Peter Jacoby

Upper respiratory tract bacterial carriage in aboriginal and non-aboriginal children in a semi-arid area of Western Australia

Background: Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are associated with otitis media (OM). Indigenous children experience particularly high rates of OM. Few studies worldwide have described upper respiratory tract (URT) carriage in Indigenous and non-Indigenous children living in the same area. Aim: The aim of this study was to describe URT bacterial carriage in Aboriginal and non-Aboriginal children in the Kalgoorlie-Boulder area, Western Australia, as part of an investigation into causal pathways to OM. Methods: Five hundred four and 1045 nasopharyngeal aspirates were collected from 100 Aboriginal and 180 non-Aboriginal children, respectively, followed from birth to age 2 years. Standard procedures were used to identify bacteria. Results: Overall carriage rates of S. pneumoniae, M. catarrhalis and H. influenzae in Aboriginal children were 49%, 50% and 41%, respectively, and 25%, 25% and 11% in non-Aboriginal children. By age 2 months S. pneumoniae and M. catarrhalis had been isolated from 37% and 36% of Aboriginal children and from 11% and 12% of non-Aboriginal children, respectively. From age 3 months onward, carriage rates in Aboriginal children were 51% to 67% for S. pneumoniae and M. catarrhalis and 42% to 62% for H. influenzae; corresponding figures for non-Aboriginal children were 26% to 37% for S. pneumoniae and M. catarrhalis and 11% to 18% for H. influenzae. Non-Aboriginal children had higher carriage rates in winter than in summer, but season had little effect in Aboriginal children. Staphylococcus aureus carriage was highest under age 1 month (55% Aboriginal, 61% non-Aboriginal) and was always higher in non-Aboriginal than Aboriginal children. Conclusions: Interventions are needed to reduce high transmission and carriage rates, particularly in Aboriginal communities, to avoid the serious consequences of OM.

Low–moderate prenatal alcohol exposure and risk to child behavioural development: a prospective cohort study

Please cite this paper as: Robinson M, Oddy W, McLean N, Jacoby P, Pennell CE, de Klerk N, Zubrick S, Stanley F, Newnham J. Low–moderate prenatal alcohol exposure and risk to child behavioural development: a prospective cohort study. BJOG 2010;117:1139–1152.

The Long-Term Effects of Breastfeeding on Child and Adolescent Mental Health: A Pregnancy Cohort Study Followed for 14 Years

OBJECTIVES To determine whether there was an independent effect of breastfeeding on child and adolescent mental health. STUDY DESIGN The Western Australian Pregnancy Cohort (Raine) Study recruited 2900 pregnant women and followed the live births for 14 years. Mental health status was assessed by the Child Behaviour Checklist (CBCL) at 2, 6, 8, 10, and 14 years. Maternal pregnancy, postnatal, and infant factors were tested in multivariable random effects models and generalized estimating equations to examine the effects of breastfeeding duration on mental health morbidity. RESULTS Breastfeeding for less than 6 months compared with 6 months or longer was an independent predictor of mental health problems through childhood and into adolescence. This relationship was supported by the random effects models (increase in total CBCL score: 1.45; 95% confidence interval 0.59, 2.30) and generalized estimating equation models (odds ratio for CBCL morbidity: 1.33; 95% confidence interval 1.09, 1.62) showing increased behavioral problems with shorter breastfeeding duration. CONCLUSION A shorter duration of breastfeeding may be a predictor of adverse mental health outcomes throughout the developmental trajectory of childhood and early adolescence.

The Western Dietary Pattern Is Prospectively Associated With Nonalcoholic Fatty Liver Disease in Adolescence

OBJECTIVES:Poor dietary habits have been implicated in the development of nonalcoholic fatty liver disease (NAFLD); however, little is known about the role of specific dietary patterns in the development of NAFLD. We examined prospective associations between dietary patterns and NAFLD in a population-based cohort of adolescents.METHODS:Participants in the Western Australian Pregnancy Cohort (Raine) Study completed a food frequency questionnaire at 14 years and had liver ultrasound at 17 years (n=995). Healthy and Western dietary patterns were identified using factor analysis and all participants received a z-score for these patterns. Prospective associations between the dietary pattern scores and risk of NAFLD were analyzed using multiple logistic regression.RESULTS:NAFLD was present in 15.2% of adolescents. A higher Western dietary pattern score at 14 years was associated with a greater risk of NAFLD at 17 years (odds ratio (OR) 1.59; 95% confidence interval (CI) 1.17–2.14; P<0.005), although these associations were no longer significant after adjusting for body mass index at 14 years. However, a healthy dietary pattern at 14 years appeared protective against NAFLD at 17 years in centrally obese adolescents (OR 0.63; 95% CI 0.41–0.96; P=0.033), whereas a Western dietary pattern was associated with an increased risk of NAFLD.CONCLUSIONS:A Western dietary pattern at 14 years in a general population sample was associated with an increased risk of NAFLD at 17 years, particularly in obese adolescents. In centrally obese adolescents with NAFLD, a healthy dietary pattern may be protective, whereas a Western dietary pattern may increase the risk.

