GCH 412 Midterm Study Guide
Spring 2014

Tests will be a combination of matching, short answer, and calculations. You may use a simple calculator; no cell phone calculators are permitted. Remember to show ALL your work for calculation problems (partial credit will be given). You are also allowed one 3 X 5 index card as a resource during the exam.

Be able to define the following terms:
Morbidity: illnesses due to specific disease or health condition
Mortality: death e.g. death from various causes)
Endemic: a disease or infectious agent usually present in a community, a geographic area, or a population group.
Epidemic: the occurrence in a community or region of cases of an illness, specific health-related behavior, or other health-related events clearly in excess of normal expectancy.
Pandemic: an epidemic occurring worldwide, or over a very wide are, crossing international boundaries, and usually affecting a large number or people.
Incidence: the number of NEW cases of disease occurring in a time period.
Prevalence: the number of EXISTING cases of a disease at a specified time.
Point prevalence: the prevalence of a disease in a population at a single point in time.
Period prevalence: the prevalence of a disease in a population over a specified period of time (includes cases at the start of the period and any subsequent new cases).
Common source epidemic: tend to result in more cases occurring more rapidly and sooner than host-to-host epidemics. You want to remove exposure to this in order to decrease the epidemic.
Propagated epidemic: arise from infections being transmitted from one infected person to another. Host-to-host epidemics rise and fall more slowly than common source.
Mixed epidemic: occurs when common source epidemic is followed by person-to-person contact and the disease is spread as a propagated outbreak.
Case definition: standard set of criteria that assures that cases are consistently diagnosed. A person who has been diagnosed as having a disease, disorder, injury, or condition.
Index case: the first disease that is brought to the attention of the epidemiologist. Not always the primary case.
Primary case: the first disease case in the population.
Secondary case: those persons who become infected and ill after a disease has been introduced into a population and who become infected from contact with the primary case.
Agent: the cause of the disease.
Host: an organism, usually human or animal, that harbors a disease.
Environment: the surroundings and conditions external to the human or animal that cause or allow disease transmission.
Vector: an invertebrate animal (e.g. tick, mite, mosquito, fly) capable of transmitting an infectious agent amount vertebrates.
Reservoir: the habitat where an infectious agent lives, grows, and multiplies and is dependent on for its survival in nature. (humans are a reservoir and host)
Age adjustment: a comparison of crude mortality rates with different age structures.
Standardized mortality ratio: the ratio of observed deaths to expected deaths, where expected deaths are calculated for a typical area with the same age and gender mix by looking at the death rates for different ages and genders in the larger population.
Life expectancy: average age that the population generally dies at.
Excess death: the difference between the number of observed deaths and the expected deaths.

Be familiar with the major accomplishments of the following epidemiologists:
Hippocrates
The first epidemiologist.
Observed that different diseases occurred in different locations.
Noted that malaria and yellow fever occur more frequently in swampy areas.
Coined the terms epidemic and endemic.
Louis Pasteur
Identified the causes of rabies and showed that bacteria could cause this disease.
Investigated how sheep and humans contracted anthrax and discovered a vaccine for it.
John Snow
An anesthesiologist that made an experiment based on