Malaria

Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells. Symptoms of malaria include fever, headache, and vomiting, and usually appear between 10 and 15 days after the mosquito bite. If not treated, malaria can quickly become life-threatening by disrupting the blood supply to vital organs. In many parts of the world, the parasites have developed resistance to a number of malaria medicines.

According to the latest estimates, there were about 219 million cases of malaria in 2010 (with an uncertainty range of 154 million to 289 million) and an estimated 660 000 deaths (with an uncertainty range of 490 000 to 836 000). Malaria mortality rates have fallen by more than 25% globally since 2000, and by 33% in the WHO African Region. Most deaths occur among children living in Africa where a child dies every minute from malaria. Country-level burden estimates available for 2010 show that an estimated 80% of malaria deaths occur in just 14 countries and about 80% of cases occur in 17 countries. Together, the Democratic Republic of the Congo and Nigeria account for over 40% of the estimated total of malaria deaths globally.

Malaria is caused by Plasmodium parasites. The parasites are spread to people through the bites of infected Anopheles mosquitoes, called "malaria vectors", which bite mainly between dusk and dawn.

There are four parasite species that cause malaria in humans:

  • Plasmodium falciparum
  • Plasmodium vivax
  • Plasmodium malariae
  • Plasmodium ovale

Plasmodium falciparum and Plasmodium vivax are the most common. Plasmodium falciparum is the most deadly.

In recent years, some human cases of malaria have also occurred with Plasmodium knowlesi – a species that causes malaria among monkeys and occurs in certain forested areas of South-East Asia.

Early diagnosis and treatment of malaria reduces disease and prevents deaths. It also contributes to reducing malaria transmission. The best available treatment, particularly for P. falciparum malaria, is artemisinin-based combination therapy (ACT).

Nevertheless, resistance to antimalarial medicines is a recurring problem. Resistance of P. falciparum to previous generations of medicines, such as chloroquine and sulfadoxine-pyrimethamine (SP), became widespread in the 1970s and 1980s, undermining malaria control efforts and reversing gains in child survival.

CONTACT

For questions or interest in our research, please, contact with:

Carlota Dobaño, PhD
Barcelona Centre for International Health Research (CRESIB)
Hospital Clínic de Barcelona
Universitat de Barcelona
Rosselló 132, 4th floor
08036 Barcelona, Spain
SysMalVac@cresib.cat