Infection frequency and profile in different age groups of kidney transplant recipients

Background. Older transplant recipients have been shown to be at greater risk for infectious death than younger adults, but no study to date has looked at relative risk of infection and infection profile differences for children versus adults, which may be very different from one another. Methods. Data from primary Medicare renal transplant recipients between 1991 and 1998 (n = 64,751), as reported in the United States Renal Data System (USRDS), were analyzed for Medicare claims (both inpatient and outpatient) for infection and type of infection in the first year posttransplant. Cox regression was used to model adjusted hazard ratios (AHR) for infection. Results. Total infections among renal transplant recipients increased significantly in more recent years. Patients transplanted in or after 1995 had a significantly higher adjusted risk for infection compared to those transplanted earlier (AHR 1.34, 95% CI = 1.29 -1.39). Older adults >= 51 years of age had the highest percentage of experiencing infection, as compared to adults between 18-50 years and children <= 17 years (P < 0.001). Children were at highest risk of viral infection prior to 1995 but at lowest risk of viral infection after 1995, whereas elderly adults were at highest risk of bacterial infection throughout the study. Children experienced more claims for viral infections, whereas older transplant recipients experienced more claims for bacterial infections. Conclusions. The two extremes of transplant recipient age display very different risks for infection claim frequency and profile.