Australian Aboriginal Infants Research Articles

Experiences of using the Edinburgh Postnatal Depression Scale in the context of antenatal care for Aboriginal mothers: Women and midwives’ perspectives

ProblemRoutine administration of the Edinburgh Postnatal Depression Scale (EPDS) is intended to promote early detection and preventative support for those who may be at risk of perinatal depression and anxiety. The cultural suitability of the EPDS has not been validated in the Aboriginal Australian context. BackgroundMarked differences in health outcomes and service access between Australian Aboriginal and non-Aboriginal women and infants continue to exist. AimThis study aimed to explore the cultural validity of the EPDS through understanding the experiences of Aboriginal women and midwives. MethodsQualitative data was drawn from semi-structured interviews/yarns with 13 Perth-based Aboriginal antenatal women and 10 non-Aboriginal midwives. FindingsUtilising a grounded theory approach, thematic analysis of verbatim transcripts revealed that, surprisingly, women expressed generally favourable views of the EPDS, especially when the relationships between women and midwives were focused on. Midwives, however, expressed reservations about administering the EPDS and used the EPDS as a conversation-starter rather than as a standardised, standalone tool. DiscussionIn attempt to reconcile conflicting perspectives, analysis of recordings extended to evaluate micro-processes in the interviews. At the process level, it was clear that demand characteristics operated in some interviews, including socially desirable response biases, demand biases and acquiescent response styles. ConclusionThis highlights the need for researchers and clinicians to be trained in non-leading interview questioning techniques and in yarning methodology. Researchers and clinicians should also be aware of the cognitive biases and demand characteristics that may influence responding, likely perpetuated by dominant forces of a colonised society.

Stillbirth risks and rates for Aboriginal and Torres Strait Islander women and their babies in North Queensland.

The stillbirth rate for Australian Aboriginal and Torres Strait Islander infants remains higher than non-Indigenous rates. Risks for stillbirth include maternal factors such as ethnicity, age, geographic location, and physical health. Fetal risk factors include gestational age, birthweight and congenital anomalies. The total stillbirth rate for all babies born at the Townsville University Hospital during the study period was 11 per 1000 births. To identify Aboriginal and Torres Strait Islander stillbirth rates, risk factors and causes in North Queensland. A retrospective chart audit was conducted to identify Indigenous women who had experienced stillbirth in the Townsville University Hospital between January 2005 and December 2014. Thirty-two charts were available for audit. The stillbirth rate for non-Indigenous infants was 10.3 per 1000 births. The stillbirth rate for Indigenous infants was 11.7 per 1000 births. Almost half of the women lived in rural, remote or very remote areas. Maternal risk factors included poorer physical health, such as obesity, diabetes, hypertension, and smoking, fertility issues and lack of antenatal care. Fetal risk factors included congenital anomalies, including cardiac and skeletal abnormalities, placental disorders, and preterm birth. Stillbirth risk remains higher for Aboriginal and Torres Strait Islander women and their babies. Supporting women to enhance their health is paramount, particularly during pregnancy. Further, increasing awareness of stillbirth risk factors through education for both women and healthcare professionals will support culturally responsive care for women and their families to mitigate stillbirth risk and enhance pregnancy outcomes in non-urban Queensland.

Hearing loss among Australian Aboriginal infants and toddlers: A systematic review

AimAustralian Aboriginal and Torres Strait Islander children have among the highest rates of otitis media (OM) and associated conductive hearing loss in the world. OM begins early in life and is well-documented in the research literature. In contrast, audiology data for the infant and toddler age-groups are limited. This review aimed to summarise the recent literature on hearing loss among Aboriginal and Torres Strait Islander infants and toddlers. MethodsSystematic literature review. PubMed and ScienceDirect databases were searched for relevant journal articles. Key search terms were “Aboriginal”, “children”, “hearing loss”, “otitis media”, and their relevant synonyms. Journal articles published before 2000 were excluded. ResultsOnly two journal articles met review inclusion criteria. Ear disease and associated conductive hearing loss was significantly higher among Aboriginal and Torres Strait Islander than non-Aboriginal and Torres Strait Islander children. No intervention studies were found. ConclusionsMore research is needed to evaluate hearing health outcomes of medical (including surgical) and audiological interventions in this high-risk population.

