Infection of blood-sucking mosquitoes with dirofilariasis agent in the city of Khabarovsk and its suburban zone

Objective: to assess the infestation of blood-sucking mosquitoes with dirofilariasis pathogens in the Khabarovsk urban agglomeration.

Materials and methods: from July to September 2024 and from June to July 2025, 2736 female bloodsucking mosquitoes of the genera Culex, Anopheles, and Aedes were caught and examined in the Khabarovsk urban agglomeration. Mosquitoes were collected in the southern, central, and northern parts of Khabarovsk and adjacent territories. The study was carried out using real-time polymerase chain reaction.

Results: as a result of the studies, the genetic material of Dirofilaria repens and Dirofilaria immitis was detected in 19 pools of Culex mosquitoes and in 44 pools of Aedes mosquitoes. During the study period, the estimated infection rate of blood-sucking mosquitoes was 3.0% for Dirofilaria immitis and 0.3% for Dirofilaria repens, respectively. Dirofilaria repens DNA was not detected in any of the samples of Culex mosquitoes. During the study period, the highest infection rate of Dirofilaria immitis mosquitoes was recorded in September (EIR = 4.2%), when the capture was carried out on the territory of the Cynological Service Center.

Conclusion: The results of molecular genetic monitoring of the circulation of dirofilariasis pathogens in the city of Khabarovsk showed a predominance of mosquitoes containing Dirofilaria immitis DNA in the collections, and, obviously, reflect the situation with the infestation of the main definitive hosts dogs, which makes it relevant to conduct studies to assess the infestation of animals kept in the surveyed areas.

A high epidemiological significance of Aedes mosquitoes as carriers of Dirofilaria spp. has been established in the territory of the Khabarovsk urban agglomeration due to their high numbers and invasion by dirofilariasis pathogens.

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