Epidemiological studies on Johne’s disease in ruminants and Crohn’s disease in humans in Egypt

The correlation between Johne’s disease (JD) and Crohn’s disease (CD) in Egypt was investigated. A total of 371 human and 435 animal sera were collected from the same Egyptian governorates that had a known history of paratuberculosis infection and were subjected to screening for paratuberculosis using ELISA to assess the human/animal risk at a single time point. Five CD patients and five JD clinically infected dairy cattle were also included. Out of 435 animal serum samples, 196 (45.2%) were MAP-ELISA positive. Twenty three (6.1%) out of 371 human serum samples were MAP-ELISA positive, while 37 (9.9%) were positive for anti-Saccharomyces cerevisiae antibodies (ASCA) ELISAs. There was a very poor agreement between human MAP and ASCA ELISAs (0.036 by kappa statistics). The prevalence of MAP antibodies among humans is clearly lower than in animals. In conclusion there is an increase in Johne’s disease incidence in animals and a very weak relationship between MAP and Crohn’s disease in humans in Egypt.