Assessment of Abundance and Parasitic Contamination of Synanthropic Flies in Selected Waste Dump Sites in Awka Metropolis: A Public Health Perspective

Abstract

The study to assess the presence and types of pathogenic organisms carried by Synanthropic flies collected from selected refuse dump sites in Awka metropolis employed a cross-sectional ecological survey in Awka and surrounding areas from May 2024 to March 2025. This study assessed the abundance, species composition, and parasite carriage of synanthropic flies collected from refuse dump sites across Awka metropolis, southeastern Nigeria. A total of 1,449 flies belonging to seven species were collected from 11 locations within the study area. Musca domestica was the most abundant species (52.7%), followed by Chrysomya megacephala (19.6%) and Sarcophagidae spp. (14.0%), while Stomoxys calcitrans was the least abundant (0.8%). Fly abundance and species composition varied significantly among locations (χ² = 114.06, df = 60, p < 0.001), Okpuno recorded the highest mean abundance, whereas Amawbia had the lowest. Parasitological analysis identified 71 parasite stages belonging to eight taxa. Ascaris lumbricoides was the most prevalent parasite (36.62%), followed by Entamoeba histolytica cysts (18.31%) and Cryptosporidium species cysts (15.49%), reflecting considerable environmental faecal contamination. Musca domestica carried the highest number of parasite stages (39.4%), highlighting its dominant role as a mechanical vector. While parasite occurrence differed significantly among parasite species (p = 0.026) and parasite load varied significantly among fly species (p = 0.003), no significant association was observed between specific fly species and parasite types (p = 0.902).The high abundance of synanthropic flies and their carriage of medically important parasites in Awka metropolis pose potential public health risks. These results underscore the need for improved waste management, enhanced environmental sanitation, and effective fly control strategies to reduce fly-mediated transmission of intestinal parasites.