First Report on Ovine Paratuberculosis in the Sudan: Diagnosis Using Different Techniques

Simple Summary Paratuberculosis (PTB) is a neglected disease in Africa, and it is a hidden killer disease of large and small ruminants with utmost socio-economic importance, especially for rural communities. The disease has been reported in the Sudan in both goats and cattle, but not in sheep. In this study we report the disease for the first time in sheep in the country. We suspected this disease in a breeding flock of sheep because of a history of unknown wasting condition. In this context, we used different diagnostic techniques to detect the bacteria causing the disease and to confirm the disease presence. As sheep in the Sudan are the most important export animal, it is worthy to conduct a wide investigation to gain insight into the disease prevalence in sheep to set up preventive measures and implement control programmes, as well as raising the awareness of animal owners in the country. Paratuberculosis (PTB) has been reported in the Sudan in cattle and goats for more than 50 years but has never been reported in sheep. However, suspicion of the disease in a breeding flock of sheep in Khartoum North locality was made due to a history of unknown cause of loss of weight. Blood and faecal samples were collected from all animals (N = 59): harvested sera were tested for anti-Mycobacterium avium subsp. paratuberculosis (MAP) antibodies by Enzyme Linked Immunosorbent Assay (ELISA); faeces were screened for acid-fast bacilli by Ziehl-Neelsen staining, tested for MAP DNA by recombinase polymerase amplification (RPA) and some faecal samples were cultured for MAP isolation. Typical MAP acid-fast bacilli were seen in 10.2% (6/59) of the faecal smears, 37.5% of the tested faecal samples (12/32) were positive for MAP DNA and only 3 (5.1%) animals were seropositive for MAP. MAP positive cultures were obtained from 2 out the 6 samples showing typical MAP acid-fast bacilli; the isolates were confirmed by real-time PCR and sequencing. As sheep are animals of utmost economic importance as the main export animals for the country, this first report of ovine PTB warrants special considerations and more investigations for planning control programmes of the disease.