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J Infect Dis. 2015 Feb 23. pii: jiv109. [Epub ahead of print]
A Systematic Review and Meta-Analysis of the Seroprevalence of Influenza A (H9N2) Virus Infection Among Humans.
Khan SU1, Anderson BD2, Heil GL3, Liang S3, Gray GC4.
Author information
Abstract
INTRODUCTION:
Given that Influenza A (H9N2) subtype viruses are recognized as a pandemic threat, we evaluated the overall burden of H9N2 infections among avian-exposed human populations.
METHODS:
We performed a systematic literature search in PubMed, AGRICOLA, and Cab Abstracts databases from 1997 to 2013. Studies reporting serological evidence of human Influenza A(H9N2) infection among avian-exposed populations were included. We used a WHO-recommended case definition for serological evidence of infection through hemagglutination inhibition (HI) and microneutralization (MN) assays. We calculated overall seroprevalance through a random effects meta-analysis model.
RESULTS:
Seroprevalence figures reported by the studies ranged from 1% to 43% (median: 9%) by HI, which was not significantly different from the seroprevalence estimated through the WHO-recommended case definition (median: 1.3%, range:0.5%-42.6%). Reported seroprevalence by MN ranged from 0.6% to 9% (median: 2.7%), which was greater than the seroprevalence estimated through the WHO-recommended case definition (median: 0.3%, range: 0.1%-1.4%).
CONCLUSION:
A small proportion of avian-exposed humans had evidence of H9N2 infection. As the virus has a near global distribution in poultry, it seems likely that present surveillance efforts are missing mild or asymptomatic infections among avian-exposed persons. It seems prudent to closely monitor avian-exposed populations for H9N2 infection to provide pre-pandemic warnings.
? The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
PMID: 25712969 [PubMed - as supplied by publisher]
A Systematic Review and Meta-Analysis of the Seroprevalence of Influenza A (H9N2) Virus Infection Among Humans.
Khan SU1, Anderson BD2, Heil GL3, Liang S3, Gray GC4.
Author information
Abstract
INTRODUCTION:
Given that Influenza A (H9N2) subtype viruses are recognized as a pandemic threat, we evaluated the overall burden of H9N2 infections among avian-exposed human populations.
METHODS:
We performed a systematic literature search in PubMed, AGRICOLA, and Cab Abstracts databases from 1997 to 2013. Studies reporting serological evidence of human Influenza A(H9N2) infection among avian-exposed populations were included. We used a WHO-recommended case definition for serological evidence of infection through hemagglutination inhibition (HI) and microneutralization (MN) assays. We calculated overall seroprevalance through a random effects meta-analysis model.
RESULTS:
Seroprevalence figures reported by the studies ranged from 1% to 43% (median: 9%) by HI, which was not significantly different from the seroprevalence estimated through the WHO-recommended case definition (median: 1.3%, range:0.5%-42.6%). Reported seroprevalence by MN ranged from 0.6% to 9% (median: 2.7%), which was greater than the seroprevalence estimated through the WHO-recommended case definition (median: 0.3%, range: 0.1%-1.4%).
CONCLUSION:
A small proportion of avian-exposed humans had evidence of H9N2 infection. As the virus has a near global distribution in poultry, it seems likely that present surveillance efforts are missing mild or asymptomatic infections among avian-exposed persons. It seems prudent to closely monitor avian-exposed populations for H9N2 infection to provide pre-pandemic warnings.
? The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
PMID: 25712969 [PubMed - as supplied by publisher]