Prevalence and factors associated with Hepatitis B among children admitted in Mulago hospital.

Abstract

INTRODUCTION/BACKGROUND: Hepatitis B (HBV) is a major health problem worldwide. About 2 billion people are exposed to hepatitis B all over the world, with an estimated 350 million people being carriers. The prevalence of hepatitis B varies in different regions, with a carrier rate of 8-20% in areas of high endemicity and less than 1% in low endemic areas. Areas with a high prevalence of Hepatitis B include sub-saharan Africa, Asia and the pacific with infection occurring mainly in childhood. In Africa, most of the HBV infection occurs by the horizontal route possibly as a result of percutaneous infection through saliva, traces of blood, unsterile needles and tribal scarification. Both Hepatitis B Virus(HBV) and HIV infections have a high prevalence in sub-saharan Africa, with HBV being a common co-infection with HIV. Vaccination is the mainstay of prevention of Hepatitis B infection. According to the Uganda national sero survey, the HBV prevalence was found to be 10% among people aged 15-59 years. However there are no published studies on the prevalence and factors associated with HBV in children in Uganda. OBJECTIVES: To determine the prevalence and factors associated with Hepatitis B among children admitted on paediatric wards in Mulago hospital. STUDY DESIGN: Cross-sectional study STUDY SETTING: The study was carried out in the Acute Care Unit (ACU) and the paediatric wards of Mulago hospital. Mulago hospital is the national referral hospital in Uganda and a teaching hospital for Makerere university medical school. METHODS: Children between 6 months to 12 years whose caretakers gave informed conscent were recruited by consecutive enrolment till the sample size of 400 was obtained. Socio-demographic characteristics, Immunisation and past history were obtained. Physical examination and investigations such as HBsAG, AntiHBs, HIV and Liver function tests (LFTS) were carried out. HBV infection was defined by the presence of a positive blood test for HBsAg or antiHBc. STATISTICAL ANALYSIS: Associations between categorical variables and HBV infection were tested using the Chi-square test and Fisher’s exact test. With corresponding odds ratios and 95% confidence intervals. Logistic regression was done to determine factors that were independently associated with Hepatitis B infection. P values of less than 0.05 were considered significant. RESULTS: Four hundred children were recruited from January to March 2007. Of these, 5 did not have results for HBsAg, hence 395 were analysed. The prevalence of HBV infection was 12.9% (51/395). However, the prevalence of current HBV infection (HBsAg positive) was 1% and the prevalence of past HBV infection (antiHBc positive) was 11.9%. On bivariate analysis HBV infection was found to be associated with previous blood transfusion, OR 3.32 (95% C1(1.77-6.24), more than 4 haircuts in the past year, OR 2.47(95%C1 (1.36-4.50), past history of yellow eyes OR 2.14 (95%C1 (1.14-4.02) and being aged 60 months or more OR 1.89(95% C1 (1.01-3.54) On multivariate analysis HBV infection was only associated with previous blood transfusion OR 4.17 (95%C1 (2.73-7.65) (P=0.000) and more than 4 haircuts in the past one year OR 2.67 (95%C1 (1.44-4.97) (P=0.002) No significant association was found between hepatitis B infection and HIV status or gender CONCLUSION: The prevalence of HBV infection was 12.9%. Blood transfusion and more than 4 haircuts in the past one year were the factors associated with HBV infection. RECOMMENDATIONS: Although the prevalence of HBV was found to be low in the current study, there is need to sensitize the community about immunisation as a number of children are still susceptible to infection. A larger community based/case control study is required to further evaluate the factors associated with HBV infection.