10-Valent pneumococcal non-typeable H. influenzae protein D conjugate vaccine (PHiD-CV10) versus 13-valent pneumococcal conjugate vaccine (PCV13) as a booster dose to broaden and strengthen protection from otitis media (PREVIX_BOOST) in Australian Aboriginal children: study protocol for a randomised controlled trial

IntroductionStreptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are major otitis media pathogens that densely co-colonise the nasopharynx and infect the middle ear of Australian Aboriginal infants from very early in...

Decisions to consent for autopsy after stillbirth: Aboriginal and Torres Strait Islander women's experiences.

The stillbirth rate for Australian Aboriginal and Torres Strait Islander infants is twice that for non-Indigenous infants. Autopsy is the gold standard for fetal investigation; however, parental consent is often not given. There is little research investigating the drivers of parents' decision-making for autopsy after stillbirth. The current study explored the reasons why Aboriginal and Torres Strait Islander women did or did not give permission to autopsy after stillbirth. Five Aboriginal and/or Torres Strait Islander women participated in semi-structured interviews. Thematic analysis was conducted within a phenomenological framework. Five themes were identified as reasons for giving permission - to find out why the baby died; to confirm diagnosis; to understand future risk; to help others; and doubt about maternal causes. Four themes were identified as reasons for declining permission - not asked in a sensitive manner; not enough time to think; distress about the autopsy procedure; and unwilling to agree. There was a lack of acceptability of the lengthy timeframe for the availability of autopsy results as families usually wait between three and nine months. This lengthy waiting period negatively impacted upon families' health and wellbeing. It is important for health professionals to understand the factors that parents consider when giving permission for autopsy after stillbirth. It is hoped that an increase in autopsy rate will enhance the understanding of the causes of stillbirth and ultimately decrease the stillbirth rate for Aboriginal and Torres Strait Islander families.

Maternal fetal programming of birthweight among Australian Aboriginal infants: a population-based data linkage study

Low birthweight, which is common among Australian Aboriginal infants, has been found to persist across generations because of shared genetic and environmental factors and possibly fetal programming. Fetal programming refers to the response of a fetus to hostile uterine conditions with lifelong effects and possibly, in turn, providing a poorer uterine environment for future offspring. Fetal programming might have a greater effect in populations that have undergone rapid lifestyle transitions-for example, Indigenous populations. Disentangling causal effects is difficult, but family-based approaches could provide insights. We explored whether poor maternal fetal growth caused low birthweight in Aboriginal infants. In this data linkage study, we used linked administrative health records of 12 865 singleton Aboriginal infants born in Western Australia between 1980 and 2010 and their relatives (including siblings born in 2011). Electronic birth records included all births since 1980 with at least 20 weeks completed gestation or a birthweight of 400 g. We compared parental-offspring birthweight associations using three approaches-a regression analysis of the complete sample, adjusting for confounding variables; a comparison of the maternal-offspring and paternal-offspring associations; and a within-cousin group comparison. We used binary and continuous measures of birthweight. We categorised infants and their parents as small for gestational age (SGA) if their birthweight was below the first decile of birthweights for all singleton livebirths of the same sex and gestational age in Australia between 1998 and 2007. The relative risk (RR) of SGA birth was higher for infants with SGA mothers than for those with non-SGA mothers (RR 1·65, 95% CI 1·49 to 1·83), after adjusting for grandmaternal parity. After additional adjustment for maternal height, the risk remained higher for those with non-SGA mothers (RR 1·51, 1·36 to 1·68). The maternal birthweight Z score coefficient was 0·17 (95% CI 0·14 to 0·20), compared with 0·13 (0·10 to 0·16) for paternal birthweight, a difference of 0·03 (-0·01 to 0·08). In the cousin analysis, the maternal-offspring association was fully attenuated (0·00, 95% CI -0·05 to 0·06). Conditions in the current pregnancy were strongly associated with offspring birthweight Z score. Smoking was associated with a mean decrease of 0·39 (95% CI -0·45 to -0·34) in offspring birthweight Z score, drug misuse with a decrease of 0·31 (-0·43 to -0·20), and diabetes with an increase of 0·58 (0·39 to 0·77). We found little support for maternal fetal programming causing low offspring birthweight. The similar maternal and paternal influence on birthweight and our cousin analysis suggested transmission of genetic and environmental factors could explain much of the maternal-offspring birthweight association. Compared with other risk factors in the current pregnancy, fetal programming appears to have little or no role in the high numbers of infants with low birthweight among Aboriginal populations. National Health and Medical Research Council of Australia and Bellberry Ltd.

