title: Blood transfer devices for malaria rapid diagnostic tests: evaluation of accuracy, safety and ease of use.
abstract: BACKGROUND
  Malaria rapid diagnostic tests (RDTs) are increasingly used by remote health personnel with minimal training in laboratory techniques. RDTs must, therefore, be as simple, safe and reliable as possible. Transfer of blood from the patient to the RDT is critical to safety and accuracy, and poses a significant challenge to many users. Blood transfer devices were evaluated for accuracy and precision of volume transferred, safety and ease of use, to identify the most appropriate devices for use with RDTs in routine clinical care.
  
  
  METHODS
  Five devices, a loop, straw-pipette, calibrated pipette, glass capillary tube, and a new inverted cup device, were evaluated in Nigeria, the Philippines and Uganda. The 227 participating health workers used each device to transfer blood from a simulated finger-prick site to filter paper. For each transfer, the number of attempts required to collect and deposit blood and any spilling of blood during transfer were recorded. Perceptions of ease of use and safety of each device were recorded for each participant. Blood volume transferred was calculated from the area of blood spots deposited on filter paper.
  
  
  RESULTS
  The overall mean volumes transferred by devices differed significantly from the target volume of 5 microliters (p < 0.001). The inverted cup (4.6 microliters) most closely approximated the target volume. The glass capillary was excluded from volume analysis as the estimation method used is not compatible with this device. The calibrated pipette accounted for the largest proportion of blood exposures (23/225, 10%); exposures ranged from 2% to 6% for the other four devices. The inverted cup was considered easiest to use in blood collection (206/226, 91%); the straw-pipette and calibrated pipette were rated lowest (143/225 [64%] and 135/225 [60%] respectively). Overall, the inverted cup was the most preferred device (72%, 163/227), followed by the loop (61%, 138/227).
  
  
  CONCLUSIONS
  The performance of blood transfer devices varied in this evaluation of accuracy, blood safety, ease of use, and user preference. The inverted cup design achieved the highest overall performance, while the loop also performed well. These findings have relevance for any point-of-care diagnostics that require blood sampling.
authors.affiliation: Foundation for Innovative New Diagnostics, Lumumba Avenue, Kampala, Uganda. heidi.hopkins@finddiagnostics.org
authors.forename: Heidi
authors.initials: H
authors.lastname: Hopkins
authors.forename: Wellington
authors.initials: W
authors.lastname: Oyibo
authors.forename: Jennifer
authors.initials: J
authors.lastname: Luchavez
authors.forename: Mary Lorraine
authors.initials: ML
authors.lastname: Mationg
authors.forename: Caroline
authors.initials: C
authors.lastname: Asiimwe
authors.forename: Audrey
authors.initials: A
authors.lastname: Albertini
authors.forename: Iveth J
authors.initials: IJ
authors.lastname: González
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Gatton
authors.forename: David
authors.initials: D
authors.lastname: Bell
mesh_terms: D058731:Blood Safety / Q000379:methods; D001800:Blood Specimen Collection / Q000295:instrumentation / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000295:instrumentation / Q000379:methods*; D006282:Health Personnel; D006801:Humans; D008288:Malaria / Q000097:blood / Q000175:diagnosis*; D009549:Nigeria; D010679:Philippines; D015203:Reproducibility of Results; D014454:Uganda