Human bocavirus (HBoV) is a parvovirus whose association with respiratory disease is currently under investigation. OBJECTIVE: To determine HBoV prevalence in children with lower acute respiratory infection. METHODS: We investigated HBoV in 433 nasopharyngeal aspirates collected in 2007-2009 from children 0 to 5 years old hospitalized with bronchiolitis or pneumonia in Córdoba, Argentina. RESULTS: The general prevalence of HBoV was 21.5% and the positive cases (HBoV+) were more frequent during winter and spring. The mean age of HBoV+ patients was 6.9 months, with 87.1% of the detections corresponding to infants less than 1 year old (among which the prevalence of HBoV was 26.3% in patients < 3 months of age, 22.1% in 3 to 6 months, 25.3% in 6 to 9 months, and 18.8% in 9 to 12 months). The sequence analysis of the NP1 coding region of 15 isolates showed that all isolates from Cordoba were HBoV1 which exhibited a homology of nearly 100% both among themselves and with the originally discovered virus from 2005. CONCLUSION: Overall, our results indicate that HBoV is a significant pathogen that contributes to acute respiratory infection both on its own and during coinfection with other viruses.

Introduction. Although not useful, antibiotics are commonly prescribed in infants with viral pneumonia. Objective. To compare initial prescription and suspension rates of antibiotics in infants hospitalized with pneumonia by respiratory syncytial virus (RSV) in 2002, when introducing the viral testing, and in 2007, after 5 years of this practice. Population and methods. Children aged under 13 months hospitalized for RSV pneumonia during two years (2002 and 2007) were included. Prescription and discontinuation of antibiotics were registered. Data were analyzed using Chi squared and T tests, assuming p <0.05 as significance level. Results. Antibiotics were prescribed in 57% (40/70) of patients in 2002 and 46% of then (29/63) in 2007. After achieving RSV diagnosis, antibiotics were more frequently discontinued in 2007 than in 2002 (31/63 vs. 14/70; p= 0.012; OR: 3.73; IC 95%:1.1512.49). Conclusion. Although antibiotic empirical prescription rate was similar in both periods, after achieving RSV diagnosis antibiotics were more frequently discontinued in 2007.

Introducción. Pese a no estar indicados, los antibióticos son frecuentemente prescriptos en lactantes con neumonía viral. Objetivo. Comparar la tasa de prescripción inicial y de suspensión de antibióticos en lactantes hospitalizados por neumonía con diagnóstico de virus sincicial respiratorio (VSR), en el año 2002, cuando se incorporó el diagnóstico virológico y en el 2007, luego de 5 años de dicha práctica. Población y método. Se incluyeron menores de 13 meses internados por neumonía durante los años 2002 y 2007, con identificación de VSR y hemocultivo negativo. Se registró indicación y suspensión de antibióticos. Los datos se compararon mediante las pruebas de χ² y T. Nivel de significación p <0, 05. Resultados. Se indicaron antibióticos en 57% (40/ 70) de los pacientes en 2002 y 46% (29/63) en 2007. Su suspensión, luego de conocer el diagnóstico de VSR, fue mayor en 2007 (31/63 contra 14/70; p= 0, 012; OR:3, 73; IC 95%:1, 15-12, 49). Conclusiones. Si bien la indicación empírica de antibióticos se mantuvo relativamente estable, ante la confirmación de etiología viral se retiraron con mayor frecuencia en el último período analizado.

Objective. To evaluate the accuracy of the chest radiograph to distinguish between bacterial and viral aetiology in children with pneumonia. Population, material and methods. We analyzed the accuracy of chest radiograph for presuming aetiology using Khamapirad score in 175 children aged under five years hospitalized for pneumonia in whom etiology was identified (viral= 127 and bacterial= 48). The interpretation of the chest radiograph was made independently by a pediatrician (P) and two pediatric radiologists (R1 - R2), and masked to etiology. Kappa coefficient was calculated to within and between observed agreements. T test was applied to analyze the association between etiology (viral or bacterial) and the scores. Optimum cut-off value for the score was identified (ROC curve). Results. We found and outstanding inter-observer agreement (P vs. R1 κ= 0.80; P vs. R2 κ= 0.83). The radiographic score was significantly higher in bacterial pneumonias than in viral pneumonias (3.7 ± 1.1 vs. -1.4 ± 1.2; p= 0.001) with a very good intra observed agreement (κ= 0, 93). A radiographic score ≥1 was identified as the optimum cut-off value to distinguish bacterial from viral pneumonia. At that level the score showed sensitivity: 100% (IC 95%: 90-100); specificity: 98% (IC 95%:93-99); positive predictive value: 96% (IC 95%:85-99); negative predictive value: 100% (IC 95%: 96-100). Conclusions. The chest radiograph was accurate for distinguishing bacterial from viral pneumonia in children.

Objetivo. Analizar la validez de la radiografía de tórax para diferenciar etiología bacteriana de viral en niños internados por neumonía. Población, material y métodos. Se analizaron las radiografías de 175 menores de 5 años internados por neumonía con etiología confirmada (48 bacterianas y 127 virales). Las imágenes fueron valoradas por un pediatra (P) y dos radiólogos (R1 y R2) independientemente y a ciegas para los datos del paciente, utilizando la escala de Khamapirad (-3 a +7 puntos). Se calcularon acuerdos intra e inter observadores por índice Kappa (κ). Mediante prueba de t de Student se evaluó la asociación entre los resultados de P y la etiología, asumiendo un nivel de significación de p> 0,05. Se efectuó curva ROC (Receiver Operator Characteristic) para identificar el mejor punto de corte para predecir una etiología. Resultados. El grado de acuerdo inter-observador fue satisfactorio: κ= 0,80 entre P y R1 y κ= 0,83, entre P y R2. El puntaje radiológico asignado por P fue significativamente mayor en neumonías bacterianas que en virales (3,7 ± 1,1 vs. -1,4 ± 1,2; p= 0,001), con un excelente grado de acuerdo entre sus dos lecturas (κ= 0,93). Se identificó un puntaje radiológico ≥ 1 como el mejor punto para diferenciar neumonías bacterianas de virales. La escala mostró una sensibilidad de 100% (IC 95%= 90- 100), especificidad de 98% (IC 95%= 93-99), valor predictivo positivo de 96% (IC 95%= 85-99) y negativo de 100% (IC 95%= 96-100) para predecir etiología bacteriana. Conclusiones. La radiografía de tórax se mostró precisa y exacta para diferenciar etiología bacteriana de viral en niños internados por neumonía.