First molecular characterization ofvector species and the distribution of canine dirofilariasis in Gampaha district, Sri Lanka.

Abstract

BACKGROUND: Dirofilariasis is a vector-borne parasitic infection caused by filarial nematodes belonging to the genusSri Lanka has reported the highest prevalence of human dirofilariasis cases in Asia. Molecular-based detection ofvector species has not yet been conducted in Sri Lanka, which could provide more sensitive information by directly detecting and analyzing genetic material. The present study aimed to analyze the distribution of canine dirofilariasis and to determine thevector species in Gampaha district, Sri Lanka, using molecular-based techniques. METHODS: Mosquito sampling (n=300) was performed from October to December 2024 from different sites in Gampaha district. The gut of the mosquitoes was dissected. Genomic DNA extraction followed by PCR was performed with specific primers forspecies. The blood samples of different dog breeds (n=500) were also collected from the Gampaha district, and they were subjected to DNA extraction, PCR amplification, and sequencing. The data were analyzed by bioinformatics tools. RESULTS: Analysis of the sequence data confirmed the first molecular detection of the dirofilariasis vector in Sri Lanka;as the potential vector mosquito forandsp. The sequence ofrecorded from Sri Lanka is not available in the literature/or any database, and the sequence ofwas also determined. Further, in different dog breeds, the infection rate of microfilariae was found to be different, and the Rottweiler breed was recorded with the highest infection rate.andsp. were found in dog blood samples. The phylogenetic analysis revealed that the query sequence of theparasites isolated from the present study showed considerable homology and proximity to therecorded from India. CONCLUSION: is the vector mosquito forandsp., which caused canine dirofilariasis in the Gampaha district of Sri Lanka. No other mosquito species were identified as potential vectors ofspecies in the study area. This is, to our knowledge, the firstsequence found in the Gampaha district, Sri Lanka. The present study findings provide very important insights for targeted vector control programs forparasites in Sri Lanka.