The prevalence, risk factors analysis and evaluation of two diagnostic techniques for the detection of Cryptosporidium infection in diarrheic sheep from Pakistan.

Background: Cryptosporidium spp. is recognized as an opportunistic zoonotic parasite that infects humans as well as wild and domestic animals. This enteric protozoan is a major cause of diarrhea in humans and animals and often result in death due to severe dehydration. The present study was designed to investigate the prevalence, identification of various risk factors and evaluation of sensitivity of the two diagnostic techniques for rapid and correct detection of Cryptosporidium infection in diarrheic sheep in Pakistan.

Methods: A total of 360 fecal samples were collected and processed for detection of Cryptosporidium infection after proper preservation. These samples were properly stained with modified Ziehl-Neelsen acid staining and then examined under simple microscope at 100x magnification for confirmation of Cryptosporidium oocysts. The same samples were again processed through simple PCR for confirmation of the Cryptosporidium spp.

Results: The age wise prevalence was detected through simple microscopy and PCR. We found highest prevalence at the age of ≤1 year followed by 1-2 years of age while the lowest prevalence was recorded at the age of ≥ 2-3 years of sheep and found significant difference between different ages (P<0.05). The sex wise prevalence showed the highest prevalence in male (♂) animals detected compared to female (♀). The overall prevalence was detected 27.08% and 18.80% through PCR and simple microscopy, respectively, and significant difference between two diagnostic techniques were observed (P<0.05). Considering the seasonality, the highest prevalence was recorded through simple microscopy in autumn, summer, and spring, while the lowest in winter. These results were confirmed through PCR.

Conclusion: It was concluded that molecular detection is the most efficient, specific and sensitive technique for detection of Cryptosporidium infection than simple microscopy. Moreover sheep is the major potential source of infection to other wild and domestic animals including humans.