Impact assessment of onchocerciasis through lymphatic filariasis transmission assessment surveys using Ov-16 rapid diagnostic tests in Sierra Leone.

BACKGROUND: Onchocerciasis is endemic in 14 of Sierra Leone's 16 districts with high prevalence (47-88.5%) according to skin snips at baseline. After 11 rounds of mass treatment with ivermectin with good coverage, an impact assessment was conducted in 2017 to assess the progress towards eliminating onchocerciasis in the country. METHODS: A cluster survey was conducted, either integrated with lymphatic filariasis (LF) transmission assessment survey (TAS) or standalone with the LF TAS sampling strategy in 12 (now 14) endemic districts. Finger prick blood samples of randomly selected children in Grades 1-4 were tested in the field using SD Bioline Onchocerciasis IgG4 rapid tests. RESULTS: In total, 17,402 children aged 4-19 years in 177 schools were tested, and data from 17,364 children aged 4-14 years (14,230 children aged 5-9 years) were analyzed. Three hundred forty-six children were confirmed positive for Ov-16 IgG4 antibodies, a prevalence of 2.0% (95% CI 1.8-2.2%) in children aged 4-14 years with prevalence increasing with age. Prevalence in boys (2.4%; 95% CI 2.1-2.7%) was higher than in girls (1.6%; 95% CI 1.4-1.9%). There was a trend of continued reduction from baseline to 2010. Using data from children aged 5-9 years, overall prevalence was 1.7% (95% CI 1.5-1.9%). The site prevalence ranged from 0 to 33.3% (median prevalence = 0.0%): < 2% in 127 schools, 2 to < 5% in 34 schools and ≥ 5% in 16 schools. There was a significant difference in average prevalence between districts. Using spatial analysis, the Ov-16 IgG4 antibody prevalence was predicted to be < 2% in coastal areas and in large parts of Koinadugu, Bombali and Tonkolili Districts, while high prevalence (> 5%) was predicted in some focal areas, centered in Karene, Kailahun and Moyamba/Tonkolili. CONCLUSIONS: Low Ov-16 IgG4 antibody prevalence was shown in most areas across Sierra Leone. In particular, low seroprevalence in children aged 5-9 years suggests that the infection was reduced to a low level after 11 rounds of treatment intervention. Sierra Leone has made major progress towards elimination of onchocerciasis. However, attention must be paid to those high prevalence focal areas.

Synthesis of findings from the literature and a qualitative research study on the impacts of gender, disability, and ethnicity in Neglected Tropical Diseases programs.

INTRODUCTION: Act to End NTDs | West, a USAID-funded program that supports national governments to eliminate or control five neglected tropical diseases (NTDs) in West Africa including trachoma, lymphatic filariasis (LF), onchocerciasis, schistosomiasis and soil-transmitted helminthiasis, conducted a gender and social inclusion analysis to determine how NTDs differentially impact various populations and how gender and social norms impact NTD programs to inform future programming. METHODS: The study used a mixed methods approach including a literature review; primary qualitative data collection; and monitoring data in Côte d'Ivoire, Sierra Leone, and Ghana. RESULTS: Women and girls face additional health risks from many NTDs compared to men and boys. In addition to differential health burden, the social and economic impacts of NTD-related disability or infertility can be particularly dire for women and girls. Men were somewhat less likely to participate in mass drug administration (MDAs) due to: lack of information about campaigns, lack of access due to work, and higher levels of mistrust of the government and concerns about side effects of the medicines. Pregnant and breastfeeding women were sometimes excluded by community drug distributors (CDDs) from certain types of MDAs for which they are eligible. Training participation rates for CDDs and supervisors were nearly universally higher for men than women, even though feedback on the effectiveness of female CDDs was overwhelmingly positive, and female CDDs often have more access to other women in conservative households. The role of a CDD can lead to career and social opportunities for women. However, challenges faced by CDDs were seen as a greater barrier for women, including transportation, safety, household responsibilities, lower education levels, and low or lack of wages. DISCUSSION: Programs to address NTDs can promote equity and improve programming by increasing women's participation as CDDs and providing financial compensation. Additionally, programs should prioritize inclusive training for CDDs, and inclusive messaging about MDA for communities.

Contextual determinants of mass drug administration performance: Modelling fourteen years of lymphatic filariasis treatments in West Africa.

