Detection of Plasmodium falciparum and Plasmodium vivax subclinical infection in non-endemic region: implications for blood transfusion and malaria epidemiology

Author(s)

Maselli, Luciana M. F. ^{[1, 2]} ; Levy, Debora ^[1] ; Laporta, Gabriel Z. ^{[3, 4]} ; Monteiro, Aline M. ^[5] ; Fukuya, Linah A. ^[5] ; Ferreira-da-Cruz, Maria F. ^[6] ; Daniel-Ribeiro, Claudio T. ^[6] ; Dorlhiac-Llacer, Pedro E. ^[5] ; Sallum, Maria Anice M. ^[3] ; Bydlowski, Sergio P. ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Med, Lab Genet & Mol Hematol LIM31, BR-05403000 Sao Paulo - Brazil

^[2] Fundacao Prosangue, Hemoctr Sao Paulo, BR-05403000 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Fac Saude Publ, Dept Epidemiol, BR-01246904 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Sch Med, Lab Informat Med LIM01, BR-01246903 Sao Paulo - Brazil

^[5] Univ Sao Paulo, Sch Med, Hosp Clin, Div Hematol, BR-05403000 Sao Paulo - Brazil

^[6] Inst Osvaldo Cruz, Malaria Res Lab, BR-21045900 Rio De Janeiro, RJ - Brazil

• Document type: Journal article
• Source: Malaria Journal; v. 13, JUN 6 2014.
• Web of Science Citations: 21

Abstract

Background: In Brazil, malaria is endemic in the Amazon River basin and non-endemic in the extra-Amazon region, which includes areas of Sao Paulo state. In this state, a number of autochthonous cases of malaria occur annually, and the prevalence of subclinical infection is unknown. Asymptomatic infections may remain undetected, maintaining transmission of the pathogen, including by blood transfusion. In these report it has been described subclinical Plasmodium infection in blood donors from a blood transfusion centre in Sao Paulo, Brazil. Methods: In this cross-sectional study, representative samples of blood were obtained from 1,108 healthy blood donors at the Fundacao Pro-Sangue Hemocentro de Sao Paulo, the main blood transfusion centre in Sao Paulo. Malaria exposure was defined by the home region (exposed: forest region; non-exposed: non-forest region). Real-time PCR was used to detect Plasmodium falciparum and Plasmodium vivax. Subclinical malaria cases were geo-referenced. Results: Eighty-four (7.41%) blood donors tested positive for Plasmodium; 57 of these were infected by P. falciparum, 25 by P. vivax, and 2 by both. The prevalence of P. falciparum and P. vivax was 5.14 and 2.26, respectively. The overall prevalence ratio (PR) was 3.23 (95% confidence interval (CI) 2.03, 5.13); P. falciparum PR was 16.11 (95% CI 5.87, 44.21) and P. vivax PR was 0.47 (95% CI 0.2, 1.12). Plasmodium falciparum subclinical malaria infection in the Atlantic Forest domain was present in the mountain regions while P. vivax infection was observed in cities from forest-surrounded areas. Conclusions: The presence of Plasmodium in healthy blood donors from a region known as non-endemic, which is important in the context of transfusion biosafety, was described. Infected recipients may become asymptomatic carriers and a reservoir for parasites, maintaining their transmission. Furthermore, P. falciparum PR was positively associated with the forest environment, and P. vivax was associated with forest fragmentation. (AU)

• FAPESP's process: 12/09939-5 - Understanding the effects of landscape and biodiversity on dynamics of malaria transmission
• Grantee: Gabriel Zorello Laporta
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 09/53141-5 - Importance of subclinical malaria detection in blood donors from non-endemic areas
• Grantee: Sergio Paulo Bydlowski
• Support type: Research Grants - Research in Public Policies for the National Health Care System (PP-SUS)
• FAPESP's process: 11/20397-7 - Morphological and molecular taxonomy and phylogeny of Nyssorhynchus subgenus of Anopheles (Diptera: Culicidae), with special emphasis on Anopheles darlingi from Mata Atlântica
• Grantee: Maria Anice Mureb Sallum
• Support type: Regular Research Grants