Detection of Mansonella ozzardi among blood donors from highly endemic interior cities of Amazonas state, northern Brazil

Abstract

BACKGROUND In the Brazilian Amazon, the filarial nematode Mansonella ozzardi co-exists with malaria parasites and thick blood smear microscopy is considered the diagnostic gold standard. Transfusion of M. ozzardi microfilariae does not establish new infections, however microfilariae can survive approximately 2 years in blood-recipients with unknown risk of pathology. Data on transfusion-transmitted filariasis are lacking. This study investigated M. ozzardi parasitemias in blood donors from decentralized centers of “Fundação Hematologia e Hemoterapia do Estado do Amazonas/HEMOAM,” Northern Brazil.

STUDY DESIGN AND METHODS Cross-sectional investigation employing blood smear microscopy (n = 356) and qualitative nested-M. ozzardi-PCR (227 out of 356) in donor candidates from 19 hemocenters in interior/rural municipalities of Amazonas state. FINDINGS: Participants were mostly young males. Positivity by microscopy was 7.9% (28 out of 356) and 23.8% by M. ozzardi-PCR (54 out of 227). Parasitaemias were found in 16 out of 19 municipalities. In 54 M. ozzardi-positives, 24 were ineligible; among 30 that donated, 27 were interdicted by seropositivity (22 anti-HBc, 3 anti-HBc + HBsAg, 1 Chagas+malaria, 1 VDRL). Seropositivty was higher in M. ozzardi-PCR-positives vs M. ozzardi-PCR-negatives (OR = 15.8, 95% CI 4.5–56.1, p < 0.0001). Three M. ozzardi contaminated blood units were transfused, but no follow-up information on the recipients is available.

MAIN CONCLUSIONS Our study provides important baseline data on M. ozzardi among blood donors from the Brazilian Amazon. Further investigations in endemic areas are necessary to clarify possible association between M. ozzardi and other infections and also to elucidate whether there is any significant clinical effect upon transfusion of contaminated blood.