Malaria in a US resident blood donor following a 3‐month travel deferral

BACKGROUND: The United States defers blood donations from people who have recently traveled to or lived in malaria-endemic areas. While transfusion-transmitted malaria is rare, it primarily occurs when the donor is a previous resident of a malaria-endemic area infected with Plasmodium parasites. In 2020, the travel deferral period was revised for US residents from 1 year to 3 months after leaving a malaria-endemic area. CASE REPORT: A single unit of packed red blood cells (pRBC) was produced from a whole blood donation collected from an asymptomatic donor 109 days after return from travel to East Africa. The donor was born and resided in the United States but repeatedly traveled to the region, reportedly took malaria chemoprophylaxis, and denied previous malaria illness. Eleven days post-donation, the donor presented to a healthcare provider with flu-like symptoms and was diagnosed with Plasmodium ovale malaria 18 days after donation. Four days after diagnosis, the blood establishment was notified of the donor's malaria diagnosis; however, the pRBC had been transfused the previous day. The recipient of the pRBC was placed on treatment, repeatedly tested negative for Plasmodium parasites, and remained asymptomatic. CONCLUSIONS: We describe a near-miss of transfusion-transmitted P. ovale malaria associated with a US-resident donor despite a 3-month travel deferral. P. ovale and Plasmodium vivax forms of malaria can cause disease relapse months to years after initial infection. Additional strategies for enhancing blood safety include testing of donors with molecular assays, pathogen reduction of select blood components, and a longer travel deferral window.