Rotavirus hospitalisation in New Zealand children under 3 years of age.

OBJECTIVE: To describe the epidemiology of severe rotavirus gastroenteritis and to estimate the hospitalisation rates of this illness in New Zealand children under 3 years of age. METHODS: Children under 3 years of age with acute diarrhoea admitted to 1 of 8 study hospitals between 1 May 1998 and 30 April 2000 were surveyed. Their socio-demographic, treatment and length-of-stay data were recorded and stool samples tested by a rotavirus-specific enzyme-linked immunoassay. National hospital discharge data for infectious diarrhoea (International Classification of Diseases, ninth revision, 003-009) were reviewed, allowing population-based estimates for rotavirus-related hospitalisation in New Zealand. RESULTS: Of 2019 enrolled children, 1138 (56.4%) provided stools for testing, and of these 485 (42.6%) tested rotavirus positive. Rotavirus detection varied significantly by age (26.8% for 0 to 5 months, 42.5% for 6 to 11 months and 52.1% for children aged 12 to 35 months; P < 0.001), and by season (51.2% in winter/spring vs. 24.5% in summer/autumn; P < 0.001). While those infected with rotavirus were more likely to be dehydrated (50.6% vs. 37.4%; P < 0.001), their median hospital stay was similar (1.0 vs. 2.0 days; P = 0.09) to other children with acute gastroenteritis. The estimated national hospitalisation rate for rotavirus diarrhoea in children under 3 years, standardised for age and season, was 634 (95% CI 597, 672) per 100,000. In New Zealand, rotaviruses result in 1 in 52 children being hospitalised by 3 years of age. CONCLUSIONS: Rotavirus diarrhoea is an important, potentially vaccine-preventable cause of hospitalisation in New Zealand children, especially during winter and spring seasons.

Early-onset group B streptococcus prevention protocols in New Zealand public hospitals.

OBJECTIVE: Determine group B streptococcus (GBS) prevention protocols. METHODS: Questionnaire survey of 19 hospitals accounting for 73% of New Zealand births. RESULTS: Prevention policies were reported by 16 (84%) hospitals (bacteriological-screening n = 4, risk-factor determination n = 8, both strategies n = 4). Only five out of 12 (42%) centres using risk-assessment administered antibiotics for all high-risk criteria. Inadequate specimen collection and culture methods meant no hospital maximised culture-based strategies. Nevertheless, hospitals with prevention policies had lower early-onset GBS disease rates (0.46 versus 1.44 per 1,000 births; OR 0.32; (95% CI 0.12, 0.98)). CONCLUSIONS: Prevention strategies can be further improved by hospitals fully implementing nationally agreed guidelines.

Late antenatal carriage of group B Streptococcus by New Zealand women.

OBJECTIVES: To determine in New Zealand women the prevalence of group B Streptococcus (GBS) carriage late in pregnancy and to identify GBS colonisation risk factors, antibiotic susceptibility and serotype distribution. DESIGN: Prospective, observational study. SETTING: Community and hospital antenatal clinics in Wellington and Auckland during 1998-1999. SAMPLE: Convenience sample of 240 women between 35-37 weeks gestation. METHODS: Sociodemographic data, obstetric details and anogenital swabs were collected from each subject. Swabs were inoculated into selective media. GBS isolates underwent serotyping and antibiotic susceptibility testing. RESULTS: Two hundred and forty women (9% Maori, 11% Pacific) aged 15-41 years were recruited. Fifty-two (22%; 95% CI 17, 27) were colonised by GBS. Carriage was independently associated with younger age (59% < or = 30 years; adjusted OR 3.25; 95% CI 1.53, 6.95) and least social deprivation (57% NZ Dep 96 score +/- 3; adjusted OR 1.22; 95% CI 1.06,1.39). All GBS isolates were penicillin-susceptible, but resistance to clindamycin (15%) and erythromycin (7.5%) was detected and associated with serotype V strains. Predominant serotypes were: III (29%), Ia (21%), Ib (20%) and V (20%). CONCLUSIONS: Approximately 20% of New Zealand women carry GBS late in pregnancy, with young age a major risk factor. Increased risk in the socially advantaged, development of resistance to erythromycin and clindamycin, and emergence of new GBS serotypes are findings with important implications for prevention strategies requiring further confirmation.