Spatio-Temporal Distribution of Chrysomya Megacephala (Diptera: Calliphoridae), Mechanical Vector of Infectious Diseases in the City of Yaounde (Centre-Cameroon)

Abstract

The distribution pattern of the fly Chrysomya megacephala in the city of Yaounde in Cameroon is poorly known despite its medical relevance. Following three types of standing (urbanization level) (medium standing, spontaneous standing, and peri-urban standing), we conducted monthly catches of adult flies on three types of waste (organic, inorganic, and animal paddock). The occurrence, distribution pattern, and seasonal abundance associated with abiotic factors (temperature, relative humidity, and precipitation) of C. megacephala were studied. In total, 656 fly individuals were sampled across all sites, with the highest abundance observed in mixed organic waste in spontaneous standings. Seasonal fluctuations revealed two peaks of C. megacephala abundance, one during the long dry season and the other during the short rainy season. Spearman's correlation test showed that fly's abundance is not significantly linked to temperature, relative humidity and rainfall. The occurrences data revealed that C. megacephala in the urban area of Yaounde, C. megacephala was constant, incidental or accidental species. Chrysomya megacephala was constant only in mixed organic matter of spontaneous standings. The Fisher, Neyman and Morisita indices show that the mode of distribution of C. megacephala was aggregative. Current vector control strategies should also target sarcophagus insects like C. megacephala to reduce its abundance and the burden of hydric diseases in Yaounde neighborhoods.