Comparative Clinical, Histopathological and Molecular Approaches for PPR Diagnosis in Naturally Infected West African Dwarf (WAD) Goats

Objective: PPR is a highly contagious transboundary viral disease of small ruminants, with high morbidity and mortality especially in young animals. Infections are easily spread by close contact in natural settings, and clinically characterized by erosive stomatitis, enteritis and pneumonia. It is endemic in many countries/regions, and poses a major limitation to small ruminant production as both morbidity and mortality are usually very quick, hence the need for accurate rapid diagnosis. Clinical diagnosis of PPR in WAD goats is, in practice, often limited to the observation of the associated clinical signs and post mortem lesions due to laboratory diagnostic constraints. This study investigated the comparative efficacy of routine clinical diagnostic methods and contemporary molecular diagnosis by PCR.

Methods: 15 WAD goats adjudged to be naturally infected with PPR were assessed for clinical signs and post-mortem lesions of the disease. Tissue samples were subjected to molecular detection of viral genome via RT_PCR.

Results: The results show that the observed clinical signs and post mortem lesions in all 15 animals were consistent with the established disease profile. However, only 66.7% of the animals had detectable viral genome in tissues.

Conclusion: Although molecular/PCR diagnosis is often considered to be highly sensitive and specific, several factors undermine its diagnostic efficiency and applicability for PPR diagnosis in WAD goats. Proper modifications and adequate attention to the limiting factors are recommended to improve the diagnostic efficiency of RT-PCR for PPR diagnosis in WAD goats to enhance prompt disease diagnosis, monitoring and control.