Plasmodium genome in blood donors at risk for malaria after several years of residence in Italy
Article first published online: 7 MAY 2014
© 2014 AABB
Volume 54, Issue 10, pages 2419–2424, October 2014
How to Cite
Assennato, S. M., Berzuini, A., Foglieni, B., Spreafico, M., Allain, J.-P. and Prati, D. (2014), Plasmodium genome in blood donors at risk for malaria after several years of residence in Italy. Transfusion, 54: 2419–2424. doi: 10.1111/trf.12650
- Issue published online: 10 OCT 2014
- Article first published online: 7 MAY 2014
- Manuscript Revised: 17 FEB 2014
- Manuscript Accepted: 17 FEB 2014
- Manuscript Received: 4 DEC 2013
At present, the main risk of transfusion-transmitted malaria (TTM) in nonendemic countries is chronic, asymptomatic immigrants from malaria-endemic areas. Semi-immune donors may carry undetected parasitemia. This study examines Plasmodium infection in at-risk blood donors in Northern Italy.
Study Design and Methods
Plasma samples from 97 candidate donors and 80 controls were tested for malarial antibodies using a commercial enzyme immunoassay. The conserved 18S rRNA and the mitochondrial genes of Plasmodium were amplified to detect and quantify parasite genomes (copies/mL). Plasmodium species were identified with a species-specific nested polymerase chain reaction. Parasitemic samples were further tested by amplification of polymorphic repetitive regions in MSP-1 Block 2, MSP-2 Block 3, and glutamate-rich protein (GLURP) confirmed by sequencing.
Three of 83 seropositive (3.6%) and one of 14 seronegative at-risk candidate donors carried Plasmodium genome (4 × 103-8.5 × 104 copies/mL): two P. falciparum, one P. malariae (seronegative sample), and one coinfection with P. malariae and P. ovale. Alleles of MSP-1 (MAD20 and K1), MSP-2 (3D7 and FC27), and GLURP were amplified from Sample 261. In Sample 282 only one allele in MSP-2 (FC27) and GLURP was amplified. No alleles were detected in Samples 283 and 331.
Immigrants from endemic countries might carry infectious Plasmodium after 2 to 5 years of continuous residence in Italy. Serologic screening may miss donors carrying P. malariae. Permanent exclusion or screening for both antibodies and genome are needed to prevent TTM.