Smallpox

Smallpox is an infection caused by the variola virus, a member of the poxvirus family. Throughout history, smallpox has caused huge epidemics resulting in great suffering and enormous death tolls worldwide. In 1980, the World Health Organization (WHO) announced that a massive program of vaccination against the disease had resulted in the complete eradication of the virus (with the exception of stored virus in two laboratories).

Diagnosis, up until the eradication of smallpox, consisted of using an electron microscope to identify the virus in fluid from the papules, in the patient's urine, or in the blood prior to the appearance of the papular rash.