Seasonal pattern of early mortality and infectious complications in liver transplant recipients

Seasonal variation has been documented in the frequency and attributable mo rtality of a number of medical illnesses and infections in the nontransplan tation setting. Whether similar trends exist in transplant recipients is no t known. Seasonal rates of overall and early mortality and contributory var iables stratified by season were assessed in 190 consecutive liver transpla nt recipients who underwent transplantation over a 10-year period. The freq uency of infectious complications and rejection was also assessed and strat ified by season of transplantation. Early (deaths occurring in the first ye ar posttransplantation), but not overall, mortality correlated significantl y with seasonality. Of patients with early mortality, 43% (13 of 30 patient s) died in winter; 23% (7 of 30 patients), in spring; 13% (4 of 30 patients ), in summer; and 20% (6 of 30 patients), in fall. The frequency of deaths in winter was significantly greater than for all other seasons (P = .022). The high wintertime mortality could not be explained by previously recogniz ed risk factors portending a poor outcome, e.g., United Network for Organ S haring status, Child-Pugh score, surgical time, blood loss, pretransplantat ion and posttransplantation dialysis, infections, rejection, or increased i mmunosuppression. Strong trends toward a higher rate of cytomegalovirus dis ease in patients who underwent transplantation in fall (P = .09) and bacter ial infections in those who underwent transplantation in winter were docume nted (P = .09). There was no correlation between seasonality and rejection. Early mortality in winter in liver transplant recipients was significantly greater than if the deaths were totally random. Whether the seasonal clust ering of deaths and infections is triggered by respiratory viruses, yet unr ecognized viruses, or unknown exogenous factors remains to be determined.