Antibody response in individuals infected with avian influenza A (H5N1) viruses and detection of anti-H5 antibody among household and social contacts

J Infect Dis. 1999 Dec;180(6):1763-70. doi: 10.1086/315137.


The first documented outbreak of human respiratory disease caused by avian influenza A (H5N1) viruses occurred in Hong Kong in 1997. The kinetics of the antibody response to the avian virus in H5N1-infected persons was similar to that of a primary response to human influenza A viruses; serum neutralizing antibody was detected, in general, >/=14 days after symptom onset. Cohort studies were conducted to assess the risk of human-to-human transmission of the virus. By use of a combination of serologic assays, 6 of 51 household contacts, 1 of 26 tour group members, and none of 47 coworkers exposed to H5N1-infected persons were positive for H5 antibody. One H5 antibody-positive household contact, with no history of poultry exposure, provided evidence that human-to-human transmission of the avian virus may have occurred through close physical contact with H5N1-infected patients. In contrast, social exposure to case patients was not associated with H5N1 infection.

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Antibodies, Viral / blood*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Family Health
  • Female
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology*
  • Humans
  • Infant
  • Influenza A Virus, H5N1 Subtype*
  • Influenza A virus / immunology*
  • Influenza A virus / isolation & purification
  • Influenza, Human / immunology*
  • Influenza, Human / transmission*
  • Influenza, Human / virology
  • Interpersonal Relations
  • Male
  • Middle Aged
  • Neutralization Tests
  • Poultry / virology


  • Antibodies, Viral
  • Hemagglutinin Glycoproteins, Influenza Virus
  • hemagglutinin, avian influenza A virus