Smallpox is an acute contagious disease caused by Variola virus, a member of the orthopoxvirus family. It was one of the world’s most feared diseases. Although the names may sound alike, smallpox is not related to chicken pox which is a milder disease caused by a different virus.
Although people are concerned that the smallpox virus might be used as a weapon, this would be difficult for anyone to do. Right now, there are no cases of smallpox disease in the United States. In fact, the last case of smallpox in the United States was in 1949, and the last case in the world was in 1977. Some samples of the virus that causes the disease are still kept in laboratories, though.
Types of smallpox
Two main Types of smallpox :
1. 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.
2. Variola major. By contrast, this form of the disease kills one-third of the people it infects
Causes of Smallpox
Smallpox is caused by variola virus. The incubation period is about 12 days following exposure. Initial symptoms include high fever, fatigue, and head and backaches. A characteristic rash, most prominent on the face, arms, and legs, follows in 2-3 days. The rash starts with flat red lesions that evolve at the same rate.
You are infected the virus immediately begins replicating inside your cells first in the lymph nodes and then in your spleen and bone marrow. Eventually, the virus settles in the blood vessels in your skin and the mucous membranes of your nose and throat. When the lesions in your mouth slough off, large amounts of virus are released into your saliva. This is when you’re most likely to transmit the disease to others.
Symptoms of Smallpox
First symptoms of smallpox:The incubation period of smallpox, the time from when the virus enters the body to the beginning of symptoms, is 12 days. The first symptoms of smallpox resemble those of any acute viral illness - high fever, muscle aches, fatigue, headaches, and sometimes vomiting.
After few days later the characteristic smallpox rash appears as flat,red spots.The rash starts out flat or slightly thickened spots and quickly progresses to raised spots . These papules continue to enlarge and become filled with a clear fluid, then referred to as vesicles. The fluid in the vesicles gradually changes from clear to pus-like, and the lesions are then referred to as pustules.
Diagnosis of Smallpox
Smallpox is diagnosed by performing laboratory tests on the fluid from the lesions. An electron microscope can also be used to identify the virus in infected fluid. Blood tests for antibodies can be performed and compared to blood tests for antibodies taken 4 weeks later, but this method has obvious timing drawbacks.
Treatment of Smallpox
There is currently no cure for smallpox - although the vaccine can sometimes help those recently exposed. Scientists continue to study antiviral agents to find one that can fight smallpox, but there is no proven treatment yet. For people suffering from full-blown smallpox, “supportive therapy” intravenous fluids, medicines to control fever or pain, and antibiotics for any secondary bacterial infections - is the best-known course of action.
There is no proven treatment for smallpox, but research to evaluate new antiviral agents is ongoing. Patients with smallpox can benefit from supportive therapy such as intravenous fluids, medicine to control fever or pain and antibiotics for any secondary bacterial infections that may occur. Vaccinia immune globulin (VIG) can be used primarily to treat complications of smallpox vaccination. VIG could also be offered to persons exposed to smallpox as a prophylaxis. However, VIG must be given before their lesions began to develop, and it is most effective when given with smallpox vaccination.
