Ronan Kelly
Retired 2020
Re: New Zealand Influenza Surveillance 2012
Influenza surveillance in New Zealand
2012
First published: 9 April 2013
Revised: 17 April 2013
Lopez, L. and Q.S. Huang, Influenza Surveillance in New Zealand 2012,
2013, Institute of Environmental Science and Research Ltd (ESR): Wellington, New Zealand
SUMMARY
Influenza viruses frequently undergo antigenic changes and can cause substantial morbidity and mortality in a short space of time. National influenza surveillance in New Zealand is an essential public health component for assessing and implementing strategies to control influenza. Influenza surveillance in New Zealand monitors the incidence and distribution of influenza in the community, it assists with the early detection of influenza epidemics and identifies the predominant circulating strains. This report summarises the burden of disease in the community due to influenza, the circulating influenza virus strains, hospitalisations and immunisation coverage for 2012.
During the 2012 winter season, 4090 consultations for influenza-like illness (ILI) were reported from a national sentinel network of 85 general practices. It is estimated that ILI resulting in a visit to a general practitioner affected over 48,186 New Zealanders (1.1% of total population) during the season, compared with an estimated 41,133 people in 2011 (0.9% of total population).
Influenza activity peaked in August. Overall, ILI activity in 2012 was at a medium level compared with the 1997?2012 period. ILI consultation rates varied greatly among District Health Boards (DHBs), with the highest rates reported from Waitemata and South Canterbury DHBs.
As a key component of the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS), SARI (Severe Acute Respiratory Infections) surveillance has been established and fully functioning since 30th April 2012. The SARI surveillance and NMDS coding recorded high hospitalisation rates for very young and elderly subpopulations. SARI surveillance and NMDS coding also recorded higher hospitalisation rates for Pacific Peoples and Māori than for those of Asian, European or Other ethnic groups.
In 2012, a total of 2425 influenza viruses were detected. Of these, 87.4% were influenza A and 12.6% were influenza B. Of all the viruses typed and sub-typed (2130) during the season, the predominant strain was influenza A(H3N2) at 74.0%, 14.4% were influenza B, and 11.6% were A(H1N1)pdm09 strains. Antiviral susceptibility monitoring indicated that all influenza viruses tested (except two) were sensitive to oseltamivir. The first oseltamivir resistant influenza A(H1N1)pdm09 virus was detected from a 26 year old male who was hospitalised with an acute upper respiratory tract infection within seven days of returning to New Zealand from India. The second oseltamivir resistant influenza A(H1N1)pdm09 virus was detected from 7-month-old Samoan infant girl who was hospitalised with suspected pneumonia and had not travelled overseas prior to hospitalisation.
No significant antigenic drift was detected for influenza A(H1N1)pdm09 viruses. A(H3N2) viruses have genetically and antigenically drifted away from the A/Perth/16/2009-like strain and were closely related to A/Victoria/361/2011-like strain. Two lineages of influenza B viruses (B/Victoria and B/Yamagata lineages) were co-circulating in 2012 with an increased proportion of B/Yamagata lineage viruses. The B/Yamagata lineage viruses were antigenically closely related to the B/Wisconsin/1/2010-like strain. As a result, A(H3N2) and B components were updated for the influenza vaccine for 2013.
The recommended influenza vaccine formulation for New Zealand in 2013 is:
A(H1N1) an A/California/7/2009 (H1N1)-like strain*
A(H3N2) an A/Victoria/361/2011 (H3N2)-like strain
B a B/Wisconsin/1/2010-like strain
*Note: A/California/7/2009 is an influenza A(H1N1)pdm09 strain
...
http://www.surv.esr.cri.nz/PDF_surveillance/Virology/FluAnnRpt/InfluenzaAnn2012.pdf
Influenza surveillance in New Zealand
2012
First published: 9 April 2013
Revised: 17 April 2013
Lopez, L. and Q.S. Huang, Influenza Surveillance in New Zealand 2012,
2013, Institute of Environmental Science and Research Ltd (ESR): Wellington, New Zealand
SUMMARY
Influenza viruses frequently undergo antigenic changes and can cause substantial morbidity and mortality in a short space of time. National influenza surveillance in New Zealand is an essential public health component for assessing and implementing strategies to control influenza. Influenza surveillance in New Zealand monitors the incidence and distribution of influenza in the community, it assists with the early detection of influenza epidemics and identifies the predominant circulating strains. This report summarises the burden of disease in the community due to influenza, the circulating influenza virus strains, hospitalisations and immunisation coverage for 2012.
During the 2012 winter season, 4090 consultations for influenza-like illness (ILI) were reported from a national sentinel network of 85 general practices. It is estimated that ILI resulting in a visit to a general practitioner affected over 48,186 New Zealanders (1.1% of total population) during the season, compared with an estimated 41,133 people in 2011 (0.9% of total population).
Influenza activity peaked in August. Overall, ILI activity in 2012 was at a medium level compared with the 1997?2012 period. ILI consultation rates varied greatly among District Health Boards (DHBs), with the highest rates reported from Waitemata and South Canterbury DHBs.
As a key component of the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS), SARI (Severe Acute Respiratory Infections) surveillance has been established and fully functioning since 30th April 2012. The SARI surveillance and NMDS coding recorded high hospitalisation rates for very young and elderly subpopulations. SARI surveillance and NMDS coding also recorded higher hospitalisation rates for Pacific Peoples and Māori than for those of Asian, European or Other ethnic groups.
In 2012, a total of 2425 influenza viruses were detected. Of these, 87.4% were influenza A and 12.6% were influenza B. Of all the viruses typed and sub-typed (2130) during the season, the predominant strain was influenza A(H3N2) at 74.0%, 14.4% were influenza B, and 11.6% were A(H1N1)pdm09 strains. Antiviral susceptibility monitoring indicated that all influenza viruses tested (except two) were sensitive to oseltamivir. The first oseltamivir resistant influenza A(H1N1)pdm09 virus was detected from a 26 year old male who was hospitalised with an acute upper respiratory tract infection within seven days of returning to New Zealand from India. The second oseltamivir resistant influenza A(H1N1)pdm09 virus was detected from 7-month-old Samoan infant girl who was hospitalised with suspected pneumonia and had not travelled overseas prior to hospitalisation.
No significant antigenic drift was detected for influenza A(H1N1)pdm09 viruses. A(H3N2) viruses have genetically and antigenically drifted away from the A/Perth/16/2009-like strain and were closely related to A/Victoria/361/2011-like strain. Two lineages of influenza B viruses (B/Victoria and B/Yamagata lineages) were co-circulating in 2012 with an increased proportion of B/Yamagata lineage viruses. The B/Yamagata lineage viruses were antigenically closely related to the B/Wisconsin/1/2010-like strain. As a result, A(H3N2) and B components were updated for the influenza vaccine for 2013.
The recommended influenza vaccine formulation for New Zealand in 2013 is:
A(H1N1) an A/California/7/2009 (H1N1)-like strain*
A(H3N2) an A/Victoria/361/2011 (H3N2)-like strain
B a B/Wisconsin/1/2010-like strain
*Note: A/California/7/2009 is an influenza A(H1N1)pdm09 strain
...
http://www.surv.esr.cri.nz/PDF_surveillance/Virology/FluAnnRpt/InfluenzaAnn2012.pdf