Field evaluation of an automated RDT reader and data management device for Plasmodium falciparum/Plasmodium vivax malaria in endemic areas of Colombia

Abstract

BackgroundMassive implementation of malaria diagnostics in low-resource countries is regarded as a pivotal strategy in control and elimination efforts. Although malaria rapid diagnostic tests (RDTs) are considered a viable alternative, there are still obstacles to the widespread implementation of this strategy, such as reporting constraints and lack of proper quality assurance of RDT-based programmes at point-of-care (POC).MethodsA prospective cohort of patients, seeking routine care for febrile episodes at health centres in malaria-endemic areas of Colombia, was used to assess the diagnostic performance of a device based on smartphone technology (Deki ReaderTM, former codename “GenZero”), that assists users at POC to process RDTs. After informed consent, patients were enrolled into the study and blood samples were collected for thick blood smear (TBS) and RDT. The RDT results were interpreted by both visual inspection and Deki Reader device and concordance between visual and device interpretation was measured. Microscopy corrected by real-time polymerase chain reaction (PCR) and microscopy were “gold standard” tests to assess the diagnostic performance.ResultsIn total, 1,807 patients were enrolled at seven health centres in malaria-endemic areas of Colombia. Thirty-three Plasmodium falciparum and 100 Plasmodium vivax cases were positive by corrected microscopy. Both sensitivity and specificity were 93.9% (95% CI 69.7-95.2) and 98.7% (95% CI 98.5-99.4) for P. falciparum, and 98.0% (95% CI 90.3-98.9) and 97.9% (95% CI 97.1-98.5) for P. vivax. Percentage concordance between visual and device interpretation of RDT was 98.5% and 99.0% for P. vivax and P. falciparum, respectively.The RDT, when compared to TBS, showed high sensitivity and specificity for P. falciparum in both visual and device interpretation, and good overall diagnostic performance for P. vivax. Comparison between PCR as gold standard and visual and device interpretation showed acceptable overall performance for both species.ConclusionsThe diagnostic performance of the Deki Reader was comparable to visual interpretation of RDTs (without significant differences) for both malaria species. Providing standardized automated interpretation of RDTs at POC in remote areas, in addition to almost real-time reporting of cases and enabling quality control would greatly benefit large-scale implementation of RDT-based malaria diagnostic programmes.

Malaria, enfermedad tropical de múltiples métodos diagnósticos

“…La sensibilidad y especificidad de esta prueba oscilan entre 80-90%, independiente de la especie de Plasmodium [28]. Un estudio realizado en Colombia indica que a través de este método de microscopía, la sensibilidad es 93% y especificidad es 98,7% para P. falciparum, mientras que para P. vivax, la sensibilidad es 98% y la especificidad es 97, 9% [29]. Dentro de las dificultades que presenta este método es que solamente detecta parasitemias mayores a 50 parásitos/μL, y no permite detectar coinfecciones; esta incapacidad de detectar infecciones con baja carga de pará-sitos sanguíneos, conduce al no tratamiento de los pacientes y por ende al progreso de la enfermedad [30,31].…”

“…Presenta una sensibilidad similar a la gota gruesa, de un 95% con 100 parásitos/μL en el caso de P. falciparum. Un estudio realizado en Colombia, identificó que la especificidad de PDR en el diagnóstico de malaria por P. falciparum es 99% y por P. vivax es 98,5% [29].…”

Using electronic readers to monitor progress toward elimination of mother‐to‐child transmission of HIV and syphilis: An opinion piece

“…Similarly, studies on other diseases, such as malaria, have shown high concordance between visual and device interpretation (N98%), as well as the potential benefits of quality assurance, automated data transmission, and health system strengthening [11].…”

“…1) [11]. Automated data transmission could also reduce the potential for human error in data capture and surveillance.…”

“…When testing is decentralized, program managers may be unable to monitor testing coverage and quality; thus, local problems, such as incorrect use of the tests or misinterpretation of results by providers, incorrect reporting of the data in clinic records, and stockout of test kits or commodities, may not be identified in a timely manner. Electronic readers could provide automated, standardized interpretation of results, thereby minimizing inter-user variability and possible transcription errors [11], and may enable quality assurance to be performed remotely. The readers may be used by healthcare workers with minimal training and guide patient care since protocols can be incorporated into the reader for users to follow, thereby empowering local health workers (Fig.…”