1887
Surveillance Open Access
Like 0

Abstract

Background

Interseasonal influenza outbreaks are not unusual in countries with temperate climates and well-defined influenza seasons. Usually, these are small and diminish before the main influenza season begins. However, the 2018/19 summer-autumn interseasonal influenza period in Australia saw unprecedented large and widespread influenza outbreaks.

Aim

Our objective was to determine the extent of the intense 2018/19 interseasonal influenza outbreaks in Australia epidemiologically and examine the genetic, antigenic and structural properties of the viruses responsible for these outbreaks.

Methods

This observational study combined the epidemiological and virological surveillance data obtained from the Australian Government Department of Health, the New South Wales Ministry of Health, sentinel outpatient surveillance, public health laboratories and data generated by the World Health Organization Collaborating Centre for Reference and Research on Influenza in Melbourne and the Singapore Agency for Science, Technology and Research.

Results

There was a record number of laboratory-confirmed influenza cases during the interseasonal period November 2018 to May 2019 (n= 85,286; 5 times the previous 3-year average) and also more institutional outbreaks, hospitalisations and deaths, than what is normally seen.

Conclusions

The unusually large interseasonal influenza outbreaks in 2018/19 followed a mild 2018 influenza season and resulted in a very early start to the 2019 influenza season across Australia. The reasons for this unusual event have yet to be fully elucidated but are likely to be a complex mix of climatic, virological and host immunity-related factors. These outbreaks reinforce the need for year-round surveillance of influenza, even in temperate climates with strong seasonality patterns.

Loading

Article metrics loading...

/content/10.2807/1560-7917.ES.2019.24.33.1900421
2019-08-15
2024-04-20
http://instance.metastore.ingenta.com/content/10.2807/1560-7917.ES.2019.24.33.1900421
Loading
Loading full text...

Full text loading...

/deliver/fulltext/eurosurveillance/24/33/eurosurv-24-33-4.html?itemId=/content/10.2807/1560-7917.ES.2019.24.33.1900421&mimeType=html&fmt=ahah

