The epidemiology and prevention of pertussis in Australia

Pertussis (whooping cough) remains an important public health problem in Australia. Although mortality and morbidity from pertussis declined dramatically following the introduction of mass vaccination programs in 1953, the level of morbidity remains unacceptably high for a vaccine-preventable disease. Aims and methods The primary aims of this thesis were (i) to ascertain the epidemiology of pertussis in Australia between 1993 and 2000 by analysing and interpreting sources of routinely collected data on pertussis; and (ii) to examine the effectiveness of vaccination against pertussis in a number of ways. Data from three primary national sources (notifications of disease, hospitalisations for pertussis and death certificates) were used to examine the burden from pertussis in Australia over these eight years. Analyses included the age distribution of cases, temporal and geographic trends, comparisons of notification and hospitalisation data, and the impact of differences in the method of diagnosis of notified cases between years and age groups. In addition to analyses at the national level using data from the national databases, further detailed analyses were undertaken at the State level for New South Wales (NSW), the most populous Australian State. Pertussis vaccine coverage was estimated using data from the recently established Australian Childhood Immunisation Register (ACIR); these data were also used to track the transition from whole-cell to acellular pertussis vaccines. The different types of studies used to evaluate vaccine effectiveness were reviewed, and a method suitable for ongoing estimation of vaccine effectiveness in Australia was developed. This was then applied to the NSW data, to determine the effectiveness of pertussis vaccination in this State. Main findings The annual notification rate for pertussis in Australia ranged from 23–59 per 100 000 population over the eight years. Infants had the highest notification and hospitalisation rates in Australia — they accounted for 5 percent of notifications, 61 percent of hospitalisations and 100 percent of deaths. Age-specific notification and hospitalisation rates in children aged less than two years strongly suggested a protective effect of vaccination, with the greatest reduction in rate coinciding with eligibility to receive a second dose of pertussis vaccine at four months of age. Notification rates among 5–9 year olds progressively decreased in successive age cohorts, consistent with an effect of the introduction in 1994 of a pertussis vaccine booster for preschool-aged children. Although adults (persons aged 15 years or more) accounted for half the notifications, they had the lowest notification rate. The highest numbers of pertussis notifications were in 1997, when most jurisdictions experienced an epidemic. Notification and hospitalisation rates varied across the States and Territories and also across smaller geographic regions in NSW. Areas and years with high notification rates tended to also have high hospitalisation rates, suggesting that trends in notifications reflected trends in incidence. The number of infant hospitalisations in NSW between July 1993 and June 1999 exceeded the number of notifications by 32 percent, highlighting the extent of under-notification. Overall, and particularly amongst those aged more than 12 months, the majority of cases notified in NSW were based on the results of serological tests. The proportion diagnosed by culture of the organism was greatest in infants; the proportion diagnosed by serological tests increased with age. There was no evidence that the use of serology had increased since 1994 in NSW, hence changes in notification rates after this time are unlikely to be attributable to increased use of serological diagnosis. ACIR records indicated that in December 2000, 92 percent of one-year-old children had received three doses of diphtheria-tetanus-pertussis (DTP) vaccine and 90 percent of two-year-olds had received four doses. Vaccine coverage varied by jurisdiction. Since 1997, there was an increased use of DTP vaccines containing acellular pertussis components with a corresponding decrease in the use of vaccines containing whole-cell components. In 2000, almost all DTP vaccines administered contained acellular pertussis components. The results of the vaccine effectiveness study showed that pertussis vaccination was highly effective at preventing pertussis in NSW children, as measured by notified cases. Vaccine effectiveness was highest (91 percent) in the youngest age group ((8–23 months) and lowest (78percent) in the oldest age group (9–13 years). The screening method has not previously been used to estimate pertussis vaccine effectiveness in Australia. Conclusions This thesis demonstrates the value of integrating varied data sources in estimating the disease burden from pertussis. The data presented here show that the disease burden is substantial in all age groups, despite high levels of vaccine coverage in infants and children. This problem of disease control does not appear to be due to lack of vaccine effectiveness, but there is evidence of waning immunity over time. The analyses presented here form a basis for the ongoing monitoring of trends in pertussis epidemiology following the replacement of whole-cell by acellular pertussis vaccines, and will assist consideration of the need for additional booster doses in adolescents and adults

Linkage rate between NSW Perinatal Data Collection birth records and government school NAPLAN educational records, by gestational age at birth

