Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
Epidemiology |
The study of the occurrence, distribution, & determinants of health & disease in a population |
|
Epidemic |
A disease occurring in a large number of people in a population at the same time |
|
Pandemic |
When a disease is widespread, usually worldwide |
|
Endemic |
When a disease is constantly present in a population, usually at low incidences |
|
Incidence |
The number of new cases of the disease in a given period of time |
|
Prevalence |
The total number of new & existing cases of the disease in a population in a given time |
|
Outbreak |
When a number of cases of a disease are reported in a short period of time |
|
Subclinical infections |
Diseased individuals who show no or mild symptoms |
|
Carriers |
Individuals with subclinical infections |
|
Herd immunity |
The resistance of a group to infection due to immunity of a high proportion of the group -If a high proportion on individuals are immune to infection, then the whole population will be protected -Immunized people protect non-immunized people because the pathogen cannot be passed on, and the cycle of infectivity is broken |
|
Diseases such as influenza tend to what? |
Occur in cycles |
|
Epidemiologists |
Follow transmission of a disease by correlating geographic, climatic, social, & demographic data -Used to identify possible modes of transmission -For example, a disease limited to a tropical area may suggest something about its vector (e.g., malaria) |
|
Direct host-to-host transmission |
Infected individual transmits a disease directly to a susceptible host without the assistance of an intermediary (e.g., flu, common cold, STDs, ringworm) |
|
Indirect host-to-host transmission |
Occurs when transmission is facilitated by a living or nonliving agent |
|
Vectors |
Living agents that act as intermediaries in disease transmission |
|
Fomites |
Nonliving agents that act as intermediaries in disease transmission |
|
Common-source epidemic |
A classification of major epidemics, that usually arises from the contamination of food, where the disease shows a rapid rise to a peak incidence because a large number of individuals become ill within a relatively brief period of time Ex. Cholera |
|
Host-to-host epidemic |
A classification of major epidemics, that shows a slow, progressive rise and a gradual decline Ex. Influenza and Chicken pox |
|
Reservoirs |
Sites in which infectious agents remain viable and from which individuals can become infected -Some propagate in humans and animals (SARS bats) -Non-living matter can be a reservoir (Ex. soil is a reservoir for Clostridium tetani, the cause of tetanus) |
|
Common vehicles of infection disease include: |
-Food -Water -Air |
|
Controls directed against common vehicles |
-Food laws lowered incidence of foodborne pathogens (even recently: gloves) -Water purification reduced incidence of typhoid fever -Airborne pathogens are difficult to control |
|
What are the controls directed against the transmission of a pathogen? |
-Immunization (Ex. Smallpox, Rubella, & Tetanus) -Quarantine -Surveillance: The observation, recognition, & reporting of diseases -Pathogen eradication: The goal is to remove all of a pathogen from any reservoir (e.g. small pox (eradicatied), polio, & potentially rabies, leprosy, & others) |
|
Emergent |
Diseases that suddenly become prevalent |
|
Re-emerging |
Diseases that have become prevalent after having been under control |
|
Emergence Factors |
-Human demographics & behavior -Technology & industry -Economic development & land use -International travel & commerce -Microbial adaptation & change -Breakdown of public health measures -Abnormal natural occurences |
|
What are the key elements in addressing emerging diseases? |
-Recognition of the disease -Intervention to prevent pathogen transmission |
|
What are the methods in preventing the spread of emerging infections in regards to public health? |
Methods include quarantine, immunization, drug treatment, & information |
|
Acquired immunodeficiency syndrome (AIDS) |
A viral disease that attacks the immune system -First reported cases were in the U.S. in 1981 -At least 70 million people have been infected worldwide with HIV -More than 25 million people have died from AIDS |
|
Antigenic drift |
Minor changes in influenza virus antigens due to gene mutation |
|
Antigenic shift |
Major change in influenza virus antigen due to gene reassortment -Ex. 2009 Swine flu pandemic (H1N1) |