Pre-Transplant Seroprevalence, Associated Factors, and PostTransplant Incidence of Toxoplasma gondii Infection Among Heart Transplant Recipients in Japan

Background. Among solid organ transplant (SOT) recipients, heart transplant (HT) recipients are at a higher risk of Toxoplasma gondii infection. As Toxoplasma seroprevalence varies by geographic location, updated local epidemiology is essential to guide preventive and therapeutic strategies. However, the Toxoplasma seroprevalence and incidence of post -transplant toxoplasmosis among SOT recipients in Japan are unknown. Methods. We performed a single -center retrospective observational study at an HT center in Tokyo, Japan. All HT recipients aged >= 18 years between 2006 and April 2019 were included. We reviewed patient charts and conducted a questionnaire survey to investigate the risk factors for infection. Results. Among 105 recipients included in the study, 11 (10.5%) were seropositive before transplant. Ninety-five recipients (90.5%), including all pre -transplant seropositive recipients, answered the questionnaire. The recipients who had lived in Okinawa (odds ratio [OR] 7.5 [95% CI 1.42-39.61]; P = .032) and who reported raw -meat eating habits (OR 4.64 [95% CI 1.0423.3]; P = .021) were more likely to be seropositive. None of the patients developed symptoms of toxoplasmosis. The post -transplant incidence of other major adverse outcomes was not signifi- cantly different according to the pre -transplant serostatus. Conclusions. About 10% of HT recipients at an HT center in Tokyo were seropositive for Toxoplasma pre -transplant, and none developed symptomatic toxoplasmosis post -transplant on trimethoprim-sulfamethoxazole. The history of raw meat consumption was associated with seropositivity; therefore, avoiding it might be recommended for HT recipient candidates.