H1N1 Flu Caused Significant Morbidity in Transplant Patients

As there is not much known about the epidemiology and outcomes of influenza infection in recipients of solid-organ transplants, Deepali Kumar MD, with the department of Transplant Infectious Diseases at the University of Alberta, in Edmonton, AB, Canada, and colleagues sought to establish the outcomes of pandemic influenza A H1N1 and factors leading to severe disease in a cohort of transplant patients. Their research was published in the August issue of Lancet Infectious Diseases.

The researchers, members of the American Society of Transplantation H1N1 Collaborative Study Group, conducted a multi-center cohort study of adults (154 patients; median age 47 years) and children (83 patients; median age 9 years) who had received organ transplants (including kidney, liver, heart, lung, and others) with microbiological confirmation of influenza A infection from April to December 2009. Using univariate analysis to identify factors leading to pneumonia, admission to hospital, and admission to an ICU, Kumar, et al. (2010) assessed 237 cases of medically attended influenza A H1N1 reported from 26 transplant centers during the study period.

The researchers report that complications-related data were available for 230 patients; 73 (32 percent) had pneumonia, 37 (16 percent) were admitted to ICUs, and 10 (4 percent) died. Antiviral treatment was used in 223 (94 percent) patients (primarily oseltamivir monotherapy). Seven (8 percent) patients given antiviral drugs within 48 hours of symptom onset were admitted to an ICU compared with 28 (22.4 percent) given antivirals later. The researchers add that children who received transplants were less likely to present with pneumonia than adults, but rates of admission to the hospital and to the ICU were similar.

Kumar, et al. (2010) concludes that influenza A H1N1 caused substantial morbidity in recipients of solid-organ transplants during the 2009-2010 pandemic, and emphasize that beginning antiviral therapy early offers clinical benefit as measured by need for ICU admission and mechanical ventilation.

Reference: Kumar D, Michaels MG, Morris MI, Green M, Avery RK, Liu C, Danziger-Isakov L, Stosor V, Estabrook M, Gantt S, Marr KA, Martin S, Silveira FP, Razonable RR, Allen UD, Levi ME, Lyon GM, Bell LE, Huprikar S, Patel G, Gregg KS, Pursell K, Helmersen D, Julian KG, Shiley K, Bono B, Dharnidharka VR, Alavi G, Kalpoe JS, Shoham S, Reid GE, Humar A. Outcomes from pandemic influenza A H1N1 infection in recipients of solid-organ transplants: a multicentre cohort study. Lancet Infect Dis. 2010 Aug;10(8):521-6.