Seroprevalence of Mycobacterium avium subspecies paratuberculosis (MAP) and evaluation of risk factors in camels of the Sultanate of Oman

摘要

Johne's disease (JD) is a World Animal Health Organization (OIE)-listed disease of ruminants including camels with serious economic impacts worldwide. A cross-sectional serological survey involving multistage simple random sampling was conducted to investigate the prevalence of JD in camels of Oman. In total, 2255 camels (254 males and 2001 females) and different ages from 553 geographically marked holdings were bled for serum. The samples were analyzed by a commercial indirect enzyme-linked immunosorbent assay (ELISA) with protein 'G' as conjugate (LSI VET Ruminant Serum Paratuberculosis Advanced, France). Results indicated a widespread herd and individual level seroprevalence, respectively of 9.2 % (95 % CI=0.7-50) and 2.6 % (95 % CI=2.0-3.4) in Oman. Differences (p0.01) were observed regarding the prevalence of JD in sampled governorates, and the highest prevalence was recorded in Dhofar (13.5 %). Higher (p>0.05) seroprevalence was observed in females (2.8 %), and their odds for testing positive were 3.69 (95 % confidence interval (CI)=0.90-15.23) times higher as compared to males (0.8 %). Seropositivity increased with the age of camels, and the highest prevalence (4.4 %) was observed in camels of more than 10 years of age (p=0.03). Large and medium size herds (odds ratio (OR)=1.77, 95% CI=0.96-3.24) where camels were kept as single species (OR=1.54, 95% CI=0.84-2.84) and confined (OR=1.93, 95% CI=1.05-3.54) were found more likely to test positive. This is the first record of seroprevalence of JD among the camels in the country which highlights their potential as an important host of the disease. The results advocate that a comprehensive control program based upon further risk analysis and molecular study should be devised in Oman.