Declining trends in Hepatitis A seroprevalence over the past two decades, 1998-2017, in Pune, Western India

Rising trend of symptomatic infections due to Hepatitis A virus infection in adolescent and adult age group: An observational study from a tertiary care liver institute in India

BACKGROUND

Hepatitis A Virus (HAV) is the most common cause of Acute Viral Hepatitis (AVH) in children. It causes self-limiting illness and rarely acute liver failure. The shifting pattern in HAV endemicity is rendering adolescents and adults vulnerable to infection.

METHODS

In this retrospective study, samples received from 14,807 patients with acute onset icteric illness from January 2014-December 2022 were analyzed. HAV infection was detected by anti-HAV IgM positivity. The cases were divided into 3 age groups, pediatric, adolescents and adults, and clinical presentations were compared.

RESULTS

Overall, 7.72%(1144) were positive for anti-HAV IgM. Of these, 60%(690) were finally included in the study. The positive cases were divided into adults, ≥18 years (44%, 304); pediatric, <12 years (31%, 212) and adolescents (25%,174) age groups. Overall males were predominant [72.4%(500)], with a median age of 16 (IQR:9-21) years. Cases were characterised into AVH (68.1%, 470/690), Acute Liver Failure (ALF) (31.4%, 217/690) and Acute-on-Chronic Liver Failure (0.43%, 3/690). AVH in the pediatric age group was 69%(146/212), adolescents was 67%(117/174), and adults was 68%(207/304). ALF cases among the 3 groups were 30%(65/212), 33%(57/174), and 31%(95/304) respectively. Overall mortality was seen in 6.52%(45/690), maximum in adolescents with ALF presentation [10.3%(18/174)]. On molecular characterization of infection, viremia was seen in 28.9%(200/690) and all the isolates were Genotype IIIA.

CONCLUSIONS

The number of adults experiencing symptomatic HAV infection was seen to increase over the years in the present study. Infection in adolescents was associated with higher mortality and ALF as the clinical presentation.

Circulation of a single hepatitis A virus genotype IIIA with two distinct clusters in different states of India

With the changing hepatitis A epidemiology in India, focal viral outbreaks are being reported from different parts of the country. This study presents Hepatitis A Virus (HAV) strain characterization (period 2009-2020) from 18 states of India. For that, blood and stool samples (n ​= ​280) were screened for HAV RNA and sequences for 5'non-coding and VP3 regions were generated from positive samples (n ​= ​68). Presence of a single IIIA genotype in all samples indicated IIIA being the only HAV genotype currently circulating in India. Interestingly, it was evident that these strains form two distinct groups suggesting independent evolution of these two clusters.

Need for hepatitis A prevention in patients with chronic liver disease in the changing epidemiological setting of India

The burden of chronic liver disease (CLD) in India is high, particularly among middle-aged men, with nearly 220,000 deaths due to cirrhosis in 2017. CLD increases the risk of infection, severe disease (e.g. hepatitis A virus or HAV superinfection, acute-on-chronic liver failure, fulminant hepatic failure), and mortality. Hence, various countries recommend HAV vaccination for CLD patients. While historic Indian studies showed high seroprevalences of protective HAV antibodies among Indian adults with CLD, the most recent ones found that nearly 7% of CLD patients were susceptible to HAV infection. Studies in healthy individuals have shown that HAV infection in childhood is decreasing in India, resulting in an increasing population of adults susceptible to HAV infection. As patients with CLD are at increased risk of severe HAV infection, now may be the time to recommend HAV vaccination among people with CLD in India.