Antigenic detection of Cryptosporidium parvum in urban and rural dogs in Ahvaz district, southwestern Iran

Cryptosporidium parvum is a zoonotic protozoan parasite with a wide range of vertebrate hosts. The present study was conducted to determine the prevalence of Cryptosporidium parvum in urban and rural dogs of the Ahvaz area. Faecal samples were collected randomly from 93 dogs between May 2005 and September 2007. The studied dogs were divided into two groups (urban and rural) and based on age into three groups (<6 months, 6 months–3 years and >3 years). The results were analyzed by using Chi-square analysis and Fischer’s exact test. Prevalence to Cryptosporidium parvum antigens was 4.3% (4 of 93) by means of ELISA, indicating that this antigen is present in the ecosystem. The infection was more prevalent in rural dogs (6.4%; 3 of 47) in comparison with urban dogs (2.17%; 1 of 46), nevertheless, there were no significant differences between the different groups (P>0.05), but the infection was more prevalent in diarrheic dogs (17.65%; 3 of 17) compared with non-diarrheic dogs (1.3%; 1 of 76), and the difference was significant (P=0.019). Infection was not significant in the different age groups (P>0.05). Concurrent detection of Cryptosporidium parvum with canine distemper (one sample) and parvovirus (one sample) were shown in the studied dogs. Modified Ziehl-Neelsen staining was also carried out and the prevalence of infection was 2.15% (2 of 93). The use of ELISA allowed the detection of more positive cases than light microscopy. This study showed that Cryptosporidium parvum can be a risk factor, particularly for those dogs in contact together in the population of urban and rural dogs.