What is Malaria?
Malaria is a life-threatening disease caused by a parasite and transmitted to humans by mosquito bite. With between one and three million deaths annually and 3.000 children deaths daily, it remains one of the globe's leading infectious killers. The majority of its victims are children under the age of five and pregnant women.
Malaria is caused by a one-celled parasite called plasmodium. The most common strain, plasmodium falciparum is also the deadliest. It is responsible for 95% of malaria related deaths, worldwide, especially in Africa. Malaria works by infiltrating human cells - first the liver, then the blood stream - growing and multiplying until the infected red blood cells rupture, freeing the parasites to attack and enter other red blood cells. Toxins released when the red cells burst are what causes the typical fever, chills and flu-like symptoms. In many cases, particularly in children and pregnant women, complications of the infection may lead to life-threatening anaemia or cerebral malaria and even death. In cerebral malaria, the infected red cells obstruct the blood vessels in the brain. Other vital organs can also be damaged. Widespread poverty and poor health infrastructure mean that many Africans lack access to bed nets and medicines that can protect and cure them from malaria. Furthermore, growing resistance in endemic countries to the most widely available, affordable and prescribed drugs such as chloroquine are quickly rendering these therapies ineffective.
Burden of the disease
Malaria is a major public health problem in more than 90 countries, inhabited by close to 2.5 billion people, or 40% of the world's population. The disease is estimated to kill a child every 30 seconds and to cause up to 350 million new infections worldwide every year. Malaria is the biggest killer disease for children in Africa (more than AIDS, TB or any other disease) and a primary cause of death and poverty. Over 60% of malaria cases and 90% of malaria deaths are recorded in Africa. Developing countries spend up to 40% of their health expenditure on malaria. Coupled with its burden on families, the disease is undermining development in some of the poorest countries in the world.
Malaria's catastrophic economic impact
Malaria is clearly an immense barrier to development and malaria-endemic countries are among the very poorest in the world. Malaria costs Africa $12 billion in lost productivity each year, while it is estimated that annual economic growth of malaria-endemic countries is 1.3% lower than non malaria-endemic ones. Countries where malaria has been brought under control have experienced immediate accelerated economic growth, as shown in specific areas in Mozambique. According to estimates, sub-Saharan Africa's Gross Domestic Product (GDP) would be up to 32% greater today had malaria been eliminated 35 years ago. This would mean up to $100 billion added to the region's current GDP, a sum nearly five times greater than all development aid provided to Africa last year.
Solutions to fight malaria
Malaria has been brought under control and even eliminated in many parts of Asia, Europe and the Americas. Yet in Africa, with very efficient mosquito vectors, increasing drug resistance and struggling health systems, malaria infections have actually increased over the last three decades. Infections worldwide now number around 350 to 500 million cases a year, with over a million deaths, mostly among the young in Africa.
Experts agree that to control malaria, and ultimately to ensure that families can live malaria-free lives, a comprehensive approach is necessary. Such an approach involves providing insecticide-treated bed nets, spraying the inside walls of houses with insecticides, providing access to diagnosis and antimalarial drugs, and providing a packet of interventions through strengthened antenatal care services for pregnant women. Underpinning these four is education - empowering families and communities with the knowledge and resources to combat this disease. Additionally, while we work to control malaria through available tools, we need to continue to support the development of a vaccine.
Long-lasting insecticide-treated bed nets (LLINs) work by creating a protective barrier against mosquitoes at night, when the vast majority of transmissions occur. The African malaria mosquitoes generally bite late at night or early morning, between 10pm and 4am. Most mosquito nets can accommodate more than one person - a mother and an infant or a few siblings - for up to three to five years. A net treated with special insecticides offers about twice the protection of an untreated net, and through its repellency, can even protect other people in the room outside the net. When enough people (about 70 percent) sleep under LLINs, entire communities, even houses without an LLIN, can be made safer.
Killing Mosquitoes (Indoor Residual Spraying)
While LLINs are generally effective in Africa wherever they can be consistently used, sometimes specialized teams are organized to spray an insecticide on the inside walls of houses (a process known as Indoor Residual Spraying, or IRS). This helps kill the female mosquito after she feeds on a person, reducing malaria transmission to others. In some special circumstances, teams are also organized to eliminate or treat mosquito breeding sites with another type of environmentally-friendly insecticide. However, because the African malaria mosquitoes are so prolific and have such a broad range of breeding habits, this type of "larval control" may only be applicable in some areas, as determined by local assessment.
Artemisinin-based combination therapies (ACTs) are the most effective drugs currently available for treating malaria. New cheaper ACTs need to be developed and strategies to deliver them need to be implemented and evaluated so they can be accessed by the people who need them. The Bill & Melinda Gates Foundation and the Medicines for Malaria Venture are helping to develop new drugs; while the President's Malaria Initiative, Global Fund to Fight AIDS, Tuberculosis and Malaria, and the World Bank's Booster Program for Malaria Control in Africa are working with Ministries of Health on delivery and access issues.
In addition to artemisinin-based combination therapies, pregnant women can be helped by administering at least two monthly treatment doses of sulfadoxine-pyrimethamine (SP) during the second and third trimesters of pregnancy. More than 70 percent of pregnant women in Africa attend antenatal clinics at least once during their pregnancy. A regime of SP helps protect pregnant women from possible death and anemia and also prevents malaria-related low birthweight in infants, which causes about 100,000 infant deaths annually in Africa.
Whether it is around how to properly and consistently use a bed net, how to recognize the illness in a child and take appropriate measures (like administering new artemisinin-based combination therapies), how to protect pregnant women and unborn children, or the importance of indoor residual spraying, a large part of effort in the future will be directed at educating families in Africa about malaria. One of the most important early messages is that LLINs work. While there are other types of mosquitoes that bite during the day or early evening, the malaria mosquitoes bite late at night, and LLINs are far more cost effective than aerosols or burning mosquito coils. We envision creating kits and other tools to make the job of such on-the-ground education easier and more effective.
Development of a Vaccine
At the same time that we work to control malaria through available tools, we need to continue to support the development of a vaccine. As with any disease, finding a vaccine to protect individuals from malaria would create the best possible defense. Around the world, from Sweden to Kenya, from Australia to the United States, world class physicians are working on this important research. However, the malaria parasites have proven to be remarkably adaptable, meaning they change their characteristics as antibodies are developed; this adaptability has made finding a vaccine especially challenging. Most experts agree that the world is at least a decade away from any sort of effective vaccine. In the meantime, we need to concentrate on providing solutions for prevention and treatment that exist today.