References

  1. Australian Government Department of Health. Australian influenza surveillance report. No. 11, 8 to 21 October 2018. Canberra: Department of Health; 2018. Available from: https://www1.health.gov.au/internet/main/publishing.nsf/Content/95C0B11D8F89FAD9CA2583310081EB12/$File/flu-11-2018.pdf
  2. Australian Government Department of Health. 2017 influenza season in Australia: a summary from the National Influenza Surveillance Committee. Canberra: Department of Health; 2017. Available from: https://www1.health.gov.au/internet/main/publishing.nsf/Content/097F15A91C05FBE7CA2581E20017F09E/$File/2017-season-summary-22112017.pdf
  3. Australian Government Department of Health. National Notifiable Diseases Surveillance System. Canberra: Department of Health; 2019. Available from: http://www9.health.gov.au/cda/source/cda-index.cfm
  4. Australian Government Department of Health. Australian Influenza Surveillance Report. No. 3, 20 May to 2 June 2019. Canberra: Department of Health; 2019. Available from: https://www1.health.gov.au/internet/main/publishing.nsf/Content/4D293F7E2BC0D652CA258410007C304F/$File/flu-03-2019.pdf
  5. NSW Influenza surveillance reports for 2019. Sydney: NSW Ministry of Health. [Accessed: 22 Jul 2019]. Available from: https://www.health.nsw.gov.au/Infectious/Influenza/Pages/reports.aspx
  6. Hobson D, Curry RL, Beare AS, Ward-Gardner A. The role of serum haemagglutination-inhibiting antibody in protection against challenge infection with influenza A2 and B viruses. J Hyg (Lond). 1972;70(4):767-77. PMID: 4509641 
  7. Tilmanis D, van Baalen C, Oh DY, Rossignol JF, Hurt AC. The susceptibility of circulating human influenza viruses to tizoxanide, the active metabolite of nitazoxanide. Antiviral Res. 2017;147:142-8.  https://doi.org/10.1016/j.antiviral.2017.10.002  PMID: 28986103 
  8. Shu Y, McCauley J. GISAID: Global initiative on sharing all influenza data - from vision to reality. Euro Surveill. 2017;22(13):30494.  https://doi.org/10.2807/1560-7917.ES.2017.22.13.30494  PMID: 28382917 
  9. Katoh K, Standley DM. MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Mol Biol Evol. 2013;30(4):772-80.  https://doi.org/10.1093/molbev/mst010  PMID: 23329690 
  10. Stamatakis A. RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics. 2014;30(9):1312-3.  https://doi.org/10.1093/bioinformatics/btu033  PMID: 24451623 
  11. Sagulenko P, Puller V, Neher RA. TreeTime: Maximum-likelihood phylodynamic analysis. Virus Evol. 2018;4(1):vex042.  https://doi.org/10.1093/ve/vex042  PMID: 29340210 
  12. Xu R, Zhu X, McBride R, Nycholat CM, Yu W, Paulson JC, et al. Functional balance of the hemagglutinin and neuraminidase activities accompanies the emergence of the 2009 H1N1 influenza pandemic. J Virol. 2012;86(17):9221-32.  https://doi.org/10.1128/JVI.00697-12  PMID: 22718832 
  13. An Y, Parsons LM, Jankowska E, Melnyk D, Joshi M, Cipollo JF. N-glycosylation of seasonal influenza vaccine hemagglutinins: implication for potency testing and immune processing. J Virol. 2019;93(2):e01693-18.  https://doi.org/10.1128/JVI.01693-18  PMID: 30355697 
  14. Australian Government Department of Health. Australian influenza surveillance report. No. 6, 1 to 14 July 2019. Canberra: Department of Health; 2019. Available from: https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu-flucurr.htm/$File/flu-06-2019.pdf
  15. New South Wales Ministry of Health. Influenza surveillance weekly report, Week 22: 27 May to 2 June 2019. Sydney: New South Wales Ministry of Health; 2019. Available from: https://www.health.nsw.gov.au/Infectious/Influenza/Publications/2019/weekending-02062019.pdf
  16. Hadfield J, Megill C, Bell SM, Huddleston J, Potter B, Callender C, et al. Nextstrain: real-time tracking of pathogen evolution. Bioinformatics. 2018;34(23):4121-3.  https://doi.org/10.1093/bioinformatics/bty407  PMID: 29790939 
  17. Van Durme J, Delgado J, Stricher F, Serrano L, Schymkowitz J, Rousseau F. A graphical interface for the FoldX forcefield. Bioinformatics. 2011;27(12):1711-2.  https://doi.org/10.1093/bioinformatics/btr254  PMID: 21505037 
