Seroprevalence of Toxoplasma gondii infection in sheep and goats from different geographical regions of the world: Systematic review and meta‐analysis

Abstract

The Toxoplasma gondii is an obligate intracellular protozoan parasite which significantly impact small ruminant productivity, international animal trade and transboundary movement of animal across the globe. The seroprevalence of T. gondii infection (toxoplasmosis) in sheep and goats is widely studied in many parts of the world and there is a lack of comprehensive information on prevalence estimates considering the global and regional perspectives. The aim of the study was to use systematic review and metaanalysis methods to estimate the global and regional pooled seroprevalence of T. gondii infection in sheep and goats, as well as factors that influence prevalence estimations.Relevant articles reporting the seroprevalence of toxoplasmosis in sheep and/goats were searched in five electronic databases, including PubMed, Web of Science, Scopus, Embase and ProQuest. After the publications were checked to verify they fit the inclusion criteria, a total of 225 articles were included in the systematic review and meta-analysis, reflecting data from 70 countries/regions. The pooled prevalence was estimated using a random effect meta-analysis model. Overall, the seroprevalence of T. gondii infection was 33.86% (95% CI: 30.47-37.25%) in sheep and 31.78% (95% CI: 28.99-34.58%) in goats, with significant variation in prevalence estimates across geographical locations (p < .001). Substantial heterogeneity (I 2 > 75%) was observed in most pooled seroprevalence estimates. The T. gondii infection in global sheep and goat population showed uptrend over the period. This information would be useful for epidemiologist, health authorities and farmers in order to plan future T. gondii survey and infection management strategies both locally and internationally.

A Review of Toxoplasma gondii in Animals in Greece: A FoodBorne Pathogen of Public Health Importance

“…Ewes had a significantly higher seroprevalence than male sheep in one study [43], most likely because male sheep have a more robust immune response against the parasite due to hormonal differences [72][73][74]. This finding agrees with a recent meta-analysis on sheep T. gondii seroprevalence and associated risk factors [71]. Regarding rams, sexual transmission is possible, and an experimental study demonstrated that T. gondii reduces the quality parameters of sperm (viability, motility, velocity), while sulphadimidine treatment did not revert the sperm cell morphological abnormalities [75].…”

“…Estimations ranged from 23% in Crete in 1995 [48] to 90% in Trikala in 2019 [44], with most studies finding seropositivity of around 50% and an upward trend throughout the years, as seen in Table 1. Compared to the global pooled seroprevalence in sheep at 33.86% and the pooled European seroprevalence at 41.01% [71], it becomes evident that Greece has higher seroprevalence and is endemic for ovine toxoplasmosis.…”

“…Regarding rams, sexual transmission is possible, and an experimental study demonstrated that T. gondii reduces the quality parameters of sperm (viability, motility, velocity), while sulphadimidine treatment did not revert the sperm cell morphological abnormalities [75]. Concerning age, sheep older than four years had higher seroprevalence than younger sheep, most likely due to increased exposure to T. gondii and not because old sheep are more susceptible [7,43,71,76]. It is worth noting that cats were present in all farms in one of these studies and had free access to the feedstuff [43].…”

Effective factors in the pathogenesis of Toxoplasma gondii

“…Toxoplasma gondii ( T. gondii ) is an opportunistic intracellular parasitic protozoan that can infect intermediate hosts (including humans, ruminants, rodents, and birds) [ [1] , [2] , [3] , [4] , [5] , [6] ]. This parasite has been reported even in cold-blooded animals and they can act as the source of infection for the various hosts that feed on them [ 7 ].…”

Serological Study of Toxoplasmosis in Slaughtered Animals in Mousl, Iraq

“…It is one of the causes of abortion and stillbirth when the first infection occurs. The disease is a major cause of abortion in sheep and goats in Uruguay, New Zealand, the United Kingdom and Australia (Dubey, 2003;Ahaduzzaman & Hasan, 2022).…”