Antibiotic prophylaxis and recurrent urinary tract infection in children.

BACKGROUND: Antibiotics are widely administered to children with the intention of preventing urinary tract infection, but adequately powered, placebo-controlled trials regarding efficacy are lacking. This study from four Australian centers examined whether low-dose, continuous oral antibiotic therapy prevents urinary tract infection in predisposed children. METHODS: We randomly assigned children under the age of 18 years who had had one or more microbiologically proven urinary tract infections to receive either daily trimethoprim-sulfamethoxazole suspension (as 2 mg of trimethoprim plus 10 mg of sulfamethoxazole per kilogram of body weight) or placebo for 12 months. The primary outcome was microbiologically confirmed symptomatic urinary tract infection. Intention-to-treat analyses were performed with the use of time-to-event data. RESULTS: From December 1998 to March 2007, a total of 576 children (of 780 planned) underwent randomization. The median age at entry was 14 months; 64% of the patients were girls, 42% had known vesicoureteral reflux (at least grade III in 53% of these patients), and 71% were enrolled after the first diagnosis of urinary tract infection. During the study, urinary tract infection developed in 36 of 288 patients (13%) in the group receiving trimethoprim-sulfamethoxazole (antibiotic group) and in 55 of 288 patients (19%) in the placebo group (hazard ratio in the antibiotic group, 0.61; 95% confidence interval, 0.40 to 0.93; P = 0.02 by the log-rank test). In the antibiotic group, the reduction in the absolute risk of urinary tract infection (6 percentage points) appeared to be consistent across all subgroups of patients (P > or = 0.20 for all interactions). CONCLUSIONS: Long-term, low-dose trimethoprim-sulfamethoxazole was associated with a decreased number of urinary tract infections in predisposed children. The treatment effect appeared to be consistent but modest across subgroups. (Australian New Zealand Clinical Trials Registry number, ACTRN12608000470392.)

A pilot study of the use of oral ivermectin to treat head lice in primary school students in Australia.

Head lice are a common, costly public health problem worldwide. We aimed to determine the feasibility of an ivermectin intervention program. Consenting students in two schools were screened for head lice. Infested students and siblings at one school were offered a head lice fact sheet and two doses of oral ivermectin, 7 days apart. Parents of infested students in the other school were given the same fact sheet and asked to treat the child and siblings using their preferred topical treatment. Seven hundred two of 754 (93.1%) students enrolled in the two schools were screened; 40 (5.3%; 95% CI 3.7-6.9) had head lice; 31 (9.4%; 95% CI 6.1-12.2) in the intervention school and nine (2.5%; 95% CI 1.1-3.8) in the control school. Subsequently 93.6% of children in the intervention school were treated with oral ivermectin. No adverse events were reported. At 6 months the reduction in the head lice infestation rates for the intervention and control schools were 87% and 56%, respectively. This pilot study suggests that school wide screening for head lice and the administration of oral ivermectin is feasible and acceptable. A randomized controlled trial at 20 schools is planned.

Contrasting longitudinal and cross-sectional relationships between insulin resistance and percentage of body fat, fitness, and physical activity in children-the LOOK study.

BACKGROUND: Knowledge of individual changes in insulin resistance (IR) and longitudinal relationships of IR with lifestyle-associated factors are of important practical significance, but little longitudinal data exist in asymptomatic children. We aimed to determine (a) changes in the homeostatic model of insulin resistance (HOMA-IR) over a 2-yr period and (b) comparisons of longitudinal and cross-sectional relationships between HOMA-IR and lifestyle-related risk factors. METHODS: Our subjects, 241 boys and 257 girls, were assessed at age 8.1 yr (SD 0.35) and again 2 yr later for fasting blood glucose and insulin, dual X-ray absorptiometry-assessed percentage of body fat (%BF), pedometer-assessed physical activity (PA), and cardio-respiratory fitness (CRF) by multistage running test. RESULTS: HOMA-IR was initially 9% greater in girls than boys and 27% greater 2 yr later. There was no evidence of longitudinal relationships between HOMA-IR and %BF in boys or girls, despite significant cross-sectional relationships (p < 0.001). In boys, there was evidence of a longitudinal relationship between HOMA-IR and both PA (p < 0.001) and CRF (p = 0.05). In girls, we found a cross-sectional relationship between HOMA-IR and CRF (p < 0.001). CONCLUSIONS: HOMA-IR increases between 8 and 10 yr of age and to a greater extent in girls. Longitudinal, unlike cross-sectional, relationships do not support the premise that body fat has any impact on HOMA-IR during this period or that PA or CRF changes affect HOMA-IR in girls. These data draw attention to difficulties in interpreting observational studies in young children.

