COMPARISONS OF THE CLINICAL FEATURES AND OUTCOMES OF CHILDREN PRESENTING WITH INFLUENZA-LIKE ILLNESSES, INCLUDING A (H1N1) PDM09 AND SEASONAL INFLUENZA, IN A UNIVERSITY HOSPITAL, THAILAND.

In Thailand, during the A(H1N1)pdm2009 pandemic, 82% of fatal cases did not received the specific treatment within 48 hours of the onset of symptoms. Specific diagnostic tests, especially RT-PCR, were not available throughout the country. To assist early clinical diagnosis and treatment, this study compared the clinical features and treatment outcomes of children presenting with influenza-like illness (ILIs). These included confirmed cases of A(H1N1)pdm2009, as well as seasonal influenza and cases for which no cause could be specified. The medical records of patients aged less than 15 years with ILIs, who had RT-PCR performed for influenza virus between May 2009 and December 2011 at Srinagarind Hospital, were reviewed. Clinical features, chest radiographs and treatment outcomes were compared between those positive for A(H1N1)pdm2009, and those with seasonal influenza and/or the unspecified causes group. In 179 complete medical records, 27.4% were positive for A(H1N1)pdm2009, 13.4% for seasonal influenza and the cause of illness in the remainder was unspecified. Both A(H1N1)pdm2009 and seasonal influenza viruses infected older children more than did the unspecified group (group median ages 96,48 and 24 months, respectively). Sore throat, headache and myalgia were significantly more frequent in the A(H1N1)pdm2009 group than in the other two groups (p < 0.001). Half of all children had pneumonia but there were no significant differences among groups. There was no mortality in this study. In conclusion, sore throat, headache and myalgia were the significant clinical features suggestive of A(H1N1)pdm2009 infection in children and might be helpful indicators prompting early administration of specific treatments in the settings where definitive laboratory tests are not available.