Increasing trends of herpes zoster in Australia.
BACKGROUND
Increasing trends in incidence of herpes zoster (HZ) have been reported in Australia and internationally. This may reflect the impact of childhood VZV vaccination programs introduced universally in Australia in late 2005. The objective of this study was to evaluate changes in incidence of HZ and PHN in Australia over time, and associated healthcare resource utilisation.


METHODS
Australian data on general practice (GP) encounters for HZ, specific antiviral prescribing data from the pharmaceutical benefits scheme, emergency department presentations from the states of NSW and Victoria and national hospitalisation data for HZ were analysed for time trends using regression models. Two time periods (2000-2006 and 2006-2013) were compared which correspond broadly with the pre- and post- universal VZV vaccination period.


RESULTS
All data sources showed increasing rates of HZ with age and over time. The GP database showed a significant annual increase in encounters for HZ of 2.5 per 100,000 between 1998 and 2013, and the rates of prescriptions for HZ increased by 4.2% per year between 2002 and 2012. In the 60+ population HZ incidence was estimated to increase from 11.9 to 15.4 per 1,000 persons using GP data or from 12.8 to 14.2 per 1,000 persons using prescription data (p<0.05, between the two periods). Hospitalisation data did not show the same increasing trend over time, except for the age group ≥80 years. Most emergency visits for HZ were not admitted, and showed significant increases over time.


CONCLUSIONS
The burden of HZ in Australia is substantial, and continues to increase over time. This increase is seen both pre- and post-universal VZV vaccination in 2005, and is most prominent in the older population. The substantial burden of HZ, along with ageing of the Australian population and the importance of healthy ageing, warrants consideration of HZ vaccination for the elderly.
School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia; National Centre for Immunisation Research (NCIRS), Sydney, Australia.
Raina
R
MacIntyre
bioCSL, Melbourne, Australia.
Alicia
A
Stein
Family Medicine Research Centre, University of Sydney, Sydney, Australia.
Christopher
C
Harrison
Family Medicine Research Centre, University of Sydney, Sydney, Australia.
Helena
H
Britt
School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia.
Abela
A
Mahimbo
Westmead Millennium Institute, University of Sydney, Sydney, Australia.
Anthony
A
Cunningham
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006562:Herpes Zoster / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D014739:Victoria / Q000453:epidemiology; D055815:Young Adult
D000998:Antiviral Agents