OBJECTIVETo investigate the viral etiology in hospitalized children with acute lower respiratory tract infections (ALRTI) plus platelet disorders.

METHODSA total of 255 children with ALRTI plus platelet disorders and 442 children with ALRTI and normal platelets, all of whom were hospitalized between March 2010 and February 2011, were included in the study. Their nasopharyngeal aspirate samples were collected, and RT-PCR or PCR was performed to detect 14 viruses.

RESULTSOf 255 ALRTI patients with platelet disorders, thrombocytosis was found in 253 cases (99.2%) and thrombocytopenia in 2 cases (0.8%). Among ALRTI patients with platelet disorders, 173 (67.8%) were infected with at least one virus, with human rhinovirus as the most common one, followed by parainfluenza virus type 3 (PIV3) and respiratory syncytial virus (RSV). The detection rate of PIV3 in the abnormal platelet group was significantly higher than in the normal platelet group (P<0.05). In contrast, the detection rate of influenza virus B (IFVB) in the abonormal platelet group was significantly lower than in the normal platelet group (P<0.05). The age distribution showed significant difference between the abnormal and normal platelet groups (P<0.01). Platelet disorders were mainly found in children under one year of age (P<0.01).

CONCLUSIONSThrombocytosis is often found in children with ALRTI caused by viruses, especially PIV3, but infection with IFVB seldom causes platelet disorders. Hospitalized children with ALRTI under one year tend to develop platelet disorders.