title: Alternative transmission routes in the malaria elimination era: an overview of transfusion-transmitted malaria in the Americas.
abstract: Transfusion-transmitted (TT) malaria is an alternative infection route that has gained little attention from authorities, despite representing a life-threatening condition. There has been no systematic review of this health problem in American countries. The aim of this study was to describe the clinical and epidemiological characteristics of TT malaria in the Americas and identify factors associated with lethality based on the studies published in the literature.
  
  
  
  Potentially relevant papers in all languages were retrieved from MEDLINE and LILACS. Additional articles were obtained from reviews and original papers. Publications on screening of candidate blood donors and on surveillance of TT malaria cases were included. Odds ratios with respective 95% confidence intervals (95% CI) were calculated. Epidemiological characteristics of blood donors of TT malaria cases, including a pooled positivity of different tests for malaria diagnosis, were retrieved.
  
  
  
  A total of 63 publications regarding TT malaria from seven countries were included, from 1971 to 2016. A total of 422 cases of TT malaria were recorded. Most TT malaria cases were in females (62.0%) and 39.5% were in the ≥61 years-old age group. About half of all cases were from Mexico (50.7%), 40.3% from the United States of America (USA) and 6.6% from Brazil. Gyneco-obstetrical conditions (67.3%), surgical procedures (20.6%) and complications from neoplasias (6.1%) were the most common indications of transfusion. Packed red blood cells (RBCs) (50.7%) and whole blood (43.3%) were the blood products mostly associated with TT malaria. Cases were mostly caused by Plasmodium malariae (58.4%), followed by Plasmodium vivax (20.7%) and Plasmodium falciparum (17.9%). A total of 66.6% of cases were diagnosed by microscopy. Incubation period of 2-3 weeks was the most commonly observed (28.6%). Lethality was seen in 5.3% of cases and was associated with living in non-endemic countries, P. falciparum infection and concomitant neoplastic diseases.
  
  
  
  There is an important research and knowledge gap regarding the TT malaria burden in Latin American countries where malaria remains endemic. No screening method that is practical, affordable and suitably sensitive is available at blood banks in Latin American countries, where infections with low parasitaemia contribute greatly to transmission. Lethality from TT malaria was not negligible. TT malaria needs to be acknowledged and addressed in areas moving toward elimination.
authors.affiliation: Universidade do Estado do Amazonas, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.|Fundação de Hematologia e Hemoterapia do Amazonas, Av. Constantino Nery, 4397, Chapada, Manaus, AM, 69050-002, Brazil.
authors.forename: Regina M
authors.initials: RM
authors.lastname: Alho
authors.affiliation: Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.
authors.forename: Kim Vinícius Amaral
authors.initials: KV
authors.lastname: Machado
authors.affiliation: Universidade do Estado do Amazonas, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.|Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.
authors.forename: Fernando F A
authors.initials: FF
authors.lastname: Val
authors.affiliation: Fundação de Hematologia e Hemoterapia do Amazonas, Av. Constantino Nery, 4397, Chapada, Manaus, AM, 69050-002, Brazil.
authors.forename: Nelson A
authors.initials: NA
authors.lastname: Fraiji
authors.affiliation: Universidade do Estado do Amazonas, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.
authors.forename: Marcia A A
authors.initials: MA
authors.lastname: Alexandre
authors.affiliation: Universidade do Estado do Amazonas, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.|Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.
authors.forename: Gisely C
authors.initials: GC
authors.lastname: Melo
authors.affiliation: , Recife, PE, Brazil.
authors.forename: Judith
authors.initials: J
authors.lastname: Recht
authors.affiliation: Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Av. Brasil, 4365, Manguinhos, Rio de Janeiro, RJ, 21040-360, Brazil.
authors.forename: André M
authors.initials: AM
authors.lastname: Siqueira
authors.affiliation: Universidade do Estado do Amazonas, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil. wueltonmm@gmail.com.|Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil. wueltonmm@gmail.com.
authors.forename: Wuelton M
authors.initials: WM
authors.lastname: Monteiro
authors.affiliation: Universidade do Estado do Amazonas, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.|Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Av. Pedro Teixeira, 25, Dom Pedro, Manaus, AM, 69040-000, Brazil.|Instituto de Pesquisas Leônidas & Maria Deane, Fundação Oswaldo Cruz, Rua Terezina, 476, Adrianópolis, Manaus, AM, 69057-070, Brazil.
authors.forename: Marcus V G
authors.initials: MV
authors.lastname: Lacerda
mesh_terms: D001938:Brazil / Q000453:epidemiology; D018562:Disease Transmission, Infectious; D006801:Humans; D008288:Malaria / Q000401:mortality / Q000469:parasitology / Q000635:transmission*; D008800:Mexico / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000302:isolation & purification; D010965:Plasmodium malariae / Q000302:isolation & purification; D010966:Plasmodium vivax / Q000302:isolation & purification; D016019:Survival Analysis; D065227:Transfusion Reaction; D014481:United States / Q000453:epidemiology
keywords: Blood transfusion; Malaria; Plasmodium; Transfusion-transmitted malaria