What is Smallpox? The basics

The CDC (2007) states that ‘Smallpox is a serious, contagious, and sometimes fatal infectious disease’.  Smallpox is characterised by a distinctive rash that appears on the surface of the skin, the rash further develops into blisters filled with fluid.

The Variola Virus that is responsible for smallpox has been affecting humans for thousands of years. The virus can be spread via direct contact with an infected person or their bodily fluids, objects such as clothes can also become contaminated and spread the virus from person to person CDC (2007). There are two main strains of the Variola Virus, Variola Minor and Variola Major, they both affect the host in slightly different ways.

Variola Minor is the less severe strain of the disease, unfortunately it is the least common it is only responsible for less than 10% of all smallpox cases.

Variola Major is the more common strain of the disease, it is also much more severe with a death rate of around 30% CDC (2007). Variola Major has four different forms:

Ordinary Smallpox – this accounts for around 90% of smallpox cases.

Modified Smallpox – this is a milder form of the disease and usually occurs in people who have previously had the smallpox vaccination.

Flat Smallpox – also known as malignant smallpox, this is an extremely severe version. The fluid filled blisters do not break the surface of the skin and instead lay under the surface.

Hemorrhagic- this is a very rare form, death is extremely likely to occur. Hemorrhages develop under the skin and within mucus membranes.  

References

CENTRE FOR DISEASE CONTROL AND PREVENTION.2007.Smallpox overview.[online]Atlanta.CDC.gov. Available from http://www.bt.cdc.gov/agent/smallpox/overview/disease-facts.asp
[Accessed 2 April 2013]








http://www.medscape.com/viewarticle/472400_2