Malaria is a life-threatening, infectious disease caused by a protozoa (unicellular microorganism belonging to the genus Plasmodium).
What are the other Names for this Condition? (Also known as/Synonyms)
- Biduoterian Fever
- Black Water Fever
- Quartan Malaria
What is Malaria? (Definition/Background Information)
- Malaria is a life-threatening, infectious disease caused by a protozoa (unicellular microorganism belonging to the genus Plasmodium). There are 4 types of protozoan parasites, which cause the condition in humans
- It is spread by mosquitoes (specifically by the female Anopheles mosquito) to humans and others animals. Malaria is very prominent during rainy seasons, since mosquitoes breed in larger numbers, during this season
- The intensity of the disease is dependent on the Plasmodium type that infects, the health status of the individual, the transmission vector, and the environment
- Malaria is normally diagnosed using a blood test, and prescription anti-malarial medications form the usual line of treatment
Who gets Malaria? (Age and Sex Distribution)
- Malaria infects all individuals, irrespective of age, gender, and race
- The disease is especially observed among people, who live in the tropical and sub-tropical areas of Asia, Africa, Central and South America
- However, certain African individuals with a particular blood group, called Duffy positive, are immune to Malaria
What are the Risk Factors for Malaria? (Predisposing Factors)
Following are the risk factors for Malaria:
- Living in or visiting tropical areas, where Malaria is endemic
- Young children and infants carry a higher risk of contracting the disease
- Pregnant women and their unborn children are higher prone to Malaria (vertical transmission)
- Individuals travelling from non-endemic places (where Malaria is non-existent), to the tropical/sub-tropical regions, carry a much higher percentage of risk
- Individuals with very weak immune system, such as those suffering from HIV, AIDS infection
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Malaria? (Etiology)
Malaria is caused by any of the 4 parasitic species of Plasmodium (protozoans), which include:
- Plasmodium vivax
- Plasmodium falciparum
- Plasmodium malariae
- Plasmodium ovale
Among these the vivax and falciparum species are the most common, and Plasmodium falciparum transmits the most deadly form of Malaria. The parasites enter the bloodstream and infect the red blood cells.
It spreads in the human body by the bite of an infected female Anopheles mosquito. These mosquitoes breed in large numbers, in open water bodies (like ponds, water puddles, fields), when the temperature and humidity conditions are also favorable.
What are the Signs and Symptoms of Malaria?
The most common signs and symptoms of Malaria, which appear 1-2 weeks after being bitten by the infected mosquito, include:
- Moderate to severe chills, and high fever (these are the first non-specific symptoms that appear)
- Paroxysm (sudden attack) of fever rigors, chills, and sweats, every 48 or 72 hours
- Arthralgia (joint pains)
- Nausea, vomiting, and diarrhea
- Muscle ache
Individuals infected with severe Plasmodium falciparum Malaria may develop bleeding problems, liver/kidney failure, shock, problems affecting the central nervous system, and may move into a coma state. These complications can be lethal, if proper treatment is not administered.
How is Malaria Diagnosed?
A diagnosis of Malaria would involve the following:
- A blood smear test is performed to visualize the parasites in the red blood cells, under a microscope
- Quantitative buffy coat (QBC) is a lab blood analysis technique to detect Malaria. But, with this test, the species identification (Plasmodium type causing infection) cannot be established
- Rapid Diagnostics Test: It is a blood test to analyze malarial antigens formed in the body. However, these are more expensive and not as widely available, as the blood smear test
In addition to the above, the following tests may help determine the extent of various organ involvements by malarial infection. These include:
- Dipstick test of urine
- Liver function test
- Kidney function test
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Malaria?
Malaria can cause the following complications:
- Breathing difficulties, due to lung inflammation
- Organ failure: Kidney failure, or liver failure, or splenic rupture, which can be fatal
- Severe anemia, since the red blood cells are primarily infected
- Low blood sugar resulting in coma or death
- Cerebral Malaria due to Plasmodium falciparum infection
With cerebral Malaria, the blood vessels to the brain are blocked; the brain swells, resulting in brain damage. Seizures and other neurological abnormalities may cause the individual to go into a coma state. If the condition is not treated quickly, it could result in death. Despite treatment, there is a 15-20% mortality rate.
How is Malaria Treated?
