Eye Exams Reveal How Malaria Causes Death
Scientists reported on Wednesday that the human eye could help doctors understand how an acute form of malaria attacks the brain, a discovery shedding light on new and better treatments for one of Africa’s biggest killers.
Tests in patients have shown for the first time that the build-up of infected blood cells in the narrow blood vessels of the brain leads to a potentially lethal lack of oxygen to the brain.
Eye exams detected tiny blood vessel blockages in the brains of people with cerebral malaria, which they believe starve brain cells and cause the disease.
The researchers said the finding means that drugs such as statins, which help improve circulation, could be used in new treatments to fight cerebral malaria.
Nick Beare of the Royal Liverpool University Hospital, who led the research, said they discovered multiple small areas of blockages where the brain isn’t getting enough blood and oxygen they believe are critical in causing coma and death in cerebral malaria.
The World Health Organization’s latest statistics show that malaria killed 881,000 people and infected 247 million worldwide in 2006, mainly in Africa. Many malaria experts say those numbers underestimate the problem.
Malaria parasites enter the bloodstream from bites by infected mosquitoes and live in red blood cells, making them stick to the inside of narrow blood vessels and causing blockages.
Most deaths occur as a result of cerebral malaria, where red blood cells infected by malaria parasites build up into the brain, leading to coma, convulsions and often death. There have been few promising results for a vaccine, but one effective treatment is Novartis AG’s Coartem.
But Beare said the problem with these treatments is they only target the parasite and do not address problems that can lead to coma and death.
The researchers examined the retinas of 34 children in Malawi who were admitted to hospital with suspected cases of cerebral malaria.
The technique involves injecting dye into the children’s arms that passes through the retina’s blood vessels. The researchers then observed blockages under fluorescent light they believe cause cerebral malaria.
Beare believes this window into the brain has opened up further knowledge of what makes cerebral malaria so deadly.
The effects of cerebral malaria can be reversed with no lasting damage to the patient’s cognitive functions or vision if caught in time.
"We looked at the eye because the retina — the tissue at the back of the eye that picks up light — is really an extension of the brain."
Beare believes these new findings point to new therapeutic measures for treating cerebral malaria more effectively, particularly in comatose children.
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