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

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.