Sixty Years (1957–2017) of Research on Toxoplasmosis in China—An Overview

Abstract

Toxoplasma gondii is a ubiquitous zoonotic pathogen belonging to apicomplexan parasites. Infection in humans and animals may cause abortion and other severe symptoms under certain circumstances, leading to great economical losses and public health problems. T. gondii was first discovered in China in 1955 and the corresponding work was published in 1957. Since then, a lot of work has been done on this parasite and the diseases it causes. This review summarizes the major progress made by Chinese scientists over the last 60 years, and gives our perspectives on what should be done in the near future. A wide variety of diagnostic approaches were designed, including the ones to detect T. gondii specific antibodies in host sera, and T. gondii specific antigens or DNA in tissue and environmental samples. Further work will be needed to translate some of the laboratory assays into reliable products for clinic uses. Epidemiological studies were extensively done in China and the sero-prevalence in humans increased over the years, but is still below the world average, likely due to the unique eating and cooking habits. Infection rates were shown to be fairly high in meat producing animals such as, pigs, sheep, and chickens, as well as in the definitive host cats. Numerous subunit vaccines in the form of recombinant proteins or DNA vaccines were developed, but none of them is satisfactory in the current form. Live attenuated parasites using genetically modified strains may be a better option for vaccine design. The strains isolated from China are dominated by the ToxoDB #9 genotype, but it likely contains multiple subtypes since different ToxoDB #9 strains exhibited phenotypic differences. Further studies are needed to understand the general biology, as well as the unique features of strains prevalent in China.

Prevalence, Risk Factors, and Genotypes of Toxoplasma gondii in Food Animals and Humans (2000–2017) From China

“…This finding indicates that T. gondii oocysts are widely distributed in the country. This viewpoint was also verified by other reports ( Pan et al, 2017 ; Yang et al, 2017a ). Furthermore, the popularity of hotpot with undercooked mutton and pork increases the risk of human T. gondii infection in China, with other food animals also remaining as threats to public health ( Guo et al, 2015 ; Yang et al, 2017b ).…”

“…Approximately 0.3% of pregnant women have been diagnosed with an acute infected of T. gondii during pregnancy (1990–2010) ( Gao et al, 2012 ). Pan et al (2017) have shown that the prevalence of animal T. gondii infections in sheep, swines, and chickens in China from 2010 to 2017 is significantly higher than that in humans. Most reports about T. gondii from China have been published in local journals, which are generally inaccessible to readers around the world.…”

Legal aspects associated with the lack of possibilities of preventing the spread of toxocarosis and toxoplasmosis in Poland

“…Not all playgrounds, including sandboxes, are protected against cats, especially since these animals are active at nig ht. 3,4,7,30,31,33,36,40,51,[102][103][104][105] The risks to children is amplified due to their geophagy, and frequent face touching especially around the mouth and nose. Also, due to their small posture, children are exposed to airborne forms of invasive parasites which rise up with the dust.…”

2-Amino-1,3,4-thiadiazoles as prospective agents in trypanosomiasis and other parasitoses

“…It is estimated that one-third of the world's population is infected by this parasite, with more than 2 million people affected every year in the European region. In addition, T. gondii can infect more than 200 warmblooded animal species causing toxoplasmosis in them (115,116). According to WHO, it is estimated that 95 % of people with an immunocompetent system will not develop clinical symptoms when they are infected with T. gondii, or they may experience mild influenza--like symptoms such as fever, headache or myalgia that quickly pass (116).…”

“…Tachyzoites can be detected in the host's leukocytes or in the bloodstream where they circulate freely. These tachyzoites localize in brain, liver and muscle tissue and develop into bradyzoite tissue cysts (115,118,119).…”