Viruses associated with acute respiratory infection in a community-based cohort of healthy New Zealand children.

Acute respiratory infections (ARIs) are a major cause of morbidity among children. Respiratory viruses are commonly detected in both symptomatic and asymptomatic periods. The rates of infection and community epidemiology of respiratory viruses in healthy children needs further definition to assist interpretation of molecular diagnostic assays in this population. Children otherwise healthy aged 1 to 8 years were prospectively enrolled in the study during two consecutive winters, when ARIs peak in New Zealand. Parents completed a daily symptom diary for 8 weeks, during which time they collected a nasal swab from the child for each clinical ARI episode. A further nasal swab was collected by research staff during a clinic visit at the conclusion of the study. All samples were tested for 15 respiratory viruses commonly causing ARI using molecular multiplex polymerase chain reaction assays. There were 575 ARIs identified from 301 children completing the study, at a rate of 1.04 per child-month. Swabs collected during an ARI were positive for a respiratory virus in 76.8% (307 of 400), compared with 37.3% (79 of 212) of swabs collected during asymptomatic periods. The most common viruses detected were human rhinovirus, coronavirus, parainfluenza viruses, influenzavirus, respiratory syncytial virus, and human metapneumovirus. All of these were significantly more likely to be detected during ARIs than asymptomatic periods. Parent-administered surveillance is a useful mechanism for understanding infectious disease in healthy children in the community. Interpretation of molecular diagnostic assays for viruses must be informed by understanding of local rates of asymptomatic infection by such viruses.

Maternal supplementation alone with Lactobacillus rhamnosus HN001 during pregnancy and breastfeeding does not reduce infant eczema.

BACKGROUND: In a randomized placebo-controlled trial, we previously found that the probiotic Lactobacillus rhamnosus HN001 (HN001) taken by mothers from 35 weeks of gestation until 6 months post-partum if breastfeeding and their child from birth to age 2 years halved the risk of eczema during the first 2 years of life. We aimed to test whether maternal supplementation alone is sufficient to reduce eczema and compare this to our previous study when both the mother and their child were supplemented. METHODS: In this 2-centre, parallel double-blind, randomized placebo-controlled trial, the same probiotic as in our previous study (HN001, 6 × 109 colony-forming units) was taken daily by mothers from 14-16 weeks of gestation till 6 months post-partum if breastfeeding, but was not given directly to the child. Women were recruited from the same study population as the first study, where they or their partner had a history of treated asthma, eczema or hay fever. RESULTS: Women were randomized to HN001 (N = 212) or placebo (N = 211). Maternal-only HN001 supplementation did not significantly reduce the prevalence of eczema, SCORAD ≥ 10, wheeze or atopic sensitization in the infant by 12 months. This contrasts with the mother and child intervention study, where HN001 was associated with reductions in eczema (hazard ratio (HR): 0.39, 95% CI 0.19-0.79, P = .009) and SCORAD (HR = 0.61, 95% 0.37-1.02). However, differences in the HN001 effect between studies were not significant. HN001 could not be detected in breastmilk from supplemented mothers, and breastmilk TGF-ß/IgA profiles were unchanged. CONCLUSION: Maternal probiotic supplementation without infant supplementation may not be effective for preventing infant eczema.

Indoor visible mold and mold odor are associated with new-onset childhood wheeze in a dose-dependent manner.

Evidence is accumulating that indoor dampness and mold are associated with the development of asthma. The underlying mechanisms remain unknown. New Zealand has high rates of both asthma and indoor mold and is ideally placed to investigate this. We conducted an incident case-control study involving 150 children with new-onset wheeze, aged between 1 and 7 years, each matched to two control children with no history of wheezing. Each participant's home was assessed for moisture damage, condensation, and mold growth by researchers, an independent building assessor and parents. Repeated measures of temperature and humidity were made, and electrostatic dust cloths were used to collect airborne microbes. Cloths were analyzed using qPCR. Children were skin prick tested for aeroallergens to establish atopy. Strong positive associations were found between observations of visible mold and new-onset wheezing in children (adjusted odds ratios ranged between 1.30 and 3.56; P ≤ .05). Visible mold and mold odor were consistently associated with new-onset wheezing in a dose-dependent manner. Measurements of qPCR microbial levels, temperature, and humidity were not associated with new-onset wheezing. The association between mold and new-onset wheeze was not modified by atopic status, suggesting a non-allergic association.

