A large percentage of the Spanish population under 30 years of age is not protected against hepatitis A

Abstract

A seroepidemiological study was conducted to assess the seroprevalence of hepatitis A (HAV) antibodies in the Spanish general population in 1992-93. A total of 2744 subjects (1337 men and 1437 women) in the 5-59 years age range were stratified by gender and age (5-12, 13-19, 20-29, 30-39, 40-49, 50-59 years). The presence of total anti-HAV antibodies was investigated using a commercial enzyme immunoassay. Fifty-five percent (95% CI: 53.5-57. 2%) of the subjects were positive for anti-HAV antibodies, the age-standardized anti-HAV prevalence being 65.4%. Prevalence of seropositive subjects increased with increasing age (chi(2) = 996, 17; P < 0.0001), being 11%, 25% and 54% for the 5-12, 13-19 and 20-29 age groups respectively. The results from this study showed a remarkable decline in seroprevalence rates among children, adolescents and young adults. The large number of susceptible subjects in these groups of the population has public health implications in a country with intermediate HAV prevalence.

Marked decrease in the incidence and prevalence of hepatitis A in the Basque Country, Spain, 1986–2004

“…All together, the data in the present study confirm that the Basque Country is an area with low endemicity. Decreases in the seroprevalence and in infection rates are also currently observed in some countries and regions of southern Europe [8,9,[15][16][17][18] and in economies in transition in other continents [18]. The speed at which this change has taken place in the Basque Country is marked and although susceptibility to HAV infection increased in the general population, no large outbreak has occurred.…”

“…In this study, there were no men in the population aged o20 years. However, in large seroepidemiological studies performed in Spain, the seroprevalence rates did not differ by gender [8,9]. Although it is well known that children play an important role in HAV transmission and serve as a source of infection for the general population [2,10], children are not currently a common source of infection as infection among them is rare.…”

Exposure to HAV infection in patients with chronic liver disease in Italy, a multicentre study*

“…A steady reduction in the incidence of HAV infection has been observed in Italy and in several other western countries over the last three decades [3,[8][9][10][11][12]. In Italy, the incidence of acute hepatitis A declined from 10/100 000 cases in 1985 to 6/100 000 in 1997 [13][14][15], because of a pro-gressive reduction in the spread of the infection in children, teenagers and young adults [10].…”

Seroepidemiology of hepatitis A virus infection among school children in Delhi and north Indian patients with chronic liver disease: Implications for HAV vaccination

“…[3][4][5] During recent years, several reports from developing nations have suggested a shift in the HAV epidemiology (from high to intermediate or low endemicity), presumably because of improved hygiene and sanitation. [6][7][8][9][10][11][12][13] Such observations have led to a recommendation for mass vaccination of all children in these countries. Vaccination has also been recommended for patients with chronic liver disease because of increased risk of dec-ompensation in these patients subsequent to HAV superinfection.…”