Infection of immunocompromised patients by avian H9N2 influenza A virus

J Infect. 2011 May;62(5):394-9. doi: 10.1016/j.jinf.2011.02.007. Epub 2011 Feb 26.

Abstract

Avian influenza A (H9N2) virus is transmitted sporadically from avian species to human causing mild diseases in immunocompetent person. We report two cases of human infection in immunocompromised patients in Hong Kong between 2008 and 2009. One patient had uneventful recovery with viral shedding at day 10 after symptom onset despite her underlying acute lymphoblastic leukaemia. The other patient with post-bone marrow transplant chronic graft-versus-host disease and bronhioltis obliterans went into respiratory failure. Genetic analysis revealed that these cases were caused by different genetic variants which are circulating in poultry in this region. Review of literature identified another 9 human cases reported in Southern China since 1988. It is possible that human infection with H9N2 is more common than what has been recognized. Continuous surveillance of H9N2 influenza virus infection in human is warranted.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Marrow Transplantation / adverse effects
  • China
  • Female
  • Genotype
  • Hong Kong
  • Humans
  • Immunocompromised Host*
  • Infant
  • Influenza A Virus, H9N2 Subtype / classification
  • Influenza A Virus, H9N2 Subtype / genetics
  • Influenza A Virus, H9N2 Subtype / isolation & purification*
  • Influenza, Human / complications
  • Influenza, Human / diagnosis*
  • Influenza, Human / pathology
  • Influenza, Human / virology*
  • Middle Aged
  • RNA, Viral / genetics
  • Respiratory Insufficiency / diagnosis
  • Respiratory Insufficiency / etiology
  • Time Factors
  • Virus Shedding

Substances

  • RNA, Viral