Cameroon: Scientists develop Loascope, an instrument that measures the level of onchocerciasis infection

Teams at the Institute of Research for Development (IRD) and the Centre of Research on Filariasis and other Tropical Diseases (Centre de Recherche sur les Filarioses et autres Maladies Tropicales - CRFILMT), have
completed an innovative strategy in Cameroon opening the door to the eradication of onchocerciasis in the forest areas of Central Africa.

The researchers thus developed between February and May 2017 a tool that allows measurement in every individual, of the level of infection by Loa loa in order to ensure that the treatment is without risk. If the infection is not found or if it exists below a level where there are no risks of serious secondary effects (which is the case in more than 95% of the population), treatment by the drug "Mectizan" can be administered.

On the other hand, if the person presents a very high level of infection, they are not given Mectizan and an alternative individually-tailored treatment protocol is proposed (establishment of such treatment, which is spread over four weeks, cannot be envisaged for all the population). Thus, this strategy combining an initial test before treatment is called Test and Treat.

The project team perfected an instrument allowing precise and quick measurement (in less than three minutes) of the level of Loa loa infection with a drop of blood taken from the tip of a finger. This instrument, the Loascope, is made up of a small optical magnifying device linked to a smartphone. It is thus perfectly portable and adapted to field usage conditions. In 2015, the Test and Treat strategy allowed more than 15,000 people to be treated in the Okola health area, in the Centre region of Cameroon, without any cases of serious secondary effects. This first phase showed the feasibility of such a strategy in the framework of treatment on a large scale.

Written by Ashembwom Stephanie