title: Coinfection with Staphylococcus aureus increases risk of severe coagulopathy in critically ill children with influenza A (H1N1) virus infection.
abstract: OBJECTIVE
  H1N1 influenza with coinfections has been implicated to have high morbidity and mortality. We hypothesized that critically ill children with 2009 H1N1 and coinfections are at a higher risk of developing disseminated intravascular coagulation.
  
  
  METHODS
  The chart review included demographics, length-of-stay, severity of illness score (Pediatric Risk of Mortality III acute physiology score), clinical laboratories, and outcomes at hospital day 90 data. Patients were classified as having methicillin-sensitive or -resistant Staphylococcus aureus, other, or no coinfections.
  
  
  METHODS
  Single-center pediatric intensive care unit.
  
  
  METHODS
  Sixty-six consecutive patients with 2009 H1N1 and influenza A infection.
  
  
  METHODS
  None.
  
  
  RESULTS
  : There were 12, 22, and 32 patients with methicillin-sensitive or -resistant Staphylococcus aureus, other, and no coinfections, respectively. Pediatric critical care unit length-of-stay was 11, 10, and 5.5 days (median), and survival at day 90 was 83%, 96%, and 91% in patients with methicillin-sensitive or -resistant Staphylococcus aureus, other, and no coinfections. Patients with methicillin-sensitive or -resistant Staphylococcus aureus coinfections compared to patients with other, and no coinfections had higher Pediatric Risk of Mortality III acute physiology scores (14 [6-25] vs. 7 [2-10], p = .052 and 6 [2.5-10], p = .008; median [interquartile range]), higher D-dimer (16.1 [7.9-19.3] vs. 1.6 [1.1-4], p = .02 and 2.3 [0.8-8.7] µg/mL, p = .05), longer prothrombin time (19.3 [15.4-25.9] vs. 15.3 [14.8-17.1], p = .04 and 16.6 [14.7-20.4] secs, p < .39) at admission, and lower day-7 platelet counts (90K [26-161K] vs. 277K [98-314], p = .03 and 256K [152-339]/mm, p < .07). Patients with methicillin-sensitive or -resistant Staphylococcus aureus coinfections compared to patients without coinfections were more likely to be sicker with Pediatric Risk of Mortality III acute physiology score >10 vs. <10 (relative risk 2.4; 95% confidence interval 1.2-4.7; p = .035) and have overt disseminated intravascular coagulation (relative risk 4.4; 95% confidence interval 1.3-15.8, p = .025).
  
  
  CONCLUSIONS
  During the 2009-2010 H1N1 pandemic, pediatric patients with influenza A and methicillin-sensitive or -resistant Staphylococcus aureus coinfections were sicker and more likely to develop disseminated intravascular coagulation than patients with other or no coinfections.
authors.affiliation: Section of Critical Care Medicine, Department of Pediatrics, Baylor College of Medicine/Texas Children's Hospital, Houston, TX, USA. tcnguyen@texaschildrenshospital.org
authors.forename: Trung
authors.initials: T
authors.lastname: Nguyen
authors.forename: Ursula G
authors.initials: UG
authors.lastname: Kyle
authors.forename: Nancy
authors.initials: N
authors.lastname: Jaimon
authors.forename: M Hossein
authors.initials: MH
authors.lastname: Tcharmtchi
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Coss-Bu
authors.forename: Fong
authors.initials: F
authors.lastname: Lam
authors.forename: Jun
authors.initials: J
authors.lastname: Teruya
authors.forename: Laura
authors.initials: L
authors.lastname: Loftis
mesh_terms: D001778:Blood Coagulation Disorders / Q000382:microbiology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D060085:Coinfection / Q000150:complications*; D016638:Critical Illness; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000382:microbiology; D015278:Intensive Care Units, Pediatric; D008297:Male; D008485:Medical Audit; D018570:Risk Assessment; D012720:Severity of Illness Index; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013211:Staphylococcus aureus