Hepatitis B virus markers among teenagers in the Araguaia region, Central Brazil: Assessment of prevalence and vaccination coverage.

[Guest guest]

Vaccine. 2011 May 23. [Epub ahead of print]

Hepatitis B virus markers among teenagers in the Araguaia region, Central

Brazil: Assessment of prevalence and vaccination coverage.

Melo LV, Silva MA, Calçada CD, Cavalcante SR, Souto FJ.

Source

Centro Universitário do Araguaia, Universidade Federal de Mato Grosso [Araguaia

University Center of the Federal University of Mato Grosso], Rodovia BR-070, Km

5, Barra do Garças 78600-000, Mato Grosso, Brazil.

Abstract

The Brazilian hepatitis B (HBV) vaccination program for neonates was implemented

in 1998 and broadened to include young people up to 20 years of age in 2001.

However, HBV coverage of teenagers has not been systematically assessed in

Brazil. A cross-sectional study was performed to estimate the magnitude of HBV

infection and vaccine coverage among adolescent students regularly enrolled in

the public schools of Barra do Garças, a city located in the state of Mato

Grosso, Brazil. A representative sample was randomly obtained and participants

were interviewed and had blood samples collected to test for HBV markers. The

sample was composed of 576 subjects, 51% of which were females. The average age

was 15, with the group ranging from 12 to 20 years of age. There were 29

anti-HBc reactive participants (5.0%). Four out of 29 were HBsAg positive

(0.7%). Anti-HBs alone (vaccinated profile) showed in 323 (56.1%) students and

224 (38.9%) were negative for all HBV markers. Increasing age was associated

with HBV exposure in a χ(2) for trend analysis (p=0.004). The prevalence of

anti-HBs alone decreased as the subjects' age increased. Multivariate analysis

showed independent association between HBV infection and the start of sexual

activity. Another associated variable was the fact that the some students were

enrolled in two low-income neighborhood schools. Our findings classify this area

as low endemic for HBV and suggest that there is a progressive decrease in the

spread of HBV in the region due to the introduction of universal vaccination of

neonates. Approximately half of the adolescents 15 years or older were not

immunized, which raises a concern in terms of the need to increase the

vaccination rate for this segment of the population.

Published by Elsevier Ltd.

PMID: 21605613 [PubMed - as supplied by publisher]

[Guest guest]

Vaccine. 2011 May 23. [Epub ahead of print]

Hepatitis B virus markers among teenagers in the Araguaia region, Central

Brazil: Assessment of prevalence and vaccination coverage.

Melo LV, Silva MA, Calçada CD, Cavalcante SR, Souto FJ.

Source

Centro Universitário do Araguaia, Universidade Federal de Mato Grosso [Araguaia

University Center of the Federal University of Mato Grosso], Rodovia BR-070, Km

5, Barra do Garças 78600-000, Mato Grosso, Brazil.

Abstract

The Brazilian hepatitis B (HBV) vaccination program for neonates was implemented

in 1998 and broadened to include young people up to 20 years of age in 2001.

However, HBV coverage of teenagers has not been systematically assessed in

Brazil. A cross-sectional study was performed to estimate the magnitude of HBV

infection and vaccine coverage among adolescent students regularly enrolled in

the public schools of Barra do Garças, a city located in the state of Mato

Grosso, Brazil. A representative sample was randomly obtained and participants

were interviewed and had blood samples collected to test for HBV markers. The

sample was composed of 576 subjects, 51% of which were females. The average age

was 15, with the group ranging from 12 to 20 years of age. There were 29

anti-HBc reactive participants (5.0%). Four out of 29 were HBsAg positive

(0.7%). Anti-HBs alone (vaccinated profile) showed in 323 (56.1%) students and

224 (38.9%) were negative for all HBV markers. Increasing age was associated

with HBV exposure in a χ(2) for trend analysis (p=0.004). The prevalence of

anti-HBs alone decreased as the subjects' age increased. Multivariate analysis

showed independent association between HBV infection and the start of sexual

activity. Another associated variable was the fact that the some students were

enrolled in two low-income neighborhood schools. Our findings classify this area

as low endemic for HBV and suggest that there is a progressive decrease in the

spread of HBV in the region due to the introduction of universal vaccination of

neonates. Approximately half of the adolescents 15 years or older were not

immunized, which raises a concern in terms of the need to increase the

vaccination rate for this segment of the population.

Published by Elsevier Ltd.

PMID: 21605613 [PubMed - as supplied by publisher]