Community implementation of human landing and non-human landing collection methods for Wuchereria bancrofti vectors

In the drive towards elimination of lymphatic filariasis, enhanced surveillance of vector mosquitoes requires sound sampling methods which can be easily implemented and accepted by communities. Several tools have been validated as alternatives to human landing catches (HLC) for this purpose, but little is known about their effectiveness compared to HLC in terms of the vector density patterns. This study aimed at assessing the efficiency of four mosquitoes collecting tools (HLC, Center for Diseases Control (CDC) light trap, Double Net trap, Window Exit trap). These four sampling tools were evaluated in three different villages (Bapla, Ouessa and Koudjo) in Burkina Faso, when mosquito collection was managed by local people in each community. The results showed that HLC remained the most effective collection method in terms of vector abundance in all villages, followed by double net traps. Except in Bapla, the double net trap collected more Anopheles than CDC light traps. Across the study, the prevalence of Wuchereria bancrofti infection was estimated to be 0.6% and observed only in Anopheles gambiae sensu stricto. The Double Net trap is the least expensive of all three methods and was well accepted by the community. In conclusion, double net traps can be recommended for communities to use for lymphatic filariasis (LF) vector surveillance program for xeno-monitoring of post transmission assessment survey evaluation. Based on prevalence the mass drug administration (MDA) could be stopped in these villages without risk of resurgence of the disease, according to the current recommendations of World Health Organization (WHO). Set up surveillance and continue to use vector control tools

Risk factors associated with failing pre-transmission assessment surveys (pre-TAS) in lymphatic filariasis elimination programs: Results of a multi-country analysis.

Achieving elimination of lymphatic filariasis (LF) as a public health problem requires a minimum of five effective rounds of mass drug administration (MDA) and demonstrating low prevalence in subsequent assessments. The first assessments recommended by the World Health Organization (WHO) are sentinel and spot-check sites-referred to as pre-transmission assessment surveys (pre-TAS)-in each implementation unit after MDA. If pre-TAS shows that prevalence in each site has been lowered to less than 1% microfilaremia or less than 2% antigenemia, the implementation unit conducts a TAS to determine whether MDA can be stopped. Failure to pass pre-TAS means that further rounds of MDA are required. This study aims to understand factors influencing pre-TAS results using existing programmatic data from 554 implementation units, of which 74 (13%) failed, in 13 countries. Secondary data analysis was completed using existing data from Bangladesh, Benin, Burkina Faso, Cameroon, Ghana, Haiti, Indonesia, Mali, Nepal, Niger, Sierra Leone, Tanzania, and Uganda. Additional covariate data were obtained from spatial raster data sets. Bivariate analysis and multilinear regression were performed to establish potential relationships between variables and the pre-TAS result. Higher baseline prevalence and lower elevation were significant in the regression model. Variables statistically significantly associated with failure (p-value ≤0.05) in the bivariate analyses included baseline prevalence at or above 5% or 10%, use of Filariasis Test Strips (FTS), primary vector of Culex, treatment with diethylcarbamazine-albendazole, higher elevation, higher population density, higher enhanced vegetation index (EVI), higher annual rainfall, and 6 or more rounds of MDA. This paper reports for the first time factors associated with pre-TAS results from a multi-country analysis. This information can help countries more effectively forecast program activities, such as the potential need for more rounds of MDA, and prioritize resources to ensure adequate coverage of all persons in areas at highest risk of failing pre-TAS

Baseline drivers of lymphatic filariasis in Burkina Faso

Lymphatic filariasis (LF) is a parasitic disease that is endemic throughout sub-Saharan Africa, infecting approximately 40 million people. In Burkina Faso, mass drug administration (MDA) for LF with ivermectin and albendazole has been ongoing since 2001, and by 2006 all endemic health districts were receiving MDA with a therapeutic coverage of at least 65%. As MDA activities scale down, the focus is now on targeting areas where LF transmission persists with alternative elimination strategies. This study explored the relationship between village-level, baseline LF prevalence data collected in 2000 with publicly available meteorological, environmental and demographic variables in order to determine the factors that influence the geographical distribution of the disease. A fitted multiple logistic regression model indicated that the length of the rainy season, variability in normalized difference vegetation index (NDVI) and population density were significantly positively associated with LF prevalence, whereas total annual rainfall, average June-September temperature, mean NDVI, elevation and the area of cotton crops were significantly negatively associated. This model was used to produce a baseline LF risk map for Burkina Faso. An extended model which incorporated potential socio-demographic risk factors also indicated a significant positive relationship between LF prevalence and wealth. In overlaying the baseline LF risk map with the number of MDA rounds, plus an insecticide-treated net (ITN) ownership measure, the central southern area of the country was highlighted as an area where baseline LF prevalence was high and ITN coverage relatively low (<50%), while at least 10 rounds of MDA had been undertaken, suggesting that more concentrated efforts will be needed to eliminate the disease in these areas

Elimination of lymphatic filariasis in west African urban areas: is implementation of mass drug administration necessary?

