Cryptosporidium in asymptomatic children in Southern Xinjiang, China and the potential of zoonotic transmission

Background: Cryptosporidium is a primary cause of diarrhea in children globally. However, there is limited information on the prevalence and genetic characterization of Cryptosporidium in children in Xinjiang, China. This study aimed to assess the genetic characteristics and epidemiological status of Cryptosporidium in asymptomatic children in Southern Xinjiang, China. Methods: : A total of 609 fecal samples were collected from kindergartners aged 2-6 y from 11 counties of Southern Xinjiang, China. We used nested PCR amplification of partial SSU rDNA gene to screen the samples for Cryptosporidium spp. The isolates containing C. parvum and C. hominis were further subtyped by a 60-kDa glycoprotein ( gp60 ). We used MEGA7 to construct a phylogenetic tree to study the genetic relationship between the gp60 subtypes of these two species via the Maximum Likelihood method based on the Tamura-Nei model. Results: : Only 1.3% (8/609) of asymptomatic children were confirmed as infected with Cryptosporidium with 2.0% (6/299) infection rate in boys and 0.6% (2/310) infection rate in girls. Three Cryptosporidium species were identified including C. felis (37.5%; 3/8), C. hominis (37.5%; 3/8) and C. parvum (25.0%; 2/8). Three C. hominis subtypes (IbA9G3, IdA14 and IfA12G1) and two C. parvum subtypes (IIdA14G1 and IIdA15G1) were also found. Conclusions: : This study was the first to identify the presence of cryptosporidium in asymptomatic children in Southern Xinjiang, China. The presence of zoonotic C. parvum subtypes IIdA14G1 and IIdA15G1 indicates possible crossspecies transmission of Cryptosporidium between children and animals.