The epidemiology of invasive group A streptococcal disease in Victoria, Australia.
OBJECTIVE
To estimate the incidence and severity of invasive group A streptococcal infection in Victoria, Australia.


METHODS
Prospective active surveillance study.


METHODS
Public and private laboratories, hospitals and general practitioners throughout Victoria.


METHODS
People in Victoria diagnosed with group A streptococcal disease notified to the surveillance system between 1 March 2002 and 31 August 2004.


METHODS
Confirmed invasive group A streptococcal disease.


RESULTS
We identified 333 confirmed cases: an average annual incidence rate of 2.7 (95% CI, 2.3-3.2) per 100,000 population per year. Rates were highest in people aged 65 years and older and those younger than 5 years. The case-fatality rate was 7.8%. Streptococcal toxic shock syndrome occurred in 48 patients (14.4%), with a case-fatality rate of 23%. Thirty cases of necrotising fasciitis were reported; five (17%) of these patients died. Type 1 (23%) was the most frequently identified emm sequence type in all age groups. All tested isolates were susceptible to penicillin and clindamycin. Two isolates (4%) were resistant to erythromycin.


CONCLUSIONS
The incidence of invasive group A streptococcal disease in temperate Australia is greater than previously appreciated and warrants greater public health attention, including its designation as a notifiable disease.
O'Grady
Kerry-Ann F
KA
School of Population Health, Department of Paediatrics, University of Melbourne, Melbourne, VIC. k.ogrady@unimelb.edu.au
Kelpie
Loraine
L
Andrews
Ross M
RM
Curtis
Nigel
N
Nolan
Terence M
TM
Selvaraj
Gowri
G
Passmore
Jonathan W
JW
Oppedisano
Frances
F
Carnie
John A
JA
Carapetis
Jonathan R
JR
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005194:Family Practice / Q000706:statistics & numerical data; D019115:Fasciitis, Necrotizing / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007755:Laboratories, Hospital / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology / Q000401:mortality / Q000473:pathology; D013297:Streptococcus pyogenes / Q000235:genetics / Q000302:isolation & purification*; D014739:Victoria / Q000453:epidemiology