MALARIA

Malaria is a dreadful disease. More than two million people die of this disease every year. The word malaria is derieved from an italian word meaning "foul air". It was Sir Ronald Ross, who for the first time in 1902 conclusively proved that malaria is caused by mosquitoes. He was awarded nobel prize for this discovery. Scientific experiments have proved that Malaria is caused by a parasite known as Plasmodium. The parasites of malaria are carried by the female Anapheles mosquito in it's belly, which is connected with the salivary gland. When the female anopheles mosquitoe bites some healthy person, the parasite of malaria enter his blood along with the saliva. These parasites attact the RBC and destroy them as a result the victim gets shivering and fever.   
Precautions       
Malaria can be easily treated now, when somebody suffers from malaria, he is given Chloroquin tablets. Doctors advise Primaquin tablets also for protection from malaria attacks. They say that in order to stop the disease, It is essential to eliminate anapheles mosquito. To prevent malaria, DDT insectisides should be sprayed to destroy the anapheles mosquitoes. Accumilation of water should should be prevented so that mosquitoes may not breed there.

TUBERCULOSIS

Tuberculosis is an extremely infectious and dangerous disease. It is generally called T.B. This is spread by bacteria called Mycobacterium tuberculosis. When afflicted with this disease, tuberoles of hard tissue grow inside the lungs. These nodules are composed of millions of cells. The german scientist Robert koch discovered the bacteria of this disease in 1882. They are rod shaped, and approximately 1/7000 mm in length and 1/6000 mm in breadth.    
Symptoms  
A patient afflicted with T.B. often gets violent attacks of cough. while coughing he sprays small drops of water and sputum in to the air around. These contain the bacteria of this disease.  If somebody inhales them, he can also get infected. A man suffering from this disease can transmit it to all the people around him.   
          In 1944, A miracle drug called 'Streptomycin' was discovered for the treatment of this disease. A few years later two more medicines Para- amminosalicylic acid and sonicotinic acid hydrazide, were discovered.  
Precautions 
A patient of tuberculosis should not be kept at home, because he can infect his family members or neighbours. The victim should be immediately in to some T.B. sanatorium or hospital. This disease can be easily detected with X-rays. A vaccine has also been developed for the prevention of this disease. This is known as BCG vaccine. If a new born child, with in a few days of birth, is given an injection of this vaccine, He becomes immune to T.B

SMALL POX (Variola virus)

Small pox is transmitted by droplet infection, either directly from an infected person to another person or by handling of articals infected by the small pox patient. 
Symptoms 
The virus is believed to lodge in the naso pharynx and to invade the regional lymphatic system. This is followed by the dissemination of the virus via the blood stream to all tissues and especially the skin.  An initial fever occurs followed by the rash consisting of the small papules that appear first along the hairline and later on the face and other parts of the body. These papules or pustules become larger and are filled with fluid. The fever recurs and the patient becomes severly ill with generalised symptoms. As the pustules regress, Scabs are formed, which leave the crater like scars charecteristic of small pox.  
There are two kinds of various virus. 
(1) variola major, which causes severe symptoms and has a fatelity rate of 10 to 30 percent; and  
(2) The less virulent variola minor (alastrim) with a fatality rate of only 0.1 to 0.3 percent. except for the difference in virulence, the two viruses cannot be distuinguised. 

CHOLERA

Cholera is a disease of antiquity and has been the cause of untold suffering and death. Cholera is transmited in water and food contaminated with excreta from patients and convalescent carriers.In the small intestine the organisms adhere to the epithelium, multiply, and produce the enterotoxin. The symptoms include vomiting and profuce diarrheal stools that result in severe dehydration, loss of minerals, increased blood acidity, and hemoconcentration. Replacement of fluid salt and bicarbonates is essential to treat cholera.