|
The viruses belonging to the genus Orthopoxvirus of the family
Poxviridae are among the pathogens heading the list of microorganisms that
have had an important role in the interactions between the humankind and
infectious agents. Until recently, smallpox, caused by variola virus, was the
most dangerous epidemic disease of humans, spreading as a conflagration.
The toll of this infection was a tremendous number of human lives. Only in
the previous century, smallpox killed about 300 million people. The variola
virus is unique in that the only sensitive host of this pathogen is the man;
moreover, the case-fatality rate of smallpox may exceed 30%. Variola virus
is a strict anthroponosis unable to be retained in wild nature in animal
organisms.
Another orthopoxvirus-cowpox virus-occupies one of the most
honorable places in the history of medicine. In 1796, already one hundred
years before the kingdom of viruses was discovered by Dmitri Ivanovsky in
1892, the famous experiments of Edward Jenner commenced use of cowpox
virus for infecting people in order to protect them from smallpox, thereby
opening the era of vaccine prevention of communicable diseases. |
