Viruses are organisms that are 100 times smaller than bacteria. They consist of genetic material surrounded by a protective protein coat. After invading cells, viruses take over the cell's reproductive machinery to reproduce themselves. In doing so, they cause disease and sometimes death. Examples of viral diseases include influenza, AIDS, chickenpox, mumps, measles, yellow fever, dengue fever, smallpox, hepatitis, Ebola, and Venezuelan equine encephalitis.
Although smallpox was controlled with vaccinations in the 20th century, it still poses a great threat as a biological weapon. Smallpox is caused by a virus and is highly contagious, spreading rapidly and killing tons of people in a relatively short time period. About half the victims die within two weeks from the exposure and there has not been any effective treatment. Vaccinations are the main protection, but they must be given prior to infection. The initial symptoms resemble those of the flu, but severe pus-filled blisters appear on the victim's skin and leave deep scars on the body.
"Smallpox today... is the only or one of the only dangerous plague diseases that have been eradicated. But there are... in Russia and in the United States CDC, there are copies of the germ that are stored... There is a fear that if these stored germs get into the wrong hands, it could be a problem." - listen
Mr. Barry Zimmerman, Author of Killer Germs
Ebola is a virus that causes ebola hemorrhagic fever, a fatal disease characterized by abrupt and varied symptoms. Initial symptoms can include high fever, sore throat, nausea, and exhaustion. The ebola virus was recently discovered and has no known cure. It usually kills within days of infection.
People can be exposed to Ebola from direct contact with blood or secretions of an infected person. The virus is often spread through friends and families who come into close contact with such secretions when caring for infected individuals. In Africa, transmission of Ebola often occurs within hospital, known as nosocomial transmission. Unsterilized needles or syringes and lack of protective clothing contribute to nosocomial transmission.
Often times, it is mistaken for malaria or dysentery, but internal/external bleeding separates ebola from other common bacterial infections. Ebola has been popularized by many literature works including Executive Orders by Tom Clancy and Biohazard by Ken Alibek.