A team from the Politecnico di Milano, comprising Prof. Riccardo Bertacco from the Department of Physics and three PhD students Francesca Milesi, Marco Giacometti and Lorenzo Coppadoro, is in Cameroon, where they are developing the Tid Mekii project.
The subject of the research is a new malaria diagnostic system which our researchers are testing in the field. Tid Mekii, in fact, means “malaria” in Ewondo, the Bantu language spoken in that area.
Every morning in Africa, outside hospitals and dispensaries, queues form with tens of people waiting for a blood test to find out if their fever is due to malaria. Malaria is a very serious and extremely widespread disease: the World Health Organization estimates that there were 216 million new cases and 445,000 deaths in 2016 alone, mainly in Africa.
The causative agent of the disease, Plasmodium, infects red blood cells in humans where it reproduces, destroying haemoglobin and transforming it into paramagnetic hemozoin crystals, until the membrane ruptures releasing new parasites into the bloodstream.
The diagnostic tests currently available in African dispensaries do not provide effective screening for the population; consequently, still too many people are dying from an easily curable disease.
TMek is a compact system, designed using the “lab-on-a-chip” approach, where complex operations are engineered and miniaturised into a low-cost, disposable microchip which is connected via USB to an electronic reading device. A drop of blood is collected on a slide, then placed in contact with the silicon chip. Infected red blood cells and hemozoin crystals are attracted to magnetic concentrators in the chip, while healthy cells sediment. iRBCs (infected red blood cells) and HCs (hemozoin crystals) are detected by measuring the variation in electrical impedance between the electrodes placed at each concentrator.
Currently the most sensitive malaria detection method is based on gene recognition of the various strains of plasmodium through the PCR method, which is complicated, expensive and not available in African dispensaries. The standard method that is currently used in Africa due to its ease of use involves placing infected red blood cells in a drop of blood on an optical microscope. Although this method is sufficiently sensitive, it requires very skilled staff, there can be variability in interpreting the results and analysis times are long. Recently new rapid diagnostic tests (RDTs) have been introduced, in Africa too, that are based on antibody-antigen interaction, but their low sensitivity means they can’t be used for early diagnosis and they return a high number of false positives due to the underlying presence of the antigen in patients living in endemic regions.
In this context, the innovative lab-on-a-chip test TMek offers the following benefits:
- sensitivity level comparable to the standard currently in use;
- ability to identify all types of malaria parasites, as it is a pan-plasmodium test;
- ability to quantify the number of diseased RBCs by monitoring the intensity and stage of the disease;
- fast execution (less than 5 minutes, compared to 25 minutes with an RDT or 40 minutes with the standard);
- costs less than €10;
- suitable for use in tropical areas where there are no specialised staff.
TMek came from a research project financed by the Polisocial Awards, the Politecnico di Milano’s social responsibility programme.
The device has been patented by the Politecnico di Milano as a “Social patent”. The research group launched an ethical start-up with social objectives which, in collaboration with NGOs operating in Africa, aims to complete validation work on the technology in the field and commence the marketing stage, potentially in partnership with other companies in the biomedical sector.
This release was first published by Politecnico di Milano.