Trends and Estimation of Hepatitis B Infection Cases in Malaysia, 2003–2030

Background and Context

Hepatitis B virus (HBV) infection is a significant public health problem in Malaysia and throughout the Asia-Pacific region. Malaysia is classified as having intermediate HBV endemicity, with estimated seroprevalence rates ranging from 1.1 to 9.8 per cent depending on the population studied. An estimated one million Malaysians are chronically infected with HBV, and the infection remains a leading cause of chronic liver disease, liver cirrhosis, and hepatocellular carcinoma in the country. Cirrhosis ranks among the top ten causes of major disease burden in Malaysia, and liver cancer is the fifth most common cancer and one of the most fatal.

Malaysia introduced universal hepatitis B vaccination for newborns in 1989, and the national immunisation coverage rate for infants reached 96.32 per cent by 2013. The vaccination programme has been a major public health success, substantially reducing HBV seroprevalence among younger age cohorts. However, a large reservoir of chronically infected adults who were not covered by the infant vaccination programme continues to drive ongoing transmission and disease burden. Against this backdrop, this study aimed to analyse the trend of hepatitis B cases in Malaysia from 2003 to 2012 and to project future case numbers for an 18-year period from 2013 to 2030.

Study Design and Methods

The study employed a secondary data analysis approach using national hepatitis B case notification data from the Ministry of Health Malaysia for the period 2003 to 2012, combined with Malaysian population projections for 2010 to 2040 produced by the Department of Statistics Malaysia. Trend analysis was conducted by fitting regression and trend lines to the reported annual HB case data, and these models were then used to project estimated HB case numbers and incidence rates for each Malaysian state from 2013 to 2030. The analysis was stratified by state to identify geographic variation in both historical trends and projected future burden.

Key Results

The trend analysis revealed a complex pattern of HB case notification over the 10-year study period. Following a peak at the beginning of the study period, HB cases decreased for six consecutive years from 2003, likely reflecting the ongoing impact of the universal infant vaccination programme introduced in 1989, which was beginning to protect increasingly larger cohorts of the Malaysian population. However, from 2010 onwards, the number of reported cases began to increase again, suggesting the emergence of new dynamics in HBV transmission or changes in surveillance and detection practices.

The geographic distribution of cases showed substantial state-level variation. Sabah, located in East Malaysia (Malaysian Borneo), reported the highest number of HB cases during the 2003–2012 period, followed by Pahang and Wilayah Persekutuan (Federal Territory, encompassing Kuala Lumpur and Putrajaya). Perlis, the smallest state in terms of both area and population, reported the lowest number of cases.

The projections for 2013 to 2030 estimated that both the number of HB cases and the incidence rates would increase in all states except Penang, which was projected to show a declining trend. This largely unfavourable projection reflected the ongoing contribution of the unvaccinated adult cohort, potential waning of vaccine-induced immunity in some individuals, migration patterns, and the increasing life expectancy of chronically infected individuals.

Implications for National HBV Elimination Strategy

The study’s projections carried significant implications for Malaysia’s efforts to meet the World Health Organization’s goal of eliminating hepatitis B as a public health threat by 2030. The WHO Global Health Sector Strategy on Viral Hepatitis, adopted in 2016, set ambitious targets including a 90 per cent reduction in new infections and a 65 per cent reduction in deaths from viral hepatitis by 2030. The finding that HB case numbers were projected to increase in most Malaysian states suggested that the existing prevention and control strategies—while successful in reducing transmission to newborns—were insufficient to achieve elimination without substantial additional interventions targeting the adult population.

The high HB burden in Sabah warranted particular attention. Sabah faces unique public health challenges including geographic remoteness, healthcare access barriers for rural and indigenous communities, and a large migrant worker population from neighbouring countries with high HBV endemicity. Strengthened screening, treatment access, and targeted vaccination catch-up programmes in Sabah and other high-burden states were identified as priorities.

Subsequently, Malaysia developed its first National Strategic Plan for Hepatitis B and C (NSPHBC 2019–2023), which outlined comprehensive strategies across five domains: governance, prevention, surveillance and research, diagnosis and treatment, and capacity building. Community-based screening campaigns, such as the Hepatitis Free Pahang initiative, revealed that only 13.1 per cent of chronically infected Malaysians were aware of their HBV status and only 0.7 per cent had received prior antiviral treatment—highlighting the enormous gap between infection prevalence and the cascade of care.

Limitations

The study relied on notified HB cases, which likely underestimate the true burden of infection due to underdiagnosis and underreporting. The projection methodology, while providing useful trend estimates, was based on linear extrapolation from historical data and did not account for potential future changes in policy, vaccination coverage, treatment access, or population dynamics. The projections also could not incorporate the potential impact of new interventions that might be implemented during the projection period. Additionally, changes in surveillance practices, diagnostic criteria, or reporting requirements over the study period may have influenced the observed trends independently of actual changes in disease incidence.