Using linked data and family studies to understand multigenerational causes of low birthweight among Australian Aboriginal infants

IntroductionLow birthweight is common among Aboriginal infants. Birthweight is correlated across generations due to the transmission of genetic and environmental factors. Another cause may be fetal programming, where a fetus’ response to a hostile environment leads to poor adult health and, in turn, a poor uterine environment for her offspring.
 Objectives and ApproachIdentifying a causal relationship between maternal birthweight and offspring birthweight is difficult. However, we can gain insights by approaching the question from several different angles, including family studies involving both parents and cousins who share maternal grandparents. Family studies using linked data are possible with data from Western Australia (WA), the only Australian state with a database of family relationships.
 We used linked birth, hospital, mental health, and family relationship records of 12,865 Aboriginal singletons born 1998 to 2011 in WA whose mother also linked to a WA birth record from 1980 onwards, and their parents’ records.
 Results17% of births were small for gestational age. Using a linear regression model with a generalised estimating equation approach for offspring birthweight z-score (BWZ), the coefficient for maternal BWZ was 0.17 (95% CI: 0.14, 0.20), compared to 0.13 (95% CI: 0.10, 0.16) for paternal BWZ. The difference in coefficients (0.03 [95% CI: -0.01, 0.08]) provides only limited support for the fetal programming hypothesis. Other associations with offspring BWZ were much larger, including maternal smoking (-0.39 [95% CI: -0.45, -0.34]). After restricting the sample to cousins with shared maternal grandparents (fixed-effects model), the mother-offspring association was fully attenuated (-0.01 [95% CI: -0.07, 0.05]), suggesting transmission of maternal genetic and environmental factors alone can explain the association, though the 95% confidence interval was wide.
 Conclusion/ImplicationsIf fetal programming is an important cause of low birthweight, Aboriginal people would be disproportionately affected, following generations of low birthweight and chronic disease. However, the family studies indicate fetal programming has a limited role compared to other risk factors in the current pregnancy.

Poor birth outcomes among Aboriginal Western Australians and smoking, alcohol and substance misuse, and assault

IntroductionOn average, Aboriginal neonates in Western Australia (WA) weigh 200g less than non-Aboriginal infants and are 2-3 times more likely to be preterm, stillborn, or die neonatally. They are also more likely to be exposed in utero to maternal behaviour risks like smoking, due to factors such as intergenerational trauma.
 Objectives and ApproachWe aimed to estimate the proportion of small for gestational age (SGA) births, preterm births, and perinatal deaths of Western Australian Aboriginal infants from 1998-2010 attributable to maternal smoking, alcohol misuse, drug misuse, and assault against the mother. We used linked birth, hospital, mental health, and death records of all Aboriginal singletons and their parents. Using logistic regression with a generalized estimating equation approach, associations between birth outcomes and the four risk factors of interest were estimated after adjusting for maternal age, height and health. Using coefficients from these models, we estimated adjusted population attributable fractions (PAFs).
 ResultsOf 28,119 births, 16% of infants were SGA, 13% were preterm and 2% died perinatally. 51% of infants were exposed to maternal smoking, alcohol misuse, drug misuse, and/or assault, and 37% [95% CI: 35%, 40%] of SGA births, 16% [95% CI: 14%, 19%] of preterm births and 20% [95% CI: 12%, 28%] of perinatal deaths were attributable to these factors, predominantly smoking. The PAFs for alcohol misuse (for example, for SGA, 3% [95% CI: 2%, 3%]) are likely to be underestimates as it is difficult to identify alcohol misuse using administrative data.
 Conclusion/ImplicationsWhile smoking rates have dropped considerably, reduction measures have been less successful among Aboriginal women than non-Aboriginal women. Significant improvements in perinatal health are possible with identification and support of effective risk reduction approaches for Aboriginal women, as well as their communities and families.

