title: Role of horizontal transmission in hepatitis B virus spread among household contacts in north India.
abstract: OBJECTIVE
  Familial clustering of HBV provides epidemiological evidence for the different modes of spread of the virus. Though the majority of the studies have addressed the issue of perinatal transmission in India, only a few reports have dealt with other modes of transmission.
  
  
  METHODS
  The study was prospectively designed and data were collected from a total of 265 household contacts of 91 index patients with HBV-related chronic liver disease between January 2006 and July 2007. The prevalences of HBsAg and various antibodies; anti-HBs, anti-HBc and anti-HBe, were estimated in all household contacts using ELISA and VIDAS.
  
  
  RESULTS
  Among the various household contacts, the highest prevalence of HBsAg was seen in the pediatric age group (kids 1-15 years: 37.0%) and especially in siblings (48.3%), with statistical significance (p < 0.001). Hepatitis B virus (HBV) serological markers were found more commonly in contacts of female (68.8%) index patients as compared to males (p > 0.05). The development of anti-HBV antibodies showed an increasing trend with age (p < 0.001), with the highest prevalence in parents.
  
  
  CONCLUSIONS
  Horizontal transmission plays an important role in contributing to the high prevalence of HBsAg especially in young children. Hence, this age group needs to be targeted for primary prevention and effective vaccine.
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Swati
authors.initials: S
authors.lastname: Gupta
authors.forename: Richa
authors.initials: R
authors.lastname: Gupta
authors.forename: Y K
authors.initials: YK
authors.lastname: Joshi
authors.forename: Sarman
authors.initials: S
authors.lastname: Singh
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D018562:Disease Transmission, Infectious; D005190:Family; D005192:Family Health; D005260:Female; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000635:transmission*; D006801:Humans; D007118:Immunoassay; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012737:Sex Factors; D035781:Siblings
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens