title: Prevalence of and risk factors associated with Cryptosporidium infection in an underdeveloped rural community of southwest China.
abstract: BACKGROUND
  Cryptosporidium spp. is an important intestinal protozoan causing diarrhea in humans, livestock, and wild animals. Cryptosporidium infection remains a major public health issue, but its epidemiology in humans is still unclear, particularly in rural China. This study was designed to determine the prevalence of and risk factors associated with Cryptosporidium infection in a rural southwestern Chinese community.
  
  
  METHODS
  A community-based cross-sectional survey was conducted among 687 residents of a small town in a Yi autonomous prefecture of southwest China in 2014. Blood samples were examined using a broad set of quality-controlled diagnostic methods for hepatitis B virus (HBV) and human immunodeficiency virus (HIV). Stool specimens were processed using the modified acid-fast staining method, and microscopically examined for Cryptosporidium infection. Univariable and multivariable analyses were performed to determine the risk factors associated with Cryptosporidium infection.
  
  
  RESULTS
  The majority of the participants were Yi people with poor living conditions and unsatisfactory hygiene habits, and the study area was of very low socioeconomic status. Of the 615 individuals included in the analysis, 14 (2.3%) were HIV positive, 51 (8.3%) were infected with HBV, and 74 (12.0%) had Cryptosporidium infection. The prevalences of HIV/HBV, HIV/Cryptosporidium, and HBV/Cryptosporidium co-infections were 0.3%, 0.3%, and 1.8%, respectively. The prevalence of HBV infection was higher in individuals with Cryptosporidium infection (χ2= 5.00, P = 0.03). Owning livestock or poultry was an important risk factor for Cryptosporidium infection (aOR = 2.27, 95% CI: 1.01-5.08, P < 0.05). Cryptosporidium infection was significantly associated with HBV infection (aOR = 3.42, 95% CI: 1.47-7.92, P < 0.01), but not with HIV infection (aOR = 0.57, 95% CI: 0.07-4.39, P = 0.59).
  
  
  CONCLUSIONS
  The prevalence of Cryptosporidium infection was high in the rural area of southwestern China that was investigated, and there was a significant association between HBV infection and Cryptosporidium infection. Further investigations are needed to determine the significance of Cryptosporidium infection in patients infected with HBV.
authors.affiliation: School of Public Health, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Yang
authors.affiliation: School of Public Health, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China. z_yibiao@hotmail.com.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China. z_yibiao@hotmail.com.|Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China. z_yibiao@hotmail.com.
authors.forename: Yi-Biao
authors.initials: YB
authors.lastname: Zhou
authors.affiliation: School of Public Health, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
authors.forename: Peng-Lei
authors.initials: PL
authors.lastname: Xiao
authors.affiliation: School of Public Health, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: School of Epidemiology, Public Health and Preventive Medicine, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON, K1H 8M5, Canada.
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA.|Emerging Pathogens Institute, University of Florida, 2055 Mowry Road, Gainesville, FL, 32611, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Liang
authors.affiliation: Puge Center for Disease Prevention and Control, 6 Qingnian Road, Puge County, Sichuan, 615300, China.
authors.forename: Wu-Li
authors.initials: WL
authors.lastname: Yihuo
authors.affiliation: School of Public Health, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
authors.forename: Xiu-Xia
authors.initials: XX
authors.lastname: Song
authors.affiliation: School of Public Health, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.|Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong'an Road, Xuhui District, Shanghai, 200032, China.
authors.forename: Qing-Wu
authors.initials: QW
authors.lastname: Jiang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000469:parasitology; D003458:Cryptosporidium / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011203:Poverty; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D055815:Young Adult
keywords: China; Cryptosporidium; Hepatitis B virus; Human immunodeficiency virus; Prevalence; Risk factors; Rural areas