Search
 Health Topics » Fever & Infection » Buzz Off !!   Login
  

  
  Fever & Infection

April 2011
Buzz Off !!
Dr Usha Srinivasan
 

About 3.3 billion people - half of the world's population - are at risk of malaria. Every year, this leads to about 250 million malaria cases and nearly one million deaths. People living in the poorest countries are the most vulnerable.


Malaria has been a disease that has persisted in India for centuries, so much so that even Ancient Indian medical literature like the Charaka Samhita also addresses it. Though India’s National Malaria Eradication Programme of 1958 was highly successful, it later suffered repeated setbacks due to technical, operational and administrative reasons and the cases started rising again. Malaria has now staged a dramatic comeback in India after its near eradication in the early and mid sixties.
   
The World Health Organisation observes 25th April as World malaria Day. The theme of the fourth World Malaria Day - Achieving Progress and Impact - heralds the international community's renewed efforts to assess progress towards zero malaria deaths by 2015.

What Causes Malaria?
Four species of the plasmodium parasite can infect humans; the most serious forms of the disease being caused by Plasmodium falciparum. The types of malaria caused by Plasmodium vivax, Plasmodium ovale and Plasmodium malariae are generally not fatal. The natural ecology of malaria involves malaria parasites infecting successively two types of hosts: humans and female anopheles mosquitoes.

In humans, the parasites grow and multiply first in the liver cells and then in the red cells of the blood. In the blood, successive broods of parasites grow inside the red cells and destroy them, releasing daughter parasites (merozoites) that continue the cycle by invading other red cells.

Pale Facts
Anaemia is caused when red blood cells are destroyed by the parasites, and is a common manifestation of all types of malaria.
  • It is more common and poses more problems for pregnant women and for children.
  • In developing countries of the tropics, pre-existing anaemia, most commonly due to malnutrition and helminthiasis (parasitic infection in children), compounds the problem.
  • In falciparum malaria, one of the deadliest forms, which is becoming increasingly resistant to anti-malarial drugs, anaemia can develop rapidly due to acute haemolysis.
  • The degree of anaemia correlates with parasitemia, a condition in which parasites are present in the blood.
  • It is also associated with high serum bilirubin (the bile pigment in the red blood cells), and creatinine (a component in our blood dependent on muscle mass which is flushed out by the kidneys) levels.
  • Pregnancy, secondary bacterial infections and bleeding disorders like disseminated intravascular coagulation can aggravate the anaemia.
  • Children may have severe anaemia even with low parasitemia and in such cases the reticuloendothelial cells (or the immune system) exhibit abundant malarial pigments.
  • Thus, anaemia in malaria is multi-factorial. The causes include obligatory destruction of red cells at merogony (asexual division of parasites), accelerated destruction of non-parasitised red cells, bone marrow dysfunction that can persist for weeks, shortened red cell survival and increased clearance from the spleen.
  • Massive gastrointestinal haemorrhage can also contribute to the anaemia of malaria.
5 Repercussions
  1. When malaria brings about fever, vomiting and nausea come along. Treatment with antimalarials, especially chloroquine may lead to nausea and vomiting.
  2. Some patients have gastrointestinal haemorrhage and may vomit blood (haematemesis).
  3. Enlargement of the liver and spleen can also occur, which can be deduced through examination.
  4. Jaundice is common in falciparum malaria. Most often it is caused by haemolysis (rupturing of red blood cells, releasing the haemoglobin into the surrounding) and accordingly, there is elevation of the unconjugated bilirubin levels.
  5. Liver dysfunction may also be seen in cases of severe falciparum malaria. Such patients have:
  6. • Conjugated hyperbilirubinemia.
    • Marked elevations of aspartate aminotransferase and alanine aminotransferase and prolongation of prothrombin.
    • Massive haemolysis.
    • Disseminated intravascular coagulation.
Occasionally, malaria patients become comatose due to cerebral malaria and with a setting of jaundice, may mimic viral hepatitis with fulminant hepatic failure (the severe impairment of liver functions in the absence of pre-existing liver disease). The enlarged spleen may rupture, presenting as severe abdominal pain, requiring emergency surgery.

It Can Be Treated
These findings alone do not imply severe liver dysfunction in malaria. Clinical signs of liver failure are never due to malaria and in such cases, other associated hepatic diseases, like viral hepatitis, should be considered. The mild elevation in serum bilirubin and enzyme levels usually return to normal within three to five days of effective antimalarial treatment. No other specific treatment is needed.

To sum it up, malaria can present the gastroenterologist with multiple challenges of anaemia, jaundice, enlarged liver and spleen – at times as an emergency as in cases of encephalopathy (a brain disease) and rupture of the spleen. It is necessary to identify the exact condition, as malaria can be completely treated.
 

Dr. Usha Srinivasan is Sr. Consultant Medical Gastroenterologist at Apollo Hospitals, Chennai


    
 Also See