Epidemiological studies on the role of fish in transmitting some zoonotic diseases to man

ABSTRACT

This study was performed for determination of the role played by fish in transmitting some bacterial and parasitic zoonoses to man. A total of 300 fish of Tilapia spp. were collected [50 from a farm in El-Fayoum Governorate, 100 from a farm in Beni-Suef Governorate and 150 from Beni-Suef markets]. In addition, 73 humans [60 fish sellers and 13 farm workers] were examined. Staph. aureus, Aeromonas hydrophila, Proteus spp., Shigella spp. Pseudomonas aeruginosa and Pseudomonas fluorescence were isolated from the examined fish at percentages of 4.3, 9.7, 3.0, 1.7, 2.0 and 2.0, respectively. Among the isolated bacteria, Staph. aureus, Proteus spp. and Shigella spp. were found restricted to fish skin and gills, while Aeromonas hydrophila and Pseudomonas spp. were isolated from all the examined fish bodyparts [skin, gills, muscles and internal organs] with varying percentages. Out of the examined fish, 26.7% were harboring parasitic cysts including metacercariae of CHnostomum complanatum, Heterophyes heterophyes, Centrocestus armatus and Haplorchis pumilio. Examination of hand swabs obtained from humans demonstrated that 12.3% revealed a positive result for Staph. aureus. Among farm worker stool samples examined, 7.7% tested positively for Staph. aureus and 15.4% were Aeromonas hydrophila-positivQ. None of the parasites recovered from fish was detectable in humans. It was concluded that fish sold in the examined localities may occasionally represent a serious threat to public health as a result of its content of zoonotic fish pathogens