Effectiveness of Clindamycin and Intravenous Immunoglobulin, and Risk of Disease in Contacts, in Invasive Group A Streptococcal Infections

BACKGROUND The use of clindamycin and intravenous immunoglobulin (IVIG) in treatment of invasive group A streptococcal (iGAS) infection, and the need for prophylactic antibiotics in close contacts, remains contentious. Controlled trials are unlikely to be conducted, so prospective, observational studies provide the best data to inform practice. METHODS We conducted population-based, prospective, active surveillance of iGAS infections throughout the state of Victoria, Australia (population 4.9 million), from March 2002 through August 2004. RESULTS Eighty-four cases of severe iGAS infection (streptococcal toxic shock syndrome, necrotizing fasciitis, septic shock, or GAS cellulitis with shock) were identified. Clindamycin-treated patients had more severe disease than clindamycin-untreated patients but lower mortality (15% vs 39%; odds ratio [OR], 0.28; 95% confidence interval [CI], .10-.80). Among those who received concurrent IVIG, the fatality rate was lower still (7%). The adjusted point estimate of the OR for mortality was lower in clindamycin-treated patients (0.31; 95% CI, .09-1.12) and clindamycin plus IVIG-treated patients (0.12; 95% CI, .01-1.29) compared with clindamycin-untreated patients. Three confirmed cases of iGAS infection occurred in household contacts of index cases. The incidence rate of iGAS disease in contacts was 2011 (95% CI, 413-5929) times higher than the population incidence in Victoria. CONCLUSIONS Our data suggest that clindamycin treatment of patients with severe iGAS infections substantially reduces mortality and that this effect may be enhanced by concurrent treatment with IVIG. The dramatically increased risk of iGAS disease among household contacts within 1 month of the index case highlights a potential role for antibiotic prophylaxis.

Association Between Socioeconomic Status and the Development of Asthma: Analyses of Income Trajectories

OBJECTIVES Using data on 2868 children born in the Western Australian Pregnancy Cohort (Raine) Study, we examined the association between changes in family socioeconomic status and childhood asthma. METHODS We determined the likelihood (odds ratio) of a child having asthma at ages 6 and 14 years for 4 family-income trajectories (chronic low, increasing, decreasing, and never low) over the childs lifetime. The trajectories were created from longitudinal latent-class models. RESULTS We found a 2-fold increased risk of asthma at age 14 years among children who had lived in a low-income family since birth, especially for girls. Asthma was less likely to occur in children born to single parents; income rose over time in many of these families. Compared with children in chronic low-income families, children in households with increasing incomes had a 60% lower risk of asthma. Single-point measures of low income were not found to be associated with asthma. CONCLUSIONS Chronic exposure to a low-income environment from birth was associated with the development of persistent asthma. There was also a protective effect against asthma among those children whose families had moved out of poverty.

Physical and Mental Health in Mothers of Children with Down Syndrome

OBJECTIVE To identify the relationship between characteristics of the child with Down syndrome and the health of their mother. STUDY DESIGN Families with a child/young adult with Down syndrome (<25 years) provided information related to the health of the child, functioning and behavior, and the health and well-being of the mother (n = 250). RESULTS The mean physical health score of mothers was 50.2 (SD = 9.6). Factors associated with lower mean physical health scores were as follows: child having a current heart problem (P = .036), a higher body mass index (P = .006), and higher (poorer) scores on the Developmental Behavior Checklist. Better physical health scores were seen in mothers whose children required no help/supervision in learning new skills (P = .008) and domestic tasks (P = .014). The mean mental health score of mothers was 45.2 (SD = 10.6), significantly lower than the norm of 50 (P < .0001). Associated child factors included current ear problems (P = .079), muscle/bone problems (P = .004), >4 episodes of illness in past year (P = .016), and higher scores on the DBC (P < .0001). CONCLUSIONS The most important predictors of maternal health were childrens behavioral difficulties, everyday functioning and current health status. Mothers of children with Down syndrome appear to experience poorer mental health and may require greater support and services to improve behavior management skills for their child and their own psychological well-being.

