Lower seroprevalence of Toxoplasma gondii in swine from central China after an outbreak of African swine fever.

Weitao Xie,Shilin Xin,Longxian Zhang,Yurong Yang,Xiangrui Li,Gaiping Zhang,Nan Jiang

doi:10.1051/parasite/2021053

Abstract

Toxoplasma gondii is widespread worldwide and can infect swine. This study evaluated the seroprevalence of T. gondii in swine from central China after an outbreak of African swine fever (ASF). A total of 2683 swine serum samples were collected from farms in four provinces. Of the serum samples, 1.42% (38/2683) (95% CI, 1.03–1.94) tested positive for T. gondii IgG antibody by a modified agglutination test (MAT) (cut-off: 1:25). Comparing with the results of previous studies, specifically our survey from before the outbreak, the seroprevalence of T. gondii in swine from central China was significantly decreased after the occurrence of ASF (OR = 7.679, 2015–2017 vs. 2019–2020). In general, the proportion of seropositive animals increased with the age of the swine, indicating post-natal transmission of T. gondii. Furthermore, there was a significant difference in seroprevalence between suckling pigs and weaned pigs (p < 0.05). This is the first large-scale investigation of T. gondii infection in swine after an ASF outbreak in China. The lower seroprevalence of T. gondii in swine after ASF may be due to stricter biosecurity measures on the farms, but results indicated swine exposure to zoonotic parasites despite these measures. This highlights that pigs must be considered a potential source of human T. gondii infections.

Highlights

Toxoplasma gondii is a widely distributed obligate intracellular parasitic protozoan that infects virtually all warmblooded animals, including humans and swine [5]
This study investigated the seroprevalence of T. gondii infection in swine from Chinese farms and compared the seroprevalence before and after the Materials and methods
The seroprevalence values for T. gondii in swine were 2.64% (7/265, 95% CI, 1.18–5.46) in 2019 and

Summary

Introduction

Toxoplasma gondii is a widely distributed obligate intracellular parasitic protozoan that infects virtually all warmblooded animals, including humans and swine [5]. About million people worldwide are chronically infected with. T. gondii [14, 17]. Infection with T. gondii is usually asymptomatic in healthy people, but can be severe in people with immunodeficiency [5]. There are two main modes of transmission of T. gondii: horizontal transmission, mainly through oral infection, and vertical transmission through the placenta [11, 15]. Swine are susceptible to T. gondii, with seroprevalence ranging from 0% to 96.6% in different regions of the world [8]. China is the largest pork producer and consumer worldwide [18]. The positive serum rate of T. gondii in China was 32.9%

Methods

Results

Conclusion