title: Comparison of clinical presentation of respiratory tract infections in H1N1/09-positive and H1N1/09-negative patients.
abstract: The true burden of influenza in children is difficult to assess and is probably underestimated as clinical signs are usually nonspecific, and formal viral identification is rarely searched. In this study, we compare the clinical features of infections related to the new H1N1/09 influenza virus with infections due to other respiratory viruses in children consulting in a tertiary care pediatric hospital in Geneva. Between October 1, 2009 and February 10, 2010, 109 patients were recruited, with a median of age of 7 years (range 0.1-18). There were 75 H1N1/09-positive patients (69%), and 32 (43%) had identified risk factors such as asthma or a history of wheezing. Fever (87%), cough (92%), and rhinitis (85%) were the most frequent reported presenting symptoms in both patient groups. H1N1/09-positive patients were significantly older (median of 8.2 vs. 4.6 years) and were more likely to have risk factors (43% vs. 24%) and myalgias (41% vs. 20%). H1N1/09-negative patients had more wheezing episodes (29% vs. 9%), higher rates of dyspnea (28% vs. 20%) and of hospital admissions (35% vs. 16%).
  
  
  CONCLUSIONS
  Clinical signs cannot reliably differentiate H1N1/09-positive and H1N1/09-negative patients, although we found a higher proportion of myalgias in H1N1/09-positive patients. Severity of disease was lower in H1N1/09-positive than in H1N1/09-negative patients, mostly because of a higher proportion of asthma/wheezing episodes among H1N1/09-negative patients.
authors.affiliation: Department of Pediatrics, Children's Hospital of Geneva, University Hospitals of Geneva, Geneva 14, Switzerland.
authors.forename: Pierre-Alex
authors.initials: PA
authors.lastname: Crisinel
authors.forename: Constance
authors.initials: C
authors.lastname: Barazzone
authors.forename: Laurent
authors.initials: L
authors.lastname: Kaiser
authors.forename: Arnaud G
authors.initials: AG
authors.lastname: L'Huillier
authors.forename: Jean
authors.initials: J
authors.lastname: Taguebue
authors.forename: Noémie
authors.initials: N
authors.lastname: Wagner
authors.forename: Cristina
authors.initials: C
authors.lastname: Delcò
authors.forename: Claire-Anne
authors.initials: CA
authors.lastname: Siegrist
authors.forename: Klara M
authors.initials: KM
authors.lastname: Posfay-Barbe
mesh_terms: D000293:Adolescent; D000998:Antiviral Agents / Q000627:therapeutic use; D001249:Asthma / Q000150:complications; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D006760:Hospitalization; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology*; D053139:Oseltamivir / Q000627:therapeutic use; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000209:etiology; D012307:Risk Factors; D003294:Seizures, Febrile / Q000209:etiology
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir