NSW Public Health Bulletin最新文献

Unlabelled: This annual report, the third in the series, documents trends in immunisation coverage in NSW for children, adolescents and the elderly, to the end of 2011.

Methods: Data from the Australian Childhood Immunisation Register, the NSW School Immunisation Program and the NSW Population Health Survey were used to calculate various measures of population coverage.

Results: During 2011, greater than 90% coverage was maintained for children at 12 and 24 months of age. For children at 5 years of age the improvement seen in 2010 was sustained, with coverage at or near 90%. For adolescents, there was improved coverage for all doses of human papillomavirus vaccine, both doses of hepatitis B vaccine, varicella vaccine and the dose of diphtheria, tetanus and acellular pertussis given to school attendees in Years 7 and 10. Pneumococcal vaccination coverage in the elderly has been steadily rising, although it has remained lower than the influenza coverage estimates.

Conclusion: This report provides trends in immunisation coverage in NSW across the age spectrum. The inclusion of coverage estimates for the pneumococcal conjugate, varicella and meningococcal C vaccines in the official coverage assessments for 'fully immunised' in 2013 is a welcome initiative.

Measles has been eliminated in NSW for more than a decade; however outbreaks associated with international travel do occur. This EpiReview describes the epidemiology of measles in NSW from 2002-2011. A total of 281 cases of measles were notified during the period, an average annual notification rate of 0.41 notifications per 100 000 population (range: 0.06-1.25). There were 139 hospitalisations recorded with a measles diagnosis in the 10-year reporting period, corresponding to a rate of 0.20 hospitalisations per 100 000 population. Of the 80 measles virus specimens genotyped, five genotypes were identified: D9 (38%), D8 (24%), D4 (16%), D5 (14%) with H1 identified less frequently (9%). No single genotype was associated with local transmission across successive years. To sustain good measles control, children should be vaccinated against measles on time through routine childhood immunisation, and all young adults who travel internationally should be vaccinated. Clinician awareness remains important in the early identification and control of measles to avoid further transmission during outbreaks and to enable the timely implementation of public health measures.

Aim: This report summarises Australian passive surveillance data for adverse events following immunisation in NSW for 2011.

Methods: Analysis of de-identified information on all adverse events following immunisation reported to the Therapeutic Goods Administration.

Results: 449 adverse events following immunisation were reported for vaccines administered in 2011; this is slightly higher than in 2010 (n=439) and the second highest number since 2003. The most commonly reported reactions were injection site reaction, fever, allergic reaction and malaise. A large number of injection site reactions were reported following administration of the 23-valent pneumococcal polysaccharide vaccine in adults aged 65 years and over (97.4/100000 doses) and in children aged less than 7 years following administration of the 13-valent pneumococcal conjugate vaccine (29.4/100000 doses) and combined diphtheria, tetanus, pertussis (acellular) and inactivated poliovirus (quadrivalent)-containing vaccines (47.1/100000 doses). Only 10% of the reported adverse events were categorised as serious. There were two reports of death however both were attributed to causes other than vaccination.

Conclusion: The increased number of reports in 2011 is attributable to the high rates of injection site reactions in children associated with the administration of combined diphtheria, tetanus, pertussis (acellular) and inactivated poliovirus (quadrivalent)-containing vaccines and the 13-valent pneumococcal conjugate vaccine, as well as in adults following receipt of the 23-valent pneumococcal polysaccharide vaccine.

Aim: To describe the epidemiology of selected vaccine-preventable diseases in NSW for 2011.

Methods: Data from the NSW Notifiable Conditions Information Management System were analysed by: local health district of residence, age, Aboriginality, vaccination status, and organism, where available. Risk factor and vaccination status data were collected by public health units for case-patients following notification under the NSW Public Health Act 1991*.

Results: Outbreaks of measles and pertussis were reported in 2011, associated with unimmunised groups for measles, and a variety of factors for pertussis. Notification rates for other selected vaccine-preventable diseases remained stable.

Conclusion: Vaccine-preventable diseases are generally well controlled in NSW. However, pertussis remains an important public health issue. To prevent measles high population vaccination coverage, including vaccination in risk groups, is essential.

Aim: To analyse trends in hepatitis A notifications and information on exposure to risk factors, in particular international travel, collected through routine surveillance in NSW.

Methods: Hepatitis A notification data for the period 2000-2009 were extracted from the Notifiable Diseases Database and analysed by age group, gender, area of residence and exposure risk factors, including travel, food eaten and contact with other possible infectious cases.

Results: The notification rate for hepatitis A in NSW fell from 3.0 cases per 100000 population in 2000 to 1.4 cases per 100000 population in 2009. Notification rates were highest among people aged 20-24 years and residents of metropolitan Sydney. Travel to a country where hepatitis A is endemic was a risk exposure identified in 43% of cases.

Conclusion: International travel to highly endemic countries continues to be the most common risk factor for hepatitis A infection notified in NSW despite recommendations that travellers be vaccinated prior to travel to these areas.

Sample size calculations before conducting a health study or clinical trial are important to provide evidence that the proposed study is capable of detecting real associations between study factors. This review aims to clarify statistical issues related to the calculation of sample sizes and is illustrated with an example of a recent study design to improve health outcomes related to water and sewage in NSW Aboriginal communities. The effect of power, significance level and effect size on sample size are discussed. Calculations of sample sizes for individual-based studies are modified for more complex trial designs by multiplying individual-based estimates by an inflationary factor.