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.

[Highly active antiretroviral therapy in HIV sero-positive children. Disease progression by baseline clinical, immunological and virological status]. / Tratamiento antirretroviral de gran actividad en niños VIH positivos. Evolución de la enfermedad relacionada con parámetros clínicos, inmunológicos y virológicos al comienzo del tratamiento.

INTRODUCTION: Highly active antiretroviral therapy (HAART) has been administered to children infected with human immunodeficiency virus (HIV) since 1996. This kind of therapy is effective in achieving viral suppression and stopping disease progression but prolonged administration increases the risk of toxic effects, favours the onset of viral resistance and leads to decreased adherence. The aim of the present study was to determine prognostic factors among clinical, immunological and virological parameters at the beginning of HAART. POPULATION AND METHODS: We performed a prospective-retrospective observational analysis of a cohort or 564 HIV+ children assisted in Hospitals of Buenos Aires and Rosario, Argentina, treated with HAART since 1998 (media of treatment: 46.78 months. Range: 2-91 months). Patients were divided in groups according to age (younger or older than one year), and outcome (favourable or unfavourable). Stage, CD4 lymphocytes percentage, CD4 lymphocyte cell count and viral load at the beginning of treatment were analyzed with outcome by means of chi(2) tests, and logistic regression. RESULTS: No differences were observed on the percentage of CD4 T cells and viral load at baseline, between children under one year of age with good (n= 79) or bad outcomes (n= 4). Among older children (450 with good outcome, 31 with unfavourable), the following were identified as predictors of bad outcome: HAART initiation during stage C (p= 0.006), CD4 T-cell percentage below 15 percent (p< 0.001) and CD4 absolute value below 500 cells/mm(3) (p= 0.003). CONCLUSIONS: Children older than one year will have better outcome when HAART is initiated before stage C, with more than 15% CD4 or more than 500 cells/mm(3).

Evolución de infección por virus varicela zóster en niños infectados perinatalmente con el virus de la inmunodeficiencia humana / Outcome of infection by varicella-zoster virus in children prinatally infected by human immunodeficiency virus

ResumenIntroducción. Los niños infectados con el virus de lainmunodeficiencia humana (VIH) tienen un riesgoalto de desarrollar herpes zóster pocos meses o añosdespués de la primoinfección con virus varicelazóster (VVZ). Algunos autores han referido compli-caciones graves debido a la infección por VVZ enestos niños, por lo que se recomienda el tratamientocon aciclovir por vía intravenosa.Objetivos. 1) Estimar la incidencia de infección porVVZ en niños infectados verticalmente con el virusde la inmunodeficiencia humana, 2) determinar elperfil clínico de la infección por VVZ en los niñoscon VIH perinatal referido a su estado clínico-in-munológico, y 3) establecer las características de lascomplicaciones observadas en los tratados conaciclovir por vía oral o intravenosa y en los notratados.Población, material y métodos. Estudio retrospectivo,observacional. Revisamos las historias clínicas de60 niños con infección vertical por VIH, seguidos ennuestro Hospital entre 1990 y 2001. El diagnósticode infección por VVZ se basó en criterios clínicos. Seconsideró primer evento a varicela y eventos ulte-riores a herpes zóster y la recurrencia de varicela.En ambos grupos de pacientes se analizó el estadode la enfermedad (CDC/1994) y el recuento delinfocitos CD4 más próximo a la infección por VVZ,así como la presencia o no de complicaciones en losniños tratados con aciclovir oral o intravenoso y enlos no tratados. Se realizó análisis estadístico conestimación de porcentajes y medidas de tendenciacentral. Cuando fue necesario se estimaron interva-los de confianza del 95%.

Introduction. Children infected with HIV have anextremely high risk of developing zoster within afew months or a few years after primary infection with varicella zoster virus (VZV). Some authors have observed serious complications due to VZV infections and recommended the treatment with IV acyclovir in these patients. Objective. 1) To estimate the incidence of VZV infection in perinatal HIV infection. 2) To determine the clinical outcome of the VZV infection inperinatally HIV infected children related to theirclinical and immunological status. 3) To establish the characteristics of the complications in those treated with oral or intravenous acyclovir and innon-medicated patients. Population, material and methods. Retrospective and observational study. We reviewed the charts of 60 patients with perinatal HIV infection, followed up at our hospital between 1990 and 2001. The VZV infection diagnosis was based on clinical criteria. Varicella was considered as the first event andherpes zoster and recurrent varicella, as further events. In both groups of patients we analyzed the status of the disease (CDC/1994), as well as the most recent CD4 cell count. The occurrence of complications and their outcome related to the treatment with intravenous or oral acyclovir and in non medicated patients, was also assessed. We performed statistical analysis with estimation of averages and measures of central trend. When needed, confidence intervals (95%) were estimated. Results. Out of the 60 patients evaluated 33 (55%)had one or more events of VZV infection. 17 were boys and 16 were girls with a mean age of 79.5 months. 26 episodes were due to varicella, 21 to herpes zoster and 4 to recurrent varicella. From the children with varicella, 42.3% were in clinical statusB or C, 85.7% were in immunological status 2 or 3.80.9% of the patients with herpes zoster and 100% of those with recurrent varicella were in clinical status B or C. 100% of the children with two or more events were...