Norovirus Infections in Kidney Transplant Recipients

Norovirus (NoV) infection frequently progresses to chronic disease after kidney transplant (KTx). This study aims to assess potential risk factors helping to determine patients at risk of chronic NoV infection and to analyze the effect of NoV on allograft outcome. Additionally, we assessed the effectiveness of intravenous immunoglobulin (IVIg) therapy for chronic NoV infection.

The study enrolled 60 KTx patients requiring hospitalization because of NoV infection. Clinical parameters, severity of NoV infection and potential risk factors were evaluated. Outcome parameters were clinical symptoms, rehospitalizations, persistent shedding of virus, and effects on allograft function.

Patients were divided into 2 groups: 29 had acute NoV infection only, 31 progressed to chronic NoV infection. Chronic NoV infection was defined as a recurrence of clinical symptoms plus redetection of NoV in stool. Lymphocyte-depleting induction therapy and diabetes mellitus were independent risk factors for chronic infection. For patients with chronic NoV infection, length of stay in hospital was significantly prolonged (P = 0.024). Allograft function remained impaired in the chronic NoV group 6 and 12 mo after initial admission. IVIg was administered to 18 patients with chronic NoV infection. No further clinical symptoms of NoV infection occurred in 13 (72%) of these patients. However, NoV was still detectable in stool specimens from 10 (77%) of these patients.

Chronic NoV infection is associated with reduced allograft function. Administration of IVIg to patients with chronic NoV infection seems beneficial in achieving freedom from clinical symptoms, despite limited effects on shedding of virus.