Integrated Prevalence Assessment of Wuchereria bancrofti and Onchocerca volvulus in Three Co-Endemic Districts of Gambella Region, Ethiopia.

Lymphatic filariasis (LF) and onchocerciasis (OV) are among the neglected tropical diseases (NTD) targeted for elimination in Ethiopia. We used a transmission assessment survey (TAS-1) to evaluate the serological status of OV in three co-endemic districts in Gambella simultaneously. During May and June 2019, blood samples were collected from 6- to 7-year-old children who were randomly selected through standard community-based TAS methodology. Children were tested for both circulating filarial antigen (CFA) for LF via filariasis test strip and for Onchocerca volvulus 16 (Ov16) antibody for OV via laboratory-based ELISA. A total of 3,377 children from 150 villages in the three districts were tested; 1,823 (54.0%) were male. All three districts had CFA results below the critical threshold for stopping LF mass drug administration (MDA). In contrast, 40 children (1.2%) were positive for Ov16 antibody, well above the WHO's OV stop MDA threshold of 0.1%. The integrated assessment indicated two programmatic decisions: stop MDA for LF and continue MDA for OV. Accordingly, albendazole MDA was discontinued in the districts but ivermectin MDA continued. This integrated assessment showed that a random sample for TAS can give important information about OV transmission status in co-endemic areas.

Evaluation of Treatment Coverage and Enhanced Mass Drug Administration for Onchocerciasis and Lymphatic Filariasis in Five Local Government Areas Treating Twice Per Year in Edo State, Nigeria.

The western region of Edo state in southern Nigeria is highly endemic for onchocerciasis. Despite years of mass drug administration (MDA) with ivermectin (IVM), reports suggest persistently high prevalence of onchocerciasis, presumably because of poor coverage. In 2016, twice-per-year treatment with IVM (combined with albendazole for lymphatic filariasis in the first round where needed) began in five local government areas (LGAs) of Edo state. We undertook a multistage cluster survey within 3 months after each round of MDA to assess coverage. First-round coverage was poor: among 4,942 people of all ages interviewed from 145 clusters, coverage was 31.1% (95% confidence intervals [CI]: 24.1-38.0%). Most respondents were not offered medicines. To improve coverage in the second round, three LGAs were randomized to receive MDA through a "modified campaign" approach focused on improved supervision and monitoring. The other two LGAs continued with standard MDA as before. A similar survey was conducted after the second round, interviewing 3,362 people in 87 clusters across the five LGAs. Coverage was not statistically different from the first round (40.0% [95% CI: 31.0-49.0%]) and there was no significant difference between the groups (P = 0.7), although the standard MDA group showed improvement over round 1 (P < 0.01). The additional cost per treatment in the modified MDA was 1.6 times that of standard MDA. Compliance was excellent among those offered treatment. We concluded that poor mobilization, medicine distribution, and program penetration led to low coverage. These must be addressed to improve treatment coverage in Edo state.