title: Prevalence and risk factors of Ascaris lumbricoides (Linnaeus, 1758), Trichuris trichiura (Linnaeus, 1771) and HBV infections in Southwestern China: a community-based cross sectional study.
abstract: BACKGROUND
  Intestinal helminths do not cause severe diseases in general, however, when combined with other diseases such as immunodeficiency diseases, there would be massive complications. Infections with Hepatitis B Virus (HBV) may lead to immunological disturbances and defects of cellular immunity and there is a need of clarification whether HBV infections are associated with infections with intestinal helminths.
  
  
  METHODS
  A community-based cross sectional study was conducted in Tezi town, Puge County of the Liangshan Prefecture, southwestern China from October 23rd to November 3rd, 2014. Four hundred and thirty eight people (median age = 37 years, IQR = 22-49) were enrolled in this study. Modified Kato-Katz thick smear was used to detect intestinal helminths. HBV DNA was quantified to confirm HBV infection.
  
  
  RESULTS
  Among the 438 participants, 9.1%, 13.5% and 30.6% were infected with HBV, A. lumbricoides (L., 1758) and T. trichiura (L., 1771), respectively; 7.1% (30/438) were infected with both A. lumbricoides and T. trichiura and 2.3% (10/438) were co-infected with HBV and A. lumbricoides. The multivariate logistic regression analysis showed that age (21-30 years versus >50 years: OR = 6.66, 95% CI = 2.15-20.68), drug abuse (OR = 6.96, 95% CI = 1.11-43.90), A. lumbricoides infection (OR = 3.60, 95% CI = 1.48-8.75), fertilization with faeces after disposal (OR = 0.15, 95% CI = 0.04-0.47) and working on a farm (OR = 4.59, 95% CI = 1.44-14.63) were significantly associated with HBV infection. Having toilets at home was negatively related to A. lumbricoides infection (OR = 0.52, 95% CI = 0.27-0.98) and T. trichiura infection (OR = 0.48, 95% CI = 0.28-0.80).
  
  
  CONCLUSIONS
  Ascaris lumbricoides was independently associated with HBV infection, and faeces might be the medium of HBV transmission. Improving hygiene conditions and habits are essential to reduce the risks of A. lumbricoides and T. trichiura infections.
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. xiaopl90@163.com.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. xiaopl90@163.com.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. xiaopl90@163.com.
authors.forename: Peng-Lei
authors.initials: PL
authors.lastname: Xiao
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 1057339623@qq.com.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 1057339623@qq.com.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 1057339623@qq.com.|Department of Epidemiology, School of Public Health, Fudan University, Room 307, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 1057339623@qq.com.
authors.forename: Yi-Biao
authors.initials: YB
authors.lastname: Zhou
authors.affiliation: School of Epidemiology, Public Health and Preventive Medicine, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada. yue.chen@uottawa.ca.
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 14211020013@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 14211020013@fudan.edu.cn.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 14211020013@fudan.edu.cn.
authors.forename: Ya
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 13211020008@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 13211020008@fudan.edu.cn.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 13211020008@fudan.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 13211020003@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 13211020003@fudan.edu.cn.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. 13211020003@fudan.edu.cn.
authors.forename: Jian-Chuan
authors.initials: JC
authors.lastname: Gao
authors.affiliation: Puge Center for Disease Prevention and Control, 4 Qing Nian Road, Puge County, Liangshan Prefecture, Sichuan Province, 615399, China. lwucdc@163.com.
authors.forename: Wu-Li
authors.initials: WL
authors.lastname: Yihuo
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. xxsong@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. xxsong@fudan.edu.cn.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. xxsong@fudan.edu.cn.
authors.forename: Xiu-Xia
authors.initials: XX
authors.lastname: Song
authors.affiliation: Fudan University School of Public Health, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. jiangqw@fudan.edu.cn.|Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. jiangqw@fudan.edu.cn.|Fudan University Center for Tropical Disease Research, Building 8, 130 Dong An Road, Xuhui District, Shanghai, 200032, China. jiangqw@fudan.edu.cn.
authors.forename: Qing-Wu
authors.initials: QW
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001196:Ascariasis / Q000453:epidemiology*; D017164:Ascaris lumbricoides / Q000302:isolation & purification; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000302:isolation & purification; D006509:Hepatitis B / Q000453:epidemiology*; D006515:Hepatitis B virus / Q000302:isolation & purification; D006801:Humans; D015995:Prevalence; D012307:Risk Factors; D014257:Trichuriasis / Q000453:epidemiology*; D014258:Trichuris / Q000302:isolation & purification
chemical_list: D004279:DNA, Viral