COMPREHENSIVE STUDY ON PARASITIC CONTAMINATION IN HOUSE FLIES

House flies (Musca domestica) are ubiquitous vectors of pathogens, including intestinal parasites, posing significant public health risks. This study aimed to investigate the prevalence of parasitic contamination in house flies collected from various sites in Thi-Qar province, Iraq, using direct microscopic examination and molecular techniques. A total of 500 flies were collected from butchers, fish and chicken shops, garbage sites, vegetable stores, and residential houses. Direct microscopy revealed that 60% (300/500) of flies were contaminated with parasites, while 40% (200/500) were parasite-free. The external surfaces of flies showed higher contamination (41%) compared to internal contents (19%). Molecular detection via conventional PCR targeting the small subunit ribosomal RNA (SSU rRNA) gene was employed for Entamoeba histolytica, Giardiaintestinalis, Microsporidium sp., Cryptosporidium sp., Cyclospora sp., and Cystoisospora sp. The most prevalent parasite was E. histolytica (36%), followed by Microsporidium sp. (24.7%) and Cryptosporidium sp. (17%). This study highlights the role of house flies in transmitting parasitic infections and underscores the need for improved sanitation and vector control measures in urban and periurban environments.