So you were the unfortunate one to open our letter! Well welcome to our guinea pig project.
  You have just been infected with anthrax, whereas your friend who is also reading one of our deadly
  letters was infected by smallpox.  

  ANTHRAX

  What is anthrax? 
  Anthrax is the name given to a infectious disease caused by bacteria, Bacillus anthracis. And the 
  Bacillus anthracis can be found in all parts of the world. Anthrax is known for infecting domesticated
  animals, such as, pigs, goats, sheep, etc.

  Where does it come from? 
  It comes from domesticated animals, and is found in the ground the animals roam around, and in the
  plants and food that they eat.  

  How does it get to people?
  There are three general methods for the anthrax to enter the human body, cutaneous, ingestion, and
  inhalation.

  The natural way is for people to come in contact with the anthrax by coming in close contact with
  the domesticated animal that has the anthrax. Or the person can eat the infected meat of the animal
  that has anthrax.  

  The way it gets to people the unnatural way is through bioterrorism. The bioterrorist exposes the
  people to the anthrax whether through airborne anthrax spores or direct contact with the anthrax
  powder form.

  How much does it take to infect the person?
  There are many conflicting numbers for the amount of spores that need to enter the body in order
  for infection to start. The numbers range from 10,000 – 100 spores. However all the sources agree
  that the most important factor of infection the person is the method that the anthrax enters the body.

  SMALLPOX

  What is smallpox?
  Smallpox is the name given to an infectious disease caused by bacteria, Variola virus. Smallpox is a 
  viral disease that is unique to humans. The virus is transmitted from one human to another. There are
  two forms of the variola virus, there is the variola major and the variola minor. Variola minor is a
  more minor and less deadly form.  Another two forms of smallpox is the hemorrhagic and the
  malignant forms. Hemorrhagic is 100% fatal and the malignant form is frequently fatal.

  Where does it come from?
  Small pox is no longer found in the world. It was eradicated in 1977, however strains were kept in
  labs around the world for research and vaccination purposes.

  How does it get to people?
  The natural method for the smallpox virus (variola virus) to get to a person is getting it from
  someone else. The smallpox virus is passed from people to people through the saliva and water
  vapour that the infected people breathe out.

  Another method for the smallpox virus to get to people is through the acts of bioterrorism. The
  bioterrorist can contaminate a liquid and then use the liquid to make an aerosol spray and spray a
  population with the smallpox virus, or they can infect individual people and hope that it spreads and
  is passed on from person to person.

  How much does it take to infect the person?
  The amount of the variola virus it takes to get infected is unknown to the medical world, however it
  is speculated that it may only take a few virons (single viruses).