negative.

Read more in Herrador et al.: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0006471

Countries: Equatorial Guinea

Identification of serosurveilance antigens for schistosomiasis

To identify antigens that can be produced as recombinant proteins and to document elimination of schistosomiasis.

To identify antigens that differentiate between infections with Schistosoma mansoni and Schistosoma haematobium and that can be used in an ELISA, lateral flow assay or multiplex format.

Diseases: Schistosomiasis

Ongoing Post-treatment Surveillance for Lymphatic Filariasis in Bangladesh

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.

 

Countries: Bangladesh

Single vs. multiple treatments of praziquantel in intestinal African schistosomiasis: a randomized, double-blind, placebo controlled trial investigation using new diagnostic tools

Rigorous assessment of the efficacy of (multiple) doses with Praziquantel in the treatment of S. mansoni infections using standard and novel highly sensitive diagnostic tools.

Countries: Cote d'Ivoire
Diseases: Schistosomiasis

TakeUp: Testing the Impact of Incentives on Compliance with Community-based Mass Deworming through a Field Experiment in Kenya

•What is the influence of social and behavioural incentives on the increase in cost-effective demand for deworming medication among adult population?

•What is the impact of social incentives on take-up and cost-effectiveness of deworming treatment?

•What is the impact of consumption incentives on take-up and cost-effectiveness deworming treatment?

•Can any increase in takeup be attributed to signaling effect wherein individuals are motivated to access treatment in order to demonstrate that they have engaged in pro-social behavior?

Countries: Kenya

Assessment of LF status in Two Urban Settings of Benin (Cotonou and Porto-Novo)

To determine whether there is LF transmission in Cotonou and Porto-Novo, which 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. 

Preliminary study findings:

  • While mass drug administration (MDA) in Benin is on track to eliminate LF in most endemic cities, 50 such cities – including the country’s largest cities, Cotonou and Porto Novo – never received treatements.
  • In 2016, more than 15 years after mapping, LF endemicity was re-evaluated in Cotonou and Porto Novo to put in place adequate strategies for LF elimination. This study constituted that re-mapping effort.
  • The various surveys, conducted in vectors and humans through collection of entomological and parasitological data, reveal an absence of LF transmission in Cotonou and Porto Novo.
  • The results demonstrate that the number of cities endemic for LF in Benin has dropped from 50 to 48.
  • However, the study revealed a lack of awareness of LF by residents and health workers, highlighting the need for more education and awareness raising on the disease.
Countries: Benin

Mapping LF-Loa Coendemicity in South Sudan

Mapping LF-Loa Coendemicity in South Sudan

Countries: South Sudan

Mapping LF-Loa Coendemicity in Angola

Mapping LF-Loa Coendemity

Countries: Angola

Mapping LF-Loa Coendemicity in Chad

Mapping LF-Loa Coendemicity

Countries: Chad

Understanding the best uses of the Supervisor's Coverage Tool for monitoring school-based distributions

To compare the feasibility and programmatic implications of employing the Supervisor's Coverage Tool in schools vs. communities to monitor a school-based MDA.

The Supervisor’s Coverage Tool (SCT) is a rapid in-process monitoring tool for improving mass drug administration (MDA) coverage that has been approved by WHO for use in communities.  However, questions remain as to whether it may also serve as a useful tool when implemented in schools.  To answer this question, a direct comparison of school- vs. community-based SCT implementation was conducted in 13 Supervision Areas (SAs) in 7 Local Government Areas (LGAs), in 3 states in Nigeria.  Within each SA, one SCT was conducted in the school and an independent SCT was conducted in a village within the catchment area of the same school. The SCTs were all monitoring the coverage for the same school-based MDA for praziquantel and mebendazole. The goal was to understand how the information learned through the SCT would vary based on the two different sampling frames. 

