Persistence of anti-HBs 5 years after the introduction of routine infant and adolescent vaccination in Italy.

A population survey was conducted to assess the duration of anti-HBs levels > 10 IU/l in vaccinees living in Lazio Region (Italy) 5 years after the introduction (15 June 1991) of compulsory vaccination of new-borns and 11-year-old children. A random sample of 1192 (533 children born in 1991--92 and 659 adolescents born in 1979--81) was selected. In 92.9% of children and 94.1% of adolescents anti-HBs titres were protective (> or = 10 IU/l). These subjects with protective titres were divided into three categories: low responders (anti-HBs titres = 10--500 IU/l), medium responders (anti-HBs titres = 501--2000 IU/l) and high responders (anti-HBs titres > 2000 IU/l). Factors associated with the level of response were analysed, using a multiple politomic logistic regression analysis. Greater age at first dose (11--12 years) was associated with higher titres (OR = 2.1, 95% CI = 1.4--3.2 for medium responders and OR = 3.0, 95% CI = 1.9--4.8 for high responders). Simultaneous administration of DT vaccine was associated with lower titres (OR = 0.4, 95% CI = 0.2-0.8 for medium responders and OR = 0.3, 95% CI = 0.1--0.7 for high responders).

Viral hepatitis in the Bhutanese population: preliminary results of a seroepidemiological investigation.

A seroepidemiological study of the prevalence of markers related to the most common forms of viral hepatitis was carried out in Bhutan on 1,666 healthy people of both sexes, from the general population. A group of 440 pregnant women were screened separately. Our results suggest that in Bhutan, hepatitis A and hepatitis B are widespread, while there is a low prevalence of hepatitis C and E. Anti-HAV (anti-hepatitis A virus) was found in all 171 tested subjects over 12 years of age, and anti-HBc (anti-hepatitis B core antigen) in 63.1% of 1,666 tested people. On the other hand, anti-HEV proved positive in 2.0% of 257 tested subjects, and anti-HCV in only 1.3% of 611 tested subjects. Hepatitis B surface antigen (HBsAg) was found in 5.9% of the sample from the general population (5.2% in children, 5.6% in young people and 6.3% in adults) and in 5.4% of the pregnant women. Furthermore, 29.1% of HBsAg-positive pregnant women were HBeAg- and HBV DNA-positive, too. Comparing the pregnant women's prevalence data to those found in children, we suggest that the main route of HBV transmission in the Bhutanese population is vertical, from mother to child; this finding is important for the implementation of a correct anti-HBV vaccination strategy in Bhutan.

Hepatitis A, B, C and D in a community in Italy of immigrants from NE Africa.

A total of 213 subjects from a community in Italy of immigrants from Somalia and other NE African countries were enrolled in this study to evaluate the prevalence of HAV, HBV, HCV and HDV infections and to assess their possible risk factors. Of the subjects, 45 per cent (96) were female and 24 per cent (52) were under 12 years old. The age range was from 1 to 67 years and the mean age was 24 years. Eighty-three per cent (177 subjects) were born in Somalia, 10 per cent (21 subjects) in Ethiopia, and the rest in Djibouti, Egypt or Saudi Arabia. The 213 subjects were administered a questionnaire which covered socio-demographic characteristics and risk factors resulting from Western medical practice, traditional medicine, personal behaviour and living conditions. Blood was drawn from 209 subjects to ascertain the presence of HbsAg, HBeAg, anti-HAV, anti-HBc, anti-HBs, anti-HCV and anti-HDV. The results of this study show an HAV prevalence of 96 per cent (an 87.5 per cent prevalence in children under 12), and an HBV prevalence of 32 per cent (a 3.3 per cent prevalence of HBsAg carriers). No subject under 11 was HBV positive and no woman tested positive for HBeAg, confirming the extreme unlikelihood of vertical transmission of HBV. The prevalence of HBV is closely correlated with age (ranging from 2 per cent in those under 12 to 59 per cent in subjects over 39).(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B mass immunization of adolescents: a pilot study in a community.

The National Type Specific Hepatitis Surveillance System (SEIEVA) and seroepidemiological studies have shown that in addition to newborns from mothers who are carriers for hepatitis B surface antigen (HBsAg), adolescents are at high risk of acquiring type B hepatitis virus because of increasing importance of the heterosexual transmission of this virus. In order to evaluate logistic problems and acceptance rate of adolescents to mass vaccination against hepatitis B, a pilot study was carried out among all 7th grade children registered in the 9 schools of an hepatitis B endemic area located in the suburbs of Naples. After meetings held by the local health department with school teachers and parents, 1219 out of 1250 (97.5%) invited children received the first dose of hepatitis B vaccine; 1215 and 1209 received, respectively, the second and third doses. Anti-hepatitis B surface antigen (anti-HBs) values were studied in 406 subjects one month after the third dose, and 21 out of 406 (5.2%) had anti-HBs values less than 10 IU/L. We consider 95% of subjects with anti-HBs values greater than 9 IU/L a good achievement for a field vaccination program. The high acceptance rate of vaccination found in our study outlines the importance of active offer of vaccination combined with school involvement.

Age-specific prevalence of hepatitis A virus infection among teenagers in Sardinia.

In 1989, the prevalence of antibodies to hepatitis A virus (anti-HAV) in a sample of 1350 Sardinian teenagers aged 14 to 19 years was estimated by Elisa method. The overall anti-HAV prevalence was 20%; it increased from 12.3% among 14-16 year old subjects to 27.4% in subjects aged 17-19 years (P less than 0.01). A slight female preponderance was observed (22.1% versus 17.9) but no statistically significant difference was attained. Compared with the corresponding figure (71.6% of prevalence rate) observed in North Sardinia in 1980, the results of the present study show a dramatic reduction in anti-HAV prevalence among teenagers. A significant association was found with sociodemographic factors: subjects whose fathers had less than six years of schooling, had a 2.1-fold risk (C.I. 95% = 1.5-3.1) and subjects belonging to a household of 6 or more under one roof had a 1.7-fold risk (C.I. 95% = 1.2-2.3) of previous exposure to hepatitis A virus (HAV) infection. These findings indicate that exposure to HAV in Sardinia is decreasing, probably because of improvements in socio-economic conditions during recent years. However, overcrowding and short paternal education appear to be important determinants of infection.

Cytomegalovirus infection in day care centers in Rome, Italy: viral excretion in children and occupational risk among workers.

From nine day care centers in Rome, Italy, 253 children of middle to low socioeconomic classes were examined for cytomegalovirus (CMV) excretion in saliva. The overall excretion rate was 13%, with no marked differences between centers. Socioeconomic level, age of enrollment, chronological age, length of attendance, and number of siblings did not have any discernible influence on viral shedding. The most notable result is that during the second year of age, 100% of the excretors had been breast fed, but only 60% in the third year, indicating that maternal transmission is the most likely source of children's infection early in life. Serologic survey of 82 female workers in day care centers, 82 matched housewives, and 229 female students aged 14 to 18 years who were in training to care for children showed that at 14 years of age the CMV seropositivity rate is 85, which suggests that primary infection during childbearing age is an uncommon event in Rome.