NHMRC, NSW Ministry of Healt

Intrapartum epidural analgesia and breastfeeding: a prospective cohort study

BACKGROUND Anecdotal reports suggest that the addition of fentanyl (an opioid) to epidural analgesia for women during childbirth results in difficulty establishing breastfeeding. The aim of this paper is to determine any association between epidural analgesia and 1) breastfeeding in the first week postpartum and 2) breastfeeding cessation during the first 24 weeks postpartum. METHODS A prospective cohort study of 1280 women aged > or = 16 years, who gave birth to a single live infant in the Australian Capital Territory in 1997 was conducted. Women completed questionnaires at weeks 1, 8, 16 and 24 postpartum. Breastfeeding information was collected in each of the four surveys and women were categorised as either fully breastfeeding, partially breastfeeding or not breastfeeding at all. Women who had stopped breastfeeding since the previous survey were asked when they stopped. RESULTS In the first week postpartum, 93% of women were either fully or partially breastfeeding their baby and 60% were continuing to breastfeed at 24 weeks. Intrapartum analgesia and type of birth were associated with partial breastfeeding and breastfeeding difficulties in the first postpartum week (p < 0.0001). Analgesia, maternal age and education were associated with breastfeeding cessation in the first 24 weeks (p < 0.0001), with women who had epidurals being more likely to stop breastfeeding than women who used non-pharmacological methods of pain relief (adjusted hazard ratio 2.02, 95% CI 1.53, 2.67). CONCLUSION Women in this cohort who had epidurals were less likely to fully breastfeed their infant in the few days after birth and more likely to stop breastfeeding in the first 24 weeks. Although this relationship may not be causal, it is important that women at higher risk of breastfeeding cessation are provided with adequate breastfeeding assistance and support.Christine Roberts is supported by a National Health and Medical Research Council (NHMRC) of Australia Public Health Practitioner Fellowship and Siranda Torvaldsen is supported by a NHMRC Australian Research Training Fellowship. The cohort study was supported by a project grant from The Canberra Hospital Private Practice Fund. Additional funding was provided by The Canberra Hospital Auxiliary, the Nurses' Board of the Australian Capital Territory, and the Australian Capital Territory Department of Health & Community Care

\u27It\u27s good to have wheels!\u27: Perceptions of cycling among homeless young people in Sydney, Australia

Participation in sporting or recreational programs can be unattainable for many disadvantaged young people. Encouraging regular cycling is an important public health strategy to increase participation in physical activity and expand personal transport options for marginalised youth. Perceptions and attitudes toward cycling were explored in eight focus groups, involving 47 young people who were experiencing or at risk of homelessness in central and south-western Sydney, Australia. The benefits of cycling for physical activity, personal transport, independence and social inclusion were recognised. Barriers to regular cycling included compliance with mandatory helmet legislation; a lack of cycling skills and experience; a paucity of cycling infrastructure and reliance on cars for personal transport; and access to affordable bicycles and equipment. A comprehensive multi-strategic approach that engages marginalised young people is required to improve access and enable increased participation in cycling activities

Automated data extraction from general practice records in an Australian setting: Trends in influenza-like illness in sentinel general practices and emergency departments

<p>Abstract</p> <p>Background</p> <p>Influenza intelligence in New South Wales (NSW), Australia is derived mainly from emergency department (ED) presentations and hospital and intensive care admissions, which represent only a portion of influenza-like illness (ILI) in the population. A substantial amount of the remaining data lies hidden in general practice (GP) records. Previous attempts in Australia to gather ILI data from GPs have given them extra work. We explored the possibility of applying automated data extraction from GP records in sentinel surveillance in an Australian setting.</p> <p>The two research questions asked in designing the study were: Can syndromic ILI data be extracted automatically from routine GP data? How do ILI trends in sentinel general practice compare with ILI trends in EDs?</p> <p>Methods</p> <p>We adapted a software program already capable of automated data extraction to identify records of patients with ILI in routine electronic GP records in two of the most commonly used commercial programs. This tool was applied in sentinel sites to gather retrospective data for May-October 2007-2009 and in real-time for the same interval in 2010. The data were compared with that provided by the Public Health Real-time Emergency Department Surveillance System (PHREDSS) and with ED data for the same periods.</p> <p>Results</p> <p>The GP surveillance tool identified seasonal trends in ILI both retrospectively and in near real-time. The curve of seasonal ILI was more responsive and less volatile than that of PHREDSS on a local area level. The number of weekly ILI presentations ranged from 8 to 128 at GP sites and from 0 to 18 in EDs in non-pandemic years.</p> <p>Conclusion</p> <p>Automated data extraction from routine GP records offers a means to gather data without introducing any additional work for the practitioner. Adding this method to current surveillance programs will enhance their ability to monitor ILI and to detect early warning signals of new ILI events.</p

