What is Smallpox and what are its main causes?
What is Smallpox?
Smallpox is a very serious infection which is caused by a virus named variola, which is a member of the poxvirus family. Smallpox has been a greatly feared disease because it was responsible for huge epidemics. Smallpox gets its name from the pus-filled blisters that form during the illness. Smallpox is not related to chicken pox, which is a milder disease and is caused by a different virus.
Types of smallpox
Two main forms of smallpox exist:
Variola minor. This is a milder form of the disease and causes a less serious illness. It's fatal in less than 1 percent of people who contract it.
Variola major. By contrast, this form of the disease kills one-third of the people it infects.
If a person becomes infected with smallpox, it may take anywhere from 7 to 17 days for symptoms to develop. At first a person may have flu-like symptoms such as high fever, fatigue, headaches, and backaches.
Smallpox affected people of all ages. In temperate zones, incidence was highest during the winter; in the tropics, during the hot, dry months. Smallpox was transmitted directly by respiratory droplets or dried scales of virus-containing lesions or indirectly through contact with contaminated linens or other objects.
Variola major was contagious from onset until after the last scab was shed.
The initial signs and symptoms of smallpox, which appear about two weeks after infection, resemble those of the flu: fever, fatigue and headache. Later, severe pus-filled blisters appear on the skin that eventually leave deep, pitted scars. Once symptoms develop, there's no effective treatment for smallpox and no known cure.
What are the causes of Smallpox?
Variola (the virus that causes smallpox) is a member of the orthopoxvirus genus, which also includes viruses such as cowpox, monkeypox, orf, and molluscum contagiosum. Poxviruses are the largest animal viruses, visible with a light microscope.
After the virus entered the body, there was a 12–14 day incubation period during which the virus multiplied, although no symptoms were recognizable. After the incubation period, symptoms appeared abruptly and included fever and chills, muscle aches, and a flat, reddish purple rash on the chest, abdomen, and back.
Smallpox was a relatively contagious disease. The virus could be transferred from one person to another in a number of ways. A person could catch the virus by touching the lesions of an infected person.
It spreads through tiny drops of the infected person's saliva when the person coughs, talks, or sneezes. Smallpox usually passes from person to person during close, face-to-face contact.
The virus could also be transferred in droplets of moisture produced during coughing or sneezing. And a person could get the virus from books, blankets, utensils, or other objects used by someone with the disease.
Smallpox usually requires face-to-face contact to spread.
Social factors played a major role in the transmission of smallpox. Because it spread by face-to-face contact with another person, it thrived in the crowded conditions of poverty. Smallpox is highly infectious, but it is not as contagious as measles or the flu. If the virus ran out of humans to infect, it could not spread.
Ask Questions Share Answers Discussion Forum . Also read about Herbal Remedies Natural Cure Home Remedies and Home Remedies
Smallpox is a very serious infection which is caused by a virus named variola, which is a member of the poxvirus family. Smallpox has been a greatly feared disease because it was responsible for huge epidemics. Smallpox gets its name from the pus-filled blisters that form during the illness. Smallpox is not related to chicken pox, which is a milder disease and is caused by a different virus.
Types of smallpox
Two main forms of smallpox exist:
Variola minor. This is a milder form of the disease and causes a less serious illness. It's fatal in less than 1 percent of people who contract it.
Variola major. By contrast, this form of the disease kills one-third of the people it infects.
If a person becomes infected with smallpox, it may take anywhere from 7 to 17 days for symptoms to develop. At first a person may have flu-like symptoms such as high fever, fatigue, headaches, and backaches.
Smallpox affected people of all ages. In temperate zones, incidence was highest during the winter; in the tropics, during the hot, dry months. Smallpox was transmitted directly by respiratory droplets or dried scales of virus-containing lesions or indirectly through contact with contaminated linens or other objects.
Variola major was contagious from onset until after the last scab was shed.
The initial signs and symptoms of smallpox, which appear about two weeks after infection, resemble those of the flu: fever, fatigue and headache. Later, severe pus-filled blisters appear on the skin that eventually leave deep, pitted scars. Once symptoms develop, there's no effective treatment for smallpox and no known cure.
What are the causes of Smallpox?
Variola (the virus that causes smallpox) is a member of the orthopoxvirus genus, which also includes viruses such as cowpox, monkeypox, orf, and molluscum contagiosum. Poxviruses are the largest animal viruses, visible with a light microscope.
After the virus entered the body, there was a 12–14 day incubation period during which the virus multiplied, although no symptoms were recognizable. After the incubation period, symptoms appeared abruptly and included fever and chills, muscle aches, and a flat, reddish purple rash on the chest, abdomen, and back.
Smallpox was a relatively contagious disease. The virus could be transferred from one person to another in a number of ways. A person could catch the virus by touching the lesions of an infected person.
It spreads through tiny drops of the infected person's saliva when the person coughs, talks, or sneezes. Smallpox usually passes from person to person during close, face-to-face contact.
The virus could also be transferred in droplets of moisture produced during coughing or sneezing. And a person could get the virus from books, blankets, utensils, or other objects used by someone with the disease.
Smallpox usually requires face-to-face contact to spread.
Social factors played a major role in the transmission of smallpox. Because it spread by face-to-face contact with another person, it thrived in the crowded conditions of poverty. Smallpox is highly infectious, but it is not as contagious as measles or the flu. If the virus ran out of humans to infect, it could not spread.
Ask Questions Share Answers Discussion Forum . Also read about Herbal Remedies Natural Cure Home Remedies and Home Remedies
0 ความคิดเห็น:
แสดงความคิดเห็น