Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2017 Oct;22(7):1300-1312.
doi: 10.1111/resp.13114. Epub 2017 Jul 5.

A clinical approach to the threat of emerging influenza viruses in the Asia-Pacific region

David S C Hui  1   2 , Nelson Lee  1   2 , Paul K S Chan  2   3
Affiliations
Review

A clinical approach to the threat of emerging influenza viruses in the Asia-Pacific region

David S C Hui et al. Respirology. 2017 Oct.

Abstract

Seasonal influenza epidemics and periodic pandemics are important causes of morbidity and mortality. Patients with chronic co-morbid illness, those at the extremes of age and pregnant women are at higher risks of complications requiring hospitalization, whereas young adults and obese individuals were also at increased risk during the A(H1N1) pandemic in 2009. Avian influenza A(H5N1) and A(H7N9) viruses have continued to circulate widely in some poultry populations and infect humans sporadically since 1997 and 2013, respectively. The recent upsurge in human cases of A(H7N9) infections in Mainland China is of great concern. Sporadic human cases of avian A(H5N6), A(H10N8) and A(H6N1) have also emerged in recent years while there are also widespread poultry outbreaks due to A(H5N8) in many countries. Observational studies have shown that treatment with a neuraminidase inhibitor (NAI) for adults hospitalized with severe influenza is associated with lower mortality and better clinical outcomes, especially when administered early in the course of illness. Whether higher than standard doses of NAI would provide greater antiviral effects in such patients will require further investigation. High-dose systemic corticosteroids were associated with worse outcomes in patients with severe influenza. There is an urgent need for developing more effective antiviral therapies for treatment of influenza infections.

Keywords: avian influenza; respiratory tract infections; seasonal; treatment; viral.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Structure of influenza A virion. The virion of influenza A contains a host‐derived lipid envelope, embedding the haemagglutinin (HA, found as trimer), neuraminidase (NA, found as tetramer) and matrix protein 2 (M2, found as tetramer). HA is required for attachment (binding between the virion and the sialic acid residues on the host cell surface). NA is used for cleaving sialic acid receptors from the host cell membrane for new virion release. M2 is an ion channel for virion internal acidification, contributing to viral uncoating. The HA : NA ratio ranges from 4:1 to 5:1. Underlying the viral envelope, there is a layer of the matrix protein 1 (M1). Inside the virion, a nuclear export protein (NEP/NS2) is also found. Eight single‐stranded, negative‐sensed viral RNA molecules are coated with nucleoproteins and bound by the RNA polymerase complex: polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2) and polymerase acidic protein (PA).
Figure 2
Figure 2
Geographic distribution of the fifth wave of human infection with avian influenza A(H7N9) in Mainland China.29 Cases include those reported from October 2016 to 25 March 2017. Two cases in Beijing were imported from Hebei and Liaoning. Two cases in Yunnan Province were imported from Jiangxi.
Figure 3
Figure 3
Geographic distribution of human infection with avian influenza A(H5N6) in Mainland China.29 Cases include those reported from 2014 till 25 March 2017. One case in Jiangxi was imported from Guangdong.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Yuen KY, Chan PK, Peiris M, Tsang DN, Que TL, Shortridge KF, Cheung PT, To WK, Ho ET, Sung R et al. Clinical features and rapid viral diagnosis of human disease associated with avian influenza A H5N1 virus. Lancet 1998; 351: 467–71. - PubMed
    1. Gao R, Cao B, Hu Y, Feng Z, Wang D, Hu W, Chen J, Jie Z, Qiu H, Xu K et al. Human infection with a novel avian‐origin influenza A (H7N9) virus. N. Engl. J. Med. 2013; 368: 1888–97. - PubMed
    1. WHO China statement on H5N6, 2014. [Accessed 12 Feb 2017.] Available from URL: http://www.wpro.who.int/china/mediacentre/releases/2014/20140507/en/
    1. Chen H, Yuan H, Gao R, Zhang J, Wang D, Xiong Y, Fan G, Yang F, Li X, Zhou J et al. Clinical and epidemiological characteristics of a fatal case of avian influenza A H10N8 virus infection: a descriptive study. Lancet 2014; 383: 714–21. - PubMed
    1. Wei SH, Yang JR, Wu HS, Chang MC, Lin JS, Lin CY, Liu YL, Lo YC, Yang CH, Chuang JH et al. Human infection with avian influenza A H6N1 virus: an epidemiological analysis. Lancet Respir. Med. 2013; 1: 771–8. - PMC - PubMed

Publication types

MeSH terms

Substances