Relationship between the population incidence of febrile convulsions in young children in Sydney, Australia and seasonal epidemics of influenza and respiratory syncytial virus, 2003-2010: a time series analysis

<p>Abstract</p> <p>Background</p> <p>In 2010, intense focus was brought to bear on febrile convulsions in Australian children particularly in relation to influenza vaccination. Febrile convulsions are relatively common in infants and can lead to hospital admission and severe outcomes. We aimed to examine the relationships between the population incidence of febrile convulsions and influenza and respiratory syncytial virus (RSV) seasonal epidemics in children less than six years of age in Sydney Australia using routinely collected syndromic surveillance data and to assess the feasibility of using this data to predict increases in population rates of febrile convulsions.</p> <p>Methods</p> <p>Using two readily available sources of routinely collected administrative data; the NSW Emergency Department (ED) patient management database (1 January 2003 - 30 April 2010) and the Ambulance NSW dispatch database (1 July 2006 - 30 April 2010), we used semi-parametric generalized additive models (GAM) to determine the association between the population incidence rate of ED presentations and urgent ambulance dispatches for 'convulsions', and the population incidence rate of ED presentations for 'influenza-like illness' (ILI) and 'bronchiolitis' - proxy measures of influenza and RSV circulation, respectively.</p> <p>Results</p> <p>During the study period, when the weekly all-age population incidence of ED presentations for ILI increased by 1/100,000, the 0 to 6 year-old population incidence of ED presentations for convulsions increased by 6.7/100,000 (P < 0.0001) and that of ambulance calls for convulsions increased by 3.2/100,000 (P < 0.0001). The increase in convulsions occurred one week earlier relative to the ED increase in ILI. The relationship was weaker during the epidemic of pandemic (H1N1) 2009 influenza virus.</p> <p>When the 0 to 3 year-old population incidence of ED presentations for bronchiolitis increased by 1/100,000, the 0 to 6 year-old population incidence of ED presentations for convulsions increased by 0.01/100,000 (P < 0.01). We did not find a meaningful and statistically significant association between bronchiolitis and ambulance calls for convulsions.</p> <p>Conclusions</p> <p>Influenza seasonal epidemics are associated with a substantial and statistically significant increase in the population incidence of hospital attendances and ambulance dispatches for reported febrile convulsions in young children. Monitoring syndromic ED and ambulance data facilitates rapid surveillance of reported febrile convulsions at a population level.</p

A randomised controlled trial of a community-based healthy lifestyle program for overweight and obese adolescents: the Loozit® study protocol

<p>Abstract</p> <p>Background</p> <p>There is a need to develop sustainable and clinically effective weight management interventions that are suitable for delivery in community settings where the vast majority of overweight and obese adolescents should be treated. This study aims to evaluate the effect of additional therapeutic contact as an adjunct to the Loozit^®group program – a community-based, lifestyle intervention for overweight and lower grade obesity in adolescents. The additional therapeutic contact is provided via telephone coaching and either mobile phone Short Message Service or electronic mail, or both.</p> <p>Methods and design</p> <p>The study design is a two-arm randomised controlled trial that aims to recruit 168 overweight and obese 13–16 year olds (Body Mass Index z-score 1.0 to 2.5) in Sydney, Australia. Adolescents with secondary causes of obesity or significant medical illness are excluded. Participants are recruited via schools, media coverage, health professionals and several community organisations. Study arm one receives the Loozit^®group weight management program (G). Study arm two receives the same Loozit^®group weight management program plus additional therapeutic contact (G+ATC). The 'G' intervention consists of two phases. Phase 1 involves seven weekly group sessions held separately for adolescents and their parents. This is followed by phase 2 that involves a further seven group sessions held regularly, for adolescents only, until two years follow-up. Additional therapeutic contact is provided to adolescents in the 'G+ATC' study arm approximately once per fortnight during phase 2 only. Outcome measurements are assessed at 2, 12 and 24 months post-baseline and include: BMI z-score, waist z-score, metabolic profile indicators, physical activity, sedentary behaviour, eating patterns, and psychosocial well-being.</p> <p>Discussion</p> <p>The Loozit^®study is the first randomised controlled trial of a community-based adolescent weight management intervention to incorporate additional therapeutic contact via a combination of telephone coaching, mobile phone Short Message Service, and electronic mail. If shown to be successful, the Loozit^®group weight management program with additional therapeutic contact has the potential to be readily translatable to a range of health care settings.</p> <p>Trial registration</p> <p>The protocol for this study is registered with the Australian Clinical Trials Registry (ACTRNO12606000175572).</p