  18. Fielding JE, Regan AK, Dalton CB, Chilver MB, Sullivan SG. How severe was the 2015 influenza season in Australia? Med J Aust. 2016;204(2):60-1.  https://doi.org/10.5694/mja15.01094  PMID: 26821099 
  19. Kelly HA, Grant KA, Tay EL, Franklin L, Hurt AC. The significance of increased influenza notifications during spring and summer of 2010-11 in Australia. Influenza Other Respir Viruses. 2013;7(6):1136-41.  https://doi.org/10.1111/irv.12057  PMID: 23176174 
  20. Geoghegan JL, Saavedra AF, Duchêne S, Sullivan S, Barr I, Holmes EC. Correction: Continental synchronicity of human influenza virus epidemics despite climactic variation. PLoS Pathog. 2018;14(2):e1006903.  https://doi.org/10.1371/journal.ppat.1006903  PMID: 29414984 
  21. Feng S, Chiu SS, Chan ELY, Kwan MYW, Wong JSC, Leung CW, et al. Effectiveness of influenza vaccination on influenza-associated hospitalisations over time among children in Hong Kong: a test-negative case-control study. Lancet Respir Med. 2018;6(12):925-34.  https://doi.org/10.1016/S2213-2600(18)30419-3  PMID: 30442587 
  22. Mossong J, Hens N, Jit M, Beutels P, Auranen K, Mikolajczyk R, et al. Social contacts and mixing patterns relevant to the spread of infectious diseases. PLoS Med. 2008;5(3):e74.  https://doi.org/10.1371/journal.pmed.0050074  PMID: 18366252 
  23. Scott S. Flu vaccine stocks to be boosted after early rush saps supplies across Australia. Sydney: ABC; 2018. Available from: https://www.abc.net.au/news/2018-05-26/flu-vax-to-get-boost-after-shortage/9801904
  24. Tsou TP, Su CP, Huang WT, Yang JR, Liu MT. Influenza A(H3N2) virus variants and patient characteristics during a summer influenza epidemic in Taiwan, 2017. Euro Surveill. 2017;22(50).  https://doi.org/10.2807/1560-7917.ES.2017.22.50.17-00767  PMID: 29258649 
  25. Zhu H, Lee ACY, Li C, Mak WWN, Chen YY, Chan KH, et al. Low population serum microneutralization antibody titer against the predominating influenza A(H3N2) N121K virus during the severe influenza summer peak of Hong Kong in 2017. Emerg Microbes Infect. 2018;7(1):23.  https://doi.org/10.1038/s41426-018-0041-1  PMID: 29511175 
  26. Sunagawa S, Iha Y, Taira K, Okano S, Kinjo T, Higa F, et al. An epidemiological analysis of summer influenza epidemics in Okinawa. Intern Med. 2016;55(24):3579-84.  https://doi.org/10.2169/internalmedicine.55.7107  PMID: 27980256 
  27. Australian Government Bureau of Meterology. Six-monthly rainfall totals for Australia. Melbourne: Bureau of Meterology. [Accessed: 22 Jul 2019]. Available from: http://www.bom.gov.au/jsp/awap/rain/index.jsp?colour=colour&time=latest&step=0&map=totals&period=6month&area=nat
  28. Kissling E, Rose A, Emborg HD, Gherasim A, Pebody R, Pozo F, et al. Interim 2018/19 influenza vaccine effectiveness: six European studies, October 2018 to January 2019. Euro Surveill. 2019;24(8):1900121.  https://doi.org/10.2807/1560-7917.ES.2019.24.1900121  PMID: 30808440 
  29. Skowronski DM, Leir S, Sabaiduc S, Murti M, Dickinson JA, Olsha R, et al. Interim estimates of 2018/19 vaccine effectiveness against influenza A(H1N1)pdm09, Canada, January 2019. Euro Surveill. 2019;24(4):1900055.  https://doi.org/10.2807/1560-7917.ES.2019.24.4.1900055  PMID: 30696523 
  30. Zost SJ, Parkhouse K, Gumina ME, Kim K, Diaz Perez S, Wilson PC, et al. Contemporary H3N2 influenza viruses have a glycosylation site that alters binding of antibodies elicited by egg-adapted vaccine strains. Proc Natl Acad Sci USA. 2017;114(47):12578-83.  https://doi.org/10.1073/pnas.1712377114  PMID: 29109276 
  31. Patterson Ross Z, Komadina N, Deng YM, Spirason N, Kelly HA, Sullivan SG, et al. Inter-seasonal influenza is characterized by extended virus transmission and persistence. PLoS Pathog. 2015;11(6):e1004991.  https://doi.org/10.1371/journal.ppat.1004991  PMID: 26107631 
  32. Australian Bureau of Statistics. 3218.0 - Regional Population Growth, Australia, 2017-18. Canberra: Australian Bureau of Statistics. [Accessed: 22 Jul 2019]. Available from: https://www.abs.gov.au/AUSSTATS/[email protected]/Lookup/3218.0Main+Features12017-18?OpenDocument
/content/10.2807/1560-7917.ES.2019.24.33.1900421
Loading

Data & Media loading...

Supplementary data

Submit comment
Close
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error