Surveys Recover 1584 Mosquitoes across Two Malaysian Sites
Researchers collected 1584 mosquitoes representing 16 species during entomological surveys conducted between April–July 2024 and November 2024–February 2025. Field teams utilized Human Landing Catch and Mosquito Magnet traps across two distinct locations: the forested area of Bukit Gasing and the coastal area of Pulau Carey.
Community analysis revealed significant differences in mosquito assemblages between the two sites, yielding a stress value of 0.015 and an $R^2$ of 0.41. Pulau Carey yielded populations primarily characterized by Culex and Mansonia species. Bukit Gasing showed strong associations with Aedes and Armigeres kesseli, while Armigeres subalbatus overlapped across both locations.
Molecular Screening Detects Brugia Pahangi in Pulau Carey Vectors
Laboratory analysis of the collected specimens identified one infective-stage L3 larva of Brugia pahangi through mosquito dissection of an Ar. subalbatus specimen from Pulau Carey. Molecular screening subsequently detected B. pahangi in 5 of 68 pools of Ar. subalbatus from the same coastal site, establishing an overall minimum infection rate of 3.16 per 1000 mosquitoes.
The screening did not detect Brugia malayi in any of the tested samples. Sequencing of two positive pools yielded high-quality genetic data deposited in GenBank under accession numbers PV611840 and PV612037, demonstrating clustering with Southeast Asian B. pahangi strains sourced from animals and vectors.
Host-Feeding Patterns Reveal Potential Bridge Vectors
Blood meal analysis established that 47.87 percent of the collected mosquitoes contained detectable vertebrate DNA. Among these, Ar. subalbatus and Culex quinquefasciatus exhibited the highest host diversity, feeding across multiple vertebrate hosts including humans, cats, dogs, and monkeys.
These broad feeding habits indicate that both species function as potential bridge vectors, facilitating contact between human and animal hosts in non-endemic settings. Although the study found no established evidence of sustained transmission, the presence of infective-stage larvae and diverse blood meals suggests the potential for zoonotic filarial transmission risk.
Key Details of the Entomological Investigation
- Survey Dates: Conducted from April–July 2024 and November 2024–February 2025.
- Collection Sites: Bukit Gasing (forested) and Pulau Carey (coastal).
- Total Specimens: 1584 mosquitoes across 16 species.
- Infection Rate: 3.16 per 1000 mosquitoes for B. pahangi in Ar. subalbatus pools.
Frequently Asked Questions
What methods did researchers use to collect mosquitoes in Malaysia?
Field teams deployed Human Landing Catch methods alongside Mosquito Magnet traps during sampling periods between April–July 2024 and November 2024–February 2025.
Which mosquito species tested positive for Brugia pahangi?
Molecular screening and dissection identified Armigeres subalbatus specimens from Pulau Carey carrying the pathogen, yielding a minimum infection rate of 3.16 per 1000 mosquitoes.
Did the study confirm active human transmission of the parasite?
The investigation did not establish evidence of sustained transmission, though researchers noted that infective-stage larvae and multi-host feeding patterns suggest the potential for zoonotic filarial transmission risk.