Identifying vulnerable population groups: On-time infant vaccination coverage in Australia

IntroductionImmunisation coverage is a good measure of immunisation program effectiveness. Coverage of the 3-dose infant schedule in Australia assessed at age 12 months is >90%. Timeliness is an important goal for population immunity, but on-time coverage of the 2-4-6 month schedule and coverage in specific populations is rarely reported.
 Objectives and ApproachWe conducted a retrospective population-based cohort study of 1.9 million Australian births, 1996-2012 (approximately 42% of Australia’s population). Individual data from state-held birth and perinatal records were combined with Commonwealth-held immunisation and death records, through probabilistic linkage. We assessed on-time coverage across 13 demographic and perinatal characteristics of diphtheria-tetanus-pertussis vaccines (DTP) defined as vaccination 14 days prior to the scheduled due date, to 30 days afterwards.
 ResultsOn-time DTP vaccination coverage in non-Aboriginal infants was 88.1% for the 2-month dose, 82.0% for 4-month dose, and 76.7% for 6-month dose; 3-dose coverage was 91.3% when assessed at 12 months. On-time DTP coverage for Aboriginal infants was 77.0%, 66.5%, and 61.0%; 3-dose coverage at 12 months was 79.3%. Appreciable differences in on-time coverage were observed across population subgroups. On-time coverage in non-Aboriginal infants born to mothers with ≥3 previous pregnancies was 62.5% for the 6-month dose (47.9% for Aboriginal infants); up to 23.5% lower than for first-borns. Infants born to mothers who smoked during pregnancy had coverage 8.7-10.3% lower than infants born to non-smoking mothers for the 4- and 6-month dose. A linear relationship was apparent with increasing socio-economic disadvantage and decreasing on-time coverage.
 Conclusion/ImplicationsOn-time vaccination coverage of the 2-4-6 month schedule is only 50-60% across specific population subgroups representing a significant avoidable public health risk. Australian Aboriginal infants, multiparous mothers, and those who are socio-economically disadvantaged are key groups most likely to benefit from targeted programs addressing vaccine timeliness.

Exploring factors impacting early childhood health among Aboriginal and Torres Strait Islander families and communities: protocol for a population-based cohort study using data linkage (the ‘Defying the Odds’ study)

IntroductionEmpirical evidence on family and community risk and protective factors influencing the comparatively high rates of potentially preventable hospitalisations and deaths among Aboriginal and Torres Strait Islander infants and children...

Wideband absorbance in Australian Aboriginal and Caucasian neonates.

Despite the high prevalence of otitis media in Australian Aboriginal infants and children, the conductive mechanism of the outer and middle ear of Aboriginal neonates remains unclear. Differences in characteristics of the conductive pathway (outer and middle ear) between Aboriginal and Caucasian neonates have not been systematically investigated by using wideband acoustic immittance measures. The objective of this study was to compare wideband absorbance (WBA) in Australian Aboriginal and Caucasian neonates who passed or failed a screening test battery containing high-frequency tympanometry and distortion product otoacoustic emissions (DPOAEs). A cross-sectional study design was used. The mean WBA as a function of frequency was compared between Aboriginal and non-Aboriginal neonates who passed or failed the test battery. A total of 59 ears from 32 Aboriginal neonates (mean age, 51.9 h; standard deviation [SD], 18.2 h; range, 22-86 h) and 281 ears from 158 Caucasian neonates (mean age, 42.4 h; SD, 23.0 h; range, 8.1-152 h) who passed or failed 1000-Hz tympanometry and DPOAEs were included in the study. WBA results were analyzed by using descriptive statistics and t tests with Bonferroni adjustment. An analysis of variance with repeated measures was applied to the data. Aboriginal and Caucasian neonates had almost identical pass rates of 61%, as determined by the test battery. Despite the apparently equal pass rates, the mean WBA of Aboriginal neonates who passed the test battery was significantly lower than that of their Caucasian counterparts at frequencies between 0.4 and 2 kHz. The mean WBA of Aboriginal neonates who failed the test battery was significantly lower than that of their Caucasian counterparts who also failed the test battery at frequencies between 1.5 and 3 kHz. Both Aboriginal and Caucasian neonates who failed the test battery had significantly lower WBA values than their counterparts who passed the test battery. This study provided convincing evidence that Aboriginal neonates had significantly lower WBA values than their Caucasian counterparts, although both groups had equal pass rates, as determined by the test battery. Although the two ethnic groups showed significant differences in WBA, the factors contributing to such differences remain undetermined. Further research is warranted to determine the factors that might account for the difference in WBA between the two ethnic groups.

