Hepatitis A sero-epidemiology in Singapore: a changing pattern

Area of Science:

• Epidemiology
• Virology
• Public Health

Background:

• Hepatitis A virus (HAV) infection is a significant public health concern.
• Understanding seroprevalence trends is crucial for disease control strategies.

Purpose of the Study:

• To determine the seroprevalence of immunoglobulin G antibody against the hepatitis A virus (IgG anti-HAV) in a healthy adult population.
• To analyze trends in HAV exposure over time and across different age groups.

Main Methods:

• Sera from 896 healthy volunteers aged 15-56 years were analyzed for IgG anti-HAV.
• Data were collected between 1987 and 1991.
• Seroprevalence rates were compared across age groups, sexes, and races, and analyzed for temporal trends.

Main Results:

• The overall IgG anti-HAV seroprevalence was 27%.
• Seroprevalence increased with age, from 0.9% in those aged 10-19 to 48.1% in those aged 40-49, and reached 100% in individuals over 50.
• A downward trend in seroprevalence was observed from 33% in 1987 to 21.4% in 1991.
• No significant differences were found between sexes or races.

Conclusions:

• Hepatitis A virus exposure has decreased compared to previous decades (1975, 1984-1985).
• Hepatitis A virus infection is no longer predominantly an infection of children and adolescents in this region.
• The findings suggest a potential shift in HAV epidemiology, possibly due to improved sanitation or vaccination efforts.