A disease caused by the presence of the sporozoan Plasmodium in human or other vertebrate erythrocytes, usually transmitted to humans by the bite of an infected female mosquito of the genus Anopheles that previously sucked blood from a person with malaria.” Malaria is a preventable and treatable disease.
If malaria is diagnosed and treated early on, the duration of the infection can be considerably shortened, which in turn reduces the risk of complications and death.
Human infection begins with the exoerythrocytic cycle in liver parenchyma cells, followed by a series of erythrocytic schizogenous cycles repeated at regular intervals; production of gametocytes in other erythrocytes provides future gametes for another mosquito infection; characterized by episodic severe chills and high fever, prostration, occasionally fatal termination.
According to WHO (World Health Organization), the majority of Malaria deaths occur among children in sub-Saharan Africa, killing an African child every 30 seconds. Not only is Malaria associated with poverty, it is also a cause of poverty and an important obstacle to economic development.
There are five types of Malaria:
(1) Plasmodium vivax (P. vivax) - milder form of the disease, generally not fatal. However, infected people still need treatment because their untreated progress can also cause a host of health problems. This type has the widest geographic distribution globally. About 90% of infections in India are due to P. vivax. This parasite has a liver stage and can remain in the body for years without causing sickness. If the patient is not treated, the liver stage may re-activate and cause relapses - malaria attacks - after months, or even years without symptoms.
(2) Plasmodium malariae (P. malariae) - milder form of the disease, generally not fatal. However, the infected human still needs treatment because no treatment can also lead to a host of health problems. This type of parasite has been known to stay in the blood of some people for several decades.
(3) Plasmodium ovale (P. ovale) - milder form of the disease, generally not fatal. However, the infected human still needs to be treated because it may progress and cause a host of health problems. This parasite has a liver stage and can remain in the body for years without causing sickness. If the patient is not treated, the liver stage may re-activate and cause relapses - malaria attacks - after months, or even years without symptoms.
(4) Plasmodium falciparum (P. faliparum) - the most serious form of the disease. It is most common in Africa, especially sub-Saharan Africa. Current data indicates that cases are now being reported in areas of the world where this type was thought to have been eradicated.
(5) Plasmodium knowlesi (P. knowlesi) - causes malaria in macaques but can also infect humans.How does a human become infected with Malaria?
The female Anopheles mosquito transmits the parasite to a human when it takes a blood meal - it bites the human in order to feed on blood. Only the female Anopheles mosquito can transmit malaria, and it must have been infected through a previous blood meal taken from an infected human. When the mosquito bites an infected person a minute quantity of the malaria (plasmodium) parasite in the blood is taken. Approximately one week later that same infected mosquito takes its next blood meal. The plasmodium parasites mix with the mosquito's saliva and are injected into the host (human being).
Human-to-human transmission of Malaria
As the parasite exists in human red blood cells, malaria can be passed on from one person to the next through organ transplant, shared use of needles/syringes, and blood transfusion. An infected mother may also pass malaria on to her baby during delivery (birth) - this is called 'congenital malaria'.
You cannot catch Malaria by just sitting next to an infected person, or breathing in next to them when they cough and sneeze.
What are the symptoms of Malaria?
In areas where Malaria is endemic people may have immunity or semi-immunity, and therefore have either no symptoms or few symptoms. The severity of the Malaria depends on three things: 1. The type of parasite. 2. Your immunity. 3. Whether you still have your spleen.
- Early stage symptoms of Malaria
- A high temperature (fever)
- Tiredness (fatigue)
Symptoms may occur in cycles, each time they come they might do so at different levels of severity. How long symptoms last may also vary, depending on each cycle. However, at the beginning of the illness, symptoms may not follow this typical pattern.Other common symptoms may include:
- Dry cough
- Back pain
- Muscle ache
- Enlarged spleen
- Very rare symptoms may include:
- Impairment of brain function
- Impairment of spinal cord function
- Seizures (fits)
- Loss of consciousness
- People who are infected with the P. falciparum parasite and become ill generally have much more serious symptoms, which may become fatal.
What is the incubation period of Malaria?
Incubation period refers to how long it takes from initial infection to the appearance of symptoms. This generally depends on the type of parasite:
- P. falciparum - 9 to 14 days
- P. vivax - 12 to 18 days
- P. ovale - 12 to 18 days
- P. malariae - 18 to 40 days
- Malaria exists in parts of Africa, Asia, the Middle East, Central/South America, Hispaniola, and Oceania
- 350-500 million people each year are diagnosed with Malaria
- Over 1 million people die from malaria each year
- Most malaria deaths occur in sub-Saharan Africa
- Most people who die of malaria are children
- Malaria was the 4th cause of childhood death in developing countries in 2002
- 10.7% of childhood deaths in developing countries were caused by malaria in 2002
What are the treatments for Malaria?
According to WHO, in endemic areas treatment should start within 24 hours after the first symptoms appear. A person with uncomplicated malaria can be treated as an outpatient, while those with severe malaria need to be hospitalized. In non-endemic areas WHO recommends that patients with uncomplicated or severe malaria should be kept under clinical observation if possible.
A person who is infected with P. falciparum and has severe symptoms, but cannot take oral medications, should be given treatment intravenously. The problem of drug resistant malaria parasites
New strains of Plasmodium falciparum have become resistant to artemisnin, the key drug against Malaria, researchers from the University of Oxford and the Wellcome Trust Sanger Institute, both in England, reported in the journal Nature Genetics (April 28th, 2013 issue).
Prevention of malaria
Malaria can be prevented by taking several simple precautions. Awareness of the risk of malaria in high risk zones is the first step to preventing malaria. Mosquito bites can be prevented by using covered clothes and mosquito repellents.
While travelling to a malaria endemic zone, antimalarial tablets may be prescribed to prevent contracting malaria. Immediate diagnosis and treatment can help prevent complications and death.
Diagnostic uses of the QUASMO,s Quantity bufy coating
Quantity bufy coating (QuBC) is a laboratory test to detect infection with malaria or other blood parasites. The blood is taken in a QuBC capillary tube which is coated with acridine orange (a fluorescent dye) and centrifuged; the fluorescing parasites can then be observed under ultraviolet light at the interface between red blood cells and bufy coating. This test is more sensitive than the conventional thick smear and in > 90% of cases the species of parasite can also be identified. In cases of extremely low white blood cell count, it may be difficult to perform a manual differential of the various types of white cells, and it may be virtually impossible to obtain an automated differential. In such cases the medical technologist may obtain a buffy coat, from which a blood smear is made. This smear contains a much higher number of white blood cells than whole blood.
After centrifugation, one can distinguish a layer of clear fluid (the plasma), a layer of red fluid containing most of the red blood cells, and a thin layer in between. Making up less than 1% of the total volume of the blood sample, the bufy coating (so-called because it is usually buff in hue), contains most of the white blood cells and platelets. The bufy coating is used, for example, to extract DNA from the blood of mammals (since mammalian red blood cells are anucleate and do not contain DNA). The buffy coat is usually whitish in color, but is sometimes green if the blood sample contains large amounts of neutrophils (which are high in green myeloperoxidase). The layer next to bufy coating contains granulocytes and red blood cells.