Adherence to management guidelines for growth faltering and anaemia in remote dwelling Australian Aboriginal infants and barriers to health service delivery.

BackgroundRemote dwelling Aboriginal infants from northern Australia have a high burden of disease and frequently use health services. Little is known about the quality of infant care provided by remote health services. This study describes the adherence to infant guidelines for anaemia and growth faltering by remote health staff and barriers to effective service delivery in remote settings.MethodsA mixed method study drew data from 24 semi-structured interviews with clinicians working in two remote communities in northern Australia and a retrospective cohort study of Aboriginal infants from these communities, born 2004–2006 (n = 398). Medical records from remote health centres were audited. The main outcome measures were the period prevalence of infants with anaemia and growth faltering and management of these conditions according to local guidelines. Qualitative data assessed clinicians’ perspectives on barriers to effective remote health service delivery.ResultsData from 398 health centre records were analysed. Sixty eight percent of infants were anaemic between six and twelve months of age and 42% had documented growth faltering by one year. Analysis of the growth data by the authors however found 86% of infants experienced growth faltering over 12 months. Clinical management and treatment completion was poor for both conditions. High staff turnover, fragmented models of care and staff poorly prepared for their role were barriers perceived by clinicians’ to impact upon the quality of service delivery.ConclusionAmong Aboriginal infants in northern Australia, malnutrition and anaemia are common and occur early. Diagnosis of growth faltering and clinicians’ adherence to management guidelines for both conditions was poor. Antiquated service delivery models, organisation of staff and rapid staff turnover contributed to poor quality of care. Service redesign, education and staff stability must be a priority to redress serious deficits in quality of care provided for these infants.

Describing the growth and rapid weight gain of urban Australian Aboriginal infants

The aims of this paper are to describe the growth of urban Australian Aboriginal infants from birth to 24 months of age and to identify the proportion of these infants experiencing rapid weight gain (RWG) and overweight/obesity. The Gudaga Study is a longitudinal birth cohort of 159 Australian Aboriginal children born on the urban fringe of Sydney. Birthweight and length were extracted from hospital data. Children with a birthweight >1500 grams were included in the analysis (n = 157). Weight, length and head circumference were measured at 2-3 weeks and then six-monthly until 24 months of age. Age- and gender-specific Z-scores were determined from the Centers for Disease Control (CDC) 2000 growth charts for weight, length, head circumference and body mass index (BMI). The proportion of children experiencing RWG (an increase in weight-for-age Z-scores ≥0.67 between birth and 12 months) was calculated. The association between RWG and ≥85th CDC percentile for BMI at 24 months was tested using Pearson's χ². The mean weight of Gudaga infants was less than the CDC mean length-for-age at birth and 2-3 weeks of age but greater than CDC mean length-for-age and weight-for-age at 18 and 24 months of age. Overall, 42 infants (34.4%) experienced RWG, and 45 infants (36.9%) were overweight/obese at 24 months of age. A greater proportion of those who experienced RWG (61.9%) were overweight/obese at 24 months than those who did not experience RWG (23.8%). Our study suggests a concerning proportion of urban Indigenous infants experience RWG and overweight/obesity in early childhood.

