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edited by Craig Mellis (craig.mellis@sydney.edu.au)

Salmonella outbreak from pet frogs

Non-typhoidal Salmonella infections, an important cause of gas-troenteritis, are mainly food borne but can be contractedthrough contact with reptiles and amphibians. Epidemiologistsfrom the US Centers for Disease Control investigated a cluster ofcases of gastroenteritis caused by a common strain of Salmonellatyphimurium.1 They identified 376 cases in 44 states over 4 years,of whom 29% were hospitalised. Over two-thirds (69%) werechildren <10 years old. Patients or care givers were interviewedabout possible exposures in the 7 days before onset. Frog expo-sure was reported by 61% of cases interviewed and 79% ofthose who knew the type reported contact with aquatic Africandwarf frogs. A case control study matched cases with age-matched controls who had recent Salmonella infections but witha different strain from the outbreak strain: 67% of cases but only3% of controls had frog exposure. Environmental samples frompatients’ homes and a day care centre grew isolates indistin-guishable from the outbreak strain. A gastroenteritis historyshould include asking about frogs.

Reference

1 Mettee Zarecki SL et al. Pediatrics 2013; 131: 724–31.

Reviewer: David Isaacs, david.isaacs@health.nsw.gov.au

Randomised controlled trial of less-violenttelevision for pre-schoolers

Pre-school-age children in the USA watch an estimated 4.4 h aday of television in the home and day care. There is concern that

children may imitate violent content. A randomised controlledtrial involving 565 children aged 3–5 years in Seattle compareda ‘media diet’ intervention with a control group who received anutritional intervention designed to promote healthier eatinghabits.1 The media diet encouraged parents to replace violent orage-inappropriate content of all media but mainly television andvideos, with age-appropriate educational or ‘pro-social’ content.The content was changed without decreasing the total durationof viewing. An initial home visit was followed up with news-letters, monthly telephone calls and sample videos withpro-social content. The primary outcome was the Social Com-petence and Behavior Evaluation (SCBE) as measured by theparent, a possible source of bias because the parents doing theevaluation were aware of the study aims. The SCBE is describedas a well-validated measure with subscales for internalising(anxious, depressive and withdrawn) and externalising (angry,aggressive and oppositional) behaviours and for social compe-tence. At 6 months, the overall SCBE score and the externalis-ing and social competence subscales were significantly better inthe intervention group than the controls. The internalisingsubscale trended towards the intervention group. At 12 monthsthe difference in the externalising subscale was no longer sta-tistically significant. Importantly, the greatest effect of the inter-vention was seen in boys from low-income families.

Reference

1 Christakis DA et al. Pediatrics Published online February 18 2013.doi: 10.1542/peds.2012-1493

doi:10.1111/jpc.12433

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Journal of Paediatrics and Child Health 49 (2013) 1080–1081© 2013 The Authors

Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians)

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Reviewer: David Isaacs, Children’s Hospital at Westmead(david.isaacs@health.nsw.gov.au)

Blood pressure in adolescence

It is uncertain what blood pressure level in an adolescentshould alarm us and whether we should be looking at systolicor diastolic blood pressure. Conscription in Sweden was com-pulsory and the initial enrollment included a medical exami-nation. An extraordinary record linkage study followed justover 1.2 million Swedish army recruits, mean age 18.4 years,between 1969 and 1995 for a median of 24 years (range 0–37).1

The authors linked the unique personal identification numberof each Swedish citizen to national death and emigration reg-isters to examine the relationship between blood pressure andmortality, due to any cause or due to cardiovascular disease(12.5% of the total).

The authors found that the risk of dying from cardiovasculardisease correlated better with diastolic than with systolic bloodpressure and that there seemed to be a threshold diastolic pres-sure of 90 mm Hg above, which the risk started to increaseconsiderably. In contrast, for systolic pressure, the lowest riskwas with systolic pressures of about 130 mm Hg, and mortalityrose gently either side of this in a U-shaped curve (see Figure 1).These remarkable new data afford the basis to design studies onthe effect of treating adolescents with raised blood pressurelevels to see if interventions can reduce mortality.

Reference

1 Sundstrom J et al. BMJ 2011; 342: d643.

Link: http://www.bmj.com/content/342/bmj.d643.full.pdf

Reviewer: David Isaacs, davidi@chw.edu.au

Adolescent obesity and sleep duration

Obese adolescents sleep shorter, although most studies havebeen cross-sectional. A longitudinal study in Philadelphia fol-lowed 1390 children from age 14 to 18 years.1 One weaknesswas that heights and weights used to calculate body mass index(BMI) were self-reported. Mean BMI increased from 14 to 18,with the greatest increase at the 90th BMI percentile. Eachadditional hour of sleep was associated with a significantdecrease in BMI at all percentile points from 10th to 90th, butthe association was strongest at the upper end of the BMIdistribution. Helping adolescents sleep longer may be a valuabletool in preventing obesity.

Reference

1 Mitchell JA et al. Pediatrics 2013; 131: e1428–34.

Reviewer: David Isaacs, david.isaacs@health.nsw.gov.au

Fig. 1 Systolic blood pressure and risk of death (dotted lines represent

95% confidence intervals).

Heads Up

Journal of Paediatrics and Child Health 49 (2013) 1080–1081© 2013 The AuthorsJournal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians)

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