Lymphatic filariasis in Africa is caused by the parasite Wuchereria bancrofti and remains a major cause of morbidity and disability in 74 countries globally. A key strategy of the Global Programme for the Elimination of Lymphatic Filariasis, which has a target elimination date of 2020, is the treatment of entire endemic communities through mass drug administration of albendazole in combination with either ivermectin or diethylcarbamazine. Although the strategy of mass drug administration in combination with other interventions, such as vector control, has led to elimination of the infection and its transmission in many rural communities, urban areas in west Africa present specific challenges to achieving the 2020 targets. In this Personal View, we examine these challenges and the relevance of mass drug administration in urban areas, exploring the rationale for a reassessment of policy in these settings. The community-based mass treatment approach is best suited to rural areas, is challenging and costly in urban areas, and cannot easily achieve the 65% consistent coverage required for elimination of transmission. In our view, the implementation of mass drug administration might not be essential to interrupt transmission of lymphatic filariasis in urban areas in west Africa. Evidence shows that transmission levels are low and that effective mass drug distribution is difficult to implement, with assessments suggesting that specific control measures against filariasis in such dynamic settings is not an effective use of limited resources. Instead, we recommend that individuals who have clinical disease or who test positive for W bancrofti infection in surveillance activities should be offered antifilarial drugs through a passive surveillance approach, as well as morbidity management for their needs. We also recommend that more precise studies are done, so that mass drug administration in urban areas is considered if sustainable transmission is found to be ongoing. Otherwise, the limited resources should be directed towards other elements of the lymphatic filariasis programme. [Abstract copyright: Copyright © 2018 Elsevier Ltd. All rights reserved.

Efficacy and risk of harms of repeat ivermectin mass drug administrations for control of malaria (RIMDAMAL): a cluster-randomised trial

International audienceBackground Ivermectin is widely used in mass drug administrations for controlling neglected parasitic diseases, and can be lethal to malaria vectors that bite treated humans. Therefore, it could be a new tool to reduce plasmodium transmission. We tested the hypothesis that frequently repeated mass administrations of ivermectin to village residents would reduce clinical malaria episodes in children and would be well tolerated with minimal harms. Methods We invited villages (clusters) in Burkina Faso to participate in a single-blind (outcomes assessor), parallelassignment, two-arm, cluster-randomised trial over the 2015 rainy season. Villages were assigned (1:1) by random draw to either the intervention group or the control group. In both groups, all eligible participants who consented to the treatment and were at least 90 cm in height received single oral doses of ivermectin (150–200 μg/kg) and albendazole (400 mg), and those in the intervention group received five further doses of ivermectin alone at 3-week intervals thereafter over the 18-week treatment phase. The primary outcome was cumulative incidence of uncomplicated malaria episodes over 18 weeks (analysed on a cluster intention-to-treat basis) in an active case detection cohort of children aged 5 years or younger living in the study villages. This trial is registered with ClinicalTrials.gov, number NCT02509481. Findings Eight villages agreed to participate, and four were randomly assigned to each group. 2712 participants (1333 [49%] males and 1379 [51%] females; median age 15 years [IQR 6–34]), including 590 children aged 5 years or younger, provided consent and were enrolled between May 22 and July 20, 2015 (except for 77 participants enrolled after these dates because of unavailability before the first mass drug administration, travel into the village during the trial, or birth), with 1447 enrolled into the intervention group and 1265 into the control group. 330 (23%) participants in the intervention group and 233 (18%) in the control group met the exclusion criteria for mass drug administration. Most children in the active case detection cohort were not treated because of height restrictions. 14 (4%) children in the intervention group and 10 (4%) in the control group were lost to follow-up. Cumulative malaria incidence was reduced in the intervention group (648 episodes among 327 children; estimated mean 2·00 episodes per child) compared with the control group (647 episodes among 263 children; 2·49 episodes per child; risk difference –0·49 [95% CI –0·79 to –0·21], p=0·0009, adjusted for sex and clustering). The risk of adverse events among all participants did not differ between groups (45 events [3%] among 1447 participants in the intervention group vs 24 events [2%] among 1265 in the control group; risk ratio 1·63 [1·01 to 2·67]; risk difference 1·21 [0·04 to 2·38], p=0·060), and no adverse reactions were reported

