Persistent Dengue Infection in an Immunosuppressed Patient Reveals the Roles of Humoral and Cellular Immune Responses in Virus Clearance

Detailed understanding of the roles of humoral and cellular immune responses in sterilizing dengue virus (DENV) infection in humans is required to inform effective vaccine development. We report an unusual case of persistent DENV infection in a lymphopenic renal transplant recipient who was therapeutically immunosuppressed to prevent organ rejection. Following resolution of symptomatic dengue, this patient remained positive for DENV3 RNA in the blood for 4 months and viruric up to 9 months post-infection despite demonstrable levels of serum neutralizing antibodies throughout this period. Full resolution of DENV infection instead coincided with recovery of CD8+ T cell counts during reversal from lymphopenia. Taken collectively, our observations suggest a role for cellular immunity in sterilizing DENV infection in humans. Any dengue vaccine should thus be able to induce both humoral and cellular immunity that respectively prevent symptomatic infection and enable effective viral clearance. [Display omitted] •Dengue virus infection persisted in a lymphopenic renal transplant patient•RNAemia and viruria lasted 4 and 9 months, respectively, despite detectable antibodies•Viruria only resolved when CD8+ count increased to the lower limit of normal Examining a lymphopenic kidney transplant patient presented with dengue virus (DENV) infection, Ng et al. observed that the virus persisted in blood and urine despite detectable antibodies. Full resolution of DENV infection coincided with recovery of CD8+ counts, suggesting a role of cellular immunity in sterilizing dengue virus infection.