title: Community prevalence of hepatitis B infection and modes of transmission in Tamil Nadu, India.
abstract: OBJECTIVE
  There have been very few community based studies on prevalence of hepatitis B virus (HBV) infection in India. We undertook this study to determine the prevalence of HBV infection in a southern State of India, Tamil Nadu and to describe the important factors related to transmission of the virus in the community.
  
  
  METHODS
  Analysis of stored blood samples from a representative population of Tamil Nadu from an earlier community cluster survey on sexually transmitted diseases (STD) prevalence using proportionate to population size (PPS) technique was done. Serum markers of HBV viz., hapatitis B surface antigen (HBsAg), hepatitis B e antigen (HBe Ag) and antibody to surface antigen (anti-HBs) were performed.
  
  
  RESULTS
  1981 subjects were screened in the study. HBsAg prevalence was 5.7 per cent (CI 4.6- 6.8) with 23.5 per cent (25/106) of these having positive HBe-antigen. Community seroprevalence (HbsAg + anti-HBs) of hepatitis B infection was 27.4 per cent (CI: 25.3-29.5) with the highest prevalence of 32.7 per cent (CI: 30.2-35.2) noted in the 15-20 yr age group. Significant independent association (OR 1.4; P=0.006) was detected with family history of exposure to HBV infection by logistic modeling. Other risk factors noted to have significant association were use of disposable needles during injection (OR 0.5; P=0.02) in men, smoking (OR 3; P=0.04) and use of condom (OR 0.6; P=0.08) in women.
  
  
  CONCLUSIONS
  This community based study shows a high prevalence of hepatitis B infection in the state of Tamil Nadu with the highest prevalence being in the younger (15-20 yr) age group. High prevalence rate in childhood with e-antigenemia seen in 23.5 per cent of HBsAg positive subjects suggest childhood transmission. Poor injection practices and high-risk sexual behavior were found to be additional risk factors for transmission of the disease in the community.
authors.affiliation: Christian Medical College and Hospital, Vellore, India. kurien123@hotmail.com
authors.forename: T
authors.initials: T
authors.lastname: Kurien
authors.forename: S P
authors.initials: SP
authors.lastname: Thyagarajan
authors.forename: L
authors.initials: L
authors.lastname: Jeyaseelan
authors.forename: A
authors.initials: A
authors.lastname: Peedicayil
authors.forename: P
authors.initials: P
authors.lastname: Rajendran
authors.forename: S
authors.initials: S
authors.lastname: Sivaram
authors.forename: S G
authors.initials: SG
authors.lastname: Hansdak
authors.forename: G
authors.initials: G
authors.lastname: Renu
authors.forename: P
authors.initials: P
authors.lastname: Krishnamurthy
authors.forename: K
authors.initials: K
authors.lastname: Sudhakar
authors.forename: J C
authors.initials: JC
authors.lastname: Varghese
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology* / Q000635:transmission*; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006513:Hepatitis B e Antigens / Q000097:blood; D006801:Humans; D007194:India / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D012307:Risk Factors
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens