Hepatitis B in Oman, risk factors and sequelae
BackgroundHepatitis B is a major public health problem worldwide. The prevalence of hepatitis B is dependent on the modes in which it is transmitted. There are two common modes of hepatitis B virus (HBV) spread: vertical (mother to neonate) and the horizontal (via infected blood or body fluids). Chronic infection with HBV can progress to liver cirrhosis and liver cancer (hepatocellular carcinoma; HCC). Oman is regarded as an intermediate endemicity region and has had neonatal vaccine against HBV since 1990; however, little research has been conducted in Oman regarding risk factors for hepatitis B and its contribution to end stage liver disease and HCC. Aims To identify the prevalence of major risk factors for acquiring hepatitis B in Omani patients currently infected with HBV (positive hepatitis B surface antigen (HBsAg)). To estimate the contribution of hepatitis B to liver cirrhosis in Oman. MethodsThe prevalence of major risk factors was identified by interviewing HBsAg positive patients using a standard questionnaire. Patients were recruited from outpatient clinics at two tertiary referral hospitals in Oman’s capital city Muscat.Data on patients with liver cirrhosis admitted to two tertiary hospitals in Muscat over a period of seven years was abstracted from medical records. The diagnosis of cirrhosis was confirmed using defined criteria and the aetiology confirmed from the results of diagnostic tests including HBV serology. This data was analysed to estimate the contribution of HBV to cirrhosis in the cohort. ResultsFor the first objective, 279 patients were interviewed. The number of male and female patients was similar, and 75.5% of the participants were aged 20 – 39 years. Antenatal screening was the most common means of detecting HBV infection in women and prior to blood donation was the most common means of identifying HBV infection in men. With respect to HBV transmission risk factors, intra-familial contact with HBV infected persons and behavioural risks such as body piercing (females) and barber shaving (males) were more common than nosocomial risk factors. Knowledge about HBV infection was scarce among our participants.For the second objective, we identified records from 419 patients with cirrhosis. The median age was 59 years and males accounted for two thirds of the total studied population. 97.1% of patients were of Omani ethnicity. There was evidence of previous or current HBV infection (positive anti-bodies to hepatitis B core antigen) in 51.3% of the cirrhotic patients. 21.5% had active HBV (positive HBsAg). Of the patients with current HBV 91.2% were infected with HBV alone while 8.8% were co-infected with hepatitis C virus (HCV). Hepatitis C was present in 30.5% of cirrhotic patients and nearly half of those patients had evidence of past exposure to HBV. When stratified by gender, HBV infection was more common among male cirrhotic patients compared to females. ConclusionsThis study found that risk factors for HBV infection in Omani patients include direct contact of infected individuals within a family and exposure to high-risk behaviours such as piercing and barber shaving. Reducing vertical and horizontal transmission of hepatitis B in Oman could be improved by the implementation of routine antenatal screening of pregnant women and a greater focus on contact screening respectively. Future work is required to determine whether the association with behavioural risk factors is causal, particularly piercing and shaving at barber shops. If confirmed, relatively simple and effective interventions could be developed to reduce the risk of horizontal transmission related to these activities.We found that third of the patients identified with liver cirrhosis had past exposure to HBV and 20% had evidence of chronic infection. Most patients were of older age and male sex. This group of patients may benefit from antiviral therapy to prevent decompensation and regular surveillance for early diagnosis and treatment of HCC. Further research is required to assess the role of other exposures (alcohol, co-infection with other viruses) in the prognosis of hepatitis B to cirrhosis in Oman.
Advisor: Priest, Patricia; McCall, John
Degree Name: Bachelor of Medical Science with Honours
Degree Discipline: Department of Preventive and Social Medicine
Publisher: University of Otago
Keywords: HBV; Oman; Cirrhosis; Hepatitis
Research Type: Thesis