title: High burden of invasive group A streptococcal disease in the Northern Territory of Australia.
abstract: Although the incidence of invasive group A streptococcal disease in northern Australia is very high, little is known of the regional epidemiology and molecular characteristics. We conducted a case series of Northern Territory residents reported between 2011 and 2013 with Streptococcus pyogenes isolates from a normally sterile site. Of the 128 reported episodes, the incidence was disproportionately high in the Indigenous population at 69·7/100 000 compared to 8·8/100 000 in the non-Indigenous population. Novel to the Northern Territory is the extremely high incidence in haemodialysis patients of 2205·9/100 000 population; and for whom targeted infection control measures could prevent transmission. The incidences in the tropical north and semi-arid Central Australian regions were similar. Case fatality was 8% (10/128) and streptococcal toxic shock syndrome occurred in 14 (11%) episodes. Molecular typing of 82 isolates identified 28 emm types, of which 63 (77%) were represented by four emm clusters. Typing confirmed transmission between infant twins. While the diverse range of emm types presents a challenge for effective coverage by vaccine formulations, the limited number of emm clusters raises optimism should cluster-specific cross-protection prove efficacious. Further studies are required to determine effectiveness of chemoprophylaxis for contacts and to inform public health response.
authors.affiliation: Centre for Disease Control,Tiwi,NT,Australia.
authors.forename: R
authors.initials: R
authors.lastname: Boyd
authors.affiliation: National Centre for Epidemiology and Population Health,Australian National University,Canberra,ACT,Australia.
authors.forename: M
authors.initials: M
authors.lastname: Patel
authors.affiliation: Royal Darwin Hospital,Tiwi,NT,Australia.
authors.forename: B J
authors.initials: BJ
authors.lastname: Currie
authors.affiliation: Division of Global and Tropical Health,Menzies School of Health Research,Charles Darwin University,Casuarina,NT,Australia.
authors.forename: D C
authors.initials: DC
authors.lastname: Holt
authors.affiliation: Division of Global and Tropical Health,Menzies School of Health Research,Charles Darwin University,Casuarina,NT,Australia.
authors.forename: T
authors.initials: T
authors.lastname: Harris
authors.affiliation: Centre for Disease Control,Tiwi,NT,Australia.
authors.forename: V
authors.initials: V
authors.lastname: Krause
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D015876:Northern Territory / Q000453:epidemiology; D015995:Prevalence; D012772:Shock, Septic / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D013297:Streptococcus pyogenes / Q000302:isolation & purification*; D055815:Young Adult
keywords: Infectious disease epidemiology; Streptococcus pyogenes; public health emerging infections; streptococcal infections; vaccines