Effectiveness of 7-valent pneumococcal conjugate vaccine against radiologically diagnosed pneumonia in indigenous infants in Australia.

OBJECTIVE: To evaluate the effectiveness of the 7-valent pneumococcal conjugate vaccine (PCV7) in preventing pneumonia, diagnosed radiologically according to World Health Organization (WHO) criteria, among indigenous infants in the Northern Territory of Australia. METHODS: We conducted a historical cohort study of consecutive indigenous birth cohorts between 1 April 1998 and 28 February 2005. Children were followed up to 18 months of age. The PCV7 programme commenced on 1 June 2001. All chest X-rays taken within 3 days of any hospitalization were assessed. The primary endpoint was a first episode of WHO-defined pneumonia requiring hospitalization. Cox proportional hazards models were used to compare disease incidence. FINDINGS: There were 526 pneumonia events among 10,600 children - an incidence of 3.3 per 1000 child-months; 183 episodes (34.8%) occurred before 5 months of age and 247 (47.0%) by 7 months. Of the children studied, 27% had received 3 doses of vaccine by 7 months of age. Hazard ratios for endpoint pneumonia were 1.01 for 1 versus 0 doses; 1.03 for 2 versus 0 doses; and 0.84 for 3 versus 0 doses. CONCLUSION: There was limited evidence that PCV7 reduced the incidence of radiologically confirmed pneumonia among Northern Territory indigenous infants, although there was a non-significant trend towards an effect after receipt of the third dose. These findings might be explained by lack of timely vaccination and/or occurrence of disease at an early age. Additionally, the relative contribution of vaccine-type pneumococcus to severe pneumonia in a setting where multiple other pathogens are prevalent may differ with respect to other settings where vaccine efficacy has been clearly established.

Sexual disruption in a second species of wild cyprinid fish (the gudgeon, Gobio gobio) in United Kingdom freshwaters.

To establish whether the intersex condition seen in the roach (Rutilus rutilus) in United Kingdom (UK) rivers was species specific or a more general phenomenon in fish, evidence for sexual disruption was sought in a second cyprinid species, the gudgeon (Gobio gobio). Gudgeon were collected from the Rivers Aire and Lea (at locations that receive high-volume discharges of sewage treatment works [STW] effluent and that contain intersex roach) and from two still waters, and their gonads were examined histologically for evidence of intersexuality (the simultaneous presence of oocytes and testicular tissue). Intersex gonads were found at all sites, with the highest incidences occurring at one of the still waters (Lakeside Fisheries: 15%) and at sites on the River Aire (Thwaite Weir, Silsden Bridge, and Knostrop: 14, 13, and 12%, respectively). In the River Lea and Longton Park Lake, the incidence of intersexuality in gudgeon was 6%. In most cases, intersex gonads were characterized by a few primary oocytes/gonad section in an otherwise normal testis. However, at some sites on the River Aire (Thwaite Weir and Knostrop), the intersex condition was more severe. At Thwaite Weir, for example, more than half of the gonad in 40% of the intersex fish was comprised of ovarian tissue. Elevated concentrations of plasma vitellogenin both in male and in intersex fish indicated that fish had been exposed to estrogen(s). Some of the gudgeon were found at sites several kilometers downstream of any point discharge of STW effluent; therefore, the results likely are representative of this species in wild populations found in typical UK river ecosystems. Together with the findings in the roach, these data on the gudgeon confirm that sexual disruption in fish in UK rivers is not species specific.

Hospitalized community-acquired pneumonia in the elderly: an Australian case-cohort study.

This study describes the epidemiology of community-acquired pneumonia (CAP) in elderly Australians for the first time. Using a case-cohort design, cases with CAP were in-patients aged > or = 65 years with ICD-10-AM codes J10-J18 admitted over 2 years to two tertiary hospitals. The cohort sample was randomly selected from all hospital discharges, frequency-matched to cases by month. Logistic regression was used to estimate risk ratios for factors predicting CAP or associated mortality. A total of 4772 in-patients were studied. There were 1952 cases with CAP that represented 4% of all elderly admissions: mean length of stay was 9.0 days and 30-day mortality was 18%. Excluding chest radiograph, 520/1864 (28%) cases had no investigations performed. The strongest predictors of CAP were previous pneumonia, history of other respiratory disease, and aspiration. Intensive-care-unit admission, renal disease and increasing age were the strongest predictors of mortality, while influenza vaccination conferred protection. Hospitalization with CAP in the elderly is common, frequently fatal and a considerable burden to the Australian community. Investigation is ad hoc and management empirical. Influenza vaccination is associated with reduced mortality. Patient characteristics can predict risk of CAP and subsequent mortality.

ICD-10 codes are a valid tool for identification of pneumonia in hospitalized patients aged > or = 65 years.

This study examines the validity of using ICD-10 codes to identify hospitalized pneumonia cases. Using a case-cohort design, subjects were randomly selected from monthly cohorts of patients aged > or = 65 years discharged from April 2000 to March 2002 from two large tertiary Australian hospitals. Cases had ICD-10-AM codes J10-J18 (pneumonia); the cohort sample was randomly selected from all discharges, frequency matched to cases by month. Codes were validated against three comparators: medical record notation of pneumonia, chest radiograph (CXR) report and both. Notation of pneumonia was determined for 5098/5101 eligible patients, and CXR reports reviewed for 3349/3464 (97%) patients with a CXR. Coding performed best against notation of pneumonia: kappa 0.95, sensitivity 97.8% (95% CI 97.1-98.3), specificity 96.9% (95% CI 96.2-97.5), positive predictive value (PPV) 96.2% (95% CI 95.4-97.0) and negative predictive value (NPV) 98.2% (95% CI 97.6-98.6). When medical record notation of pneumonia is used as the standard, ICD-10 codes are a valid method for retrospective ascertainment of hospitalized pneumonia cases and appear superior to use of complexes of symptoms and signs, or radiology reports.

