inoculation

Examples of inoculation in the following topics:

• Smallpox in Boston, 1721

  • Thevariable inoculated takes two levels: yes or no, indicating whether the person was inoculated or not.
  • The people of Boston self-selected whether or not to be inoculated.
  • 2.44:P(result = died | inoculated = no) = P(result = died and inoculated = no)/P(inoculated = no) = 0.1356/0.9608= 0.1411.
  • 2.45: P(result = died | inoculated = yes) = P(result = died and inoculated = yes) P(inoculated = yes)= 0.0010/0.0392 = 0.0255.
  • The death rate for individuals who were inoculated is only about 1 in 40 while the death rate is about 1 in 7 for those who were not inoculated.

• Inoculation of Live Animals

  • They need living cells for replication, which can be provided by inoculation in live animals among other methods used to culture viruses (cell culture or inoculation of embryonated eggs).
  • Inoculation of human volunteers was the only known method of cultivation of viruses and understanding viral disease.
  • In the past few decades, animal inoculation has been employed for virus isolation.
  • Handling of animals and inoculation into various routes requires special experience and training.
  • Growth of the virus in inoculated animals may be indicated by visible lesions, disease, or death.

• General multiplication rule

  • Suppose we are given only two pieces of information: 96.08% of residents were not inoculated, and 85.88% of the residents who were not inoculated ended up surviving.
  • Among the 96.08% of people who were not inoculated, 85.88% survived:P(result = lived and inoculated = no) = 0.8588 × 0.9608 = 0.8251 This is equivalent to the General Multiplication Rule.
  • Use P(inoculated = yes) = 0.0392 and P(result = lived |inoculated = yes) = 0.9754 to determine the probability that a person was both inoculated and lived.
  • If 97.45% of the people who were inoculated lived, what proportion of inoculated people must have died?
  • 2.50: The samples are large relative to the difference in death rates for the "inoculated" and "not inoculated" groups, so it seems there is an association between inoculated and outcome.

• Tree diagrams

  • We see the population as split by inoculation: yes and no.
  • The first branch for inoculation is said to be the primary branch while the other branches are secondary.
  • This tree diagram splits the smallpox data by inoculation into the yes and no groups with respective marginal probabilities 0.0392 and 0.9608.
  • For example, the top branch in Figure 2.17 is the probability that result = lived conditioned on the information that inoculated = yes.
  • P(inoculated = yes and result = lived) = P(inoculated = yes) × P(result = lived|inoculated = yes) = 0.0392 × 0.9754 = 0.0382

• Positive Externalities

  • A person becomes inoculated against a disease, those around him benefit because they cannot catch the disease from him.
  • That one person could choose to abstain from receiving the shot; since everyone else got inoculated, he can't get the disease from the others because they can't catch the flu.
  • That person would be a free rider since he would benefit from inoculations without incurring any cost.

• Koch and Pure Culture

  • Additionally, it must be absent in healthy organisms prepared and maintained in a pure culture capable of producing the original infection, even after several generations in culture retrievable from an inoculated animal and cultured again.
  • The streak plate method is a way to physically separate the microbial population and is done by spreading the inoculate back and forth with an inoculating loop over the solid agar plate.

• Pure Culture

  • Once the growth medium in the petri dish is inoculated with the desired bacteria, the plates are incubated at the best temperature for the growing of the selected bacteria (for example, usually at 37 degrees Celsius for cultures from humans or animals or lower for environmental cultures).
  • The experimenter would inoculate liquid broth with bacteria and let it grow overnight (they may use a shaker for uniform growth).

• Tissue Culture of Animal Viruses

  • Upon receipt, the specimen is inoculated into several different types of cell culture depending on the nature of the specimen and the clinical presentation.
  • The inoculated tubes should be incubated at 35-37oC in a rotating drum.

• Colonization and Growth

  • The variables involved in the outcome of a host becoming inoculated by a pathogen and the ultimate outcome include: the route of entry of the pathogen and the access to host regions that it gains, the intrinsic virulence of the particular organism, the quantity or load of the initial inoculant, and the immune status of the host being colonized.

• Diagnosing Microbial Diseases

  • The streak plate method is a way to physically separate the microbial population, and is done by spreading the inoculate back and forth with an inoculating loop over the solid agar plate.