Toxoplasma gondii in cattle in Brazil: a review.

Daniella Ferreira Cordeiro Gomes,Solange Maria Gennari,Anaiá Da Paixão Sevá,Álvaro Ferreira Júnior,Welber Daniel Zanetti Lopes,Cairo Henrique Sousa De Oliveira,Felipe Da Silva Krawczak,Éverton Kort Kamp Fernandes

doi:10.1590/s1984-29612019106

Abstract

Toxoplasma gondii is an apicomplexan protozoan that is frequently found in both humans and animals worldwide. The aim of this review was to list important aspects of Toxoplasma gondii infection in cattle in Brazil. The frequency of occurrence of T. gondii antibodies in Brazilian cattle ranges from 1 to 89.1%, depending on the region evaluated, based on data from 1978 to 2018. However, some characteristics of T. gondii infection in cattle remain uncertain, such as the role of meat intake in transmitting the parasite to humans. Most information regarding T. gondii infection among Brazilian cattle is limited to evaluations of the frequency of occurrence of antibodies. About 70% of the diagnoses of infection in these ruminants in Brazil are made via the indirect fluorescence antibody test (IFAT). Nevertheless, little is known about the population structure of this protozoan in cattle. It is necessary to expand the studies on toxoplasmosis in cattle, in order to better understand T. gondii infection in these animals and its implications for Brazilian public health.

Highlights

Toxoplasmosis is one of the most common parasitic infections in both humans and animals
Some points regarding the epidemiology of T. gondii infection in cattle remain uncertain (Dubey & Jones, 2008; Opsteegh et al, 2011a)
The results suggested the existence of an epidemic T. gondii population structure in Brazil, in which a variety of recombination had resulted from genetic exchanges and a few clonal lineages had expanded successfully throughout the country

Summary

Introduction

Toxoplasmosis is one of the most common parasitic infections in both humans and animals. From a homogenate prepared from the small intestine of an infected cow, Dubey (1992) reported the presence of a T. gondii isolate identified as CTI, which was considered highly pathogenic to mice Failure to isolate this protozoan in cattle may be explained by difficulty in detecting T. gondii in tissues consequent to the limited size of the samples examined in these studies (Opsteegh et al, 2019). In Brazil, depending on the region studied, high frequency of occurrence of T. gondii antibodies is reported in cattle herds (Dubey et al, 2012), indicating that this protozoan has widespread circulation and that infected animals are commonly present. That any comparison and interpretation of epidemiological data needs to be done with caution, because of the limited number of studies per Brazilian state and the use of different diagnostic techniques with different cutoff points in heterogeneous sample groups (Hosein et al, 2016)

Diagnostic Method

Findings

Conclusion