Clustering of Psychosocial Symptoms in Overweight Children

Objective: The aims of the present study were to (i) examine the relationship between childrens degree of adiposity and psychosocial functioning; and (ii) compare patterns of clustering of psychosocial measures between healthy weight and overweight/obese children. Method: Cross-sectional data from a population-based cohort of 158 healthy weight, 77 overweight, and 27 obese children aged 8–13 years were analysed. Height, weight depression, quality of life, self-esteem, body dissatisfaction, eating disorder symptoms, peer relationships and behavioural and emotional problems were measured. Results: Multi-level analysis showed significant linear associations between child body mass index z-scores and the psychosocial variables, with increasing adiposity associated with increasing levels of psychosocial distress. Principal components analyses indicated subtle differences between the healthy weight and overweight/obese groups with regards to the clustering of psychosocial measures. In particular, in overweight/obese, but not in healthy weight children, global self-worth clustered with body image and eating disorder symptoms. Conclusions: The psychosocial burden of excess weight is significant and broad reaching, with overweight/obese children showing multiple significant psychosocial problems.

Estimation of influenza vaccine effectiveness from routine surveillance data.

Background Influenza vaccines are reviewed each year, and often changed, in an effort to maintain their effectiveness against drifted influenza viruses. There is however no regular review of influenza vaccine effectiveness during, or at the end of, Australian influenza seasons. It is possible to use a case control method to estimate vaccine effectiveness from surveillance data when all patients in a surveillance system are tested for influenza and their vaccination status is known. Methodology/Principal Findings Influenza-like illness (ILI) surveillance is conducted during the influenza season in sentinel general practices scattered throughout Victoria, Australia. Over five seasons 2003–7, data on age, sex and vaccination status were collected and nose and throat swabs were offered to patients presenting within three days of the onset of their symptoms. Swabs were tested using a reverse transcriptase polymerase chain reaction (RT-PCR) test. Those positive for influenza were sent to the World Health Organization (WHO) Collaborating Centre for Reference and Research on Influenza where influenza virus culture and strain identification was attempted. We used a retrospective case control design in five consecutive influenza seasons, and estimated influenza vaccine effectiveness (VE) for patients of all ages to be 53% (95% CI 38–64), but 41% (95% CI 19–57) adjusted for age group and year. The adjusted VE for all adults aged at least 20 years, the age groups for whom a benefit of vaccination could be shown, was 51% (95% CI 34–63). Comparison of VE estimates with vaccine and circulating strain matches across the years did not reveal any significant differences. Conclusions/Significance These estimates support other field studies of influenza vaccine effectiveness, given that theoretical considerations suggest that these values may underestimate true effectiveness, depending on test specificity and the ratio of the influenza ILI attack rate to the non-influenza ILI attack rate. Incomplete recording of vaccination status and under-representation of children in patients from whom a swab was collected limit the data. Improvements have been implemented for prospective studies.

Sleep problems in Rett syndrome

Rett syndrome (RTT) is a severe neurological disorder, affecting mainly females. It is generally caused by mutations in the MECP2 gene. Sleep problems are thought to occur commonly in Rett syndrome, but there has been little research on prevalence or natural history. An Australian population-based registry of cases born since 1976 has been operating since 1993, with current ascertainment at 300. The Australian Rett Syndrome Database (ARSD) consists of information about Rett syndrome cases including their functional ability, behaviour, sleep patterns, medical conditions and genotype. The cases range in age from 2 to 29 years. The aim of this study was to investigate the type and frequency of sleep problems, relationships with age and MECP2 mutation type and to evaluate changes over time. Parents or carers of the subjects with Rett syndrome were asked to complete a questionnaire about sleep problems on three separate occasions (2000, 2002 and 2004). Regression modelling was used to investigate the relationships between sleep problems, age and mutation type. Sleep problems were identified in over 80% of cases. The prevalence of night-time laughter decreased with age and the prevalence of reported night-time seizures and daytime napping increased with age. The prevalence of sleep problems was highest in cases with a large deletion of the MECP2 gene and in those with the p.R294X or p.R306C mutations. Sleep problems are common in Rett syndrome and there is some variation with age and mutation type.