How many people are affected?
Every year, more than 500 million people become severely ill with malaria and up to one million people die. Half the world’s population is at risk, in more than 100 tropical countries. Most cases and deaths are in sub-Saharan Africa, followed by South East Asia.
How is malaria spread?
Malaria is mainly transmitted by female anopheles mosquitoes, with bites occurring between dusk and dawn. Malaria can also be spread through contaminated blood transfusions and from pregnant women to their foetus. Congenital malaria is more common in a first pregnancy.
No vaccine exists yet, but prevention measures can be reasonably effective. People living in areas with endemic malaria will often have developed some immunity to the disease.
Who is most at risk?
Pregnant women and infants. Pregnant women have lower immunity. This makes malaria a major cause of sickness and death among pregnant women and new mothers. Around 50 million women living in countries with endemic malaria become pregnant each year, and an estimated 10,000 of these women and 200,000 of their infants die as a result of malaria infection during pregnancy. Severe malarial anaemia contributes to more than half of these deaths.
Infection during pregnancy can lead to premature delivery, miscarriages and low birth weight infants. Low birth weight is especially dangerous – it is the greatest risk factor for deaths in the first month of life, and a major contributor to deaths in the under fives.
90% of malaria deaths occur in children under the age of five. Young children in endemic areas are particularly at risk because they have not yet built up any immunity. Severe malaria also develops very quickly in young children and can cause death within 24 hours if not treated.
- People caught in emergencies. Natural disasters and conflict can displace large numbers of people with no previous or limited exposure to malaria into new locations where malaria is prevalent. They will have less immunity than people who have grown up in an endemic area.
- People affected by climate change. In coming years climate change is set to bring changes in temperature and surface water that will affect the life cycle of mosquitoes and the range of areas they can live. This means mosquitoes may spread malaria to previously unaffected areas, putting millions more people at risk.
- People living with HIV have an increased risk of contracting malaria. Being HIV-positive can also reduce the effectiveness of malaria treatment.
Which countries are most affected?
Malaria has been brought under control and even eliminated in much of Europe, the Americas and parts of Asia. But it remains endemic in many African countries and a serious problem in many parts of South East Asia. Africa accounted for over 90% of malaria deaths in 2006.
Learn more about preventing and treating malaria.
Last modified: 13/01/2011
