Malaria is a mosquito-borne infectious disease caused by unicellular parasites of the Plasmodium group. According to the World Health Organisation, in 2018, there were an estimated 228 million new cases of malaria resulting in 405,000 deaths worldwide. Recent strategies such as the distribution of insecticide-treated nets have had some success but a definitive solution has been elusive.
Recently, however, a discovery was made in Kenya that could open new avenues for malaria disease control. Specifically, researchers found that a microorganism called Microsporidia MB has the ability to completely block malaria parasite development in Anopheles arabiensis mosquitoes.
As mosquitoes transmit malaria to humans, protecting them from the parasite could in turn protect us.
Interestingly, the study also found that:
1) Microsporidia MB is already present in A. arabiensis mosquitoes in the wild;
2) Microsporidia MB does not appear to decrease the fitness of A. arabiensis mosquitoes; and
3) Microsporidia MB is passed between A. arabiensis mosquitoes and also to their offspring with relatively high efficiency.
These points make for promising results if Microsporidia MB is to be used as a malaria control measure. Nevertheless, the article still leaves many questions unanswered.
Is the blocking effect transferable to other mosquitoes? Is it really possible to scale-up without affecting the viability of mosquito populations in the wild? Why is Microsporidia MB found naturally in only 5% of the mosquitoes tested?
Perhaps the big question is how exactly does Microsporidia MB block malaria parasite development in mosquitoes? Some preliminary theories are described in the linked article below.
In Europe, if a substance found in nature can be shown to produce a technical effect, e.g. anti-malarial activity, it may be patentable. In addition, if a microorganism is discovered to exist in nature and to produce an anti-malarial substance, the microorganism itself may also be patentable as one aspect of the invention.
In the case of Microsporidia MB, the researchers suggest that rather than a single substance, the presence of the microbe itself may alter the immune system or metabolism of the mosquito.
Though methods of treatment practiced on the human or animal body are not patentable in Europe, a composition comprising a microorganism for use in such a method could certainly be patentable. From my own work, probiotics come to mind as an example.
Patents relating to the prevention and treatment of malaria have been around for a while. Could we see an increase in applications directed to microorganism compositions for such purposes? Time will tell.
The researchers could not find a single mosquito carrying the Microsporidia that was harbouring the malaria parasite. And lab experiments, published in Nature Communications, confirmed the microbe gave the mosquitoes protection.