Xenomonitoring and Molecular Characterization of Brugia malayi from Mansonia annulifera in Alappuzha, Kerala, India.

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.