Prevalence and Risk Factors of Cryptosporidium Infection in Children Hospitalized for Diarrhea in Guangzhou, China

Abstract

This study was conducted to determine the prevalence, species and risk factors of Cryptosporidium infection in children hospitalized for diarrhea in Guangzhou region of China. A cross-sectional study was conducted to assess the prevalence and risk factors of Cryptosporidium infection in children (2 weeks to 10 years old) who were hospitalized for diarrhea. Cryptosporidium oocysts were detected using direct immunfluorescent assay and species were determined by sequencing a fragment (~800 bp) of the 18S rRNA gene. A questionnaire contains host, sociodemographic, family, hygiene, diet, zoonotic, and environmental risk factors was administered to patients to identify key factors associated with infections. The observed Cryptosporidium prevalence was 6.9% and the true prevalence was estimated to be 9.0%. Cryptosporidium infection was similar between male (7.4%) and female (6.1%) children and negatively associated with age (i.e., infection was more likely in younger children). Infections in children were significantly associated with family members' diarrhea within past one month. Infection in children in suburban hospitals (7.8%) was significantly higher than that in urban hospitals (2.1%). The overall prevalence of Cryptosporidium in rainy season was significantly higher than that in non-rainy seasons. DNA sequences of the 18S rRNA gene from infected children were 99.12% to 100% identical to sequences in the GenBank of C. parvum isolates from humans and animals. Future works should determine the sources of zoonotic Cryptosporidium and routes of waterborne exposure in the rainy season in this region.

Assessment of Microbiological Safety of Water in Public Swimming Pools in Guangzhou, China

“…No significant differences in the occurrence of the two protozoal parasites were found between pools in urban and suburban areas. This is converse to our previous findings that prevalence of Cryptosporidium was significantly higher in children hospitalized in suburban hospitals than in urban hospitals in the same area [ 17 ]. This is probably because of the different transmission routes of Cryptosporidium in children patients living in urban and suburban areas.…”

“…Due to limited numbers of (oo) cysts detected from pool water we did not characterize the two parasites by genotyping, hence the genotypes and zoonotic potential of the two parasites in pool water were unknown. In our previous study we found that the dominant species of Cryptosporidium in children hospitalized for diarrhea in the same area was C. parvum , a species that infects humans and a wide range of animals [ 17 ]. Also, because of the limited numbers of oocysts detected in samples, we did not assess the viability of oocysts, therefore, it was unknown if the oocysts detected in pool water were infective.…”

“…This survey was conducted between 20 June and 4 September 2013. Due to the potential differences in public health conditions between suburban and urban districts within the Guangzhou area [ 17 ], the suburban Baiyun district and the urban Haizhu district were chosen for sampling. In total 39 pools, including 27 pools from the Baiyun district (21 residential pools, 6 pools from two water parks) and 12 pools from the Haizhu district (5 residential pools, 3 school pools, and 4 pools from one water park) were enrolled in the study.…”

“…The Chi-square (χ 2 ) test was applied to assess the potential differences in Giardia and Cryptosporidium presence in water between suburban and urban swimming pools, because we found the prevalence of Cryptosporidium was significantly higher in children hospitalized in suburban hospitals than in urban hospitals in the same area in a previous study [ 17 ]. Logistic correlation was applied to analyze whether the presence of P. aeruginosa was associated with the levels of free residual chlorine in water.…”

Molecular identification and antiprotozoal activity of silver nanoparticles on viability of Cryptosporidium parvum isolated from pigeons, pigeon fanciers and water

“…Previous studies in human cryptosporidiosis have reported similar isolation rates. For example, Chen, et al 43 , found C. parvum infection in 6.9% of tested children in China. Additionally, several studies have found that immunocompromised individuals have high prevalence of cryptosporidiosis than healthy individuals 44 , 45 .…”