HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (43) Citing Articles via Google Scholar Google Scholar Articles by Wong, S. S. Y. Articles by Yuen, K.-y. Search for Related Content PubMed PubMed Citation Articles by Wong, S. S. Y. Articles by Yuen, K.-y. Related Content Global Medicine

Avian Influenza Virus Infections in Humans^*

^* From the Department of Microbiology, Research Centre of Infection and Immunology, State Key Laboratory of Emerging Infectious Disease, Faculty of Medicine, The University of Hong Kong, Hong Kong.

Correspondence to: Kwok-yung Yuen, MD, Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital, 102 Pokfulam Rd, Hong Kong; e-mail: hkumicro{at}hkucc.hku.hk

Abstract

Seroepidemiologic and virologic studies since 1889 suggested that human influenza pandemics were caused by H1, H2, and H3 subtypes of influenza A viruses. If not for the 1997 avian A/H5N1 outbreak in Hong Kong of China, subtype H2 is the likely candidate for the next pandemic. However, unlike previous poultry outbreaks of highly pathogenic avian influenza due to H5 that were controlled by depopulation with or without vaccination, the presently circulating A/H5N1 genotype Z virus has since been spreading from Southern China to other parts of the world. Migratory birds and, less likely, bird trafficking are believed to be globalizing the avian influenza A/H5N1 epidemic in poultry. More than 200 human cases of avian influenza virus infection due to A/H5, A/H7, and A/H9 subtypes mainly as a result of poultry-to-human transmission have been reported with a > 50% case fatality rate for A/H5N1 infections. A mutant or reassortant virus capable of efficient human-to-human transmission could trigger another influenza pandemic. The recent isolation of this virus in extrapulmonary sites of human diseases suggests that the high fatality of this infection may be more than just the result of a cytokine storm triggered by the pulmonary disease. The emergence of resistance to adamantanes (amantadine and rimantadine) and recently oseltamivir while H5N1 vaccines are still at the developmental stage of phase I clinical trial are causes for grave concern. Moreover, the to-be pandemic strain may have little cross immunogenicity to the presently tested vaccine strain. The relative importance and usefulness of airborne, droplet, or contact precautions in infection control are still uncertain. Laboratory-acquired avian influenza H7N7 has been reported, and the laboratory strains of human influenza H2N2 could also be the cause of another pandemic. The control of this impending disaster requires more research in addition to national and international preparedness at various levels. The epidemiology, virology, clinical features, laboratory diagnosis, management, and hospital infection control measures are reviewed from a clinical perspective.

Key Words: adamantane • avian influenza • H5N1 • H7N7 • influenza A virus • neuraminidase inhibitors

This article has been cited by other articles:

				C. Sandrock and N. Stollenwerk Acute Febrile Respiratory Illness in the ICU: Reducing Disease Transmission Chest, May 1, 2008; 133(5): 1221 - 1231. [Abstract] [Full Text] [PDF]

				R. S. Irwin The New "Face" of CHEST Heralds a New Era Chest, January 1, 2006; 129(1): 1 - 3. [Full Text] [PDF]