Evaluation of Vectorial Capacity of Houseflies and Cockroaches for Transmitting Human Intestinal Parasites

Abstract

Houseflies and cockroaches are adapted to live in close association with human habitations. They carry lots of medically important parasites and pathogens to humans and animals. The study was carried out in Malegaon city of District Nashik (M.S., India). The objective of the present work was to investigate the presence of human intestinal parasites transmitted mechanically by these insects and to evaluate prevalence of diarrhea in the present study area. Houseflies and cockroaches were collected for a period of four months (July to October, 2020) from different areas like kitchen, restaurants, canteen, garbage piles, grocery stores, and fish and meat shops. Microscopic examination of intestinal parasites was conducted by using standard procedure. A total of 265 flies (166 Musca domestica, 49 Chrysomya megacephala, 31 Musca autumnalis, 19 Musca sorbens) and 230 cockroaches (137 Periplaneta americana, 54 Blatella germanica, 39 Blattella orientalis) were collected and examined for possible human intestinal parasites. Of the total examined flies and cockroaches, 181 (68.3%) flies and 163 (70.9%) cockroaches were found to be carriers of various parasites. A total of four protozoan and three helminth parasites were isolated from these insects. The most common protozoan and helminth parasites were Balantidium coli and Ascaris lumbricoides. There were also higher numbers of cockroaches positive for Balantidium coli and Entamoeba coli than houseflies. Similarly, females of both the insects were found to be more vectorial than males. Significant correlation (r=0.95197) was found between the incidence of diarrhea and number of positive flies. These data suggest that both the insects should be considered potential mechanical vectors of human intestinal parasites in the present study area.