Successful completion of onchocerciasis elimination mapping (OEM) in Niger, West Africa.

BACKGROUND: By 1987, onchocerciasis in Niger had been successfully controlled in the six endemic river basins. In 2017, onchocerciasis elimination mapping (OEM) was carried out to determine if there was any ongoing transmission in the country as a whole. METHODS: The recommended OEM procedures were implemented. RESULTS: Ten districts, that included 35 villages, required field investigation as sites of possible transmission. None of these were found capable of supporting black fly breeding, nor was there any evidence of the presence of Simulium sp. flies. CONCLUSIONS: The implementation of OEM indicates that there is no transmission of onchocerciasis currently taking place in these newly assessed sites in Niger.

Morbidity hotspot surveillance: A novel approach to detect lymphatic filariasis transmission in non-endemic areas of the Tillabéry region of Niger.

The Niger Lymphatic Filariasis (LF) Programme is making good progress towards the elimination goal and scaling up morbidity management and disability prevention (MMDP) activities. Clinical case mapping and the increased availability of services has prompted patients to come forward in both endemic and non-endemic districts. The latter included Filingué, Baleyara and Abala districts of the Tillabéry region, and in 2019, 315 patients were found during a follow-up active case finding activity, suggesting it may have low transmission. The aim of this study was to assess the endemicity status in areas reporting clinical cases, 'morbidity hotspots', in three non-endemic districts of the Tillabéry region. A cross-sectional survey was conducted in 12 villages in June 2021. Filarial antigen was detected using the rapid Filariasis Test Strip (FTS) diagnostic, and information obtained on gender, age, residency length, bed net ownership and usage, and presence of hydrocoele and/or lymphoedema. Data were summarised and mapped using QGIS software. A total of 4058 participants between 5 and 105 years old were surveyed, with 29 (0.7%) participants found to be FTS positive. Baleyara district had significantly higher FTS positive rates than the other districts. No significant differences were found by gender (male 0.8%; female 0.6%), age group (<26 years 0.7%; ≥26 years 0. 7%), and residency length (<5 years 0.7%; ≥5 years 0.7%). Three villages reported no infections; seven villages <1%, one village 1.1% and one village 4.1%, which was on the border of an endemic district. Bed net ownership (99.2%) and usage (92.6%) was very high and there was no significant difference between FTS infection rates. The results indicate that there are low levels of transmission in populations, including children, living in districts previously classified as non-endemic. This has implications for the Niger LF programme in terms of delivering targeted mass drug administration (MDA) in transmission hotspots, and MMDP services, including hydrocoele surgery to patients. The use of morbidity data may be a practical proxy to trigger mapping of ongoing transmission in low endemic areas. Continued efforts to study morbidity hotspots, post-validation transmission, cross-border and cross-district endemicity are needed to meet the WHO NTD 2030 roadmap targets.

Neglected tropical diseases: comparison of the costs of integrated and vertical preventive chemotherapy treatment in Niger.

BACKGROUND: This study presents evidence on the cost of integrated preventive chemotherapy treatment (PCT) to control trachoma, schistosomiasis, lymphatic filariasis and soil-transmitted helminthiasis (STH) in Niger. Integrated PCT costs are compared with the costs of vertical PCT control. METHODS: Data were analysed for the integrated PCT of 2008 and 2009 in six districts. Receipts, treatment registers, coverage forms and drug registers provided cost and treatment information. Economic costs of the time spent on campaign activities by government staff was derived from a survey of 56 staff. Integrated control costs were compared with vertical programmes undertaken in 2005 using 2009 constant prices. RESULTS: The average economic cost of integrated PCT was US$0.19/treatment excluding drugs (US$0.38 for a district with two drug treatments). The average financial cost was US$0.09/treatment (US$0.18 for a district with two drug treatments).The average financial cost of vertical treatment was US$0.167 for trachoma, US$0.10 for schistosomiasis and STH and US$0.075 for lymphatic filariasis. The integrated programme had savings of 16% and 21% in programme costs in 2008 and 2009, respectively, compared with the vertical programmes. CONCLUSION: Further work is needed to forecast the effectiveness of alternative long-term integrated treatment strategies for control and/or elimination of neglected tropical diseases.