The global seroprevalence of Toxoplasma gondii in deer from 1978 to 2019: A systematic review and meta-analysis.

Toxoplasma gondii infecting virtually all warm-blooded animals, including humans, is an intracellular protozoan parasite. The immunocompromised patients or pregnant women infected by Toxoplasma usually can cause encephalitis or abortion. Deer are also the important intermediate host of the parasite and people can be infected by ingesting the undercooked venison. Therefore, to raise the attention of the researchers and T. gondii infection on people in deer, we conducted the meta-analysis. All potential publications on the T. gondii infection in deer were retrieved by searching the PubMed, ScienceDirect, Springer- Link, China National Knowledge Infrastructure (CNKI), WanFang, and VIP Chinese Journal Databases. Finally, a total of 48 publications were included. The pooled seroprevalence of T. gondii infection in deer was 22.92% (95% CI 17.89-28.38) calculated by the random effect model. The seroprevalence of T. gondii infection in deer was the lowest in Asia (12.72%, 95% CI 6.29-20.89), and the highest in North America (32.21%, 95% CI 20.32-45.39). The highest point estimate of deer T. gondii in detection method subgroup was using MAT (31.28%, 95% CI 20.15-43.61). The estimated pooled seroprevalence of T. gondii infection in elk (63.50%, 95% CI 50.01-76.01) was higher than other types of deer. Our meta-regression analysis found that the subgroups including region, sampling year, age, climate, and deer species may be the main heterogeneous source in our meta-analysis. It is necessary to monitor the seroprevalence of T. gondii infection in deer at all times. Furthermore, people should be taken to precautions when ingesting the venison by cooking it well before serving to prevent the T. gondii infection via eating venison.