HBV infection in indigenous children, 20 years after immunization in Taiwan: a community-based study.
OBJECTIVE
Hepatitis B virus infection is hyperendemic in Taiwan. In the past, the infection rate has been higher in indigenous villages. The prevalence of chronic HBV infection among indigenous children after immunization remains unknown.


METHODS
A total of 843 indigenous children were checked for the hepatitis B seromarker. Another 606 metropolitan children were enrolled for comparison in 2005.


RESULTS
The seroprevalences (%) of HBsAg, (hepatitis B surface antigen) anti-HBs, (antibody to hepatitis B surface antigen) and anti-HBc (antibody to hepatitis B core antigen) among indigenous and metropolitan children were 3.2 vs. 0.17 (p<0.001), 47.4 vs. 51.2 (p=0.164), and 10.7 vs. 1.7 (p<0.001), respectively. Among the indigenous children, who were divided into three age groups, the prevalences of HBsAg and anti-HBc increased with age, while anti-HBs decreased significantly (p=0.025, 0.002, and <0.001, respectively). Children with positive HBsAg had a significantly higher mean (SD) age (10.2 (2.2) vs. 9.2 (2.1) years, p=0.024) and a higher ALT value (16.4 (8.0) vs. 10.6 (8.3) IU/L, p=0.001). In a multivariable analysis, indigenous residency, older age group and abnormal ALT value were independent factors associated with positive HBsAg.


CONCLUSIONS
The seroprevalence of hepatitis B infection has obviously declined among indigenous children 20 years after mass immunization programs launched in Taiwan. However, it is still higher than that of metropolitan children. Higher rates of chronic HBV infection in the mothers might be one important explanation for this finding.
Huang
Chung-Feng
CF
Department of Occupational and Environmental Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Dai
Chia-Yen
CY
Chuang
Wan-Long
WL
Ho
Chi-Kung
CK
Wu
Ta-Chung
TC
Hou
Nai-Jen
NJ
Wang
Chao-Ling
CL
Hsieh
Ming-Yen
MY
Huang
Jee-Fu
JF
Lin
Zu-Yau
ZY
Chen
Shinn-Cherng
SC
Hsieh
Ming-Yuh
MY
Wang
Liang-Yen
LY
Tsai
Jun-Fa
JF
Chang
Wen-Yu
WY
Yu
Ming-Lung
ML
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000208:ethnology* / Q000276:immunology; D006510:Hepatitis B Antibodies / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D007114:Immunization; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D013624:Taiwan / Q000453:epidemiology
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines