Morbimortality of pandemic influenza A H1N1 infection in kidney transplant recipients requiring hospitalization: a comparative analysis with nonimmunocompromised patients.

Background: Clinical and epidemiological data of pandemic influenza A H1N1 infection in solid-organ transplant recipients have been described, but scarce data compare these outcomes with nonimmunocompromised patients.

Methods: We retrospectively reviewed and compared the clinical presentation, morbidity, and mortality of all kidney transplant (KT) and nonimmunocompromised (non-KT) patients admitted for at least 12 hr with a diagnosis of pandemic influenza A H1N1 infection in a single hospital complex during the 2009 pandemic.

Results: There were 22 patients in the KT group (29.3%) and 53 in the non-KT group (70.7%). The prevalence of diabetes was higher in KT group (27.3% vs. 5.7%) while chronic pulmonary disease was more frequent in non-KT group (34% vs. 9.1%). Clinical and radiological presentations and duration of disease were similar between the two groups. The incidence of acute renal failure was higher among KT patients (40.9% vs. 17%). No differences in the rate of intensive care unit admission (22.7% vs. 22.6%) or hospital mortality (9.1% vs. 7.5%) were observed. For the overall population, poor outcome, defined as intensive care unit admission or death, was associated with in-hospital acquisition (relative risk [RR]=42.6 [95% confidence interval {95% CI } 2.2-831.9], P=0.003), symptom onset more than 48 hr (RR=12.17 [95% CI 1.3-117.2], P=0.007), and acute renal failure (RR=11.8 [95% CI 2.9-48.8], P<0.001). Among KT recipients, in-hospital acquisition was the only covariate associate with poor outcome (RR=30.0 [95% CI 2.1-421.1], P=0.004).

Conclusions: No significant differences in morbidity and mortality were observed comparing KT and non-KT patients infected with pandemic H1N1 influenza A virus.