Validation of the rapid test Carestart(tm) G6PD among malaria vivax-infected subjects in the Brazilian Amazon.
BACKGROUND
In the Brazilian Amazon, malaria infections are primarily caused by Plasmodium vivax. The only drug that kills the hypnozoite form of P. vivax is primaquine, thereby preventing relapse. However, treating glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals with primaquine can lead to severe hemolysis. G6PD deficiency (G6PDd) affects approximately 400 million people worldwide, most of whom live in malaria-endemic areas. Therefore, clinicians need tools that can easily and reliably identify individuals with G6PDd. This study estimated the accuracy of the Carestart(tm) G6PD rapid test (Access Bio) in the diagnosis of G6PDd in male participants with and without P. vivax acute malaria.


METHODS
Male participants were recruited in Manaus. Malaria diagnosis was determined by thick blood smear. G6PD quantitative analysis was performed spectro photometrically at a wave length of 340nm. The Carestart(tm) G6PD test was performed using venous blood. Genotyping was performed for individuals whose samples had an enzyme activity less than 70% of the normal value.


RESULTS
Six hundred and seventy-four male participants were included in this study, of whom 320 had a diagnosis of P. vivax malaria. In individuals with enzyme activity lower than 30% (n=13), the sensitivity, specificity, positive predictive value, and negative predictive value of the Carestart(tm) G6PD test were as follows: 61.5% (95%CI: 35.5%-82.3%), 98.3% (95%CI: 97.0%-99.1%), 42.1% (95%CI: 23.1%-63.7%), and 99.2% (95%CI: 98.2%-82.3%), 98.3% (95%CI: 97.0%-99.1%), 42.1% (95%CI: 23.1%-63.7%), and 99.2% (95%CI: 98.2%-99.7%), respectively. Increases in sensitivity were observed when increasing the cut-off value.


CONCLUSIONS
Despite low sensitivity, Carestart(tm) G6PD remains a good alternative for rapid diagnosis of G6PDd in malaria-endemic regions.
Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil.|Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil.
Marcelo Augusto Mota
MA
Brito
Núcleo de Medicina Tropical, Universidade de Brasília, Brasília, Distrito Federal, Brazil.
Henry Maia
HM
Peixoto
Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil.|Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil.
Anne Cristine Gomes de
AC
Almeida
Núcleo de Medicina Tropical, Universidade de Brasília, Brasília, Distrito Federal, Brazil.|Instituto Nacional de Avaliação de Tecnologias em Saúde, Porto Alegre, Rio Grande do Sul, Brazil.
Maria Regina Fernandes de
MR
Oliveira
Núcleo de Medicina Tropical, Universidade de Brasília, Brasília, Distrito Federal, Brazil.|Instituto Nacional de Avaliação de Tecnologias em Saúde, Porto Alegre, Rio Grande do Sul, Brazil.
Gustavo Adolfo Sierra
GA
Romero
Faculdade de Ciências Farmacêuticas, Universidade Federal do Amazonas, Manaus, Amazonas, Brazil.
José Pereira
JP
Moura-Neto
Case Western Reserve University, Cleveland, Ohio, United States of America.
Nakul
N
Singh
Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil.|Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil.
Wuelton Marcelo
WM
Monteiro
Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil.|Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil.|Instituto de Pesquisa Leônidas & Maria Deane, Fundação Oswaldo Cruz, Manaus, Amazonas, Brazil.
Marcus Vinícius Guimarães de
MV
Lacerda
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D019353:Endemic Diseases; D005954:Glucosephosphate Dehydrogenase / Q000097:blood*; D006801:Humans; D016780:Malaria, Vivax / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D011933:Reagent Kits, Diagnostic; D005954:Glucosephosphate Dehydrogenase