title: Low sensitivity of malaria rapid diagnostic tests stored at room temperature in the Brazilian Amazon Region.
abstract: BACKGROUND
  In remote areas of the Amazon Region, diagnosis of malaria by microscopy is practically impossible. This study aimed to evaluate the performance of two rapid diagnostic tests (RDTs) targeting different malaria antigens stored at room temperature in the Brazilian Amazon Region.
  
  
  METHODS
  Performance of the OptiMal Pf/Pan test and ICT-Now Pf/Pan test was analyzed retrospectively in 1,627 and 1,602 blood samples, respectively. Tests were performed over a 15-month period. Kits were stored at room temperature in five community health centres located in the Brazilian Amazon Region. RDT results were compared with thick blood smear (TBS) results to determine sensitivity, specificity, and accuracy of the RDT.
  
  
  RESULTS
  The sensitivities of the OptiMal Pf/Pan test were 79.7% for Plasmodium falciparum malaria diagnosis and 85.7% for non-P. falciparum infections. The results showed a crude agreement of 88.5% for P. falciparum, and 88.3% for non-P. falciparum infections (Kappa index = 0.74 and 0.75, respectively). For the ICT-Now Pf/Pan test (CI 95%), the sensitivities were 87.9% for P. falciparum malaria diagnosis and 72.5% for non-P. falciparum infection. Crude agreement between the ICT-Now Pf/Pan test and TBS was 91.4% for P. falciparum and 79.7% for non-P. falciparum infection. The Kappa index was 0.81 and 0.59 for the final diagnosis of P. falciparum and non-P. falciparum, respectively. Higher levels of parasitaemia were associated with higher crude agreement between RDT and TBS.
  
  
  CONCLUSIONS
  The sensitivities of RDTs stored at room temperature over a 15-month period and performed in field conditions were lower than those previously reported.
authors.affiliation: Núcleo de Estudos de Doenças Infecciosas, Universidade Federal de Mato Grosso, Cuiabá (MT), Brazil. luteigo@gmail.com
authors.forename: Luciano T
authors.initials: LT
authors.lastname: Gomes
authors.forename: Mauro S
authors.initials: MS
authors.lastname: Tada
authors.forename: Tony H
authors.initials: TH
authors.lastname: Katsuragawa
authors.forename: Marinete M
authors.initials: MM
authors.lastname: Povoa
authors.forename: Giselle Mr
authors.initials: GM
authors.lastname: Viana
authors.forename: Maria das Gracas C
authors.initials: Md
authors.lastname: Alecrim
authors.forename: Frankllin S
authors.initials: FS
authors.lastname: De Santana-Filho
authors.forename: Ana Ruth L
authors.initials: AR
authors.lastname: Arcanjo
authors.forename: Alvaro A R A
authors.initials: AA
authors.lastname: Couto
authors.forename: Vanja S P
authors.initials: VS
authors.lastname: Calvosa
authors.forename: Andreia F
authors.initials: AF
authors.lastname: Nery
authors.forename: Cor J F
authors.initials: CJ
authors.lastname: Fontes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000953:Antigens, Protozoan / Q000097:blood*; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D016778:Malaria, Falciparum / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D055815:Young Adult
chemical_list: D000953:Antigens, Protozoan