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Investigating Smallpox. Bacteria and viruses can make you sick. The illnesses they cause can be very serious. Over the last 200 years, the number of bacterial and viral illnesses that can change your life has dropped dramatically. The v ariola virus
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Investigating Smallpox Bacteria and viruses can make you sick. The illnesses they cause can be very serious. Over the last 200 years, the number of bacterial and viral illnesses that can change your life has dropped dramatically. The variola virus is the virus that causes smallpox.
What Organisms Are Susceptible? Humans are the only natural hosts of the variola virus.
Symptoms The symptoms include a rash of raised bumps and fluid filled blisters that leave deep, pitted scars, called pockmarks, on survivors. Other symptoms include fever, headache, backache, and fatigue.
How is it spread? The fluid inside of the blisters contain the variola virus. When another person comes into direct contact with the infected body fluid the virus is passed on. It can also be spread when someone touches an object such as bedding or clothing that has the small pox virus on it.
Other Ways It Is Spread There are a small number of documented cases where smallpox has infected someone through droplet transmission carried in the air.
A person becomes contagious when they get a fever. • A person becomes more contagious when they get the rash. At this stage they are usually very sick and unable to move around the community. • The infected person is contagious until the last smallpox scab falls off.
Do We Need To Worry? Smallpox has mostly been eradicated, and you do not hear about people getting it anymore.
Ancient times, modern methods Putting germs in your body to build up immunity – the basic idea behind immunization – may seem like a modern idea, but it's actually centuries old. The fascinating history of smallpox reveals just how long this practice has been around.
In 12th-century China, people noticed that children who survived smallpox never contracted the disease again. They came up with the idea of inhaling a powder made from smallpox scabs to cause a mild case of smallpox and create immunity against the full-blown version of the dreaded disease.
The mental image is not for the squeamish, but if you think about it, it's not such a far cry from the modern-day flu mist!
Variolation This technique, called variolation, spread across Asia and was also practiced in Africa. The method varied from region to region – Persians swallowed the powder, while Turks and North Africans rubbed smallpox pus into scratches in the skin – but the concept was the same.
The Modern Smallpox Vaccine • The physician Edward Jenner was himself variolated at the age of 8 in England. Had he missed out on this, he might not have had the opportunity to grow up and develop the first smallpox vaccine.
It was generally known that milkmaids didn't catch smallpox. Jenner speculated that this was because they were exposed to cowpox, an illness that's similar to smallpox but much milder. The milkmaids only had a few blisters, felt a little tired, and had some aches.
He thought that cowpox protected them. • Jenner decided to try an experiment
With permission from the boy’s father, Jenner transferred fluid from a milkmaid’s cowpox blister into a cut on the boy’s arm.
The boy had a few aches but did not get very sick. Later, Jenner exposed the boy to small pox. The boy did not get sick. It seemed the cowpox virus could protect against smallpox! Several months later, Jenner exposed the boy to the smallpox virus again.
Again the boy stayed healthy! Jenner had found a way to prevent small pox. The cowpox virus acted as a vaccine.
His method became accepted and widely used. Historically, the U.S. Centers for Disease Control and Prevention (CDC) reports, the smallpox vaccine has prevented smallpox in 95 percent of people vaccinated.
Routine smallpox vaccination stopped in the United States in 1972 because the disease had been eradicated there. The last "natural" case of smallpox occurred in Somalia in 1977.
What’s the Point? • Scientists have developed many ways to combat some viral and bacterial infections • Using vaccinations, they have eradicated some disabling and deadly diseases. • Smallpox is one of those. Polio, chicken pox, measles, mumps, and rubella have also almost been eradicated.
Vaccinations play an important role in maintaining people’s health. • Vaccinations are usually given to children early in their lives.
