MALARIA
Malaria can be fatal disease for human beings. Approximately 300 million people around the world get infected with malaria every year. More than 2 million people die every year due to malaria disease.
Malaria is caused by a protozoan parasite Plasmodium. This disease spreads through the bite of an insect vector- the female Anopheles mosquito feeds upon plant juice.
The name Malaria was proposed by Macculochin 1827. C.L.A. Laveran in 1880, a French physician, discovered the Malarial parasite - Plasmodium in the blood of a malaria patient.He received Nobel prize for this discovery in 1907.
Main symptoms of malaria include headache, nausea, muscular pain and high fever. Each malarial attack is of 6 to 10 hours duration and consists of the three stages:
1. Cold stage, feeling of extreme cold and shivers
2. Hot stage, high fever, faster respiration and heartbeat and
3. Sweating stage, i.e., due to profuse sweating, temperature of the body goes down to normal.
Even after the patient is cured of malaria, the patient feel weak and becomes anemic. Malaria may also secondarily cause enlargement of spleen and liver. Presence of malarial parasite can be checked by blood test.
PREVENTION-
Malaria is an infectious disease. It can spread from an infected person to a healthy person (host) by the bite of female Anopheles mosquitoes (vectors). The only way to prevent malaria is to take precaution against mosquito bites.
We can protect ourselves from the bite of mosquitoes by following methods:
1. Wire- gauge should be used on doors and windows of houses to prevent entry of mosquitoes.
2. Insect- repellents (e.g., Odomos) should be used to prevent mosquito- bite.
3. One should sleep under mosquito nets.
4. Mosquito larvae can be killed by sprinkling kerosene oil on large- sized water bodies. Some larvivorous fishes such as Gambusia, minnows or trouts or birds (e.g., ducks) can be introduced in water bodies. These animals feed on mosquito larvae and hence the population of mosquito is checked. This is called biological control of mosquito.
5. Adult mosquitoes can be killed by spraying insecticides (e.g., BHC, malathion) on the walls of human dwellings. Insecticides are chemical poisons (toxicants), hence, regulation of mosquito population by them is called chemical control. The insecticide DDT is not used in the chemical control of mosquitoes, as it persists in the environment for much longer time and can cause toxicity by accumulating in the body of fishes, birds and humans through food chain.
6. The breeding grounds should be destroyed. Thus, the ditches, puddles or swamps around human dwellings should be drained or filled. We should not allow the collection of water in any uncovered containers such as water tank, pot, cooler, flower pot, discarded tires, etc.
Ø Recently Allan Porter and his team produced a genetically engineered aquatic bacteria at National Institute of Singapore. When mosquito larvae feed on these bacteria, they get killed by the toxic substance produced by these bacteria. This can prove to be an effective biological control method against malaria.
CONTROL-
A drug named Quinine, which is extracted from the bark of Cinchona tree, is used to treat a person suffering from malaria. This drug kills most of the stages of malarial parasite. There are certain other drugs (medicines) which should be taken on the advice of doctor. Scientists are trying hard to develop an antimalarial vaccine.
Ø Central Drug Research Institute (CDRI), Lucknow has developed an anti- cerebral malaria drug called – Arteether. This drug is extracted from a herbaceous plant Artemisia annua belonging to family Asteraceae.
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