Hepatitis A infection in central Tuscany in children and youths

Abstract number: 1733_715

Gentile C., Alberini I., Manini I., Montomoli E., Rossi S., Pozzi T.

In Italy, seroepidemiological studies have demonstrated a decrease in the circulation of the Hepatitis A virus (HAV). The notified cases in the SEIEVA system (Integrated Epidemiological System of Acute Viral Hepatitis) of HAV show a reduction in cases beginning in 1985 (10/100.000) up to 2004 (3.6/100.000) with a peak in 1997 connected to the epidemic that occurred in Puglia (19/100.000).

The decline in the circulation of HAV in Italy is linked to the improvement in hygienic conditions and life style, and above all to the implementation of vaccination, determining the decrease in the risk of acquiring infection during childhood.

In order to verify the trend in the diffusion of HAV infection in the geographical area of Central Italy, a seroepidemiological study on cohorts of subjects, children and youths, was carried out; the years 1992, 1998 and 2004 were considered, and for each of these years two samples from around 100 subjects aged, respectively, 0–5 and 15–20 years, were examined. All sera were refrigerated at -20°C. Each sample of sera was tested for the presence of total antibodies against HAV by the ELISA method (HAV antibody, DIESSE Diag. Senese SpA).

The obtained results show a higher prevalence of anti-HAV in youths compared to children in both 1992 (2.7% in 0–5 year-olds and 7.4% in 15–20 year-olds) and in 1998 (6.0% in 0–5 year-olds and 11.1% in 15–20 year-olds), while in 2004, infection was 16.4% in children and 5.4% in youths. The high antibody rate against HAV noted in children in 2004 could be correlated to a higher use of vaccine in this age group as a consequence of small epidemics in the infant community that occurred in Central Italy during that period. The statistical analysis of the results thus shows a significant tendency of increase in seroprotection over the years in children (c2 for linear trend = 10.7; p = 0.0011). However, the overall decrease of prevalence in subjects protected from HAV in youths (c2 for linear trend = 0.48; p = 0.49) up to the values shown in 2004 (5.4%), besides confirming the national trend of the past few years, does not allow us to hypothesise a trend toward an increase in the risk of acquiring infection in young adults.

This trend must be considered with caution because too much time probably passed between the intervals of blood collection compared to the period that is the object of our analysis.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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