Epidemiology of Blastocystis infection from 1990 to 2019 in China

Abstract

Background Blastocystis is ubiquitous presence in animals and humans worldwide and has a high level genetic diversity. The aim of this study was to conduct a summary of Blastocystis prevalence, subtypes (STs) in humans and animals in China and depict their distribution. Methods We searched for the articles related to epidemiology of Blastocystis in humans and animals throughout China which published from January 1, 1990, to July 31, 2019 in the following databases: PubMed, China National Knowledge Infrastructure (CNKI) and Wanfang database. The keywords were Blastocystis and one of the following ones: STs, subtypes, distribution, epidemiology, prevalence, infection, molecular, geographic, intestinal parasites, genetic diversity and characterization. Results In recent years, various molecular epidemiological studies have been carried out in some provinces/regions of China to identify subtypes of Blastocystis. Infants and young children, school students, hospitalized diarrhea patients, HIV/AIDS patients, tuberculosis patients, and cancer patients as respondents had been included. ST1–ST7 and ST12 were the main subtypes in Chinese population. Moreover, surveys of Blastocystis infection in animal were also conducted in some provinces of China. A variety of animals were investigated including pigs, cattle, sheep, yak, giant panda, and crested ibis (Nipponia nippon) with the main subtypes of ST1–ST8, ST10, ST12–ST14. Conclusions In recent years, some provinces/regions in China have conducted various molecular epidemiological studies to identify the Blastocystis subtypes. It is important to focus on new subtypes and mixed subtypes of infection, while increasing data on ribosomal alleles. We encourage the scientific community to start research on humans and surrounding animals (including domestic and wild animals) to better understand the possibility of Blastocystis transmission between humans and animals. We call for action among researchers studying intestinal parasitic diseases (Blastocystis), start drawing the subtype of Blastocystis and increase the subtype related to its clinical symptoms.

Symptomatic and Asymptomatic Protist Infections in Hospital Inpatients in Southwestern China

“…Five distinct Blastocystis STs were identified in the hospital inpatient population under study, including ST1-ST4 and ST7. This is well in agreement with the available molecular data from China, where ST1-ST7 and ST12 have been described at variable frequency rates in different human populations [40]. Interestingly, clinical studies on patients presenting with diarrhea have shown that ST1 was related to clinical manifestations, including diarrhea and may have, therefore, potential pathogenicity.…”

Identification of Multiple Blastocystis Subtypes in Domestic Animals From Colombia Using Amplicon-Based Next Generation Sequencing

“…Blastocystis is observed in both symptomatic and asymptomatic humans generating controversy about the pathogenic role of this microorganism and its clinical importance (6). Furthermore, Blastocystis has been observed in a wide range of both wild and domestic animals including mammals, birds, reptiles and insects (7)(8)(9)(10), highlighting a potential risk of zoonotic transmission to humans (1,8,11,12).…”

The Presence of Blastocystis in Tibetan Antelope (Pantholops hodgsonii)

“…To date, approximately 29 proposed Blastocystis subtypes have been identified in a large number of literatures ( Ma et al., 2020 ). ST1-9 and ST12 subtypes were identified in humans, while ST10-17 and ST21-28 subtypes were detected in animals ( Stensvold and Clark, 2016 ; Ning et al., 2020 ; Hublin et al., 2021 ). Of note, some subtypes were identified in both humans and animals, such as ST1, ST3, and ST5 subtypes ( Song et al., 2017 ; Wang et al., 2018a ).…”