Vaccine-Preventable Infections Among Solid Organ Transplant Recipients: A Data-Linked Cohort Study, Australia, 2000-2015

Abstract

Introduction Recipients of solid organ transplants are at risk of serious infection due to immunosuppression. Some infections are preventable with vaccination; infection rates vary with immunosuppression, vaccination rates and baseline disease prevalence. Both adherence with and response to vaccination in this population are variable, and optimum vaccination strategies continue to be refined. Objectives and Approach We aimed to characterise the incidence and complications of vaccine-preventable infections in transplant recipients. Eligible participants received an organ transplant in New South Wales, Australia, in 2000-2015. Linkage was undertaken between transplant registries and the notifiable conditions information management system. Vaccine-preventable infections were diphtheria, Haemophilus influenzae type b, influenza, invasive pneumococcal disease, measles, mumps, pertussis, poliovirus, rubella and tetanus. Standardized incidence ratios (SIR) were calculated relative to Australian population notification rates, standardizing for gender, age and calendar year. Results Among 3,394 recipients, 399 vaccine-preventable infections affected 339 (10%) recipients. Influenza was the most common vaccine-preventable infection with 352 notifications among 305 recipients. Influenza cases were 8.9 times more common among transplant recipients than the general population (95%CI: 8.0-10.0). In 36 cases (10%), hospitalization was required, and 2 deaths due to influenza were reported. There were 20 notifications of invasive pneumococcal disease (IPD) for 18 recipients. IPD occurred 10.2 times more often among transplant recipients than the general population (95%CI: 6.4-16.2). Most (n=13, 65%) cases were hospitalized, and one patient died from IPD. Cases of pertussis occurred only slightly more often than in the general population (SIR 1.5, 95%CI: 1.0-2.3). Of 26 cases, there was one reported hospitalization and no deaths due to pertussis. Only one case of mumps, and no other vaccine-preventable infections, were reported. Conclusion Transplant recipients have excess cases of influenza and IPD compared to the general population, although this has improved over time. The need for appropriate recipient vaccination is emphasized.