BACKGROUND: Effective mass drug administration (MDA) is the cornerstone in the elimination of lymphatic filariasis (LF) and a critical component in combatting all neglected tropical diseases for which preventative chemotherapy is recommended (PC-NTDs). Despite its importance, MDA coverage, however defined, is rarely investigated systematically across time and geography. Most commonly, investigations into coverage react to unsatisfactory outcomes and tend to focus on a single year and health district. Such investigations omit more macro-level influences including sociological, environmental, and programmatic factors. The USAID NTD database contains measures of performance from thousands of district-level LF MDA campaigns across 14 years and 10 West African countries. Specifically, performance was measured as an MDA's epidemiological coverage, calculated as persons treated divided by persons at risk. This analysis aims to explain MDA coverage across time and geography in West Africa using sociological, environmental, and programmatic factors. METHODOLOGY: The analysis links epidemiological coverage data from 3,880 LF MDAs with contextual, non-NTD data via location (each MDA was specific to a health district) and time (MDA month, year). Contextual data included rainfall, temperature, violence or social unrest, COVID-19, the 2014 Ebola outbreak, road access/isolation, population density, observance of Ramadan, and the number of previously completed MDAs. PRINCIPAL FINDINGS: We fit a hierarchical linear regression model with coverage as the dependent variable and performed sensitivity analyses to confirm the selection of the explanatory factors. Above average rainfall, COVID-19, Ebola, violence and social unrest were all significantly associated with lower coverage. Years of prior experience in a district and above average temperature were significantly associated with higher coverage. CONCLUSIONS/SIGNIFICANCE: These generalized and context-focused findings supplement current literature on coverage dynamics and MDA performance. Findings may be used to quantify typically anecdotal considerations in MDA planning. The model and methodology are offered as a tool for further investigation.

Community-wide prevalence and intensity of soil-transmitted helminthiasis and Schistosoma mansoni in two districts of Sierra Leone.

In Sierra Leone, nationally powered school-based surveys have documented significant progress in the control of soil-transmitted helminthiasis (STH) and schistosomiasis. In order to assess the district-level prevalence and intensity of infection among key at-risk groups outside of school age children (SAC), we conducted a multi-stage, cluster-sample household survey in Bo and Kenema districts in May 2018. From both districts, we examined 1,282 pre-school age children (PSAC), 730 school age children (SAC), and 517 adults over 14 years (including 387 women of reproductive age, or WRA) for STH and Schistosoma mansoni infection using Kato Katz technique. In Bo, STH prevalence was 8.0% (95% Upper Confidence Limit 10.2%) in PSAC, 6.4% (95% Upper Confidence Limit 9.0%) in SAC, 14.1% (95% Upper Confidence Limit 17.4%) in all adults and 11.9% (95% Upper Confidence Limit 17.4%) in WRA. In Kenema, STH prevalence was 18.1% (95% Upper Confidence Limit 20.5%) in PSAC, 17.3% (95% Upper Confidence Limit 20.7%) in SAC, and 16.9% (95% Upper Confidence Limit 20.5%) in all adults and 16.9% (95% Upper Confidence Limit 22.6%) in WRA. Hookworm species were the most prevalent of STH in both districts overall. The overall prevalence of S. mansoni was <10% in Bo and <20% in Kenema, and was similar across age groups. No moderate or heavy intensity STH infections or heavy intensity S. mansoni infections, as per World Health Organization (WHO) classification, were detected in either district. Sanitation variables, such as toilet access and quality, were independently associated with STH and S. mansoni infection. In Kenema, STH prevalence in SAC was within the WHO-defined range for annual treatment, whereas a previous nationally-powered survey estimated it to lie within the range of treatment once per two years. By utilizing community-based sampling, we were able to assess prevalence among WRA and make recommendations based on current guidance from WHO. To continue toward elimination of STH and S. mansoni as a public health problem, resources should be mobilized to increase access to and uptake of improved sanitation at community and household levels.

Gender and neglected tropical disease front-line workers: Data from 16 countries.

BACKGROUND: Delivery of preventive chemotherapy (PC) through mass drug administration (MDA) is used to control or eliminate five of the most common neglected tropical diseases (NTDs). The success of an MDA campaign relies on the ability of drug distributors and their supervisors-the NTD front-line workers-to reach populations at risk of NTDs. In the past, our understanding of the demographics of these workers has been limited, but with increased access to sex-disaggregated data, we begin to explore the implications of gender and sex for the success of NTD front-line workers. METHODOLOGY/PRINCIPAL FINDINGS: We reviewed data collected by USAID-supported NTD projects from national NTD programs from fiscal years (FY) 2012-2017 to assess availability of sex-disaggregated data on the workforce. What we found was sex-disaggregated data on 2,984,908 trainees trained with financial support from the project. We then analyzed the percentage of males and females trained by job category, country, and fiscal year. During FY12, 59% of these data were disaggregated by sex, which increased to nearly 100% by FY15 and was sustained through FY17. In FY17, 43% of trainees were female, with just four countries reporting more females than males trained as drug distributors and three countries reporting more females than males trained as trainers/supervisors. Except for two countries, there were no clear trends over time in changes to the percent of females trained. CONCLUSIONS/SIGNIFICANCE: There has been a rapid increase in availability of sex-disaggregated data, but little increase in recruitment of female workers in countries included in this study. Women continue to be under-represented in the NTD workforce, and while there are often valid reasons for this distribution, we need to test this norm and better understand gender dynamics within NTD programs to increase equity.