Basic Information on 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. Key interventions to control malaria include:prompt and effective treatment with artemisinin-based combination therapies; use of insecticidal nets by people at risk; and indoor residual spraying with insecticide to control the vector mosquitoes.

Transmission of Malaria

We get malaria by being bitten by an infected female Anopheles mosquito. Only Anopheles mosquitoes can transmit malaria and they must have been infected through a previous blood meal taken on an infected person. When a mosquito bites, a small amount of blood is taken in which contains the microscopic malaria parasites.The parasite grows and matures in the mosquito’s gut for a week or more, then travels to the mosquito’s salivary glands. When the mosquito next takes a blood meal, these parasites mix with the saliva and are injected into the bite. Once in the blood, the parasites travel to the liver and enter liver cells to grow and multiply. During this “incubation period”, the infected person has no symptoms. After as few as 8 days or as long as several months, the parasites leave the liver cells and enter red blood cells. Once in the cells,they continue to grow and multiply. After they mature, the infected red blood cells rupture, freeing the parasites to attack and enter other red blood cells. Toxins released when the red cells burst are what cause the typical fever,chills, and flu-like malaria symptoms. If a mosquito bites this infected person and ingests certain types of malaria parasites (“gametocytes”), the cycle of transmission continues.

Because the malaria parasite is found in red blood cells, malaria can also be transmitted through blood transfusion, organ transplant, or the shared use of needles or syringes contaminated with blood.Malaria may also be transmitted from a mother to her fetus before or during delivery (“congenital” malaria).

Malaria is not transmitted from person to person like a cold or the flu. You cannot get malaria from casual contact with malaria-infected people.

Prevention from Malaria

You and your family can prevent malaria by

Keeping mosquitoes from biting you, especially at night
Taking anti malarial drugs to kill the parasites (as per registered medical practitioner advice)
Eliminating places around your home where mosquitoes breed
Spraying insecticides on your home’s walls to kill adult mosquitoes that come inside
Sleeping under bed nets – especially effective if they have been treated with insecticide, and
Wearing insect repellent and long-sleeved clothing if out of doors at night

Symptoms and Diagnosis

Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells. Infection with one type of malaria, Plasmodium falciparum, if not promptly treated, may cause kidney failure, seizures,mental confusion, coma, and death.

For most people, symptoms begin 10 days to 4weeks after infection, although a person may feel ill as early as 7 days or as late as 1 year later. Two kinds of malaria, P. vivax and P. ovale,can relapse. In P. vivax and P. ovale infections, some parasites can remain dormant in the liver for several months up to about 4years after a person is bitten by an infected mosquito. When these parasites come out of hibernation and begin invading red blood cells (“relapse”), the person will become sick.

Most people, at the beginning of the disease,have fever, sweats, chills, headaches, malaise, muscles aches, nausea and vomiting. Malaria can very rapidly become a severe and life-threatening disease. The surest way for you and your health-care provider to know whether you have malaria is to have a diagnostic test where a drop of your blood is examined under the microscope for the presence of malaria parasites. If you are sick and there is any suspicion of malaria (for example, if you have recently traveled in a malaria-risk area) the test should be performed without delay.

Malaria Drugs

Once diagnosed as malaria, either on a clinical or parasitological basis, the patient should be treated early with a safe and effective antimalarial medicine, the Roll Back Malaria goal being effective treatment within 24 hours of the onset of symptoms. This is because a delay in treatment of uncomplicated malaria, specially in the non-immune patient could result in progression to severe disease which is associated with a high case fatality rate.

The management of clinical malaria includes treatment with an antimalarial medicine which should be consistent with the national treatment policy, and also supportive therapy, and referral to appropriate health facilities.

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The writer enjoys medical education and has special interest in community medicine.