Global seroprevalence and associated risk factors with Neospora caninum infection in sheep: a systematic review and meta-analysis

MENDOZA MORALES, L.F.; LAGORIO, V.; CORIGLIANO, M.; SANCHEZ LOPEZ, E.; RAMOS DUARTE, V.; CLEMENTE, M.; SANDER, V.

Conferencia; 2nd Women in Bioinformatics and Data Science LA Conference; 2021

Neospora caninum is a worldwide distributed Apicomplexan parasite that infects a wide range of hosts including livestock. However, the epidemiological and clinical relevance of neosporosis in sheep remains to be elucidated. This meta-analysis aims to estimate the global seroprevalence and risk factors (RF) associated with N. caninum infection in ovines. Searches for data were conducted in MEDLINE, PubMed, Scopus, LILACS, SciELO, Google Scholar and ScienceDirect. The random-effects model was used for the meta-analysis of the included articles, and studies were conducted with the help of MetaXL 2.0 Sofware. The global pooled seroprevalence of N. caninum in sheep was 13% (95% confidence interval (CI), 10?16). The subgroup analysis of seroprevalence based on WHO regions was as follows: Africa 43% (95% CI, 36-48), America 17% (95% CI, 13-22); Eastern Mediterranean Region 10% (95% CI, 4-16), European 7% (95% CI, 4?12), Western Pacific Region-China 4% (95% CI, 1-7), whereas subgroup analysis based on the sero-tests resulted in a 9% global seroprevalence by ELISA (95% CI, 7-12) and 17% by IFAT (95% CI, 11-23). Sheep above 1 year of age were more susceptible to neosporosis than younger individuals (OR = 1.42; 95% CI, 1.08?1.87), whereas ovines under intensive and semi-intensive systems were less susceptible than those under extensive ones (OR = 0.66; 95% CI, 0.46?0.94 and OR = 0.74; 95% CI, 0.62?0.89; respectively). The following RF were not significantly associated with N. caninum seroprevalence: sex, breed, presence of dogs on the farm and history of abortion. This meta-analysis revealed that N. caninum seroprevalence in sheep differs between WHO regions and sero-tests. In addition,associations between age and breeding system with seroprevalence suggest that the horizontal transmission route is important in this species, whereas seropositivity doesn?t seem to be associated with an increased abortion risk.