title: Outbreak of Influenza A(H1N1) in a Kidney Transplant Unit-Protective Effect of Vaccination.
abstract: Seasonal influenza vaccination is recommended for patients with end-stage renal disease (ESRD), despite suggested inferior efficacy among these patients. We characterize an outbreak of influenza A(H1N1) in a kidney transplant unit. Altogether 23 patients were treated on the ward for postoperative care after kidney transplantation during the outbreak. After the first positive case, all patients were tested with nasopharyngeal swab tests and 7 patients were diagnosed with influenza A(H1N1). Altogether 17/23 patients had received adequate seasonal influenza vaccination, of whom 2/17 tested positive for influenza (one asymptomatic, one with mild cough). Five of six unvaccinated patients were diagnosed with influenza A(H1N1); 3/5 suffered from severe respiratory failure and were treated with ventilator support in the ICU, but all died due to acute respiratory distress syndrome, whereas 2/5 suffered from mild viral pneumonitis and recovered fully. The risk of influenza infection and mortality was significantly increased in unvaccinated patients (odds ratio 37.5 [95% CI 2.7-507.5, p = 0.01] and 6.7 [95% CI 2.3-18.9, p = 0.003], respectively). Influenza A(H1N1) had a high mortality in our cohort of nonvaccinated immunosuppressed patients early after kidney transplantation. None of the vaccinated patients developed serious disease, supporting the role of vaccination also for ESRD patients.
authors.affiliation: Department of Transplant and Liver Surgery, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: I
authors.initials: I
authors.lastname: Helanterä
authors.affiliation: Department of Infectious Diseases, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: V-J
authors.initials: VJ
authors.lastname: Anttila
authors.affiliation: Department of Virology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Lappalainen
authors.affiliation: Department of Transplant and Liver Surgery, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Lempinen
authors.affiliation: Department of Transplant and Liver Surgery, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: H
authors.initials: H
authors.lastname: Isoniemi
mesh_terms: D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D004196:Disease Outbreaks; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D006085:Graft Survival / Q000276:immunology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000517:prevention & control / Q000821:virology; D007677:Kidney Function Tests; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D011379:Prognosis; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000401:mortality; D012307:Risk Factors; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines
keywords: clinical research/practice; infection and infectious agents; infectious disease; kidney (allograft) function/dysfunction; kidney transplantation/nephrology; vaccine; viral: influenza