title: Clinical characteristics of asthmatic patients with influenza-like illness and risk of severe exacerbations in Mexico.
abstract: Patients with chronic inflammatory lung diseases, such as asthma, are at higher risk for influenza-like illness (ILI) complications. Viral infections are known to trigger asthma exacerbations, but a thorough description of the clinical characteristics of ILI-associated asthma exacerbations and the role of viruses as a risk factor for severe exacerbation (SE) in ILI has not been published yet.
  
  
  
  To investigate risk factors for SE in patients with ILI and asthma.
  
  
  
  Patients with ILI symptoms were recruited from 6 hospitals of Mexico (LaRed sites) during 2010 to 2014. Those with a previous asthma diagnosis and ILI symptoms and who were 5 years or older were included. Patients were assigned as cases or controls based on symptoms reported. SE was defined when participants presented with wheezing or dyspnea and required hospitalization.
  
  
  
  A total of 486 patients with ILI and a diagnosis of asthma were included. There were no differences in the proportion, number, or type of viral illness among those with and without SE. Those with SE were less likely to report ILI symptoms. Muscle pain and nasal drip were predictors for patients not progressing to SE. A delay in seeking medical care was associated with SE (odds ratio, 2.93; 95% CI, 1.46-5.88).
  
  
  
  The presence of a particular virus did not predict SE. ILI symptoms in asthma patients are not associated with severe exacerbation. Patients with asthma should be encouraged to seek early medical care when ILI symptoms are first noticed to prevent serious complications.
authors.affiliation: Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico.
authors.forename: Paulina
authors.initials: P
authors.lastname: Paulin-Prado
authors.affiliation: National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.
authors.forename: Katherine
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Westat, Rockville, Maryland.
authors.forename: Laura
authors.initials: L
authors.lastname: Freimanis-Hance
authors.affiliation: National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.
authors.forename: Sally
authors.initials: S
authors.lastname: Hunsberger
authors.affiliation: Leidos Biomedical, Bethesda, Maryland.
authors.forename: John
authors.initials: J
authors.lastname: Beigel
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
authors.forename: Arturo Galindo
authors.initials: AG
authors.lastname: Fraga
authors.affiliation: Instituto Nacional de Pediatría, Mexico City, Mexico.
authors.forename: Ana A
authors.initials: AA
authors.lastname: Ortiz Hernandez
authors.affiliation: Instituto Nacional de Pediatría, Mexico City, Mexico.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Llamosas-Gallardo
authors.affiliation: Hospital Infantil de México "Dr. Federico Gómez," Mexico City, Mexico.
authors.forename: Sarbelio
authors.initials: S
authors.lastname: Moreno-Espinosa
authors.affiliation: Hospital Central "Dr. Ignacio Morones Prieto," San Luis Potosí, México.
authors.forename: Martin
authors.initials: M
authors.lastname: Magaña-Aquino
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
authors.forename: Guillermo M
authors.initials: GM
authors.lastname: Ruiz Palacios
authors.affiliation: Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico. Electronic address: aleravas@hotmail.com.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Ramirez-Venegas
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D012720:Severity of Illness Index; D014777:Virus Diseases / Q000453:epidemiology*