tetano
Editor, Senior Moderator
J Clin Virol. 2012 Nov 29. pii: S1386-6532(12)00399-X. doi: 10.1016/j.jcv.2012.11.002. [Epub ahead of print]
A "pre-seasonal" hospital outbreak of influenza pneumonia caused by the drift variant A/Victoria/361/2011-like H3N2 viruses, Hong Kong, 2011.
Chan MC, Lee N, Ngai KL, Wong BC, Lee MK, Choi KW, Lai RW, Chan PK.
Source
Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China. Electronic address: martin.chan@cuhk.edu.hk.
Abstract
BACKGROUND:
Beginning from late 2011 and early 2012, increasing circulation of antigenically drifted influenza A/Victoria/361/2011-like H3N2 viruses within genotype 3 of the A/Victoria/208/2009 clade have been reported in multiple European countries and elsewhere. Whether these emerging viruses are associated with increased disease severity is unclear.
OBJECTIVES:
To report the clinical and virological findings of a moderately severe hospital outbreak of A/Victoria/361/2011-like viruses that occurred in November 2011 in Hong Kong.
STUDY DESIGN:
Clinical and virological hospital outbreak investigation.
RESULTS:
The outbreak occurred in an adult psychiatric ward in November 2011, a time well before the usual local seasonal influenza winter peak. Altogether, 7 patients and 1 healthcare-worker were affected (mean age, 47 [range, 34-61] years). The attack rates among patients and healthcare-workers were 33% (7/21) and 7% (1/15), respectively. Pneumonia developed in 38% (3/8) of cases; none had underlying immunocompromised conditions. High nasopharyngeal viral loads were detected. All cases responded to antiviral treatment. Multiple amino acid mutations with reference to earlier A(H3N2) vaccine strains were mapped to key antigenic sites on hemagglutinin; however, no critical mutations on receptor binding sites were detected. Viral sequence variations jeopardized the performance of molecular diagnostic assays.
CONCLUSIONS:
Severe disease and pneumonia occurred in a substantial proportion of non-immunocompromised adults in a hospital outbreak attributed to the emerging antigenically drifted A/Victoria/361/2011-like H3N2 viruses. Close monitoring of the transmission of this drift variant is required. Further studies are also necessary to determine virus virulence.
Copyright ? 2012 Elsevier B.V. All rights reserved.
PMID:
23201458
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23201458
A "pre-seasonal" hospital outbreak of influenza pneumonia caused by the drift variant A/Victoria/361/2011-like H3N2 viruses, Hong Kong, 2011.
Chan MC, Lee N, Ngai KL, Wong BC, Lee MK, Choi KW, Lai RW, Chan PK.
Source
Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, People's Republic of China. Electronic address: martin.chan@cuhk.edu.hk.
Abstract
BACKGROUND:
Beginning from late 2011 and early 2012, increasing circulation of antigenically drifted influenza A/Victoria/361/2011-like H3N2 viruses within genotype 3 of the A/Victoria/208/2009 clade have been reported in multiple European countries and elsewhere. Whether these emerging viruses are associated with increased disease severity is unclear.
OBJECTIVES:
To report the clinical and virological findings of a moderately severe hospital outbreak of A/Victoria/361/2011-like viruses that occurred in November 2011 in Hong Kong.
STUDY DESIGN:
Clinical and virological hospital outbreak investigation.
RESULTS:
The outbreak occurred in an adult psychiatric ward in November 2011, a time well before the usual local seasonal influenza winter peak. Altogether, 7 patients and 1 healthcare-worker were affected (mean age, 47 [range, 34-61] years). The attack rates among patients and healthcare-workers were 33% (7/21) and 7% (1/15), respectively. Pneumonia developed in 38% (3/8) of cases; none had underlying immunocompromised conditions. High nasopharyngeal viral loads were detected. All cases responded to antiviral treatment. Multiple amino acid mutations with reference to earlier A(H3N2) vaccine strains were mapped to key antigenic sites on hemagglutinin; however, no critical mutations on receptor binding sites were detected. Viral sequence variations jeopardized the performance of molecular diagnostic assays.
CONCLUSIONS:
Severe disease and pneumonia occurred in a substantial proportion of non-immunocompromised adults in a hospital outbreak attributed to the emerging antigenically drifted A/Victoria/361/2011-like H3N2 viruses. Close monitoring of the transmission of this drift variant is required. Further studies are also necessary to determine virus virulence.
Copyright ? 2012 Elsevier B.V. All rights reserved.
PMID:
23201458
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23201458
