A mosquito tornado in Portugal. Photo by Filipa Scarpa
Mosquitoes are among the peskiest of insects. I am that person who gets bitten when no one else has. My friends actually use me as their own mosquito repellent – though I lure them to a spot, I keep all the attention off them.
Mosquitoes are a pain. Malaria is a killer.
Human being’s greatest enemy in fact; mosquitoes spread malaria around tropical and sub-tropical countries. There are over 200 million cases each year, slaying over 650,000 people, most of which are in the African region, and most of them children under five.
Symptoms include fever, aches and vomiting. Malaria becomes life threatening when it disrupts the blood supply to vital organs.
Photo by Ragnhild Brosvik
Contaminated female mosquitoes transmit a parasite called Plasmodium. Once bitten, these parasites pass through the liver and infect red blood cells. Inside the red blood cells they multiply like mad, causing the cell to rupture.
Plasmodium is a slippery target for potential vaccines because different proteins are produced in each stage of this cycle.
A vital component in the current treatment is artemisinin. But there are increasing reports of resistance to it. The threat of insecticide resistance is also rapidly growing.
There are, however, some positive things happening.
A recent study examined children in Tanzania with natural immunity and found antibodies in their blood latched onto a previously unknown gene. This gene, PfSEA-1, is needed by parasites in order to escape from inside red blood cells. The antibody locks them in there.
A lead researcher in the study, Jonathan Kurtis, likens the process to “trap[ping] them inside a burning house”.
“Many researchers are trying to find ways to develop a malaria vaccine by preventing the parasite from entering the red blood cell, and here we found a way to block it from leaving the cell once it has entered. If it’s trapped in the red blood cell, it can’t go anywhere – it can’t do any further damage.”
Initial trials on mice are promising. When infected with a deadly form of malaria, the vaccinated rodents lived almost twice as long as their unvaccinated buddies.
Tests on monkeys start next month and if successful, tests on people could begin within 18 months.
While it won’t prevent malaria, it will reduce symptoms. It can be used in conjunction with other treatments, attacking all stages of the cycle of infection.
It’s a really long way away still.
Luckily, a new vaccine, RTS,S, developed by GlaxoSmithKline, is expected to come out soon. It has been shown to almost halve the number of malaria cases in young children and reduce the malaria cases in infants by around a quarter.
It’s grand stuff. But Australia doesn’t suffer from malaria, so if scientists could find a way to stop them biting in the first place, I can stop having nightmares about mosquito tornadoes.