Feasibility of post-exposure-prophylaxis with single-dose rifampicin and identification of high prevalent clusters in villages' hyperendemic for leprosy in Senegal.

INTRODUCTION: Senegal is a leprosy low-endemic country with nine villages known to be hyperendemic with a leprosy incidence rate above 1,000 per million inhabitants. We aim to implement a door-to-door screening strategy associated with the administration of a single-dose-rifampicin (SDR) as post-exposure prophylaxis (PEP) to household and social contacts in these villages and to identify spatial clustering and assess the risk of leprosy in population according to the physical distance to the nearest index-case. METHODS: From October/2020 to February/2022 active door-to-door screening for leprosy was conducted in nine villages. Using an open-source application, we recorded screening results, demographic and geographic coordinate's data. Using Poisson model we analysed clustering and estimated risk of contracting leprosy in contacts according to the distance to the nearest new leprosy patient. RESULTS: In nine villages, among 9086 contacts listed, we examined 7115. Among 6554 eligible contacts, 97.8% took SDR. We found 39(0.64%) new leprosy cases among 6,124 examined in six villages. Among new cases, 21(53.8%) were children, 10(25.6%) were multibacillary and 05(12.8%) had grade 2 disability. The prevalent risk ratio and 95% confidence intervale(95%CI) adjusted by village were 4.2(95%CI 1.7-10.1), 0.97(95%CI 0.2-4.4), 0.87(95%CI 0.2-25), 0.89(95%CI 0.3-2.6) and 0.70(95%CI 0.2-2.5) for the contacts living in the same household of an index case, 1-25m, 26-50m, 51-75m and 76-100m compared to those living at more than 100m respectively. We identified nine high prevalent clusters including 27/39(69%) of new cases in 490/7,850(6%) inhabitants, with relative risks of 46.6(p-value = 0.01), and 7.3, 42.8, 8.2, 12.5, 11.4, 23.5, 22.3, and 14.6 (non-significant p-values). CONCLUSIONS: Our strategy has proved the feasibility of active screening for leprosy in contacts and the introduction of PEP for leprosy under programmatic conditions. Only individuals living in the same household as the leprosy patient had a significant risk of contracting leprosy. We documented nine clusters of leprosy that could benefit from tailored control activities while optimizing resources.

[Leprosy in children in the region of Thiès, Senegal: study determining whether or not it is a signal of recrudescence]. / La lèpre de l'enfant à Thiès/Sénégal: signal d'une recrudescence?

Leprosy is an infectious and transmissible disease. According to the WHO, the number of new cases of leprosy in children in Senegal has risen moderately since 2013. This study aimed to analyze the epidemiological, clinical, therapeutic and evolutionary features of leprosy in children in the geographical areas of two social rehabilitation villages in the region of Thiès. We conducted a retrospective study over a period of 3 years (2013-2015). All new cases of Hansen's disease aged 0 -15 years were included. Over the three year period, 39 children were included in the study, with a boy predominance (n=23, 59%). Among these children, 27 (66.7%) came from a social rehabilitation village for leprosy patients. One family member was affected by leprosy in 27 cases (69.2%). More than half of the children (23 cases, 58.9%) had multibacillary leprosy (lepromatous-lepromatous). All children underwent a 12-month treatment, at the end of which thirty-six (92.3%) children were healed. Leprosy is still present in Senegal despite the efforts made by the national programme to combat leprosy. In the light of these results, it is important to emphasize the role of active screening strategy targeted to children, which seems to have shown its effectiveness in the region. Early detection, contact tracing and early treatment are important factors in the reduction of the contagiousity of leprosy.