Background: Lymphatic filariasis is a major public health problem known for its disfiguring and debilitating effects. Alappuzha district in Kerala has been a hotspot for Brugian and Bancroftian filariasis. The efforts to combat Brugian filariasis in this region about two decades earlier led to notable decline in vector density and interruption of disease transmission. Materials and Method: A cross-sectional survey was carried out in Alappuzha district and 12 wards were selected using multistage random sampling method. An entomological survey was conducted in the selected wards. Result: Fourteen out of 69 Ma. annulifera were positive for filarial parasites. The average infection and infectivity rate was 20% and 0%. Molecular characterization of positive samples confirmed the parasites as Brugia malayi. Phylogenetic analysis of the isolates revealed that they belong to the same clade. Conclusion: This study highlights the importance of continued vector surveillance and timely intervention by appropriate vector control measures to prevent transmission of the disease.

Keywords: Alappuzha; Brugia malayi; Brugian filariasis; Mansonia annulifera; lymphatic filariasis.

背景：淋巴丝虫病是一种重要的公共卫生问题，以其毁容和致残效果而闻名。喀拉拉邦的阿勒普扎区一直是布氏线状丝虫病（Brugian filariasis）和班克罗夫特线状丝虫病（Bancroftian filariasis）的热点地区。大约二十年前，该地区为对抗布氏线状丝虫病而进行的努力导致蚊媒密度显著下降，并中断了疾病的传播。材料与方法：在阿勒普扎区进行了横断面调查，并通过多阶段随机抽样法选取了12个选区。对选定的选区开展了昆虫学调查。结果：69只马氏按蚊（Ma. annulifera）中有14只是阳性，平均感染率为20%，传染性率为0%。对阳性样本进行分子表征确认寄生虫为马来丝虫病原体（Brugia malayi）。对分离株的系统发育分析表明它们属于同一谱系。结论：这项研究强调了继续开展蚊媒监测和及时采取适当的蚊媒控制措施以防止疾病传播的重要性。

关键词：阿勒普扎；马来丝虫病原体（Brugia malayi）；布氏线状丝虫病；马氏按蚊（Mansonia annulifera）；淋巴丝虫病。