Introduction: Despite the prevalence of malaria worldwide, donor-derived transmission through solid organ transplantation is rare. Published guidelines for donor screening vary. Most require a history of residence in a malaria endemic area for at least 3 months within the preceding 3 years. We report transmission of malaria from a donor to 3 of 4 solid organ transplant recipients where donor molecular screening did not detect donor infection.
Method: A 15-year-old patient became brain dead following a spontaneous subarachnoid haemorrhage. They had no significant past medical history, however had migrated to Australia 1 year previously. Their parent volunteered that they had lived in a malaria endemic region, but had no specific knowledge of malaria infection. Donor blood testing pre-donation was negative on malaria antigen assay, and post-donation malaria LAMP (Loop-mediated isothermal amplification) test was negative. Double lungs, liver and two kidneys were retrieved and successfully transplanted.
Results: At 17 days following kidney transplant a recipient presented to hospital with fevers and malaise. Blood film showed malaria parasites, which were identified by nucleic acid testing (NAT) as Plasmodium ovale. Following this donor serum was retested using NAT and Plasmodium falciparum DNA detected. 10 days later the liver recipient and second kidney recipient presented with fevers and Plasmodium ovale parasitaemia on NAT testing. All recipients were appropriately treated with artemisinin and primaquine and made full recovery. The recipient of the lungs remained well, although given the donor status, was prophylactically treated for malaria. Retrospective testing of the donor using serology demonstrated positive serology on the Captia assay.
Conclusion: This case illustrates difficulties that may be encountered in donor screening for malaria. i) Malaria antigen testing will often be negative in the absence of parasitaemia, for example when there is dormant infection. ii) Malaria serology will usually be positive in all cases of prior infection but provides little information regarding risk of infection transmission. iii) The molecular LAMP test has been reported to have high specificity and sensitivity in the diagnosis of malaria, although failed to identify the presence of infection in this donor. In this case, neither the LAMP assay nor the specific NAT assay detected P. ovale in the donor, highlighting the difficulty in diagnosis of this particular infection. In general, initial screening using serology, where positive followed by specific NAT testing may be the optimum approach to diagnosis.