Abstract: ObjectiveTo understand possible factors influencing infection of acute hepatitis B(AHB) in Guangdong Province so as to provide scientific basis for prevention and control of it.MethodsA 1∶1 matched case-control study was conducted．Patients with newly diagnosed AHB in 6 hepatitis B (HB)surveillance sites in Guangdong Province were selected as the case group and individuals matched by the same gender,age (±1 year),and with both negative HBsAg and anti-HBs were selected as the controls.Participants were asked to complete a questionnaire about their histories of liver disease, blood transfusion/donation within 6 months,iatrogenic exposure,immunization, and life contact.Univariate and multivariate logistic regression models were used to analyze the data.ResultsFrom January 2013 to August 2015, 213 cases of AHB were reported by six surveillance sites in Guangdong Province.A total of 123 cases-control pairs (90 male pairs and 33 female pairs) were included in the final analysis.The average age was (42.02±18.11) years for the cases and (42.46±17.98) years for the controls.Age structures between the two groups were consistent (P>0.05) .Multivariate logistic regression showed that history of HB vaccination (OR:0.013，95%CI: 0.001-0.169) was a protective factor for AHB,while liver disease history(OR:152.144,95%CI:11.473-2 017.590),patients with HB or HB carriers in the family (dormitory) (OR:5.182,95%CI:1.073-25.033)and muscle/intravenous injection(OR:21.097,95%CI:3.407-130.656) were risk factors for AHB.ConclusionHB vaccination was a protective factor for AHB.Liver disease history,HB patients or carriers in the family (dormitory),and muscle/intravenous injection were risk factors.High-risk groups should be vaccinated with HB vaccines as soon as possible.