The Global Prevalence of Neospora caninum Infection in Sheep and Goats That Had an Abortion and Aborted Fetuses: A Systematic Review and Meta-Analysis

Abstract

Neospora caninum (N. caninum) can be a potential factor causing a significant rate of miscarriages in small ruminants (sheep and goats) worldwide. Therefore, the present study aimed to determine the global status of N. caninum in sheep and goats that had an abortion and aborted fetuses. Five English databases (PubMed, ScienceDirect, Web of Science, Scopus, and ProQuest) were searched for relevant scientific articles published from their inception until November 4, 2021. Finally, 21 studies conducted on sheep (1,671 aborted fetuses and 935 abortive sheep) and 10 studies on goats (130 aborted fetuses and 80 abortive goats) were included for the final meta-analysis. A random-effects meta-analysis model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Moreover, sensitivity analysis, publication bias test, and quality assessment were performed in this study. The pooled prevalence of N. caninum in aborted fetuses of sheep and goats globally was estimated to be 15% (95% CI: 9–21%) and 7% (95% CI: 2–12%) using molecular methods. Besides, the seroprevalence of N. caninum was estimated to be 17% for aborted fetuses of sheep. The overall prevalence rate of N. caninum infection in sheep that had an abortion was 3%. The present results show a relatively high prevalence of N. caninum infection in sheep that had an abortion and aborted fetuses compared to goats. Therefore, further studies using different diagnostic techniques to more accurately estimate the rate of infection in sheep and goats may help provide adequate control measures and strategies to reduce the rate of abortion in sheep and goats and reduce economic damage to the livestock industry. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42020216694).

Prevalence and risk factors of Neospora caninum in aborted fetus of sheep, goat, cattle, and buffalo

“…The global prevalence of N. caninum in aborted fetuses of sheep and goats using molecular methods was reported to be 7-15% [31]. While the prevalence in our study was 14.8% and 11.8% in sheep and goat, respectively.…”

Seroprevalence and risk factors of Toxoplasma gondii and Neospora caninum infection in black goats in Yunnan Province, Southwestern China

“…N. caninum is considered as a major cause of abortion in cattle, particularly in dairy cattle, and studies revealed that 12% to 42% of aborted fetuses from dairy cattle were infected with N. caninum (1). Furthermore, goats would abort infectious fetuses when they were inoculated with N. caninum during pregnancy, and a meta-analysis revealed that the prevalence of N. caninum in aborted fetuses of goats was 7% worldwide (10,11). Its zoonotic potential remains unknown because no evidence indicates that humans have been infected with N. caninum successfully (12,13).…”

“…Similar to T. gondii, N. caninum has also been widely concerned and studied since it was first reported in 1984 ( 9 ). N. caninum can be transmitted horizontally and vertically in herds ( 10 ). N. caninum is considered as a major cause of abortion in cattle, particularly in dairy cattle, and studies revealed that 12% to 42% of aborted fetuses from dairy cattle were infected with N. caninum ( 1 ).…”

Apicomplexans in Goat: Prevalence of Neospora caninum, Toxoplasma gondii, Cryptosporidium spp., Eimeria spp. and Risk Factors in Farms from Ecuador

“…Due to the high frequency of domestic dogs (95.8%), the odds ratio could not be determined. Canids are the final hosts of N. caninum , so their presence would be expected to be a risk factor for goats [ 30 , 41 ]. Thus, this variable should not be ruled out as a risk factor for N. caninum .…”