Malaria is treated using oral drugs or drugs that are administered intravenously. The World Health Organization notes that the protozoan parasites are becoming increasingly resistant to anti-malarial drugs, which is a challenging problem. The treatment of an individual, and the type of drug used, is based on the following parameters:
- The individual’s age, health status, other underlying medical conditions (including pregnancy), drug allergies, etc.
- Plasmodium type causing the infection
- Region or location where Malaria is contracted
- The drug resistance status of the region
The following are the common drugs used (in combination or as a single drug) to treat Malaria:
- Chloroquine is the drug of choice. In areas with chloroquine-resistant malarial strains, other drugs or combination drugs, may be used
- Quinine sulfate
- A combined dose of atovaquone and proguanil
- Primaquine is used to eradicate the parasite from the liver. Some strains of Plasmodium (ovale and vivax) may cause a relapse after a few weeks (due to their reactivation), if liver-targeted therapy is not utilized to eliminate them
Artemisinin-derived combination therapy (ACT): It is a worldwide standard treatment using combination drugs, specifically for (uncomplicated) Malaria due to P. falciparum.
How can Malaria be Prevented?
Malaria is a vector-borne disease, which is preventable. The following measures are useful in controlling transmission of the condition:
- Sleeping under mosquito nets (insecticide-treated mosquito nets) is a highly recommended practice in endemic areas
- Use mosquito repellent creams. It is also advisable to cover your skin by wearing clothes, such as full-length pants, full-sleeved shirts, etc.
- Maintain good sanitary conditions, to prevent mosquitoes from breeding. When possible, eliminate all potential mosquito habitats that contain standing water, where mosquitoes breed and lay their eggs, like water contained in temporary pools, old tires, discarded vessels, birdbaths, pots, rainwater puddles, etc.
- Sprays containing permethrin can be used on clothes; sprays containing DEET can be used on the skin
- Individuals who travel from a non-endemic region to a Malaria-endemic region have to ensure that they are aware of the risk factors and basic preventive methods
Exposure to mosquito bites may be reduced if people are aware of biting patterns of the mosquitoes. The Malaria-transmitting mosquitoes are most active during twilight and in the night. Avoiding outdoors to the extent possible or employing preventive actions during peak ‘biting’ hours may reduce risk.
What is the Prognosis of Malaria? (Outcomes/Resolutions)
- Malaria, with early diagnosis and proper treatment using suitable anti-malarial drugs, is completely curable
- Non-treatment of Malaria may lead to death, especially if the infection agent is Plasmodium falciparum
- It is estimated that about 10-40% of the individuals affected by Malaria die, even with the best medical treatment
- Even with treatment, there are chances of relapse, within a few weeks to months of initial occurrence, if Malaria is caused by Plasmodium vivax or P. ovale
Additional and Relevant Useful Information for Malaria:
- According to WHO, Malaria is a giant-killer with a potential to affect over 50% of the global population
- Children living in sub-Saharan Africa accounted for over 85% of the estimated 660,000 deaths that occurred worldwide, in the year 2010
What are some Useful Resources for Additional Information?
World Health Organization (WHO)
Avenue Appia 20 1211 Geneva 27, Switzerland
Phone: + 41 22 791 21 11
Fax: + 41 22 791 31 11
Centers for Disease Control and Prevention (CDC)
1600 Clifton Rd. Atlanta, GA 30333, USA
Phone: (404) 639-3534
Toll-Free: 800-CDC-INFO (800-232-4636)
TTY: (888) 232-6348
References and Information Sources used for the Article:
http://www.malaria.com/overview/malaria-symptoms-causes (accessed on 08/08/2012)
http://www.mayoclinic.com/health/malaria/DS00475/DSECTION=risk-factors (accessed on 08/08/2012)
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001646/ (accessed on 08/08/2012)
http://www.cdc.gov/malaria/about/index.html (accessed on 08/08/2012)
http://wwwnc.cdc.gov/travel/content/yellowbook/home-2010.aspx (accessed on 08/08/2012)
http://www.nvbdcp.gov.in/malaria-new.html (accessed on 08/08/2012)
http://www.nlm.nih.gov/medlineplus/tutorials/malaria/htm/index.htm (accessed on 08/08/2012)
http://www.who.int/mediacentre/factsheets/fs094/en/ (accessed on 08/08/2012)
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