Toxoplasmosis after allogeneic haematopoietic cell transplantation (HCT) - Disease burden and approaches to diagnosis, prevention, and management in adults and children

Abstract Background Toxoplasmosis is a rare but highly lethal opportunistic infection after allogeneic haematopoietic cell transplantation (HCT). Successful management depends on screening, early recognition and effective treatment. Objectives To review the current epidemiology and approaches to diagnosis, prevention and treatment of toxoplasmosis in adult and paediatric allogeneic HCT recipients. Source Search of the English literature published in MEDLINE up to June 30, 2020 using combinations of broad search terms including toxoplasmosis, transplantation, diagnosis, epidemiology, prevention, and treatment. Selection of articles for review and synthesis on the basis of perceived quality and relevance of content. Content Toxoplasmosis continues to be a major challenge in the management of allogeneic HCT recipients. Here we provide a summary of published case series of toxoplasmosis in adult and paediatric patients post allogeneic HCT. We review and discuss the pathogenesis, epidemiology, clinical presentation, diagnosis, and current recommendations for prevention and treatment. We also discuss impacts of toxoplasmosis in this setting and factors affecting outcome, emphasising attention to neurological, neuropsychological and neurocognitive late effects in survivors. Implications Apart from careful adherence to established strategies of disease prevention through avoidance of primary infection, identification of seropositive patients and implementation of molecular monitoring, future perspectives to improve the control of toxoplasmosis in allogeneic HCT recipients may include the systematic investigation of pre-emptive treatment, development of immunomodulatory approaches, antimicrobial agents with activity against the cyst form and of vaccines to prevent chronic infection.