Filariasis and transfusion-associated risk: a literature review

Canadian Blood Services, Microbiology, Donor and Clinical Services, Edmonton, AB, Canada. Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada. American Red Cross Scientific Affairs, Boston, MA, USA. Banco de Sangue Medical Director, Blood Bank, Hospital Sirio Libanês, São Paulo, Brasil. Department of Pathology, Transfusion Medicine Division, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Vox sanguinis. 2021
BACKGROUND AND OBJECTIVES Filariae are parasitic worms that include the pathogens Loa loa, Onchocerca volvulus, Wuchereria bancrofti, Brugia spp. and Mansonella spp. which are endemic in parts of Africa, Asia, Asia-Pacific, South and Central America. Filariae have a wide clinical spectrum spanning asymptomatic infection to chronic debilitating disease including blindness and lymphedema. Despite successful eradication programmes, filarial infections remain an important -albeit neglected - source of morbidity. We sought to characterize the risk of transfusion transmission of microfilaria with a view to guide mitigation practices in both endemic and non-endemic countries. MATERIALS AND METHODS A scoping review of scientific publications as well as grey literature was carried out by a group of domain experts in microbiology, transfusion medicine and infectious diseases, representing the parasite subgroup of the International Society of Blood Transfusion. RESULTS Cases of transfusion-transmitted filariasis are rare and confined to case reports of variable quality. Transfusion-associated adverse events related to microfilariae are confined to isolated reports of transfusion reactions. Serious outcomes have not been reported. No known strategies have been implemented, specifically, to mitigate transfusion-transmitted filariasis yet routine blood donor screening for other transfusion-transmissible infections (e.g. hepatitis B, malaria) may indirectly defer donors with microfilaremia in endemic areas. CONCLUSION Rare examples of transfusion-transmitted filariasis, without serious clinical effect, suggest that filariasis poses low transfusion risk. Dedicated mitigation strategies against filarial transfusion transmission are not recommended. Given endemicity in low-resource regions, priority should be on the control of filariasis with public health measures.
Study details
Study Design : Systematic Review
Language : eng
Credits : Bibliographic data from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine