Malaria

Definition

Malaria is an infectious disease where there are cycles of fever and chills. It is caused by a parasite known as Plasmodium, which is transmitted by certain mosquitoes. It is prevalent in tropical and sub-tropical regions of the world. Malaria is a serious infection that is often life threatening in developing nations without proper medical treatment accessible to high risk groups.

Symptoms

The symptoms of malaria can occur a few weeks after the initial infection. The symptoms are as follows :

  • Chills
  • High fever
  • Sweating, when the fever subsides

These symptoms occur in a cyclic manner repeating over 1 to 3 days depending upon the strain of the Plasmodium parasite contracted by the person. Other symptoms can include headache, body pain, nausea, vomiting, diarrhea or severe anemia. Malaria may also cause jaundice (yellowing of skin).

Severe complications can develop but usually only with an infection by Plasmodium falciparum, one of the four species of the malaria parasite. These complications include, shock, liver or kidney failure. Cerebral malaria, usually lethal, can also occur.

Causes

Malaria is caused by the infection of a parasite, Plasmodium. Four species of PlasmodiumP.vivax, P. ovale, P. malariae and P. falciparum – can cause malaria and the most serious disease is caused by Plasmodium falciparum.

Malaria parasites are transmitted to a healthy person by the bite of an infected Anopheles mosquito. The mosquito picks up the parasite by feeding on another infected person. The parasite completes a part of its life cycle in the mosquito. When bitten by an infected mosquito, the parasite enters the bloodstream of the person in its sporozoite form which then travels to the liver. Upon maturation to mesozoites in the liver, it is again released into the bloodstream. The parasite can also lie dormant in the liver for a long time. When circulating in the blood stream, it infects the red blood cells and destroys it.

The parasite can also be transmitted from mother to her unborn child, by injection using infected syringes or transfusion of infected blood. It is prevalent in tropical and sub-tropical regions. It can be present in the temperate regions but the parasite does not usually survive winter in these environments.

Treatment

Chloroquine is used to treat malaria, however some parasites are resistant to choloroquine. The treatment is then altered to one of the following :

  • Quinine in combination with other antibiotics – doxycycline, tetracycline or clindamycin
  • Atovaquone along with proguanil
  • Mefloquine or artesunate
  • Pyrimethamine and sulfadoxine in combination

The treatment usually depends upon the part of the world where the infection occurred. In severe cases hospitalization is required where other medications and additional fluids are administered intravenously, depending upon the requirements of the patient.

People living in the areas where malaria is prevalent have partial immunity towards malaria because of repeated exposure to the parasite, however, people travelling to these areas have no immunity towards the disease. Therefore prevention of malaria is important. There is no known vaccine yet to prevent malaria. However, preventive medication can be taken before, during and after travel to places where malaria is prevalent. Medication will again depend on the place of travel. Further precautions should be taken by using mosquito repellents, wearing long protective clothing and sleeping under a net.

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