Fetal growth restriction and 18‐year growth and nutritional status: Aboriginal birth cohort 1987–2007

The main objective of the work is to compare the growth and nutritional status of Australian Aboriginal term infants born with (n = 81) and without fetal growth restriction (n = 260). A prospective birth cohort study of 341 Aboriginal babies from the Top End of the Northern Territory of Australia was recruited at birth (1987-1990) and re-examined at a mean age of 18.3 years (2006-2008) for outcome measures of growth and nutrition status. Those with growth restriction at birth were 3 cm shorter (P = 0.0026) and 9 kg lighter (P = 0.0001) with head circumferences 0.95 cm smaller (P = 0.0008) than those without growth restriction. The proportions of growth restricted participants with body mass index <18.5 kg/m(2) were significantly greater (P = 0.028), and those with BMI > 25 kg/m(2) and with fat percentage >85th percentile were significantly smaller (P = 0.012 and 0.004, respectively). In this cohort, those Aboriginal babies born smaller and lighter have remained smaller and lighter at 18 years of age. However, the highest risk of later chronic noncommunicable disease has been reported in subjects who were born small and become relatively larger in later life. The continued study of this Aboriginal birth cohort will give us an opportunity to determine if and when in later life the effects of birth weight are modified by environmental nutritional factors.

Pneumococcal conjugate vaccination and otitis media: differences among high-risk and low-risk populations

Evaluation of: Mackenzie GA, Carapetis JR, Leach AJ, Morris PS. Pneumococcal vaccination and otitis media in Australian Aboriginal infants: comparison of two birth cohorts before and after introduction of vaccination. BMC Pediatr. 9, 14 (2009).The impact of the heptavalent pneumococcal conjugate vaccine (PCV7) on the natural history of otitis media (OM) has been studied recently. In a high-risk population, PCV7 significantly reduced the risk of recurrent, bilateral or multiple tympanic membrane perforation, as well as the risk of chronic suppurative OM at 9 months of age. PCV7 did not reduce the time to the development of OM nor the burden of OM. Major challenges are the polymicrobial etiology of OM (Streptococcus pneumoniae and Haemophilus influenzae) in high-risk populations and the serotype replacement among pneumococcal strains. A vaccine including nontypable H. influenzae and 11 pneumococcal serotypes has been identified as a more efficacious option for preventing OM. In the near future, the development and evaluation of a vaccine containing pneumococcal protein, such as pneumococcal surface protein A, which is a structurally variable and serologically cross-reactive surface protein important to the pneumococcal virulence, will be a potential tool against OM.

Pneumococcal vaccination and otitis media in Australian Aboriginal infants: comparison of two birth cohorts before and after introduction of vaccination

BackgroundAboriginal children in remote Australia have high rates of complicated middle ear disease associated with Streptococcus pneumoniae and other pathogens. We assessed the effectiveness of pneumococcal vaccination for prevention of otitis media in this setting.MethodsWe compared two birth cohorts, one enrolled before (1996–2001), and the second enrolled after introduction of 7-valent pneumococcal conjugate and booster 23-valent polysaccharide vaccine (2001–2004). Source populations were the same for both cohorts. Detailed examinations including tympanometry, video-recorded pneumatic otoscopy and collection of discharge from tympanic membrane perforations, were performed as soon as possible after birth and then at regular intervals until 24 months of life. Analyses (survival, point prevalence and incidence) were adjusted for confounding factors and repeated measures with sensitivity analyses of differential follow-up.ResultsNinety-seven vaccinees and 51 comparison participants were enrolled. By age 6 months, 96% (81/84) of vaccinees and 100% (41/41) of comparison subjects experienced otitis media with effusion (OME), and by 12 months 89% and 88% experienced acute otitis media (AOM), 34% and 35% experienced tympanic membrane perforation (TMP) and 14% and 23% experienced chronic suppurative otitis media (CSOM). Age at the first episode of OME, AOM, TMP and CSOM was not significantly different between the two groups. Adjusted incidence of AOM (incidence rate ratio: 0.88 [95% confidence interval (CI): 0.69–1.13]) and TMP (incidence rate ratio: 0.63 [0.36–1.11]) was not significantly reduced in vaccinees. Vaccinees experienced less recurrent TMP, 9% (8/95) versus 22% (11/51), (odds ratio: 0.33 [0.11–1.00]).ConclusionResults of this study should be interpreted with caution due to potential bias and confounding. It appears that introduction of pneumococcal vaccination among Aboriginal infants was not associated with significant changes in prevalence or age of onset of different OM outcomes or the incidence of AOM or TMP. Vaccinees appeared to experience reduced recurrence of TMP. Ongoing high rates of complicated OM necessitate additional strategies to prevent ear disease in this population.

