What will it take to eradicate malaria from the globe? Right now, there are a record number of projects in the pipeline to fight malaria, thanks to a four-fold increase in annual research and development funds worldwide, from $121 million in 1993 to $612 million in 2009. Exciting projects underway include: late stage investigational research on a vaccine that could become the world’s first commercially available vaccine for the disease; other vaccines in various stages of development; new rapid diagnostic tests; and more than four dozen drug treatments.
More than one-third of the world’s population is at risk of contracting malaria, with about 225 million cases identified each year. Malaria kills almost 800,000 people annually, mostly children in Africa under the age of five years. You may be surprised to learn that there are about 1,500 cases diagnosed in the U.S. each year, mostly among travelers to countries where malaria is prevalent such as the Dominican Republic, Brazil, sub-Saharan Africa or South Asia.
Malaria is caused by the parasite Plasmodium, which has a complex life cycle that moves from mosquito to human and back to mosquito. A mosquito bite delivers the parasite into a human host, where it enters the liver and lies dormant for about 10 days, during which time the person doesn’t know they are sick. An immature form of the parasite then leaves the liver and infects the bloodstream, causing clinical disease that can include high fevers, aches and pains, but can also quickly progress to brain damage and risk of death if left untreated. Transmission to another person happens when a mosquito takes a blood meal from an infected person, ingesting immature parasites that then go on to mature in the mosquito’s salivary glands, ready to infect another human with the next bite.
Here is more information on three particularly notable malaria initiatives in the areas of prevention, rapid diagnosis and treatment:
1. Prevention: RTS,S could be the world’s first malaria vaccine
The RTS,S vaccine is the first and only malaria vaccine currently in a large-scale Phase 3 clinical trial. RTS,S works by blocking the parasite before it can emerge from the liver. The trial is taking place in 11 sites across 7 countries in sub-Saharan Africa among over 15, 000 infants and children, and will provide important first data about the impact of this vaccine on severe malaria disease. Results reported in the New England Journal of Medicine for two of the Phase 2 studies showed that RTS,S can reduce the risk of clinical episodes of malaria by half and can be administered together with other childhood vaccines.
If the Phase 3 results are positive, the World Health Organization says that a policy recommendation is possible as early as 2015. RTS,S was developed by GlaxoSmithKline Biologicals in partnership with The PATH Malaria Vaccine Initiative(MVI), a global health nonprofit organization that relies heavily on funding from the Bill & Melinda Gates Foundation.
Ashley Birkettt, Ph.D, leads vaccine development at MVI, a robust portfolio of 10-12 projects in various stages of clinical development. He says, “RTS,S is a great achievement at the final stage of testing. We want to keep children from becoming infected, yes, but we also need to keep funding and working on the next generation vaccines that could lead to the elimination and eradication of the parasite for good.”
2. Rapid Diagnostic Tests: RDTs
RDTs are test strips that contain carefully manufactured antibodies that bind with malaria parasites in a blood sample, triggering a color change that is easy to see with the naked eye – no microscope or special technician required. RDTs are technically challenging to make, but highly accurate – a recent review of 74 different studies showed they accurately identified malaria in 19 out of every 20 cases. Accurate diagnosis is critical to ensure that patients receive the right treatment, and to help reduce drug resistance to anti-malarial drugs.
3. Treatment: Inhaled nitric oxide gas
Dr. Kevin Kain, Director of Global Health at the Medcan Clinic in Toronto, Canada, and his research team are conducting an innovative treatment trial right now in Uganda. They are testing to see if inhaled nitric oxide gas in addition to an optimal regimen of anti-malarial drugs can improve survival and decrease brain injury among children who develop severe cerebral malaria. Nitric oxide gas is usually found in the blood, but is decreased among those suffering from cerebral malaria (not to be confused with nitrous oxide or laughing gas.) Earlier mice studies showed that inhaling nitric oxide in addition to receiving anti-malarial drugs led to improved survival rates and lower rates of brain injury.
CONNECT THE DOTS
Watch the BBC World’s Kill or Cure? The Malaria Vaccine, a documentary about the race to develop a malaria vaccine. The CDC Malaria Map Application visualizes the spread of malaria around the world – click on a country to read more details about prevalence and type of malaria. Refer to the CDC’s Health Information for International Travel 2010 if you are considering international travel.