Prevalence of Cryptosporidium in Wild Brown Rat (Rattus norvegicus) Population at Shoushtar, Iran

Background: Cryptosporidiosis is a zoonotic disease with public health importance, especially for individuals with weak immune system, such as children, elderly people and immune suppressed ones. Evaluation of the prevalence of Cryptosporidium in wild rodents such as wild brown rats could help to establish an epidemiological map of Cryptosporidiosis. The aim of the current study was to assess the prevalence of Cryptosporidium in wild brown rat population at Shoushtar, Iran. Methods: In this descriptive study, 14 trapping districts were selected in Shoushtar, Iran by simple random method. Trapping conducted between January 2012 and January 2014. Trapped brown rats were euthanized and then dissected. Then, fecal content of large intestine was collected. After that, fecal samples were passing through a mesh and centrifuged at 10000 g for 10 minutes. The supernatant removed and the pellet was washed with Phosphate-buffered saline (PBS). Cryptosporidium oocysts were detected by microscopy after sugar flotation and modified acid-fast staining. The prevalence was calculated using descriptive statistics via SPSS (ver. 16). Results: A total of 42 wild brown rats were captured alive during the trapping period. From 14 trapping districts, wild brown rats were captured in 9 districts. The prevalence of Cryptosporidium in the current study was 7.1%. The three positive cases belong to 3 districts. Conclusion: The present study demonstrates that wild brown rats are contaminated with Cryptosporidium at Shoushtar, Iran. Reply to this question that either positive samples detected in this study are related to species that have public importance or not, needed molecular studies. However, previous studies with molecular techniques are limited and have controversial results.