Invasive pneumococcal disease in the population of Victoria.

OBJECTIVES: To estimate morbidity and mortality rates for invasive Streptococcus pneumoniae (pneumococcal) disease in the non-Indigenous population of Victoria. DESIGN AND SETTING: Survey using data from a statewide voluntary laboratory surveillance scheme (1989-1998), statewide hospital discharge database (1995-1998), medical records of notified patients (1994-1995) and serotyping of notified isolates (1994-1998). MAIN OUTCOME MEASURES: Incidence of pneumococcal bacteraemia and pneumonia; predisposing factors; serotypes of isolates. RESULTS: Minimum estimates of annual incidence of invasive disease, based on laboratory surveillance data for 1995-1998, were 59 per 100,000 for children aged < 2 years, 25 per 100,000 for people aged > or = 65 years, and 8 per 100,000 overall. Annual incidence of pneumococcal pneumonia, calculated from hospital discharge data, was 99 per 100,000 for those aged > or = 65 years. Manifestations of invasive pneumococcal disease varied with age, with meningitis more common in infants, and pneumonia most common in older patients. A predisposing factor for pneumococcal infection was present in 48% of patients. Most isolates from infants (83%) belonged to serotypes in the proposed seven-valent infant vaccine, and 91% of isolates from people aged > or = 2 years belonged to serotypes in the current 23-valent adult vaccine. CONCLUSIONS: S. pneumoniae continues to be a major cause of morbidity and mortality in young children and the elderly in Victoria. More widespread use of the currently available pneumococcal vaccine in adults and introduction of an effective vaccine for infants should greatly reduce incidence of the disease.

Non-toxigenic Corynebacterium diphtheriae biovar gravis: evidence for an invasive clone in a south-eastern Australian community.

OBJECTIVE: To determine the prevalence and clonality of non-toxigenic Corynebacterium diphtheriae biovar gravis in a community with two cases of endocarditis caused by this organism. SETTING: A Koorie (Aboriginal) community in Gippsland, eastern Victoria, in 1994. METHODS: Nose and throat swabs were collected from 359 community contacts of the cases and cultured for C. diphtheriae. Strains isolated from the contacts were compared by pulsed-field gel electrophoresis (after digestion with Sma1, Not1 and Sfi1) with those from the invasive cases in the same community, another invasive case in Victoria, a cluster of invasive cases in New South Wales (NSW) (1990-1991), and other stored strains isolated from skin ulcers and sore throats. RESULTS: Non-toxigenic strains of C. diphtheriae biovar gravis were isolated from throat swabs of five of the case contacts. Uniform DNA patterns were found for the two community cases, the other Victorian case, nine of ten isolates from NSW, and the five throat isolates from case contacts. CONCLUSION: An invasive clone of C. diphtheriae biovar gravis appears to have been responsible for the three Victorian cases of endocarditis. It was also present among case contacts and responsible for previous invasive cases in NSW. Prophylactic treatment should be considered for clearly defined contacts in all instances where C. diphtheriae is isolated from a normally sterile site, regardless of the toxigenic nature of the strain.