Affiliations: Department of Pediatrics, Prapokklao Hospital,
Chantaburi province, 22000, Thailand. Tel.: +66 8039301156; E-mail: [email protected]
Abstract: There is a lack of data assessing the accuracy of clinical diagnosis
of influenza in children. This study aimed to identify the clinical predictors
of influenza infections and to validate the use of clinical criteria of
influenza-like illness definition for the diagnosis of influenza in children.
Virological influenza surveillance was conducted by collecting throat swab
specimens for viral culture and clinical data from febrile children with acute
respiratory tract infection at Prapokklao Hospital from July 2005 to September
2007. The criteria of influenza-like illness definition was modified for
children and defined by the presence of fever >
38°C plus two of the following three symptoms:
headache, cough and sore throat. Two hundred and four of 838 specimens (24%)
yielded positive results for influenza virus isolates. Influenza A virus
infections were more common than influenza B virus infections. In the
multivariate analysis positive predictors of influenza infections were cough
[odds ratio (OR)=2.07 95% confidence interval (CI)=
1.26–3.39] and age > 5 years old (OR=2.30, 95% CI=1.66–3.19), whereas diarrhea was inversely associated with
influenza (OR=0.29, 95% CI=0.12–0.69). Both the
World Health Organization criteria (OR=1.82, 95% CI=1.04–3.18) and the modified criteria for children (OR=1.86, 95%
CI=1.38–2.56) showed a positive association with influenza
infections. World Health Organization criteria showed high sensitivity and
negative predictive value but low specificity and positive predictive value.
The modified criteria for children showed fair sensitivity and specificity,
high negative predictive value but low positive predictive value. According to
the average proportion of positive isolates of 24%, influenza should be
recognized as an important cause of acute respiratory tract infections in
children especially in the endemic season, but the diagnosis of pediatric
influenza cannot be established on clinical criteria alone.
