ICMR-Vector Control Research Centre, Puducherry, India.
Trop Med Int Health. 2018 Nov;23(11):1251-1258. doi: 10.1111/tmi.13143. Epub 2018 Sep 10.
Lymphatic filariasis (LF) elimination through mass drug administration (MDA) of DEC and albendazole have resulted in very low levels of infection in most endemic districts in India. But small pockets with residual microfilaraemia in the community and antigeneamia in children ('hotspots') are a cause of concern. We aimed to identify the determinants of such transmission hotspots and filarial infection in households using data from 33 communities.
The filariasis vector Culex quinquefasciatus was collected from 627 randomly selected households using gravid traps. Parallel data on environmental, entomological, demographical, socio-economical and behavioural factors were analysed to identify the determinants of hotspots and household-level infection.
Hotspots and non-hotspots did not differ significantly in terms of socio-economical and behavioural aspects, but did differ in terms of demographical and environmental factors. Logistic regression revealed that tiled and concrete houses increased the risk of an area being a hotspot by 2.0 and 2.9 times respectively. Presence of Culex breeding habitats was significantly associated with elevated risk of being a hotspot. Proximity of U-drains to a house increased the risk of filarial infection 5.8 times.
An environment suitable to Culex breeding influences continued transmission despite eight rounds of MDA, particularly in hotspots. Proximity to U-drains increases the risk of infection in households. Implementing localised vector control measures may help interrupt low-level transmission, thereby reducing the risk of resurgence in the absence of MDA.
通过大规模药物治疗（MDA）使用 DEC 和阿苯达唑消灭淋巴丝虫病（LF），已导致印度大多数流行地区的感染水平非常低。但社区中仍存在少量微丝蚴血症和儿童抗虫血症（“热点”）的小范围感染，令人担忧。我们旨在利用来自 33 个社区的数据，确定此类传播热点和家庭中丝虫感染的决定因素。
使用诱捕器从 627 个随机选择的家庭中收集致倦库蚊（Culex quinquefasciatus）。对环境、昆虫学、人口统计学、社会经济和行为因素的平行数据进行分析，以确定热点和家庭感染的决定因素。
热点和非热点地区在社会经济和行为方面没有显著差异，但在人口统计学和环境因素方面存在差异。逻辑回归显示，瓷砖和混凝土房屋使该地区成为热点的风险分别增加了 2.0 倍和 2.9 倍。存在库蚊滋生地与成为热点的风险显著相关。房屋与 U 型排水沟的接近程度使感染丝虫的风险增加了 5.8 倍。
尽管已经进行了八轮 MDA，但适合致倦库蚊滋生的环境仍会影响持续传播，尤其是在热点地区。靠近 U 型排水沟会增加家庭感染的风险。实施局部性的病媒控制措施可能有助于中断低水平传播，从而在没有 MDA 的情况下降低再次爆发的风险。
