Seroprevalence and Risk Factor of Hepatitis B immunities among Thai Health Care Workers

Abstract

Background and objective : Although Hepatitis B infection can be prevented by vaccination, it remains one of the most prevalent occupational infectious diseases among health care workers (HCWs).  This study aimed to describe seroprevalence of hepatitis B virus (HBV) and to identify factors related to HBV immunity among health care workers at Khon Kaen Hospital, Thailand.   

Methods: HCWs who had blood tested for HBV markers; HBsAg, anti-HBs and anti-HBc during January to December, 2009 were interviewed. Demographic data such as age, gender, occupation and previous HBV vaccinations were collected and analyzed using descriptive statistics.  Binary logistic regression and bivariable analysis were used to identify factors related to HBV immunity.

Results: Among the 1,548 HCWs who participated in this study, 95 were physicians, 720 were nurses, 228 were technicians and 505 were supporting workers.  The mean age was 36.6 years (range 20 – 67). The positive rates of HBsAg, anti-HBs and anti-HBc were 4.7% ( n=72), 56.8% (n=879) and 32.8% (n=507) respectively. Female (adjusted odds ratio = 1.45, 95% CI = 1.09-1.93), age > 40 years (adjusted odds ratio = 2.73, 95%CI = 2.16-3.45), being physician (adjusted odds ratio = 2.12, 95%CI = 1.28-3.52) and having a past history of 3 or more than 3 doses of HBV vaccination (adjusted odds ratio = 1.92, 95%CI = 1.51-2.44) associated significantly with having anti-HBs positive. 

Conclusions: This study showed that risk factor for immunity of hepatitis B was female, age> 40 years, being the physicians and having a past history of 3 or more than 3 doses of HBV vaccination. These findings provided a basis for HBV infection prevention policy among HCWs at Khon Kaen Hospital.

Keywords: HBsAg, Anti-HBs, Anti-HBc, health care worke