The lifestyle of our kids (LOOK) project: outline of methods.

This methods paper outlines the overall design of a community-based multidisciplinary longitudinal study with the intent to stimulate interest and communication from scientists and practitioners studying the role of physical activity in preventive medicine. In adults, lack of regular exercise is a major risk factor in the development of chronic degenerative diseases and is a major contributor to obesity, and now we have evidence that many of our children are not sufficiently active to prevent early symptoms of chronic disease. The lifestyle of our kids (LOOK) study investigates how early physical activity contributes to health and development, utilizing a longitudinal design and a cohort of eight hundred and thirty 7-8-year-old (grade 2) school children followed to age 11-12 years (grade 6), their average family income being very close to that of Australia. We will test two hypotheses, that (a) the quantity and quality of physical activity undertaken by primary school children will influence their psychological and physical health and development; (b) compared with existing practices in primary schools, a physical education program administered by visiting specialists will enhance health and development, and lead to a more positive perception of physical activity. To test the first hypothesis we will monitor all children longitudinally over the 4 years. To test the second we will involve an intervention group of 430 children who receive two 50min physical education classes every week from visiting specialists and a control group of 400 who continue with their usual primary school physical education with their class-room teachers. At the end of grades 2, 4, and 6 we will measure several areas of health and development including blood risk factors for chronic disease, cardiovascular structure and function, physical fitness, psychological characteristics and perceptions of physical activity, bone structure and strength, motor control, body composition, nutritional intake, influence of teachers and family, and academic performance.

Discordance of international adiposity classifications in Australian boys and girls - the LOOK study.

BACKGROUND: Various charts based on body mass index (BMI) and per cent body fat (%BF) are used to classify childhood body composition but outcomes may vary. AIM: The study investigated variation in incidences of childhood obesity as depicted by four classification charts. SUBJECTS AND METHODS: BMI and DXA-derived %BF were assessed in 741 children. Incidences of overweight and obesity were compared between two BMI charts and two bioelectrical impedance (BIA)-based %BF charts. RESULTS: The International Obesity Task Force (IOTF)-adopted BMI chart designated 21%, 6% (boys), and 26%, 9% (girls) as overweight and obese, respectively. Corresponding figures using the USA CDC BMI chart were 27%, 11% (boys) and 27%, 12% (girls). Using a USA-derived %BF chart incidences were 17%, 2% (boys) and 21%, 8% (girls) and using a UK-derived %BF chart 51%, 24% (boys) and 53%, 36% (girls). Sensitivity of BMI varied according to the %BF reference chart. CONCLUSIONS: In contrast to the BMI-based charts, there were considerable variations in depicted incidences of obesity between the %BF-based charts. These discordances were considered to result from previously reported variation within and between BIA and DXA %BF assessments underlying the charts. The present study highlights the need for valid, reliable, unchanging BIA and DXA procedures.

Safety and tolerability of a 2009 trivalent inactivated split-virion influenza vaccine in infants, children and adolescents.