Findings and lessons learned:

-          The SCT helped find targeted schools for which a mass drug administration (MDA) was planned but were missed. Several unregistered (illegal) schools were missed as their existence was not known, therefore they were not targeted and included in the MDA; however, upon identification of these schools through the SCT, the schools were reached during mop-up and added to the database for future MDAs.

-          An existing school feeding program increased students’ praziquantel intake in all northern Nigeria schools that were visited.

-          In two SAs, school SCT results showed good coverage; however, the actual reported school coverage was below the recommended threshold. The discrepancy was due to a great number of student absences because of farming activities or drop outs after enrolment. Since any selected student who is absent is skipped by the SCT and a new student is selected in their place, the resulting coverage classification could be an inflation of the true coverage.

-          Surveyors preferred SCT implementation in schools vs. community because household enumeration can be time-consuming.

-          When SCT results from the school and the village were directly compared for the same population, the community-based SCT always resulted in an equal or lower classification of coverage, likely because community-based SCTs include the entire target population in the sampling frame, as opposed to being limited to school-attending children.

Countries: Nigeria

Supervisor's Coverage Tool for school-based STH and community-based LF in Philippines

To determine the feasibility and best practices of using the Supervisor's Coverage Tool to monitor community and school-based distribution and integrated MDA.

The Supervisor’s Coverage Tool (SCT) is a rapid, simple, and inexpensive tool designed for use in Neglected Tropical Diseases (NTD) programs mass drug administration (MDA) to monitor drug coverage and compliance, to supervise community drug distributors (CDD), and to identify areas that may need mop-up. After successfully piloting the SCT in Ethiopia and Nigeria in 2015, additional testing of the tool was suggested to assess the feasibility of the tool in different regions and new settings. Therefore, the SCT was implemented in the Philippines in July 2016.

After the completion of training, the field work was conducted in two provinces, in six Supervision Areas (SA) consisting of one or more puroks (subdivisions) per barangay (village). Two survey populations were represented in the SCT implementation covering a community-based distribution for Lymphatic Filariasis (LF), excluding children aged 5-18 years and a school-based distribution for LF for all children aged 5-18 years. 

Findings and lessons learned:

  • The most common reasons for not swallowing drugs were fear of side effects, not feeling well, forgetting, being too busy, and the taste of the medicine.
  • When an accurate register of all the households in the SA exists, it is possible to complete the SCT in each SA in less than a day because the registers greatly aid the random selection process.
  • Implementing the SCT during the last week or two of the MDA was advantageous as it enabled the program to implement the action plan to improve the current MDA using the personnel, budget, and infrastructure that was already in place for the MDA.
  • It is important to consider whether or not Community Drug Distributors (CDD) should accompany the SCT teams during interviews, as their presence may influence the answers of the respondents.
  • It is strongly recommended that when possible, CDDs use directly observed treatment (DOT). If DOT is not possible, CDDs should remind participants that there is no advantage in delaying swallowing the drugs, and that it is actually better when everyone swallows the drugs at the same time.
  • Overall, the Philippines SCT pilot was a success, as it was the first time it was implemented in the Western Pacific region, and it was also used to monitor multiple distributions (both school- and community-based). 
Countries: Philippines

Comparison of Kato-Katz and PCR for STH

To compare the sensitivity of double-slide Kato-Katz and multi-parallel real-time polymerase chain reaction (PCR) in the detection of Ascaris, hookworm, and Trichuris infection among children in rural Bangladesh

Countries: Bangladesh

Comparison of muti-parallel qPCR and Kato-Katz for detection of STH in Kenyan children

Is the multiparallel quantitative polymerase chain reaction technique superior to Kato-Katz microscopy in assessing the intensity and prevalence of soil-transmitted helminth infections in stool?

