Are Houseflies Still Important Vector of Gastrointestinal Infections?

Abstract

The housefly, Musca domestica, is a common widely distributed insect. This study aims at assessing the role of houseflies as a vector for transmission of bacteria. In this study 100 houseflies were collected and examined. Seventy five percent flies carried no bacteria, 20% carried coliform bacteria, while five percent flies carried more than one type of bacteria. Thirty two isolates (E. coli 25%, Citrobacter spp 18.75%, Klebsiella pneumoniae 15.63%, Enterococcus spp 12.5%, Staphylococcus aureus 12.5%, Coagulase negative staphylococcus 12.5% and Proteus mirabilis 3.12%) were recovered. Classical enteric pathogenic bacteria like Salmonella, Shigella and Vibrio were not isolated from any fly. There is no human open field defecation but a number of cattle, poultry farms and agriculture land where animal manure is used is present within the flying range of the houseflies. Since, the coliforms are normal gastrointestinal flora of human, animals and birds, it can be surmised that the surrogate markers (coliform organisms) have been carried by the houseflies from the excreta of farm animals, poultry or animal manure. The study reveals that the houseflies can play a significant role in transmission of enteric bacterial pathogens. However, transmission can be prevented by maintenance of good hygiene and sanitation.