title: Pneumonia and respiratory failure from swine-origin influenza A (H1N1) in Mexico.
abstract: BACKGROUND
  In late March 2009, an outbreak of a respiratory illness later proved to be caused by novel swine-origin influenza A (H1N1) virus (S-OIV) was identified in Mexico. We describe the clinical and epidemiologic characteristics of persons hospitalized for pneumonia at the national tertiary hospital for respiratory illnesses in Mexico City who had laboratory-confirmed S-OIV infection, also known as swine flu.
  
  
  METHODS
  We used retrospective medical chart reviews to collect data on the hospitalized patients. S-OIV infection was confirmed in specimens with the use of a real-time reverse-transcriptase-polymerase-chain-reaction assay.
  
  
  RESULTS
  From March 24 through April 24, 2009, a total of 18 cases of pneumonia and confirmed S-OIV infection were identified among 98 patients hospitalized for acute respiratory illness at the National Institute of Respiratory Diseases in Mexico City. More than half of the 18 case patients were between 13 and 47 years of age, and only 8 had preexisting medical conditions. For 16 of the 18 patients, this was the first hospitalization for their illness; the other 2 patients were referred from other hospitals. All patients had fever, cough, dyspnea or respiratory distress, increased serum lactate dehydrogenase levels, and bilateral patchy pneumonia. Other common findings were an increased creatine kinase level (in 62% of patients) and lymphopenia (in 61%). Twelve patients required mechanical ventilation, and seven died. Within 7 days after contact with the initial case patients, a mild or moderate influenza-like illness developed in 22 health care workers; they were treated with oseltamivir, and none were hospitalized.
  
  
  CONCLUSIONS
  S-OIV infection can cause severe illness, the acute respiratory distress syndrome, and death in previously healthy persons who are young to middle-aged. None of the secondary infections among health care workers were severe.
authors: National Institute of Respiratory Diseases, Mexico City, Mexico. perezpad@gmail.com
authors: Rogelio
authors: R
authors: Perez-Padilla
authors: Daniela
authors: D
authors: de la Rosa-Zamboni
authors: Samuel
authors: S
authors: Ponce de Leon
authors: Mauricio
authors: M
authors: Hernandez
authors: Francisco
authors: F
authors: Quiñones-Falconi
authors: Edgar
authors: E
authors: Bautista
authors: Alejandra
authors: A
authors: Ramirez-Venegas
authors: Jorge
authors: J
authors: Rojas-Serrano
authors: Christopher E
authors: CE
authors: Ormsby
authors: Ariel
authors: A
authors: Corrales
authors: Anjarath
authors: A
authors: Higuera
authors: Edgar
authors: E
authors: Mondragon
authors: Jose Angel
authors: JA
authors: Cordova-Villalobos
mesh_terms: D018806:APACHE; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D017758:Infectious Disease Transmission, Patient-to-Professional; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000302:isolation & purification; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology / Q000628:therapy / Q000635:transmission; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D053139:Oseltamivir / Q000627:therapeutic use; D011024:Pneumonia, Viral / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality / Q000473:pathology; D011859:Radiography; D012128:Respiratory Distress Syndrome / Q000209:etiology; D012131:Respiratory Insufficiency / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir