Rising adult hepatitis A in Pakistan: Shifting trends and public health solutions

Abstract

This letter evaluates Shahid et al’s study in 2025 on the rising hepatitis A virus (HAV) among adults in Pakistan, highlighting a shift in the virus’s epidemiology. Once primarily a childhood disease in low-income regions, HAV is now increasingly affecting adults, also seen globally due to improved sanitation. The study highlights public health challenges from adult HAV infections, which can lead to complications like coagulopathy and acute liver failure. It also has limitations, including being a single-center study and lacking seroprevalence and socioeconomic data, indicating the need for further research. This letter calls for urgent public health measures to extend adult vaccination programs and improve sanitation to address the increasing HAV infection in adult populations.

Key Words: Hepatitis A; Epidemiology; Public health; Prevention and control; Adult infection

Core Tip: The rising incidence of hepatitis A virus infections among adults in Pakistan, as highlighted by Shahid et al in 2025, underscores the urgent need for expanded vaccination programs targeting high-risk groups and improved public health strategies to mitigate the impact of this evolving epidemiological threat. Enhanced surveillance, public awareness campaigns, and targeted immunization initiatives are vital for reducing transmission and preventing outbreaks. These measures will safeguard vulnerable populations and ease the burden on the healthcare system, paving the way for a more resilient and proactive public health infrastructure.

TO THE EDITOR

This article responds to the study by Shahid et al[1] in 2025 on the evolving epidemiology of hepatitis A virus (HAV) infections in Pakistan, specifically the rise in adult cases. Historically considered a pediatric disease, HAV is now increasingly affecting adult populations in low- and middle-income countries, including Pakistan. While sanitation improvements have contributed to the reduction of childhood HAV cases, these same advancements, combined with insufficient vaccination coverage, have led to a growing number of severe infections in adults[1]. This letter aims to evaluate the contributions of Shahid et al’s study[1] and discuss the broader public health challenges that demand immediate attention.

CHANGING TRENDS AND PUBLIC HEALTH SOLUTIONS FOR THE RISE OF HEPATITIS A IN ADULTS IN PAKISTAN

A significant finding in Shahid et al’s study[1] is the shift in HAV infections from children to adults, which mirrors global patterns. Similar shifts have been observed in countries like South Korea, where better sanitation has led to fewer childhood infections, leaving older populations vulnerable to more severe forms of the disease[2]. In the past, children who were exposed to HAV often experienced mild illness and developed lifelong immunity. However, due to improved hygiene, this early exposure has decreased, which now leaves adolescents and adults at a higher risk of severe complications from HAV infections[3].

To effectively address this shift, it is imperative to analyze Pakistan’s current vaccination strategies and identify their gaps. While Pakistan’s Expanded Program on Immunization primarily targets pediatric populations, it has not been expanded to include adults. This limitation leads to a significant gap in protection for high-risk groups, such as healthcare workers and individuals with chronic liver disease. Furthermore, vaccination efforts in Pakistan are often hindered by economic constraints, regional disparities, and a lack of public awareness[4].

From a clinical perspective, the study by Shahid et al[1] provides crucial insights into the severe outcomes associated with adult HAV infections. The findings underscore the fact that while HAV-related mortality remains relatively low (0.9%), especially when compared to hepatitis E virus (HEV) (7%), HAV infections in adults often result in more severe health complications. These complications include prolonged hospital stays, coagulopathy, and acute liver failure, which significantly strain healthcare systems. Given these more severe outcomes, there is a clear need for heightened clinical awareness and better healthcare resource allocation to manage HAV in adult populations[1]. Healthcare providers in Pakistan must note these findings and adopt more aggressive management strategies for adult HAV cases. In line with creating an effective prevention network, public health authorities working in Pakistan should establish a comprehensive vaccination program targeting individuals across all age groups. As successfully implemented in China, this life-cycle prevention network can reduce the risk of HAV transmission and complications[5].

The public health implications of this study are far-reaching. The authors rightly highlight the urgent need for expanded HAV vaccination programs, primarily targeting adults. However, achieving this requires balancing the economic burden and the benefits of improved public health. Examples from low-income regions, where cost-effective vaccination campaigns have been introduced, should be analyzed and adapted for Pakistan. Such programs can include co-funding models and international collaboration to overcome resource constraints[4].

Coordination with other countries, particularly China, could also provide valuable insights into tackling HAV. China has successfully reduced HAV incidence through mandatory infant vaccinations, strict public health regulations, and community awareness campaigns. Drawing on their experience, Pakistan could implement similar strategies, such as screening and vaccinating individuals at key checkpoints, including school enrollments and employment stages[6].

While pediatric vaccination programs have effectively reduced the incidence of HAV among children, they have not sufficiently addressed the growing threat to adults. In countries like the United States, introducing universal vaccination programs in the 1990s led to a 95% decrease in HAV incidence[7]. Pakistan could benefit significantly from adopting a similar strategy, focusing on high-incidence regions and high-risk populations such as healthcare workers, travelers, and those with chronic liver diseases. This should be complemented by public health campaigns promoting hygiene and sanitation to curb the spread of the virus. The study also lacks data on HAV genotypes and subtypes prevalent in Pakistan. Including such epidemiological information would provide valuable insights into the disease's transmission dynamics and assist in tailoring public health interventions. For example, genotype IA, often associated with outbreaks, may demand different mitigation strategies than other genotypes.

The study by Shahid et al[1] made a meaningful contribution by offering comparative data on HAV and HEV infections in Pakistan, providing an important context for understanding the public health impact of HAV. While the study highlights the relatively milder course of HAV compared to HEV, it emphasizes the need for proactive public health measures in light of the increasing number of adult cases. The data presented from 2019 to 2024 is a wake-up call for policymakers in Pakistan and beyond to reconsider their approach to preventing HAV outbreaks.

However, several limitations of the study[1] must be addressed. First, its narrow focus on a single tertiary care hospital may limit the generalizability of its findings. Future studies should incorporate multi-center data across diverse geographic areas in Pakistan to address this. Additionally, including seroprevalence surveys is crucial to estimating immunity levels within the population and identifying vulnerable groups. These measures would provide a more accurate picture of the disease burden and guide vaccination policies effectively. Second, socioeconomic factors, such as income, education, and access to clean water, play a critical role in HAV transmission. Future research should account for these variables to develop targeted interventions that address the root causes of HAV spread in Pakistan.

CONCLUSION

In conclusion, Shahid et al[1] offer valuable insights into the changing epidemiology of HAV in Pakistan, reflecting broader global trends where improvements in sanitation have reduced childhood infections but left adult populations vulnerable. While the study is a crucial step toward understanding the emerging public health threat HAV poses in adults, its limitations highlight the need for further research. Expanding vaccination programs to include adults, particularly high-risk groups, alongside improved sanitation and public awareness, is crucial for reducing the incidence of HAV and mitigating its public health impact. Learning from successful case studies in countries like China and incorporating seroprevalence data can significantly enhance Pakistan’s public health response to HAV.