What is malaria?

Malaria is a potentially fatal disease caused by parasites. To find out more, see our full detailed fact sheet below:

 What is malaria?

Malaria is a potentially fatal disease caused by parasites. Parasites of the genus Plasmodium are transmitted by infected Anopheles mosquitoes, which usually bite at night.

The disease occurs mainly in tropical regions of Africa and South-East Asia. However, it can also be found in many countries, such as Mexico, Central and South America, the Middle East, Turkey, Pakistan, India and several Asian countries such as China.

There are four types of human malaria. The two most common are Plasmodium falciparum (the most deadly) and Plasmodium vivax. There is also Plasmodium malariae and Plasnmodium ovale.

Malaria can be cured. With proper treatment, the parasites can be completely eliminated from the body of the person affected. The parasite types, P. vivax and P. ovale have stages of the parasite that can remain in the liver without causing symptoms.

If not treated with the right treatment, and the right dosage, these stages can be reactivated and cause a relapse of the disease, even after several months or years. The P. malariae type can also remain in the blood for decades if left untreated.

In recent years, monkey malaria (Plasmodium Knowles), has been recorded in humans in some forests in South-East Asia.

Malaria transmission

Anopheles mosquitoes become infected when they bite a person with malaria. The small amount of blood they take contains parasites. These mix with their saliva and are in turn injected into the next person they bite.

In the human body, the parasites reach the liver and can remain there dormant for several days to several months (depending on the parasite involved).

When the parasites mature, they attack the blood cells. This is when people experience the symptoms of malaria.

Because the parasite is present in blood cells, malaria can also be transmitted through blood transfusions, organ transplants or sharing contaminated needles.

Malaria can also be transmitted from a pregnant mother to her child, either before or during birth.

 Malaria: how is it diagnosed?

In order to ascertain the presence of malaria, a diagnostic test can be carried out. A drop of blood analysed under a microscope can identify the presence of the parasite.

Rapid diagnostic tests, in the form of test strips, detect specific antigens produced by malaria parasites and present in the blood.

These tests are usually used in the field by travellers or small organisations to quickly and efficiently assess populations affected by the disease.

 Malaria: who is affected?

According to a World Health Organization (WHO) report1, there were nearly 216 million episodes of malaria in 2010, 81% of which occurred in Africa and 13% in South-East Asia.

In 2010, deaths associated with malaria are estimated at 655,000, 91% of which were in various parts of Africa and most of which were children under 5 years of age.

According to the WHO, since 2000, malaria mortality rates are estimated to have declined by more than 25% worldwide and by 30% in Africa.

This progress has been made possible by measures to combat and prevent malaria in malaria-affected areas: the widespread use of mosquito nets, improved diagnostic tools and better availability of antimalarial drugs.

Since 2008, 25 April has been declared World Malaria Day to raise awareness of the global effort needed to effectively combat this disease.

 Malaria: possible complications

Most malaria-related deaths are due to the consequences of complications of the disease; it is estimated that 90% of malaria deaths occur in Africa, especially in children under 5 years of age.

Brain damage (neuromalaria)

When blood cells infected with the parasite reach the brain, resulting in delirium, loss of consciousness, coma or death.

Pulmonary oedema

A build-up of fluid in the lungs that can lead to severe breathing problems.

Organ failure

Such as kidney or liver failure or rupture of the spleen which can cause death.

Severe anaemia

Caused by the destruction of infected red blood cells.

Drop-in blood sugar

Due to some severe forms of the disease, it can cause coma or death.

Recurrent episodes

Some strains of the malaria parasite, which usually cause milder forms of the disease, can persist in the body for years and cause relapses.

Malaria: symptoms

Symptoms appear between 10 and 15 days after the bite of the infected insect. Some types of malaria parasite (Plasmodium vivax and Plasmodium ovale) can remain inactive in the liver for weeks or even months before the first signs appear.

Malaria is characterised by recurrent attacks with three phases:

• chills ;
• headache; and
• fatigue and muscle pain;
• nausea and vomiting;
• diarrhoea (occasionally).

An hour or two later :

• high fever;
• skin becomes hot and dry.

Then the body temperature drops:

• profuse sweating;
• fatigue and weakness;
• the affected person falls asleep.

Malaria infections with P. vivax and P. ovale can relapse weeks or even months after the first infection, even if the patient has left the area of infection. These new episodes are due to "dormant" hepatic forms.

Some people are more likely to develop malaria. Also, there are risk factors for developing the disease.

Find out about them here.

 Malaria: people at risk

• Travellers

Children or adults who come from countries where malaria is not present and who have therefore not developed immunity.

• Residents of areas where malaria is present

They may be frequently exposed to the disease, so they develop partial immunity, which may reduce the severity of symptoms. However, this immunity may be lost by moving to a country where the parasite is absent.

• Other

Pregnant women and their unborn children;

• People with HIV/AIDS;
• people who receive blood transfusions (rarely).
•  Malaria: risk factors

Living in or visiting tropical areas where malaria is common and where the strains present to cause the most deaths, for example:

• African countries south of the Sahara Desert;
• countries on the Indian subcontinent;
• Solomon Islands, Papua New Guinea and Haiti.

There are certain preventive measures that can be taken to prevent the contraction of malaria.

