By Holly Giles
Although it may not be breaking headlines among our COVID-19-filled world, malaria still infects over 200 million people each year according to the World Health Organisation. It is a major killer worldwide and has particular prevalence in Africa. However, its prevalence may soon be threatened by new research published this week.
Scientists from the International Centre of Insect Physiology and Ecology in Kenya have teamed up with the MRC-University of Glasgow Centre for Virus Research for this project with aim of targeting the transmission of the disease as a point of weakness in the malaria cycle. They have been able to locate a microbe living in the gut and genitals of some mosquitos which makes them unable to carry malaria. The microbe in question is Microspridia MB and in mosquitoes carrying the microbe not a single case of malaria was seen; “The data we have so far suggest it is 100% blockage, it’s a very severe blockage of malaria” explained Dr Jeremy Herren from the team. “I think people will find that a real big breakthrough” he added.
Another green light of the research is that the team have found infecting mosquitoes with the microbe is lifelong meaning the microbe remains for the whole life of the mosquito and therefore the insect is unable to carry malaria permanently. This protection can continue even after the mosquito’s death by passing the microbe to her offspring. This means if the prevalence of the microbe reaches sufficient numbers it offers a unique solution to wipe-out malaria’s main form of transmission, the mosquito bite.
“It’s a new discovery. We are very excited by its potential for malaria control. It has enormous potential,” explained Prof Steven Sinkins, from the MRC-University of Glasgow Centre for Virus Research.
The main question now for the team is how to increase the presence of this microbe within the mosquito population, where its natural level is only 5%. It is predicted to need a prevalence of 40% to make a dent in the number of malaria cases. They are currently investigating two methods of delivery. The first is to manufacture the microbe and release it en-masse to infect mosquitoes. The second more favourable option is to infect male mosquitoes in the lab (the male species do not bite) and releasing them to distribute it through infecting females during reproduction. This means it may take time but over the years the incidence of the microbe will increase and with it, the team hope, the number of cases will go down.
Herren explained the next course of action for the researchers; “Further studies will be needed to determine precisely how Microsporidia MB could be used to control malaria. The next phase of the research will investigate Microsporidia MB dynamics in large mosquito populations in screen house ‘semi-field’ facilities. The results of these studies will give us key information that will be used to determine how we could then disseminate Microsporidia MB for malaria control.”
It’s early days for the team but a crucial step forward in the fight against malaria. At this team newspapers are focused on finding a cure for COVID-19 meaning other discoveries can just slip by; this is a major breakthrough for epidemiology and worth taking notice of.