First successful field evaluation of new, one-minute haemozoin-based malaria diagnostic device

Abstract

Background: Early and accurate diagnosis of malaria is critical to the success of malaria elimination. However, the current mainstay of malaria diagnosis in the field, such as light microscopy and rapid diagnostic tests (RDTs), have limitations due to low parasite density or mutation in diagnostic markers. Methods: We evaluated an inexpensive, robust, rapid, malaria diagnostic device, called Gazelle, that employs magneto-optical detection to identify haemozoin crystals (Hz) produced by all species of human malaria parasites in infected individuals. A beam of polarised light is passed through the lysed diluted blood sample under the influence of high (~.55T) and low magnetic fields. The difference in light transmission through the sample between the high and low magnetic fields indicates presence of Hz, suggesting possible malarial infection. A total of 300 febrile patients were screened at the malaria clinic of Indian Council of Medical Research-National Institute of Research in Tribal Health (ICMR-NIRTH), Jabalpur, India, from August 2018 to November 2018. Malaria diagnosis was done using four diagnostic methods: Gazelle, light microscopy, RDT, and malaria specific Polymerase Chain Reaction (PCR). Measures of diagnostic accuracy were compared. Findings: Out of 300 febrile patients enroled and tested for the presence of malaria parasites, 262 patient samples were included in the final analysis. The sensitivity and specificity of Gazelle was 98% and 97% in comparison to light microscopy, 82% and 99% to PCR and 78% and 99% to RDT, respectively. The results of the four diagnostic methods were comparable and statistically no significant differences in sensitivity or specificity was observed between these methods. Enhanced diagnostic accuracy of Gazelle in malaria patients with no prior history of malaria treatment was observed in this study. Interpretation: The diagnostic ability of Gazelle was comparable to light microscopy and better than RDTs even in low parasitemia and in presence of pfhrp2/3 deletion mutant parasites. Gazelle may be a novel valuable diagnostic tool in resource poor settings where (i) microscopy is not feasible and (ii) pfhrp2/3gene deleted parasite are present. Its speed, cost-efficiency, and alternative to lack of microscopists makes it an important adjunct in field settings. Funding: HemexDx, India.

Performance of a sensitive haemozoin‐based malaria diagnostic test validated for vivax malaria diagnosis in Brazilian Amazon

“…Kumar et al. observed that the sensitivity and specificity of Gazelle™ was 98 and 97 % compared to light microscopy, 82 and 99 % to PCR, and 78 and 99 % to RDT, respectively, in a predominantly P. falciparum endemic area [ 25 ].…”

Internet of medical things (IoMT)-integrated biosensors for point-of-care testing of infectious diseases

“… (a) Malaria 1 NAAT LAMP kelch 13 1 c/r <20 min -- ( Malpartida-Cardenas et al, 2019 ) 2. Gazelle Magneto-optical detection haemozoin crystals 50 parasites/mL ∼1 min Yes ( Kumar et al, 2020 ) 3. MCFA Chemiluminescence-based ELISA PfHRP2 8 ng/mL -- Yes ( Ghosh et al, 2020 ) (b) Dengue fever 4.…”

“…Besides this, instrument-free detection can be easily performed in rural areas to avoid expensive molecular biology equipment e.g., paper-based microfluidics ( Reboud et al, 2019 ). Further, Kumar et al conducted successful field evaluation of battery-operated magneto-optical malaria diagnostic device ( Kumar et al, 2020 ). In comparison to detection of P. falciparum histidine rich protein-2 (Pfhrp2), this device was based on detection of hemozoin (by-product of HB) due to its prevalent nature in resistant parasites.…”

Method for Malaria Diagnosis Based on Extractions of Samples Using Non-Invasive Techniques: An Opportunity for the Nursing Clinical Practice

“…Microscopic diagnosis using blood smears is considered the gold standard, not only for the identification of Plasmodium species, but also for the quantification of parasite load in blood. However, detection can be limited in those cases with low parasite loads, in addition to having other drawbacks such as the need for an optical microscope, clean glass slides, immersion oil, reagents for staining, and most importantly, a skilled microscopist [4,5].…”

“…On the other hand, immunological techniques and the development of various RDTs have allowed quick diagnosis in the field, although with rather high economic costs [6]. However, RDTs have limitations in those cases with low parasite density or due to mutations in diagnostic markers [5]. Considering the decrease of the prevalence in many areas and the low detection limits of microscopy and RDTs, there is the need for the development of effective diagnostic strategies for field application [7].…”