Successful Control of Soil-Transmitted Helminthiasis in School Age Children in Burkina Faso and an Example of Community-Based Assessment via Lymphatic Filariasis Transmission Assessment Survey

<div><p>Background</p><p>Burkina Faso is endemic with soil-transmitted helminth infections. Over a decade of preventive chemotherapy has been implemented through annual lymphatic filariasis (LF) mass drug administration (MDA) for population aged five years and over, biennial treatment of school age children with albendazole together with schistosomiasis MDA and biannual treatment of pre-school age children through Child Health Days. Assessments were conducted to evaluate the current situation and to determine the treatment strategy for the future.</p><p>Methodology/Principal Findings</p><p>A cross-sectional assessment was conducted in 22 sentinel sites across the country in 2013. In total, 3,514 school age children (1,748 boys and 1,766 girls) were examined by the Kato-Katz method. Overall, soil-transmitted helminth prevalence was 1.3% (95% CI: 1.0–1.8%) in children examined. Hookworm was the main species detected, with prevalence of 1.2% (95% CI: 0.9–1.6%) and mean egg counts of 2.1 epg (95% CI: 0–4.2 epg). Among regions, the Centre Ouest region had the highest hookworm prevalence of 3.4% (95% CI: 1.9–6.1%) and mean egg counts of 14.9 epg (95% CI: 3.3–26.6 epg). A separate assessment was conducted in the Centre Nord region in 2014 using community-based cluster survey design during an LF transmission assessment survey (TAS). In this assessment, 351 children aged 6–7 years and 345 children aged 10–14 years were examined, with two cases (0.6% (95% CI: 0.2–2.1%)) and seven cases (2.0% (95% CI: 1.0–4.1%)) of hookworm infection was identified respectively. The results using both age groups categorized the region to be 2% to <10% in STH prevalence according to the pre-defined cut-off values.</p><p>Conclusions/Significance</p><p>Through large-scale preventive chemotherapy, Burkina Faso has effectively controlled STH in school age children in the country. Research should be conducted on future strategies to consolidate the gain and to interrupt STH transmission in Burkina Faso. It is also demonstrated that LF TAS provides one feasible and efficient platform to assess the STH situation for post LF MDA decision making.</p></div

The development and roll-out of a new hydrocoele surgery facility assessment tool for the elimination of lymphatic filariasis

Abstract A hydrocoele surgery facility assessment tool (HSFAT) was developed to assess the readiness of hydrocoele surgery services in health facilities prior to implementation of hydrocoele surgical campaigns for the elimination of lymphatic filariasis (LF). A first version of the tool was piloted in Bangladesh, Malawi and Nepal in 2019, then, following feedback from country programme managers, a second version of the tool was rolled out across countries implementing hydrocoele surgery in the Accelerating the Control of Neglected Tropical Diseases (Ascend) West and Central Africa Programme, including Benin, Burkina Faso, Ghana, Guinea, Niger and Nigeria. The HSFAT assessed facilities across 10 domains: background information, essential amenities, emergency patient transfer, laboratory capacity, surgical procedures and trained staff, infection prevention, non-disposable basic equipment, disposable basic equipment, essential medicines and current hydrocoele practices. The HSFAT results highlight key areas for improvement in different countries and can be used to develop a quality improvement plan, which may include actions with agreed deadlines to improve the readiness and quality of hydrocoele surgery services provided by the health facility, prior to implementation of surgical campaigns and assist country programmes to achieve the dossier requirements set out by the World Health Organization for the elimination of LF.</jats:p

Deworming activities through different platforms in Burkina Faso.

<p>Deworming activities through different platforms in Burkina Faso.</p

Results of STH assessment during LF TAS and school-based survey in Centre Nord in Burkina Faso in 2014.

<p>Results of STH assessment during LF TAS and school-based survey in Centre Nord in Burkina Faso in 2014.</p

Distribution of positive STH cases in surveyed clusters in the Centre Nord EU from the LF TAS-STH assessment in 2014.

<p>A) 6–7 years old, B) 10–14 years old.</p