The 1985 national immunisation survey: hepatitis A.

Area of Science:

• * Epidemiology
• * Public Health
• * Virology

Background:

• * Hepatitis A virus (HAV) infection is a significant global public health concern.
• * Understanding HAV infection prevalence is crucial for targeted prevention strategies.
• * Previous data on HAV infection rates in New Zealand children were limited.

Purpose of the Study:

• * To determine the prevalence of past hepatitis A virus infection among New Zealand children.
• * To investigate age-related trends in HAV infection.
• * To explore ethnic and geographic disparities in HAV infection risk.

Main Methods:

• * A national survey conducted in April 1985 involving approximately 3000 randomly selected children across New Zealand.
• * Sera collected from children aged 5, 10, and 15 years.
• * Enzyme-linked immunosorbent assay (ELISA) used to detect antibodies to hepatitis A virus as a marker of past infection.

Main Results:

• * Overall prevalence of past HAV infection was low, increasing with age: <1% in 5-year-olds, ~3% in 10-year-olds, and ~9% in 15-year-olds.
• * Maori children (10 and 15 years old) had approximately three times higher infection rates than European children.
• * Children residing in the eastern North Island exhibited a higher risk of infection, independent of ethnicity.

Conclusions:

• * Hepatitis A virus infection prevalence in New Zealand children increases significantly with age.
• * Ethnic and geographic factors play a role in HAV infection risk among children.
• * Findings highlight the need for continued surveillance and potential targeted interventions for hepatitis A in New Zealand.