Why Hepatitis A is no longer a simple disease in Kerala

In recent years, Hepatitis A outbreaks in Kerala have become more severe and complex, no longer simply a childhood illness. The age group affected has shifted from children to young adults, with 90% of patients now falling within the 18-40 years age range. This change has led to atypical symptoms, including prolonged high liver enzyme levels and extrahepatic complications such as bone marrow suppression.

Young adults, who are more likely to eat out, particularly at wayside shops and exotic juice shops, are particularly vulnerable.

In 2024, Kerala reported 12,437 confirmed and probable cases of Hepatitis A, resulting in 125 deaths, with 69 of those being confirmed Hep A deaths. Clinicians in the state have noted a cytokine storm, a severe immune response, in many Hep A cases, a phenomenon also observed in other infectious diseases following the Covid-19 pandemic.

The epidemiological shift in Hepatitis A patients has been starkly evident, with severe and atypical symptoms becoming more common. Dr. R. Aravind, head of infectious diseases at Thiruvananthapuram Government Medical College, highlights that these complications are rare in children but are increasingly seen in adults due to their immunological naivety.

A multi-center study conducted across six tertiary care hospitals in Kerala in 2024-25 reported atypical features such as pulmonary complications, acute kidney injury, and hemophagocytic lymphohistiocytosis (HLH) in Hepatitis A patients. Therapeutic interventions included high steroid use, plasmapheresis, continuous renal replacement therapy, and mechanical ventilation.

Another study published in BMC Infectious Diseases in April 2026 revealed that adults infected with Hepatitis A later in life had 8.4 times higher odds of moderate-to-severe disease. The immunological profile showed that adults have a larger reservoir of CD8 and primed memory T cells, leading to a higher inflammatory cytokine response, causing extensive liver damage in adults.

This trend of severe Hepatitis A cases in adults underscores the need for a universal Hepatitis A vaccination program in Kerala. Despite the state's public health successes, the lack of safe drinking water remains a significant issue, and the economic burden of Hepatitis A outbreaks is immense, with families facing an average out-of-pocket expenditure of nearly ₹25,000 per adult infected.