New normal ranges of antistreptolysin O and antideoxyribonuclease B titres for Australian children.

OBJECTIVE: To determine age-specific upper limit of normal (ULN) values of the ASO and ADB titres in children aged 4-14 years in urban Melbourne. Serology is often used to diagnose a preceding Streptococcus pyogenes infection, particularly in potential cases of rheumatic fever and post-streptococcal glomerulonephritis. The most commonly used antigens are antistreptolysin O (ASO) and antideoxyribonuclease B (ADB). Reference ranges used in Australia for these serological markers are usually based on data in adults from other countries. There are no age-specific reference values for Australian children. METHODS: Sixty-six sera from children with no history of recent streptococcal infection were obtained in May-June 2002. The children were divided into three age groups for analysis: 4-5 (n = 20), 6-9 (n = 19) and 10-14 (n = 25) years. The geometric mean titre and ULN (defined as the 80th percentile) for the ASO and ADB titres for each age group were determined in both international and log units. RESULTS: The ULN for ASO titres in each age group was 120 (2.08 log units), 480 (2.68) and 320 (2.51). The ULN for ADB titres in each age group was 100 (2.00 log units), 400 (2.60) and 380 (2.58). CONCLUSION: The ASO and ADB ULN values in school-aged children are higher than the current reference ranges suggest.

Respiratory illness during winter: a cohort study of urban children from temperate Australia.

OBJECTIVE: To examine the epidemiology and burden of respiratory illness during winter in urban children from temperate Australia. METHODS: We conducted a cohort study of healthy Melbourne children, aged from 12 to 71 months. Parents kept a daily respiratory symptom diary and recorded resource use when an influenza-like illness (ILI) occurred. RESULTS: One-hundred and eighteen children had 137 ILI episodes over 12 weeks for a rate of 0.53 ILI episodes per child-month (95% CI 0.44-0.61). Risk factors for ILI included younger age, fewer people residing in the household, structured exposure to other children outside the home, and a higher household income. Episodes had a mean duration of 10.4 days with 64 visits to a general practitioner (46.7 GP visits per 100 episodes), 27 antibiotic courses prescribed (19.7 antibiotic courses per 100 episodes), and three overnight hospitalizations (2.2 admissions per 100 episodes). Parents reported an average of 11.7 h excess time spent caring for a child per episode. CONCLUSIONS: Respiratory illnesses are a common and largely neglected cause of illness in Australian children. Pathogen-specific data are required to better assess the likely impact of available and developing vaccines and other treatment options.

Reactogenicity and immunogenicity profile of a two-dose combined hepatitis A and B vaccine in 1-11-year-old children.

This study was conducted to compare the reactogenicity, immunogenicity and safety of a combined two-dose (0, 6 months) hepatitis A and B vaccine (720ELU HAV, 20 mcg HBsAg) with the established three-dose (0, 1 and 6 months) hepatitis A and B vaccine (360ELU HAV, 10 mcg HBsAg). A total of 511 children aged 1-11 years who had not previously received a hepatitis A or B vaccine were enrolled in the study. Both vaccines were well tolerated, and were shown to be safe and immunogenic. The analysis, stratified according to two age groups (1-5 year and 6-11-year-old children) demonstrated that the reactogenicity profile of the two-dose schedule was at least as good as that of the established schedule. Both vaccines and schedules provided at least 98% seroprotection against hepatitis B and 100% seroconversion against hepatitis A, 1 month after the end of the vaccination course (Month 7).

Conjugate pneumococcal vaccines for non-indigenous children in Australia.

Childhood pneumococcal disease is associated with substantial morbidity and mortality, but total disease burden is more difficult to measure than for invasive disease caused by Haemophilus influenzae type b (Hib). A safe, effective seven-valent conjugate pneumococcal vaccine will be available in Australia by early 2001, and will certainly be indicated for high-risk groups and purchased in the private sector, as was Hib vaccine. The status of this vaccine on the Australian Standard Vaccination Schedule will require more detailed consideration of the burden and serotype distribution of pneumococcal disease in Australian children and the vaccine's likely cost-effectiveness. Postmarketing surveillance will be particularly important.

Radiological services in a hospital emergency department--an evaluation of service delivery and radiograph interpretation.

Radiological services to the Department of Ambulatory Paediatrics were audited over 1 month. Of a total of 782 separate radiographs, more than two-thirds were performed outside hours when radiologists are normally in the hospital. For only 171 of the 782 radiographs (22%) were there immediate reports by a radiologist. To determine whether the absence of immediate radiologist reports affected clinical care, a process was introduced whereby radiologists reviewed interpretation of radiographs made by resident medical officers (RMO) when no report was available. Over a 5 month period 2888 patients had radiographs when there was no immediate radiologist's report. Comparisons were made between RMO interpretation and ultimate radiologist report in 1411 of these patients. In 232 cases (16.4%) there was a discrepancy between RMO interpretation and radiologist report; 70% of these were false positive (the RMO interpreting a normal film as abnormal) while 71 were false negative (the RMO interpreting an abnormal film as normal). This study demonstrates the utility of a relatively simple quality assurance measure in situations where clinical decisions have to be made in the absence of an immediate radiologist report.