BACKGROUND: The World Health Organization declared on June 11, 2009 the first pandemic of the 21st Century caused by the novel Influenza A (H1N1) virus. The virus was observed to be clinically similar to the seasonal influenza, in which case, patients recover even without medical treatment.The virus affected the younger age group even those who are healthy, which make it different from seasonal flu.

OBJECTIVE: The study aimed to describe the clinical profile and outcome of pediatric patients with Reverse Transcription-Polymerase Chain Reaction (RT-PCR)-confirmed Influenza A (H1N1).

METHODOLOGY: Pediatric patients of the Lung Center of the Philippines seen from May 1 to July 31, 2009 for Influenza-like illness upon presentation and confirmed to have Influenza A (H1N1) virus through Reverse Transcription-Polymerase Chain Reaction (RT-PCR) assay were included in the study. Charts of patients were reviewed. Information from patients was obtained using the WHO Case Summary Form and the National Epidemiology Center Initial Screening of Influenza A (H1N1) form. The patient's demographic data, clinical characteristics, co-morbid conditions, vaccination, clinical course, complications, anti-viral medications received and adverse reactions, and over-all outcome were noted, as well as, exposure to confirmed cases and history of travel.

RESULTS: Out of the 243 RT-PCR-confirmed patients, 71.6% (n=174) came from the adolescent age group, with a median age of 13 years old. A predominance of male patients (57.2%) was noted. Fever (92%), cough (83.1%), nasal congestion (52.7%) and sore throat (35%) were the most common presenting signs and symptoms. Bronchial asthma (14.4%) was the leading co-morbidity present and pneumonia was the most common complication. Eight patients (3.3%) were hospitalized during the course of the disease. All RT-PCR-confirmed Influenza A (H1N1) patients recovered and no mortality was noted.

CONCLUSIONS: In this study, majority of the RT-PCR-confirmed Influenza A (H1N1) patients were characterized by self-limited, uncomplicated, and febrile respiratory illness, who all recovered with minimal complications.