Early pregnancy probiotic supplementation with Lactobacillus rhamnosus HN001 may reduce the prevalence of gestational diabetes mellitus: a randomised controlled trial.

The study aims to assess whether supplementation with the probiotic Lactobacillus rhamnosus HN001 (HN001) can reduce the prevalence of gestational diabetes mellitus (GDM). A double-blind, randomised, placebo-controlled parallel trial was conducted in New Zealand (NZ) (Wellington and Auckland). Pregnant women with a personal or partner history of atopic disease were randomised at 14-16 weeks' gestation to receive HN001 (6×109 colony-forming units) (n 212) or placebo (n 211) daily. GDM at 24-30 weeks was assessed using the definition of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) (fasting plasma glucose ≥5·1 mmol/l, or 1 h post 75 g glucose level at ≥10 mmol/l or at 2 h ≥8·5 mmol/l) and NZ definition (fasting plasma glucose ≥5·5 mmol/l or 2 h post 75 g glucose at ≥9 mmol/l). All analyses were intention-to-treat. A total of 184 (87 %) women took HN001 and 189 (90 %) women took placebo. There was a trend towards lower relative rates (RR) of GDM (IADPSG definition) in the HN001 group, 0·59 (95 % CI 0·32, 1·08) (P=0·08). HN001 was associated with lower rates of GDM in women aged ≥35 years (RR 0·31; 95 % CI 0·12, 0·81, P=0·009) and women with a history of GDM (RR 0·00; 95 % CI 0·00, 0·66, P=0·004). These rates did not differ significantly from those of women without these characteristics. Using the NZ definition, GDM prevalence was significantly lower in the HN001 group, 2·1 % (95 % CI 0·6, 5·2), v. 6·5 % (95 % CI 3·5, 10·9) in the placebo group (P=0·03). HN001 supplementation from 14 to 16 weeks' gestation may reduce GDM prevalence, particularly among older women and those with previous GDM.

The Probiotics in Pregnancy Study (PiP Study): rationale and design of a double-blind randomised controlled trial to improve maternal health during pregnancy and prevent infant eczema and allergy.

BACKGROUND: Worldwide there is increasing interest in the manipulation of human gut microbiota by the use of probiotic supplements to modify or prevent a range of communicable and non-communicable diseases. Probiotic interventions administered during pregnancy and breastfeeding offer a unique opportunity to influence a range of important maternal and infant outcomes. The aim of the Probiotics in Pregnancy Study (PiP Study) is to assess if supplementation by the probiotic Lactobacillus rhamnosus HN001 administered to women from early pregnancy and while breastfeeding can reduce the rates of infant eczema and atopic sensitisation at 1 year, and maternal gestational diabetes mellitus, bacterial vaginosis and Group B Streptococcal vaginal colonisation before birth, and depression and anxiety postpartum. METHODS/DESIGN: The PiP Study is a two-centre, randomised, double-blind placebo-controlled trial in Wellington and Auckland, New Zealand. Four hundred pregnant women expecting infants at high risk of allergic disease will be enrolled in the study at 14-16 weeks gestation and randomised to receive either Lactobacillus rhamnosus HN001 (6 × 10(9) colony-forming units per day (cfu/day)) or placebo until delivery and then continuing until 6 months post-partum, if breastfeeding. Primary infant outcomes are the development and severity of eczema and atopic sensitisation in the first year of life. Secondary outcomes are diagnosis of maternal gestational diabetes mellitus, presence of bacterial vaginosis and vaginal carriage of Group B Streptococcus (at 35-37 weeks gestation). Other outcome measures include maternal weight gain, maternal postpartum depression and anxiety, infant birth weight, preterm birth, and rate of caesarean sections. A range of samples including maternal and infant faecal samples, maternal blood samples, cord blood and infant cord tissue samples, breast milk, infant skin swabs and infant buccal swabs will be collected for the investigation of the mechanisms of probiotic action. DISCUSSION: The study will investigate if mother-only supplementation with Lactobacillus rhamnosus HN001 in pregnancy and while breastfeeding can reduce rates of eczema and atopic sensitisation in infants by 1 year, and reduce maternal rates of gestational diabetes mellitus, bacterial vaginosis, vaginal carriage of Group B Streptococcus before birth and maternal depression and anxiety postpartum. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registration: ACTRN12612000196842. Date Registered: 15/02/12.