title: Outcome of influenza infections in outpatients after allogeneic hematopoietic stem cell transplantation.
abstract: BACKGROUND
  Influenza can cause significant morbidity and mortality in patients after hematopoietic stem cell transplantation (HSCT). The diagnostic methods and antiviral treatment have scarcely been investigated.
  
  
  METHODS
  We retrospectively identified influenza-infected patients with upper or lower respiratory tract infection (RTI) diagnosed by culture and polymerase chain reaction (PCR) testing between November 2007 and April 2008. Treatment with oseltamivir 75 mg twice daily and serial nasal swabs were performed at the discretion of the treating physician.
  
  
  RESULTS
  We identified 21 influenza infections in 19 patients: 19 with upper RTI and 2 with lower RTI. At diagnosis, all 21 samples were positive for PCR with a median influenza load of 5.9 log(10) copies/mL. Culture was positive in 14 (67%) patients. Influenza A virus was diagnosed in 8 (38%) episodes and influenza B virus in 13 (62%) episodes. Two patients were sequentially infected by influenza A, followed by B after 38 and 47 days, respectively. Eighteen (86%) patients were treated with oseltamivir for 11 days (median, interquartile range [IQR]: 8-14). No progression to lower RTI or mortality occurred. Shedding persisted for 12 days (median, IQR: 8-13). Absolute lymphocyte count at diagnosis correlated inversely with shedding of the virus (P<0.001).
  
  
  CONCLUSIONS
  Oseltamivir is well tolerated and may reduce mortality of influenza virus-infected patients after HSCT. PCR may help to optimize diagnosis and to monitor treatment strategies.
authors.affiliation: Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Khanna
authors.forename: I
authors.initials: I
authors.lastname: Steffen
authors.forename: J-D
authors.initials: JD
authors.lastname: Studt
authors.forename: A
authors.initials: A
authors.lastname: Schreiber
authors.forename: T
authors.initials: T
authors.lastname: Lehmann
authors.forename: M
authors.initials: M
authors.lastname: Weisser
authors.forename: U
authors.initials: U
authors.lastname: Flückiger
authors.forename: A
authors.initials: A
authors.lastname: Gratwohl
authors.forename: J
authors.initials: J
authors.lastname: Halter
authors.forename: H H
authors.initials: HH
authors.lastname: Hirsch
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D001992:Bronchoalveolar Lavage Fluid / Q000821:virology; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D009980:Influenza A virus / Q000235:genetics / Q000302:isolation & purification; D009981:Influenza B virus / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000821:virology; D053139:Oseltamivir / Q000627:therapeutic use*; D016133:Polymerase Chain Reaction; D011183:Postoperative Complications / Q000175:diagnosis* / Q000188:drug therapy* / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D012189:Retrospective Studies; D013557:Switzerland; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D012367:RNA, Viral; D053139:Oseltamivir