Up to two million people die of malaria each year, most of them children under five. In Africa, malaria is the leading cause of death among young children, killing a child every 30 seconds.
There are about 500 million clinical cases of malaria each year, over 5 times as many as TB, Aids, measles and leprosy cases combined.
Of the approximately two million deaths each year from malaria, 90% occur in sub-Saharan Africa, approximately 4,500 deaths each day.
In many African countries, about 10% of hospital admissions and 20-30% of doctor’s visits are malaria-related. Pregnant women are at a high risk.
Malaria is even returning to areas of the world from which it had been eradicated, and is spreading to new areas such as Central Asia and Eastern Europe.
More people are now dying from malaria than thirty years ago.
Around 2.5 billion people (approx. 40% of the world’s population) are at risk in over 90 countries.
30 times as many people die each day from malaria as did the total number of people in the Zambian Ebola virus outbreak of 1995.
Reasons for the rise in the spread of malaria include:
• Decreased mosquito control efforts (insecticide spraying)
• Increasing drug resistance
• Increased migration and immigration
• Increase in size of endemic territories (e.g. people moving from countryside
to cities)
• Tourist and business travel (increased air travel since 1950s/60s)
• Deforestation and mining (development activities)
• Malaria is spreading to new territories for example, India, Brazil,
Sri Lanka, Turkey, and the Middle East.
Epidemiology
The malaria parasite is a microscopic organism called a Plasmodium and it
belongs to the group of tiny organisms known as protozoans.
There are four different species of malaria parasite. Plasmodium falciparum,
Plasmodium vivax, Plasmodium malaiae and Plasmodium ovale. Plasmodium falciparum
malaria is most common in Africa, south of the Sahara, accounting in large
part for the extremely high mortality in this region. There are also worrying
indications of the spread of P. falciparum malaria into new regions of the
world and its reappearance in areas where it had been eliminated.
The malaria parasite enters the human host when an infected female Anopheles
mosquito takes a blood meal. Inside the human host, the parasite undergoes
a series of changes as part of its complex life-cycle. Its various stages
allow plasmodia to evade the immune system, infect the liver and red blood
cells, and finally develop into a form that is able to infect a mosquito again
when it bites an infected person. Inside the mosquito, the parasite matures
until it reaches the sexual stage where it can again infect a human host when
the mosquito takes her next blood meal, 10 to 14 or more days later.
Malaria symptoms appear about 9 to 14 days after the infectious mosquito bite, although this varies with different plasmodium species. Typically, malaria produces fever, headache and vomiting. Several hours later, the fever subsides and a chill sets in. The cycle is repeated every 2 to 4 days. If drugs are not available for treatment or the parasites are resistant to them, the infection can progress rapidly to become life-threatening. Malaria can kill by infecting and destroying red blood cells (anaemia) and by clogging the capillaries that carry blood to the brain (cerebral malaria) or other vital organs. Progression from first symptom to death can be as little as 24 hours.