Find out about them in this fact sheet.

 Malaria: preventive measures

• Why prevent malaria?

If not treated within 24 hours, Plasmodium falciparum malaria can lead to severe and often fatal complications.

Malaria is a preventable and curable disease.

Non-immune travellers from malaria-free areas are very vulnerable to the disease when they become infected.

• Basic preventive measures

Preventive medication

If you are planning to travel to an area where malaria is present, medicines can be taken a few days or weeks before, during and after your trip. They protect against malaria parasites.

Reducing exposure to mosquitoes

Using insect repellents (those containing DEET 20% to 35% or Picaridin 20%) are the most effective) to spray the walls of houses, clothes or skin.

Other measures:

• sleep under a mosquito net impregnated or not with insecticide (permethrin);
• cover the skin by wearing trousers and long sleeves after dark;
• avoid going out from sunset to dawn.

Measures to prevent aggravation

If symptoms of the disease are experienced after travelling to a malaria-affected country, it is best to have a diagnostic test carried out without delay, as the consequences of the disease can be fatal.

Malaria: treatments

Chloroquine is the cheapest and most widely used treatment for malaria. However, in many areas, especially in Africa, the parasites have become resistant to the most common drugs. This means that the drugs used are no longer effective in curing the disease.

Some drugs, based on artemisinin, are used intravenously and exceptionally in very severe cases.

A promising natural antimalarial

Artemisinin, a substance isolated from natural mugwort (Artemisia annua), has been used for various infections in Chinese medicine for 2000 years. Chinese researchers first became interested in it during the Vietnam War, when many Vietnamese soldiers were dying of malaria after spending time in mosquito-ridden swamps.

However, the plant was known in certain Chinese regions and was administered in the form of tea at the first signs of malaria. The Chinese physician and naturalist Li Shizhen discovered its effectiveness in killing Plasmodium falsiparum in the 16th century. In 1972, Professor Youyou Tu isolated artemisinin, the plant's active substance.

In the 1990s, when parasites were becoming more resistant to conventional drugs such as chloroquine, artemisinin offered new hope in the fight against the disease. Artemisinin weakens the parasite, but does not systematically kill it. It was first used alone, then in combination with other antimalarial drugs. Unfortunately, resistance is gaining ground and since 20094, there has been an increase in the resistance of P. falciparum to artemisinin in certain regions of Asia. A constant battle to be renewed.

Resistance to antimalarial drugs

The emergence of drug resistance in malaria parasites is a worrying phenomenon. Not only does malaria cause a significant number of deaths, but ineffective treatment can have significant consequences for the long-term elimination of the disease. Poorly chosen or interrupted treatment prevents the parasite from being completely eliminated from the infected person's body. The surviving parasites, less sensitive to the drug, reproduce. Through very rapid genetic mechanisms, subsequent generations of strains become resistant to the drug. The same phenomenon occurs in mass drug administration programmes in highly endemic areas. The doses administered are often too low to kill the parasite, which then develops resistance.

Malaria, when will there be a vaccine?

No vaccine against malaria is currently approved for human use. The malaria parasite is an organism with a complex life cycle and its antigens are constantly changing. Many research projects are currently underway internationally. Of these, the most advanced is in clinical trials (phase 3) for the development of a vaccine against P. falciparum (the RTS, S/AS01 vaccine) aimed at babies aged 6-14 weeks2.

 Malaria: the opinion of Dr Jacques Allard

"Malaria is a disease that is usually very treatable, but it is always very trying and can sometimes be fatal. It is, therefore, best to prevent it. If you are planning to travel to a country where malaria is endemic, first consult your doctor or a Clinique du Voyageur (in Quebec) to obtain a prescription for an anti-malarial drug for prevention. Furthermore, if you develop a high fever and chills during your stay abroad or even several months after your return, consult a doctor quickly because the complications can be very serious.

Dr. Jacques Allard M.D. FCMFC

In the case of malaria, there are complementary approaches to treat it in a more natural way.

See the list here.

 Malaria: complementary approaches

Eucalyptus

For travellers and residents of countries affected by malaria, it is recommended to protect the skin with insect repellents. Lemon eucalyptus (E. citriodora) essential oil is a traditional remedy for repelling biting insects5 that may have similar efficacy to insect repellents containing DEET.

Vitamin A

Vitamin A is thought to reduce fever, blood parasite levels and mortality in people infected with Plasmodium falciparum. Vitamin A is thought to be an effective and inexpensive way to control the parasite3.  However, there is still insufficient research to prove that vitamin A is equivalent or superior in efficacy to drugs used in the prevention or treatment of malaria.

Here you can find additional information and contact communities or support groups to learn more about the disease.

 Malaria: Sites of interest

International UNICEF Malaria dossier. www.unicef.org

World Health Organization (WHO) Numerous articles on malaria control strategies. www.who.int

Canada Public Health Agency of Canada Frequently asked questions about malaria, fact sheets on travel

 health. www.santepublique.gc.ca

Canadian International Development Agency Canada's contribution to malaria control and prevention.

 www.acdi-cida.gc.ca

France National Malaria Reference Centre for metropolitan France

Annual reports, publications and practical information. www.cnrpalu-france.org

PLAN France Child-centred development non-governmental organisation.

 www.luttercontrelepaludisme.fr