Smallpox is caused by infection with the variola virus. The virus can be transmitted:
Aug. 16, 2014
- Directly from person to person. Direct transmission of the virus requires fairly prolonged face-to-face contact. The virus can be transmitted through the air by droplets that escape when an infected person coughs, sneezes or talks.
- Indirectly from an infected person. In rare instances, airborne virus can spread farther, possibly through the ventilation system in a building, infecting people in other rooms or on other floors.
- Via contaminated items. Smallpox can also spread through contact with contaminated clothing and bedding, although the risk of infection from these sources is less common.
- As a terrorist weapon, potentially. A deliberate release of smallpox is a remote threat. However, because any release of the virus could spread the disease quickly, government officials have taken numerous precautions to protect against this possibility, such as stockpiling smallpox vaccine.
- Friedman HM, et al. The epidemiology, pathogenesis and clinical manifestations of smallpox. http://www/uptodate.com/home. Accessed June 11, 2014.
- Hall JB, et al., eds. Principles of Critical Care. 3rd ed. New York, N.Y.: The McGraw-Hill Companies; 2005. http://accessmedicine.mhmedical.com/content.aspx?bookid=361&Sectionid=39866430. Accessed June 11, 2014.
- What you should know about a smallpox outbreak. Centers for Disease Control and Prevention. http://www.bt.cdc.gov/agent/smallpox/basics/outbreak.asp. Accessed June 12, 2014.
- Smallpox. World Health Organization. http://www.who.int/csr/disease/smallpox/faq/en/#. Accessed June 15, 2014.
- Questions and answers about smallpox disease. Centers for Disease Control and Prevention. http://www.bt.cdc.gov/agent/smallpox/faq/smallpox_disease.asp. Accessed June 12, 2014.