Identification of zoonotic Cryptosporidium parvum in fresh water ornamental fish: first report

Regarding the importance of zoonotic species of Cryptosporidium in humans and domestic animals, and the lack of information about the distribution of Cryptosporidium spp. especially the zoonotic species of aquarium ornamental fish with due attention to their relation to urban water sources and human owners, the present study was designed. Cryptosporidium has been described in more than 17 species of both fresh and saltwater fish with parasites located deep within and on the surface of the stomach or intestinal epithelium. To date, two important species of Cryptosporidium for public health, namely C. parvum and C. hominis have been identified in fish samples from cultured and wild freshwater and marine environments. In this study, identification of Cryptosporidium spp. and zoonotic Cryptosporidium parvum by histopathology and PCR amplification at the 18S rRNA locus among 100 freshwater ornamental fish were performed. Results showed that a total of 16 fish samples (16%) were identified as positive for Cryptosporidium spp. by histopathology. C. parvum was also found in two fish hosts (goldfish). The detection of zoonotic C. parvum in ornamental fish is significant and suggests that the fish might be a good contamination indicator of water with sewage and agricultural run-off.