Test #2- Lecture #9

The study of where and when disease occur and how they are transmitted within populations

number of new cases of a disease in a given area during a given period of time

number of total cases of a disease in a given area during a given period of time

few scattered cases within a population or area

relatively stable incidence within a population or area

o  Record info about the location and time of the cases of disease

o  Collect patient information

John snow (1854)

o  Mapped the locations of cholera cases in London

o  Broad Street Water pump

Involves testing a hypothesis concerning the cause of a disease

Seeks to determine the probable cause, mode of transmission, and develop new preventative measures

uses data gathered from descriptive and analytical studies.

Useful in situations in which Koch postulates cant be applied

Often retrospective- investigation occurs after on outbreak has occurred

1.      Work to limit disease transmission

-monitor water and food saftey

2.      Campaign to educate the public on healthful choices to limit disease

Infections acquired while in the health care facility

Pathogen Acquired from the health care environment

Ex: hospitals are filled with sick people shedding pathogen

direct result of a modern medical procedure

Ex: catheters, surgery

Pathogen arise from normal microbiota due to factors within the health care setting

Ex: chemotherapy