The Mosquito | The Parasite | Uncomplicated Malaria | Severe Malaria
Malaria is an infectious disease that, despite being preventable and treatable, threatens the lives of 3.3 billion people around the world. Every year malaria accounts for 660,000 deaths, the majority of which are in Sub-saharan Africa where a child dies every minute from malaria. High maternal mortality, low birth weight and maternal anaemia are also consequences of this devastating disease.
The malarial parasite is transmitted by the Anopheles mosquito. Symptoms include fever, headache, vomiting and other non specific flu-like symptoms. If suitable drugs are not administered quickly or there is parasite resistance to treatment, the infection can result in life-threatening anaemia, coma and death.
Besides its shattering impact on families and communities, malaria also influences economies and societies; reducing productivity and hindering young people’s education. This widespread disease is both a cause and a result of poverty, making it imperative that it should be controlled so that affected economies can develop and grow.
Malaria can be easily prevented, diagnosed and treated. An estimated US$ 5.1 billion is needed every year between 2011 and 2020 to achieve universal access to malaria interventions. At present, only US$ 2.3 billion is available, less than half of what would be needed.
WHO, World Malaria Report 2012
Malaria is transmitted through the bite of an infected female Anopheles mosquito, which usually feeds between sunset and sunrise. The Anopheles itself becomes infected by taking in parasites after feeding on infected human blood. The parasites then develop inside the mosquito and about a week later can be transferred to a new host when the mosquito feeds again.
Plasmodium is the malaria parasite that infects human cells. There are five species of the human Plasmodium parasite: P. falciparum, P. vivax, P. ovale, P. malariae
and P. knowlesi. P. falciparum
is the strain that causes the most severe, life threatening malaria cases. The parasite, once injected into the human host, resides in the liver for between two weeks and several months before multiplying within the red blood cells and causing the first symptoms of malaria.
For an animated illustration of the malaria life cycle and how the mosquito, parasite and human body contribute to its spread, click here
Uncomplicated malaria is the most common and widespread presentation of the disease. While it is not immediately life-threatening, it requires prompt treatment as if the P. falciparum parasite is present, it can develop into severe malaria.
The classic symptoms of malaria consist of bouts of fever that coincide with parasites bursting out of red blood cells, chills, sweats, headaches, muscle aches, nausea and vomiting.
Severe malaria occurs when infections, most commonly P.falciparum, are complicated by serious organ failures or abnormalities in the patient’s blood or metabolism.Pregnant women and children are particularly vulnerable to severe malaria .
Symptoms vary by geographical distribution and age. In Africa, particularly in children, symptoms include severe anaemia, fever and convulsions, problems with breathing, cerebral malaria, extreme weakness, hypoglycaemia, circulatory collapse, oedema, septicaemia, and occasionally kidney failure and coma. Even of those who have made it to hospital, around one fifth of patients die of severe malaria.