Ultra-sensitive RDT performance and antigen dynamics in a high-transmission Plasmodium falciparum setting in Mali.
Malar J
; 19(1): 323, 2020 Sep 03.
Article
en En
| MEDLINE
| ID: mdl-32883286
ABSTRACT
BACKGROUND:
The recent expansion of tools designed to accurately quantify malaria parasite-produced antigens has enabled us to evaluate the performance of rapid diagnostic tests (RDTs) as a function of the antigens they detect-typically histidine rich protein 2 (HRP2) or lactate dehydrogenase (LDH).METHODS:
For this analysis, whole blood specimens from a longitudinal study in Bancoumana, Mali were used to evaluate the performance of the ultra-sensitive HRP2-based Alere™ Malaria Ag P.f RDT (uRDT). The samples were collected as part of a transmission-blocking vaccine trial in a high transmission region for Plasmodium falciparum malaria. Furthermore, antigen dynamics after successful anti-malarial drug treatment were evaluated in these samples using the Q-Plex Human Malaria Array (4-Plex) to quantify antigen concentrations.RESULTS:
The uRDT had a 50% probability of a positive result at 207 pg/mL HRP2 [95% credible interval (CrI) 160-268]. Individuals with symptomatic infection remained positive by uRDT for a median of 33 days [95% confidence interval (CI) 28-47] post anti-malarial drug treatment. Biphasic exponential decay models accurately captured the population level post-treatment dynamics of both HRP2 and Plasmodium LDH (pLDH), with the latter decaying more rapidly. Motivated by these differences in rates of decay, a novel algorithm that used HRP2pLDH ratios to predict if an individual had active versus recently cleared P. falciparum infection was developed. The algorithm had 77.5% accuracy in correctly classifying antigen-positive individuals as those with and without active infection.CONCLUSIONS:
These results characterize the performance of the ultra-sensitive RDT and demonstrate the potential for emerging antigen-quantifying technologies in the field of malaria diagnostics to be helpful tools in distinguishing between active versus recently cleared malaria infections.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Plasmodium falciparum
/
Proteínas Protozoarias
/
Malaria Falciparum
/
Pruebas Diagnósticas de Rutina
/
L-Lactato Deshidrogenasa
/
Antígenos de Protozoos
Tipo de estudio:
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Adult
/
Humans
/
Middle aged
País/Región como asunto:
Africa
Idioma:
En
Revista:
Malar J
Asunto de la revista:
MEDICINA TROPICAL
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos