thursday 6 Giugno 2019Dalle 16:30 alle 18:00TMek: the revolutionary rapid diagnostic test for malaria

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Event Details

TMek: THE REVOLUTIONARY RAPID DIAGNOSTIC TEST FOR MALARIA

Program:
Ferruccio Resta, Rector, Politecnico di Milano
Riccardo Bertacco, Department of Physics, Polifab, Politecnico di Milano

The search for new rapid diagnostic tests (RDT) for malaria is a priority to fight this endemic disease, according to WHO recommendations. In fact, available RDT based on the detection of antigens, suffer from several limitations: they are not quantitative, remain positive for up to 1 month after last malaria attack, exhibit prozone effect at high parasitaemia and some false negatives.

For these reasons WHO strongly recommend the development of novel RDTs with same sensitivity of the gold standard (optical microscopy examination) but a lower percentage of false positives.

In this talk we will disclose an easy to operate lab-on-chip diagnostic test, for the quantification of the plasmodium parasitaemia, which could revolutionize the world of malaria diagnostics. The method is based on the paramagnetic susceptibility of hemozoin crystals (the malaria pigment produce by plasmodium as by-product of hemoglobin degradation) which are found within the infected red blood cells and free in the blood. A silicon microchip, with an array of Nickel posts underneath suitable electrodes, is put in contact with a smear of patient blood (7 microL) diluted with an anticoagulant and PBS, in the magnetic field produced by external magnets. Due to the competition between the magnetic and gravity force, only infected RBC and hemozoin crystals are attracted towards the concentrators, thus altering the impedance between electrodes. The entity of the impedance variation turns out to be proportional to the parasitemia and/or the hemozoin concentration, thus allowing for quantification.

TMek has been first tested at the Sacco Hospital (Milano) on control blood samples from healthy donors as well on some samples from patients affected by malaria. The test turned out to have a limit of detection for parasitaemia around 0.004%, comparable with that of currently used RDT, associated with an execution time of less than 10 minutes, to be compared with the 20 min of current TDR.

A full clinical validation in endemic zone has been carried out in Cameroon during April 2019. On more than 115 cases of patients suspected of malaria, we checked our TMek test against the gold standard and conventional RDT. At variance with RDT a negligible number of possible false positives was found, while in more than 90% of cases the result of TMek is in perfect agreement with the whole clinical situation of the patient.

TMek holds a great potential as novel rapid, quantitative and pan-plasmodic test for malaria suitable for on-field use in endemic zones. The project has been awarded with a Polisocial Awards 2018 grant and the Disruptive Innovation Prize of the 2018 edition of the Switch to Product competition for emerging start-up. Related IP has been protected via two “social patents” [5]. Next step is the miniaturization of the reader and microchip to realize a TMek equivalent of a glucosimeter.

Date e orari

giovedì 6 Giugno 2019
Dalle 16:30 alle 18:00

Luogo

Politecnico di Milano, Aula Magna

Piazza Leonardo da Vinci, 32 - Milano

Organizzatore

Politecnico di Milano

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