Objective: To describe the epidemiology of acute lower respiratory infection (ALRI) and bronchiectasis in Northern Territory Indigenous infants hospitalised in the first year of life. Design: A historical cohort study constructed from the NT Hospital Discharge Dataset and the NT Immunisation Register. Participants and setting: All NT resident Indigenous infants, born 1 January 1999 to 31 December 2004, admitted to NT public hospitals and followed up to 12 months of age. Main outcome measures: Incidence of ALRI and bronchiectasis (ICD‐10‐AM codes) and radiologically confirmed pneumonia (World Health Organization protocol). Results: Data on 9295 infants, 8498 child‐years of observation and 15 948 hospitalised episodes of care were analysed. ALRI incidence was 426.7 episodes per 1000 child‐years (95% CI, 416.2–437.2). Incidence rates were two times higher (relative risk, 2.12; 95% CI, 1.98–2.27) for infants in Central Australia compared with those in the Top End. The median age at first admission for an ALRI was 4.6 months (interquartile range, 2.6–7.3). Bronchiolitis accounted for most of the disease burden, with a rate of 227 per 1000 child‐years. The incidence of first diagnosis of bronchiectasis was 1.18 per 1000 child‐years (95% CI, 0.60–2.16). One or more key comorbidities were present in 1445 of the 3227 (44.8%) episodes of care for ALRI. Conclusions: Rates of ALRI and bronchiectasis in NT Indigenous infants are excessive, with early onset, frequent repeat episodes, and a high prevalence of comorbidities. These high rates of disease demand urgent attention.

Objective: To estimate the incidence and severity of invasive group A streptococcal infection in Victoria, Australia. Design: Prospective active surveillance study. Setting: Public and private laboratories, hospitals and general practitioners throughout Victoria. Patients: People in Victoria diagnosed with group A streptococcal disease notified to the surveillance system between 1 March 2002 and 31 August 2004. Main outcome measure: Confirmed invasive group A streptococcal disease. Results: We identified 333 confirmed cases: an average annualised 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. Conclusion: 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.