Blowflies (Diptera: Calliphoridae) as potential mechanical vectors of the protozoan cyst and helminthic eggs in Kashmir Himalaya, India

Blowflies (Diptera: Calliphoridae) are an important group of non-biting flies that are potential mechanical vectors of protozoan and helminthic pathogens. The present study was carried out to isolate and identify protozoan cysts and helminthic eggs transmitted by blowflies. Surveys were carried out at six different sites, viz., butcher shops, fish markets, garbage piles, water bodies, and open vegetation in the Kashmir Himalaya. The flies were collected with the help of a sweeping net and using day-old beef liver as bait from March 2021 to February 2023. A total of 968 blowflies were collected, out of which 83 were found carrying at least one protozoan cyst and helminthic egg with six identified species of parasites. Garbage piles were recorded with the highest number of positive cases (10.81%), while human habitation had the highest transmission rate (3.3%). Chrysomya megacephala (Fabricius) was reported to have the highest number of parasitic cysts and ova (one protozoan cyst and three helminthic eggs), while Ascaris lumbricoides and Entamoeba coli were found to be the most abundant parasites reported from the surface of these flies. The number of parasites isolated from the surface of the blowflies was statistically significant (F = 9.073, df = 1, and p = 0.014), indicating a positive association between the number of parasites isolated from blowflies and the collection sites.