Contagious caprine pleuropneumonia (CCPP): A systematic review and meta-analysis of the prevalence in sheep and goats.

Contagious caprine pleuropneumonia (CCPP) is a highly contagious respiratory disease of small ruminants that is caused by the bacterium Mycoplasma capricolum subsp. capripneumoniae. Sheep and goats are two of the species of small ruminants most at risk of CCPP. Outbreaks of CCPP cause significant economic and trade disturbances in several parts of the world. However, the extent and magnitude of CCPP in a particular geographical region is still not well known due to lack of comprehensive data on its occurrence. The present study aimed to investigate the prevalence of CCPP in sheep and goats raised in different geographical regions as well as the factors contributing to the spread of the disease. Searches were done in five online repositories: PubMed, Web of Science, Scopus, CAB Direct and Google Scholar using pre-selected key terms. Data were retrieved from the 41 articles that met the study's inclusion criteria. The pooled prevalences were determined using a random effect meta-analysis model. Prevalence of CCPP was 23.19% (95% CI: 11.90-34.47%) in sheep and 24.91% (95% CI: 20.99-28.84%) in goats. Overall, the regional level pooled prevalence estimates ranged from 8.0% (95% CI: 6.91-9.09%) to 28.70% (22.02-35.38%), depending on species and world region. Substantial heterogeneity (I2  > 75%) was observed in most pooled prevalence estimates. The results indicate high prevalences of CCPP in sheep and goats across the regions, particularly in Africa and Asia, and highlights the need to institute appropriate control measures. Active surveillance and research on risk factors are recommended.