The Indian Journal of Small Ruminants

Before converting to clinical shedders, sub-clinical carriers also shed Mycobacterium avium subsp paratuberculosis (MAP) in feces. Therefore, early diagnosis is crucial for the control of Johne's disease. Of the 21 kids (farmer's herds), 9 (42.8%) and 14 (66.7%) were found positive by blood PCR and microscopy, respectively. Out of 14 young goats (farm herds) screened, 8 (57.8%) and 4 (28.6%) were found positive by blood PCR and blood culture, respectively. Screening of farm kids (21) by ‘Indigenous ELISA kit’ (S/P ratio) revealed, 9.5, 47.6, 28.6, 0.0 and 14.3% kids as strong positive, positive, low positive, suspected and negatives reactors, respectively. Kids in ‘strong positive’ and in ‘positive and strong positive’ categories were labeled as ‘type I’ and ‘type II’ reactors (positives) for MAP infection. Proportional agreement (kappa score) between blood PCR and microscopy was substantial (71.0%) and was moderate (57.0%) between blood-PCR and ELISA (type I and type II reactors). The study reports high presence of MAP (septicemia) in kids and young goats from farmer's and farm herds. Blood-PCR was rapid, sensitive and specific for the diagnosis of sub-clinical Johne's disease.