A Case Report of Dengue Infection After Allogeneic Hematopoietic Stem Cell Transplantation in Patient with Acute B-Lymphoblastic Leukemia - China, 2025.

What is already known about this topic?: Dengue fever represents one of the most prevalent viral infections annually affecting the general population in endemic regions. It is widely recognized as an acute self-limiting disease, with the virus typically being completely cleared within 2-3 weeks post-infection, without establishing long-term latency. The current consensus is that primary infection with a specific serotype confers lifelong type-specific immunity, thereby preventing reinfection with an identical dengue virus serotype.

What is added by this report?: We report the case of a patient with leukemia who developed a confirmed dengue virus serotype 1 (DENV-1) infection during chemotherapy and targeted therapy. Notably, 6 months after the resolution of the initial infection, the same patient tested positive again for DENV-1 nucleic acid while undergoing intensive immunosuppression following allogeneic hematopoietic stem cell transplantation.

What are the implications for public health practice?: For patients undergoing hematopoietic stem cell transplantation and receiving immunosuppressive therapy, clinicians should be vigilant about the potential for persistent dengue infection, particularly in dengue-endemic regions. Furthermore, implementing prolonged serological monitoring post-infection is also crucial for the clinical management of this patient population.