The association of infant feeding with parent‐reported infections and hospitalisations in the West Australian Aboriginal Child Health Survey

To examine infant feeding associations with parent-reported infections and hospitalisations in Western Australian Aboriginal infants and children. Families in Western Australia with children under 18 years of Aboriginal or Torres Strait Islander descent were included. A stratified multi-stage sample using an area-based sampling frame was compiled. Survey weights produced unbiased estimates for the population of families with Aboriginal children. Data were collected on demographic variables, maternal and infant characteristics and parent-reported recurring chest, ear and gastrointestinal infections. The data were linked to the Hospital Morbidity System to identify hospitalisations for infections for the same children. Twenty-seven per cent of Aboriginal children were breastfed for less than three months. Parent-reported recurring chest, ear and gastrointestinal infections were reported in 47% of the 0-3 age group. Hospitalisations due to upper respiratory and gastrointestinal infections were most common in the older children, but wheezing lower respiratory infections were most common in younger children. Breastfeeding for less than three months and birth weight less than 2,500 g were risk factors for parent-reported chest infections and hospitalisations for upper and wheezing lower respiratory infections (p<0.05). Rates of parent-reported chest infections and hospitalisations due to these infections continue to be high in Aboriginal infants and children. Because breastfeeding for less than three months and low birth weight are risk factors for these infections, interventions to reduce the prevalence of low birth weight and to increase breastfeeding rates should be primary health goals in Aboriginal communities for the benefits of Aboriginal infants and children.

Immunogenicity for 16 serotypes of a unique schedule of pneumococcal vaccines in a high-risk population

Background A unique schedule of 7-valent pneumococcal conjugate vaccine (7PCV) at 2, 4 and 6 months of age and 23-valent pneumococcal polysaccharide vaccine (23PPV) at 18 months commenced for Australian Aboriginal infants in 2001. Methods Anti-capsular IgG concentrations in vaccinated and non-vaccinated (historic control) infants were determined (blinded) by (22F absorbed) ELISA. Results One month after dose 3 of 7PCV, geometric mean concentrations (GMCs) were >1.95 μg/ml and at least 89% of infants had IgG >0.35 μg/ml to all 7PCV serotypes. One month post-23PPV, IgG to 7PCV serotypes was >0.35 μg/ml for more than 96% infants (>1.3 μg/ml for at least 70%), and IgG to non-7PCV serotypes was >0.35 μg/ml for more than 50% infants (including serotype 6A, but not 12F (17%) or 19A (44%). Conclusion 7PCV and 23PPV are immunogenic in this population.

Hospitalisation for gastroenteritis in Western Australia

Aims: To document gastroenteritis hospitalisations of the 1995–96 cohort of infants born in Western Australia to mid-2002, and to assess factors associated with their hospitalisations and readmissions. Methods: Retrospective analysis...

Differing serologic responses to an Haemophilus influenzae type b polysaccharide– Neisseria meningitidis outer membrane protein conjugate (PRP–OMPC) vaccine in Australian Aboriginal and Caucasian infants — implications for disease epidemiology

This study compared Hib antibody responses to a single lot of PRP–OMPC vaccine given at 2, 4 and 12 months to 57 Aboriginal infants in rural areas of the Northern Territory and 56 Caucasian infants in Sydney, Australia. The Aboriginal infants had lower levels of antibody in cord blood ( P>0.05), which were significantly lower ( P<0.02) by 2 months of age. Antibody responses to one or two doses of vaccine, measured at 4 and 12 months of age, were similar but the geometric mean titre following the booster dose in Aboriginal infants was significantly lower (1.98 vs 6.04 mcg/ml, P=0.002). Low preimmunisation antibody is consistent with the early onset of Hib disease in Aboriginal infants before immunisation. Lower responses to boosting could correlate with persistence of Hib colonisation in indigenous populations.