Mechanical transmission of pathogenic organisms: The role of cockroaches

Abstract

Background & objectives: Cockroaches (Diploptera punctata) are basically tropical insects and will do their best to find a home that is both warm and moist. Their involvement in the transmission of tropical diseases is poorly investigated in Africa. Methods: A study on the bacterial, fungal and parasitic profile of cockroaches trapped in and around houses in Ekpoma was carried out using standard microbiological techniques. Results: Of a total of 234 cockroaches trapped from different sites (toilets, parlours, kitchens and bedrooms) in houses with pit latrines and water system, the bacterial, fungal and parasitic isolates were identical irrespective of the site, these included: E. coli, Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis, Citrobacter freundii, Enterobacter cloacae, Salmonella sp, Pseudomonas aeruginosa, Serretia marcescens, S. aureus, S. feacalis, S. epidermidis, Aeromonas sp, Candida sp, Rhizopus sp, Aspergillus sp, Mucor sp, cysts of E. hystolitica, oocysts of C. parvum, C. cayetenensis and Isospora belli, cysts of Balantidium coli, ova of Ascaris lumbricoides, Anchylostoma deodunalae, Enterobius vermicularis, ova Trichuris trichura, larva of Strongyloides stercoralis. Cockroaches trapped in the toilets of houses with pit latrines had a mean bacterial and parasites count of 12.3 × 1010 org/ml and 98 parasites/ml respectively, while those trapped in the houses with water system had a mean bacterial and parasitic count of 89.5 × 107 org/ml and 31 parasites/ml respectively. A bacterial count of 78.9 × 107 org/ml was recorded from cockroaches trapped from the kitchens of houses with pit latrines. On the other hand a mean bacterial and parasitic count of 23.7 × 106 org/ml and 19 parasites/ml were recorded from kitchens of houses with water system. Interpretation & conclusion: Cockroaches represent an important reservoir for infectious pathogens, therefore, control of cockroaches will substantially minimise the spread of infectious diseases in our environment.