prevalence of Human Bocavirus among patients 3 to 14 years old with acute wheezing

GHIETTO LUCÍA; MAJUL DIEGO; ORELLANA JORGE; ADAMO M. PILAR

Buenos Aires

Simposio; III Simposio Internacional de Virología Clínica y Avances en Vacunas; 2010

CEMIC y Sociedad Panamericana de Virología Clinica

>Wheezing in children is a common symptom: ~40% of children present wheezing sometime during the first 6 years of life, most of them in a transitory manner. The etiology of recurrent wheezing in children is usually associated with infections of the lower and upper respiratory tract and atopia. Objective: to estimate the prevalence of HBoV, a new virus associated with acute lower and upper infections of the respiratory tract, in children with acute wheezing. Methods. Samples of 40 inpatients 3 to 14 years old with acute wheezing were used to detect HBoV genome, through amplification of a fragment of NP1 by conventional PCR. The group had a balanced number of female and male children and the following distribution by age: 3-6 years, 57.5%; 7-10 years, 22.5%; 11-14 years, 20.0%. A nasal swab (NS) and a pharyngeal swab (PS) were taken from each patient; however it was possible to collect serum samples only from 25 of them (62.5%). Clínical and epidemiological features associated with positive cases (HBoV+) were analyzed. Results. 44% of 25 serum samples tested proved positive (6 of them with negative NS and PS), while 47.5% HN and 17.5% HF were positive. Considering HBoV+ cases based on the results on the NS, 57.9% corresponded to the cluster 3-6 years, with no significant differences between positive and negative patients respect to age or distribution by sex. The frequency of bronchial obstruction in the previous year was significantly different between HBoV+ and HBoV- cases (p=2.7x10-16), with 6 or more episodes in 47.5% among HBoV+ cases, and more than 3 in 79.1%. HBoV detection was associated with rhinitis (84.2% of positive patients), eczema (21.1%) and epidemiological risk factors (passive smoking: 73.7%; respiratory infections: 47.4%). In general HBoV+ cases were not associated with complications, although 10.5% evolved into pneumonia and one patient presented atelectasis and pneumothorax. Conclusion. HBoV was highly frequent in the group of patients studied (children hospitalized with acute wheezing) in the seasonal period covered. Elucidating the role of HBoV in the etiology of wheezing will require expanded sample, inclusion of control group and following up positive cases to determine clinical evolution and the persistence of the infection