Evaluation of techniques for diagnosis of Trypanosoma vivax infections in naturally infected cattle in the Zona da Mata Mineira.

Jefferson Filgueira Alcindo,Maria Clara Guimarães Vieira,Cinthya Brillante Cardinot,Thamiris Vilela Pereira Rocha,Rafael Ferreira De Araujo,Carina Franciscato,Marcos Rogério André,Kayo José Garcia De Almeida Castilho Neto,Gláucia Guimarães Amaral,Maurício Deschk,Rosângela Zacarias Machado

doi:10.1590/s1984-29612022007

Abstract

This study aimed to evaluate diagnostic techniques for trypanosomiasis, caused by Trypanosoma vivax, in naturally infected cattle in Minas Gerais, Zona da Mata. The deaths of six lactating cows with similar clinical conditions-characterized by hyporexia, hypogalactia, and recumbency-had been reported from one property. Initially, two animals were examined and diagnosed with trypanosomiasis through identification of the protozoan in a blood smear. After the initial diagnosis, all lactating cows (n=37) on the property were examined, and blood samples were collected for tests including whole blood smear, buffy coat smear, Woo's technique, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR). Woo's test, buffy coat smears, and whole blood smears indicated that 4/37 (10.81%) animals were positive for trypanosomiasis, whereas ELISA and PCR indicated that 33/37 (89.19%) and 27/37 (72.97%) animals, respectively, were positive. The agreement obtained between parasitological techniques was classified as high, while between ELISA and PCR, no agreement. In conclusion, parasitological techniques have a low capacity to identify infected animals in the chronic stage of T. vivax infection. Therefore, techniques such as PCR and/or ELISA should be used to minimize the occurrence of false negatives.

Highlights

The trypanosomiases are cosmopolitan diseases caused by protozoa of the Trypanosoma genus, with Trypanosoma vivax being the agent most relevant to etiology and pathogenicity in South American cattle (Jones & Dávila, 2001; Batista et al, 2008).In Minas Gerais, the first report of T. vivax was in the municipality of Igarapé in 2007 (Carvalho et al, 2008)
This study aimed to evaluate diagnostic techniques for T. vivax in naturally infected cattle in the Zona da Mata region of Minas Gerais, as well as to describe the epidemiological aspects of the disease in the region under study
The study was performed in January 2019, on a dairy property located in the municipality of Cipotânea, Zona da Mata region, Minas Gerais, at latitude 20°54′23′′ S and longitude 3°21ʹ37′′ W, with an area of approximately 39 ha

Summary

Introduction

The trypanosomiases are cosmopolitan diseases caused by protozoa of the Trypanosoma genus, with Trypanosoma vivax being the agent most relevant to etiology and pathogenicity in South American cattle (Jones & Dávila, 2001; Batista et al, 2008).In Minas Gerais, the first report of T. vivax was in the municipality of Igarapé in 2007 (Carvalho et al, 2008). The disease has spread to other regions of the state (Cuglovici et al, 2010; Meneses, 2016; Reis et al, 2019). The estimated seroprevalence for the state was 2.38% and positive serological results were found in all mesoregions, including the Zona da Mata Mineira, with 1.67% of seroprevalence. The parasite is dispersed in Minas Gerais State, which makes seronegative herds even more susceptible to the disease (Meneses, 2016). Other outbreaks of T. vivax in states bordering Minas Gerais, including São Paulo (Cadioli et al, 2012), Rio de Janeiro (Costa et al, 2020), Goiás (Bastos et al, 2020) and Bahia (Gomes et al, 2021) were reported

Objectives

Methods

Results