OBJECTIVE: To evaluate the safety of CSL's split-virion inactivated trivalent 2009 Southern Hemisphere formulation influenza vaccine (TIV) in children. METHODS: We enrolled 1992 healthy children into three groups: Cohorts A, ≥ 6 months to <3 years; B, ≥ 3 years to <9 years; and C, ≥ 9 years to <18 years. Children received one or two doses of 0.25 ml (22.5 µg haemagglutinin) or 0.5 ml (45 µg) TIV, depending on age and prior vaccination history. We collected post-vaccination solicited adverse event (AE) data (days 0-6), including fever (temperature: ≥ 37.5°C axilla, ≥ 38.0°C oral), unsolicited AEs (days 0-29) and serious AEs (SAEs) and new-onset chronic illnesses (NOCIs; to day 180 after last vaccination). RESULTS: At least one solicited AE was reported by 80%/78%/78% of children in Cohorts A, B and C, respectively. Systemic AEs were more common among Cohort A (72% of participants), and local AEs were more common among Cohort C (71% of participants). Fever was more common in younger cohorts, in influenza vaccine-naïve children (29% of Cohort A receiving their first dose), and following first compared with second doses. Severe fever following a first dose prevented 20 participants receiving their second scheduled vaccine dose. A 7-month-old participant had a single uncomplicated febrile convulsion on the day of vaccination. CONCLUSIONS: Nearly 80% of subjects reported at least one solicited AE following immunization. Fever prevalence was highest in vaccine-naïve Cohort A participants, similar to other paediatric studies using CSL vaccine. Further research to understand fever-related AEs in children following CSL's TIV is recommended.

Establishment of pediatric reference intervals on a large cohort of healthy children.

BACKGROUND: Reference intervals are essential in assessing the significance of laboratory results. There have been limited studies generating reference intervals from pediatric populations. We have studied a large cohort of healthy children on 3 separate occasions at 2yearly intervals. METHODS: 852 healthy 8year old children were enrolled in a community-based multidisciplinary longitudinal study investigating how early physical activity contributes to health. The same children came back for reassessment at ages 10 and 12years. Blood samples were analyzed for a total of 37 different chemistries, immunoassays or derived values. RESULTS: Reference intervals were derived for all the analytes for males and females separately. CONCLUSION: Whilst our results are largely in agreement with previously published work, we have shown that for a number of analytes, previously published work is distorted by subclinical disease.

Indomethacin and renal impairment in neonates.

Renal impairment occurs in neonates receiving indomethacin for treatment of patent ductus arteriosus. Inhibition of cyclooxygenase within the neonatal kidney results in decreased prostaglandin synthesis and consequent reduction in renal perfusion. Indomethacin has been reported to cause short-term reduction in glomerular filtration that resolves after cessation of the drug. There is little information on the long-term effects of postnatal exposure to indomethacin. The aim of this study was to determine the incidence of renal impairment in infants treated with indomethacin in a single center, to determine whether there is evidence of renal impairment on day 30 or at discharge, and to identify risk factors for renal impairment. In a retrospective study, infants of less than 30 weeks completed gestation who received indomethacin to close the ductus arteriosus were matched with infants of the same gestation, birth weight, and severity of illness. Serum creatinine and glomerular filtration rates (GFR) were obtained prior to commencing indomethacin and on days 2, 7, and 30 following indomethacin administration. Acute renal failure was defined as an increase in creatinine of greater than 25%. Of those infants who were less than 30 weeks completed gestation, 24% had acute renal failure following indomethacin administration. There was a significant elevation in serum creatinine on day 2 and day 7 ( P<0.0001, P=0.002) and a decrease in GFR on day 2 and day 7 ( P<0.0001, P=0.01) following administration of indomethacin. Renal function had normalized by day 30 or discharge. The incidence of acute renal failure in neonates treated with indomethacin is clinically significant. Renal function returns to normal by day 30. Linear regression found no statistical significance for gestational age, day of indomethacin dosing, Clinical Risk Index for Babies (CRIB) score, and presence of an umbilical artery catheter to confound the effect of indomethacin on renal function.