Pediatric hospitalizations associated with 2009 pandemic influenza A (H1N1) in Argentina.

BACKGROUND: While the Northern Hemisphere experiences the effects of the 2009 pandemic influenza A (H1N1) virus, data from the recent influenza season in the Southern Hemisphere can provide important information on the burden of disease in children. METHODS: We conducted a retrospective case series involving children with acute infection of the lower respiratory tract or fever in whom 2009 H1N1 influenza was diagnosed on reverse-transcriptase polymerase-chain-reaction assay and who were admitted to one of six pediatric hospitals serving a catchment area of 1.2 million children. We compared rates of admission and death with those among age-matched children who had been infected with seasonal influenza strains in previous years. RESULTS: Between May and July 2009, a total of 251 children were hospitalized with 2009 H1N1 influenza. Rates of hospitalization were double those for seasonal influenza in 2008. Of the children who were hospitalized, 47 (19%) were admitted to an intensive care unit, 42 (17%) required mechanical ventilation, and 13 (5%) died. The overall rate of death was 1.1 per 100,000 children, as compared with 0.1 per 100,000 children for seasonal influenza in 2007. (No pediatric deaths associated with seasonal influenza were reported in 2008.) Most deaths were caused by refractory hypoxemia in infants under 1 year of age (death rate, 7.6 per 100,000). CONCLUSIONS: Pandemic 2009 H1N1 influenza was associated with pediatric death rates that were 10 times the rates for seasonal influenza in previous years.

Does low birth weight predict obesity/overweight and metabolic syndrome in elementary school children?

BACKGROUND: We undertook this study to explore the relationship between birth weight (BW) and childhood overweight and obesity (OW/OB) and metabolic syndrome (MS). METHODS: This was a cross-sectional assessment performed in 10 elementary public schools in Buenos Aires, Argentina. Participants were 1027 students aged 9.4 +/- 2.1 years. No interventions were done. We measured the association between BW in children and OW/OB and MS at 9 years of age. RESULTS: Of the total number of children, 164 (16.0%) were OB (BMI >95(th) percentile) and 169 (16.5%) were OW [(body mass index (BMI) > or =85(th), <95(th) percentile); 61% were at Tanner 1. All students came from low socioeconomic families. The prevalence of low (< or =2500 g), normal, and high BW (> or =4000 g) was 7.0% (n = 72), 83.7% (n = 860), and 9.3% (n = 95), respectively. MS prevalence was 5.5%. There was a significant difference in mean BMI sd score (SDS) between low BW (0.07), normal BW (0.54) and high BW (0.99). There was a significant difference in mean BMI, BMI SDS, waist circumference (WC), WC SDS, and systolic blood pressure between low, normal, and high BW groups. In separate logistic regression models, low BW proved to be a protective factor against OW/OB [OR 0.32 (95% CI 0.16-0.63)], whereas high BW was associated with a higher OW/OB risk adjusted for age and sex [OR 2.48 (95% CI 1.62-3.81)]. The risk of MS was high for those with high BW [OR 3.16 (95% CI 1.38-7.24)] and not significant for those with low BW adjusted for age and sex. CONCLUSIONS: Our data indicate that low BW is not associated with OW/OB or with MS in children, whereas high BW correlates with childhood OW/OB and MS.