Fever and Ague: Malaria's Symptoms
People infected with malaria typically experience fever, shivering, pain in the joints, headache, vomiting, convulsions, and coma. Malaria is especially dangerous to pregnant women and small children. Different malarias produce fevers of varying frequency. Severe anemia is often the cause of death in endemic areas.
Anemia is a condition when a person doesn't have enough red blood cells, or hemoglobin, in the body. If hemoglobin is low, the blood can't carry enough oxygen to organs. Symptoms of anemia include weakness, faintness, shortness of breath, increased heart beat, headaches, sore tongue, nausea, loss of appetite, dizziness, bleeding gums, yellow eyes and skin, confusion, and dementia. Severe cases may have signs of heart failure.
Sickle cell anemia is a hereditary blood disorder that affects hemoglobin. Sickle-shaped cells clog blood vessels and keep oxygen from getting to the body's tissues and organs. Symptoms include pain in chest, stomach, arms, legs, and bones, jaundice, tiredness, slow growth in children and late onset of puberty. There is no cure for sickle cell anemia. Treatment may include vitamins, prevention of dehydration, and blood transfusions.
If not treated, the disease progresses to severe malaria. Malaria is especially dangerous to pregnant women and small children. Severe malaria results in coma, jaundice, kidney failure, severe anemia, and/or high parasite counts and should be treated in an intensive care unit where patients can be monitored closely.
Sickle Cell Anemia: Natural Resistance at a Price
Sickle cell anemia is a hereditary disease that affects molecules in the blood, resulting in sickle-shaped red blood cells. Individuals carrying one normal and one sick gene are called “heterozygous” carriers of the disease. They produce both normal and sickle-shaped blood cells because neither gene is dominant. It has been observed that heterozygous carriers of the disease rarely develop malaria.
It appears that sickle cell anemia occurs frequently in African populations as a result of earlier generations' exposure to malaria. In Central Africa, where malaria has been epidemic for a very long time, nearly 45 percent of the population (45 people out of 100) carry one gene for the sickle-cell trait that confers resistance to malaria. In the United States, 10 percent of African Americans are sickle-cell carriers. The presence of malaria worldwide continues the selection process and maintains the heterozygous sickle-cell population.
Malaria is diagnosed by its symptoms and microscopic examination of blood to identify the parasites in different stages of development. Ideally, blood should be collected when the patient's temperature is rising, as that is when the greatest number of parasites is likely to be found. Three consecutive days of tests that do not indicate the presence of the parasite can rule out malaria.
The presence of antibodies in the blood can help a physician determine whether a patient has been exposed to malaria, but it does not differentiate between present and past infections. In other words, the antibodies might have been present from a previous malaria infection that has since been cured, and so the presence of antibodies may indicate that a patient is reinfected, but it may not.
Rapid diagnostic tests for malaria are now available that allow the detection of antigens in a finger-prick blood sample in minutes, with sensitivity similar to that achieved by examination under a microscope. Easy-to-use dipstick tests that detect specific proteins and enzymes have the potential to enhance the speed and accuracy of diagnosis, particularly when tests are performed by untrained individuals.
Excerpted from The Complete Idiot's Guide to Dangerous Diseases and Epidemics © 2002 by David Perlin, Ph.D., and Ann Cohen. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.