Malaria

Definition

Malaria is a parasitic disease that is transmitted by mosquitoes. It is caused by a species of parasite known as Plasmodium of which 4 types may cause malaria. Healthy individuals may get infected through mosquito bites if the mosquito had previously fed on the blood of an infected person. Repeated bouts of high fever along with shivering are typical symptoms of malaria.

Warmer areas, with stagnant water bodies that are favorable for mosquitoes, are the worst affected regions. Although considered curable, repeated episodes and delayed treatment may cause malaria to become fatal. Almost a million people worldwide die every year due to this disease. Owing to the increasing resistance of malaria-causing mosquitoes towards insecticides, the disease may become an uncontrolled epidemic.

Causes

The female Anopheles mosquito requires human blood proteins for its egg formation. While feeding on the blood of an infected individual, the mosquito picks up pathogen. When this infected mosquito bites a person, the Plasmodium parasite is released into the bloodstream along with its saliva.

The mosquito carries the infective stage of Plasmodium (sporozoite) and transmits it to humans. The parasite enters the bloodstream and is passed into liver to complete its stages of development. Once mature, these parasites (merozoites) are released into the bloodstream again which then infect red blood cells, where they divide and multiply. The infected red blood cells rupture within 48 to 72 hours to release the infective parasitic forms.

Although malaria is not contagious, contact with the blood of the infected person during blood transfusions, organ transplantation or sharing used needles may transmit the disease to healthy individuals. Young children and people having a compromised immune system are more prone to malarial infections. An unborn child could also contract congenital malaria from the infected pregnant mother.

Symptoms

Typical malarial symptoms become evident within 3 to 7 days after infection. However, there are certain Plasmodium types (P. vivax and P. ovale) that lay dormant in the liver and causes infection at a later stage.

Common early symptoms include:

  • High fever
  • Chills and shivering
  • Mild to severe headache
  • Nausea and vomiting

These symptoms have a cyclic presentation. They usually appear at a particular time of the day. The severity and duration of symptoms often depend on the stage of disease.

Later on, the symptoms may become gravid leading to:

  • Muscle pain
  • Back pain
  • Enlarged spleen
  • Enlarged liver

Malaria caused by Plasmodium falciparum, called falciparum malaria, leads to more severe symptoms as it typically affects the brain and its associated functions. Damage of red blood cells often reduces their number in the bloodstream, precipitating anemic conditions.

Malaria can be diagnosed with a blood tests along with the typical symptoms and the finding of an enlarged and spleen.

Treatment

Proper treatment administered within 24 hours of the appearance of first symptoms offer complete recovery in most malarial forms. However, falciparum malaria needs immediate hospitalization and in some cases can become medical emergency.

Medication

  • Quinone derivatives like choloroquine and primaquine are most widely used anti-malarial drugs.
  • Other drugs include artemisin derivatives, malarone and doxycycline.
  • Often a combination of quinine and antibiotics like doxycycline or tetracycline is also recommended.

Prevention

Infection can be prevented by:

  • Avoiding mosquito bites by keeping the body covered and using mosquito nets
  • Controlling mosquito population around our habitats
  • Preventive medications that hampers growth of the parasite, even upon infection

 

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