2697. The Impact of Universal Deceased Donor Screening on Donor-Derived Toxoplasmosis in Solid-Organ Transplant: Report of the OPTN Ad Hoc Disease Transmission Advisory Committee (DTAC)

BACKGROUND: Donor-derived toxoplasmosis (DDT) is a severe and potentially life-threatening infection after solid-organ transplantation (SOT). Serologic testing for Toxoplasma gondii is required for all deceased donors per OPTN policy as of 4/6/17. To assess the impact of universal donor testing and the optimal approach to DDT prevention, we analyzed potential DDT cases reviewed by DTAC. METHODS: All potential Toxoplasma donor-derived transmission events adjudicated by DTAC from 2008 to 2018 were reviewed. A standardized classification algorithm was used to adjudicate each event as proven, probable, possible, unlikely, excluded or intervention without disease transmission. RESULTS: Twenty-eight potential DDT events were reported between 2008 and 2018. Proven or probable (p/p) DDT developed in 16 organ recipients from 15 donors. In the 9 years prior to the new testing requirement (January 2008–March 2017) 11 organ recipients from 10 donors had p/p DDT (0.13 transmissions per 1,000 donors); in the first 21 months of the new testing requirement 5 recipients from 5 donors had p/p DDT (0.27 transmissions per 1,000 donors), rate ratio 2.15; 95% CI 0.577, 6.90;P = 0.18. 10.2% of 18,328 donors tested between April 6, 2017 and December 31, 2018 were Toxoplasma IgG seropositive. Recipient pre-SOT serostatus was unknown in 4 of 5 and negative in 1 case of p/p DDT. Trimethoprim/sulfamethoxazole prophylaxis was either stopped at < 3 months or not used in all 5 cases. Infection was diagnosed a median of 103 days (range 42–153) post-transplant. Four of the 5 recipients died. CONCLUSION: DDT remains a morbid infection in both heart and non-heart recipients. Despite an apparent increase in DDT reporting to DTAC, it is unlikely that the actual incidence of this donor-derived event is increasing. Rather, with universal serologic screening of deceased donors and wider access to molecular diagnostics, DDT is increasingly recognized and diagnosed. To decrease risk for illness and death related to DDT, broader pre-transplant recipient serologic testing and use of prophylaxis or monitoring for high-risk serostatus recipients (Toxoplasma D+/R−) is critical. The optimal duration of prophylaxis is uncertain at this time and warrants further study. [Image: see text] DISCLOSURES: All authors: No reported disclosures.