Raeesah+Daud

Epidemics  and Immunity Done By: Raeesah Daud
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**__Epidemics and Immunity-__ **

Vaccines stimulate our Immune System to produce antibodies without us having to become infected with the actual disease. A dose of vaccine may contain- · A suspending fluid to carry the vaccine into the body, · Preservatives and stabilizers so the vaccine can be stored safely and · An adjuvant to improve the body’s Immune System.

Our Immune system realizes the disease and attacks it. **__Malaria- __**  Every twelve seconds someone in the world dies from Malaria. 2.7 Million People every year, and most of them are children under five. Up to 500 Million people are infected at any one time. The cause of this terrible disease is a ‘Parasitic Protist’ called ‘Plasmodium’. The vector for malaria is the Anopheles mosquito. The female mosquito sucks blood by inserting her proboscis, the insect’s slender feeding tube, through her victim’s skin. As she does so her saliva is injected into the human’s bloodstream. If the mosquito is infected with Plasmodium, the saliva will contain thousands of tiny thread like parasites called ‘Sporozoites’.

**__History- __**  For a few decades after the Second World War malaria seemed to be on the retreat. Quinine, derived from the bark of the Cinchona Tree, and Chloroquine, a similar synthetic compound were effective treatments. DDT insecticide sprays were used to kill the mosquito that carried the Plasmodium Parasite. Then nature caught up the Parasite and the mosquito became Immune to the chemicals being thrown at them. Malaria came back stronger than before. There were three times as many cases of malaria in the 1990’s as there had been in the 1960’s.

**__Vaccine- __** <span style="font-family: 'Tahoma','sans-serif';"> Immunologists trying to find a vaccine to defeat malaria find themselves facing many problems. Unlike a virus or a bacterium, which more or less stay the same, the malaria parasite goes through four stages of development in a human. A vaccine that is effective against the Sporozoites might have no effect on the liver or blood stages, for example. In addition, an anti-malaria vaccine would have to be extraordinary efficient. It takes just one or two Sporozoites to survive to produce tens of thousands of merozoites in the liver.



**__<span style="font-family: 'Cooper Black','serif'; font-size: 22pt;">Influenza- __**

<span style="font-family: 'Tahoma','sans-serif';"> Influenza is transmitted from human-to-human through the air. The virus infects the mucus membranes lining the upper respiratory tract. Fever, chills, fatigue and headache may last up to a week, and then recovery is usually rapid. Influenza epidemics occur when a new and highly virulent virus strain arises. Viruses change all the time. As they make billions of copies of themselves mistakes are made. Some result in a weakened or non-functioning virus, others may make it stronger. It kills by the flu leading to Pneumonia. It can also cause you to become dehydrated and you can die from dehydration.
 * __<span style="font-family: 'Tahoma','sans-serif'; font-size: 18pt;">Virus- __**



**__<span style="font-family: 'Tahoma','sans-serif'; font-size: 18pt;">History- __** <span style="font-family: 'Tahoma','sans-serif';">

In the years following the First World War, the planet was struck by a virus epidemic that was more devastating, in terms of the number of deaths, than the plague of medieval times. It began on 4 March 1918, when the first case was reported in Kansas, USA. Within four months millions of people around the world had fallen ill. Few died of the disease and most attention was focused on the approaching end of the war.

Influenza was responsible for the most devastating plague in human history — the "Spanish" flu that swept around the world in 1918 killing 675,000 people in the U.S. and an estimated 20–50 million people worldwide. No one at the time even knew what disease agent was causing the pandemic. Not until 1930 (in pigs) and 1933 (in humans) was it established that influenza is caused by a virus.


 * __<span style="font-family: 'Cooper Black','serif'; font-size: 22pt;">TUBERCULOSIS- __**

<span style="font-family: 'Tahoma','sans-serif';">Tuberculosis, or TB, is caused by a bacterium called Mycobacterium tuberculosis. The symptoms are coughs, weight loss, night sweats, fever, chest pains and coughing up blood. Tuberculosis spreads through airborne droplets sprayed out whenever an infected person coughs. These can remain in the air for around two hours, to be breathed in by someone else who will be infected in turn. **__<span style="font-family: 'Tahoma','sans-serif'; font-size: 18pt;">History- __** <span style="font-family: 'Tahoma','sans-serif';">In 1865, Jean Antoine Villemin demonstrated scientifically that tuberculosis was an infectious illness and, in 1882, Robert Koch identified Mycobacterium tuberculosis as the disease agent. Once it was known that tuberculosis was contagious, measures were taken to prevent its spread. These included isolating infected people in sanatoriums and attempting to improve living conditions in towns and cities. In 1908 the BCG vaccination was developed, giving children immunity from the disease. By the middle years of the 20th century effective antibiotics that treated and cured most cases had been developed. Across Europe and the United States tuberculosis was being defeated.