Epi Final, III

What host cannot spread the infection to other susceptible hosts under natural conditions?

What is defined as encounter of a potentially pathogenic agent with susceptible animal host and host shows IMMUNE RESPONSE to infection?

What is time period between exposure to agent (infection) and onset of clinical signs?

What is time between initiation of infection in host and when host becomes infectious to others (sheds agent)?

What is time during which host is infectious to others; from 1st shed to end of disease?

What is clinically apparent infection/overt illness?

What are 4 possible outcomes to exposure to infectious agent?

What are 3 criteria for defining a case?

What is an infection in susceptible host without clinical signs? What would be required to show presence of infection?

Does a carrier have clinical signs? Can they shed to others?

What refers to small gradual changes that occur through point mutations? These minor changes account for annual epidemics.

What is an abrupt, major change to produce novel subtypes via genetic reassortment?

What is the ability of an organism to cause infection in susceptible host? How would you calculate this?

What is the infectivity during an outbreak called? how do you calculate? Is this typically for acute or chronic disease?

What provides a measure of a disease's ability to spread?

What is proportion of infected people that develop clinical signs? How to calculate?

What is number of persons that develop severe disease?

What is the proportion of cases that eventually die from disease? How to calculate?

What is incidence of death among all individuals in population? Calculate?

What is the ability of agent to induce immune response, and how do you measure if there is a response?