Preliminary Findings and Lessons Learned

  • qPCR was more sensitive than Kato-Katz at detecting Ascaris, Trichuris, and hookworm infections in child fecal samples.
  • Very few samples were helminth positive by Kato-Katz microscopy that were not also positive by qPCR, suggesting minimal human classification error during microscopy.
  • Duplicate qPCR analysis on ~10% of samples by two separate labs (Smith and KEMRI) showed excellent concordance (97-100% agreement for each helminth species).
  • A reanalysis of the effect of a combined water, sanitation, and hand washing (WASH) intervention on child helminth infections with qPCR data compared to Kato-Katz data gave very similar results.
Countries: Kenya

Relationships among clinical signs (Follicular Trachoma) and infection and antibody

The purpose of this study is to analyze the relationships among clinical signs (follicular trachoma) and the prevalence of infection and antibody and to determine whether it may be appropriate to consider one or more alternative indicators for deciding whether trachoma programs can stop MDA.

Diseases: Trachoma

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 (Ghana)

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

Countries: Ghana

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 (Uganda)

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

Countries: Uganda

Correlating Ov16 Serology with Skin Snip Assessments (Malawi)

Comparison of different diagnostic tools during onchocerciasis mapping, including Ov16 ELISA, OV16 rapid diagnostic test (RDT) and skin snip test.

Countries: Malawi

Correlating Ov16 Serology with Skin Snip Assessments (Guinea Bissau)

Comparison of different diagnostic tools during onchocerciasis mapping, including Ov16 ELISA, OV16 rapid diagnostic test (RDT) and skin snip test.

Countries: Guinée-Bissau

Development of a Mobile Reader for Rapid Diagnostic Tests

Can a mobile reader be used to standardize the reading of rapid diagnostic tests (RDTs)?

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.

Countries: Nigeria

A Programmatic Comparison of School- and Community-Based TAS

Determine whether school-based TAS results in the same programmatic conclusion as a community-based TAS in EUs where school attendance is poor.

Preliminary Findings and Lessons Learned

This USAID project represents an innovative approach to resolve critical questions about the performance of the TAS and in particular, the question of how important 75% school attendance is to a valid TAS result.  At its core, this study addresses the concern that LF (specifically antigenemia) could be associated with school attendance, which leads to the programmatic research question: does a school-based TAS result in the same programmatic conclusion as a community-based TAS in EUs where school attendance is poor? This study will lead to a better understanding of the validity of the TAS in programmatic settings where school attendance and/or reporting of school enrollment may be poor.  It will also generate important results for the Haitian program that is looking to the TAS for guidance on stopping MDA in several EUs. The school- and community-based TAS were both conducted in a commune considered to be highly endemic (‘zone rouge’) at baseline.  Both surveys passed the TAS, with only 1 ICT positive child identified in the school TAS and 4 ICT-positive children in the community-based TAS.  The conclusion is that there appears to be no meaningful difference between school- and community-based TAS for stopping MDA decisions, even where school attendance is poor. This is the third LFSC/NTDSC study to return a null result -- perhaps it can now be considered a "non-issue" for LF.

Countries: Haiti

Post-MDA Estimated LF Prevalence

To develop models that can predict MF prevalence after a given number of rounds of MDA as a tool to identify program settings in which the response to MDA is less than predicted. 

Co-Endemicity of Lymphatic Filariasis and Loiais in the Republic of Congo

Determine Co-Endemicity of Lymphatic Filariasis and Loiais in the Republic of Congo

Countries: Congo

Schistosoma Prevalence in Mekong River Basin of Cambodia and Laos Border

Determine the Schistosoma prevalence in the Mekong River Basin on the border of Laos and Cambodia

Diseases: Schistosomiasis

Development of Mobile Reader Application at Point-of-care for POC-CCA

Develop a mobile reader application for use at the point-of care for the POC-CCA assay used for mapping and surveillance of Schistosoma mansoni. The reader apk will provide results consistent with the visual human reading of the test. Distinguishing intensity bands and reading 'Trace' results can be problematic and leads commonly to 'false positive' readings. The apk being developed will utilize a testing algorithm to better distinguish between true positive and false positive "Trace" test results. 

Countries:
Diseases: Schistosomiasis

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