Disease Detectives P2

Chronic

being long-lasting and recurrent or characterized by long suffering

Societal

relating to human society and its members

Epidemiological

Death rates decline as condition and medicine improve

encephalitis

inflammation of the brain caused by West Nile Virus

panademic

refers to an outbreak of a disease occuring over a large geographic area, possibly worldwide (pan- means entire dem means population, and -ic means pertaining to) For example, the worldwide spread of AIDS is pandemic.

vector

any agent (person or animal or microorganism) that carries and transmits a disease

fomite

any inanimate object (as a towel or money or clothing or dishes or books or toys etc.) that can transmit infectious agents from one person to another

zoonosis

..., an animal disease that can be transmitted to humans

protistans

mostly unicellular, eukaryotic, some autotrophs (algae), some heterotrophs (ingestion-protozoa), can be pathogenic

fundamental

being or involving basic facts or principles

West Nile

..., a virus transmitted by mosquitoes who hae bitten birds, causes possible encephalitis, but most recover without treatment

Outbreak

More cases of a particular disease than expected in a given area or among a specialized group of people over a particular period of time

Epidemic

The occurrence in a community or region of cases of an illness (or an outbreak) with a frequency clearly in excess of normal expectancy.

Pandemic

An epidemic over a very wide area (several countries or continents) and usually affecting a large proportion of the population.

Cluster

An aggregation of cases over a particular period closely Grouped in time and space, regardless of whether is more than the expected number

Case Definition

Limits the following characteristics: time, person and place for data collection

Risk Factor

Personal characteristics (age, sex, health) behavior or lifestyle including diet, an environment exposure, or a family trait (genetic) that might cause or add to a health problem.

Attack Rate

The rate that a group experienced an outcome or illness equal to the number sick divided by the total number in that group.

Relative Risk

A comparison of the risk of disease in the exposed group compared to the risk of disease in the unexposed group.

Case Fatality

The ratio of the number of deaths caused by a specified disease to the number of diagnosed cases of that disease.

Odds ratio

Calculated to evaluate the possible agents and vehicles of transmission. Odds for exposure cases divided by odds of for controls.

Surveillance

The systematic and ongoing collection, analysis and interpretation of health data to gain knowledge of the patterns of disease, injury and other health problems so as to work towards their prevention and control.

Case Control Study

A study type that uses cases (with the health problem) and compares them with controls (without the health problem) to find out what may have caused the problem. A type of retrospective study.

Cohort Study

A study type using two populations: one that had contact with the agent causing the disease and another that had not had contact.

Cross-Sectional study design

a survey, "snapshot in time"

Ecological study design

comparisons of geographical locations

Randomized controlled trial study design

human experiment;

Epidemic Threshold

The point where the disease in question becomes widespread (an epidemic)

Incidence Rate

The number of individuals who fall ill with a certain disease during a defined period, divided by the total population.

Prevalence

The number of all current (existing) cases in a population during a certain time period.

Morbidity

All cases fatal and nonfatal

Mortality

Measure indicating what proportion of the entire population die from each disease per year

Endemic disease

Present at a continuous level throughout a population / Geographic area; constant presence of an agent / health condition within a given geographic area / population; refers to the usual prevalence of an agent / condition.

Incubation period

Time between when a person comes into contact with a pathogen and when they show the first symptoms or signs of disease.

Agent

A causative factor, such as a biological or chemical agent that must be present (or absent) in the environment for disease occurrence in a suspectible host.

Fomite

A physical object that serves to transmit an infectious agent from person to person.

Reservoir

An ecological niche where a pathogen lives and multiplies.

Vector

An animal, most often an insect, that transmits disease.

Zoonosis

An infectious disease that is transmissible from animals to humans

Plague

A serious, potentially life threatening infectious disease that is usually transmitted by the bites of rodent fleas. Three types: bubonic, septicemic, and pneumonic.

Chain of infection

Includes: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry and susceptible host. http://o.quizlet.com/i/x7fEJDrZV82KBMxWkEPyhQ.jpg

Portal of entry

Respiratory (breathing or through the air); Ingestion (food, eating or water, drinking); Dermal contact (skin or absorption); Blood (insect bite or needle stick);

Modes of Transmission

Direct or Indirect contact; Direct can be skin to skin or soil to skin and also droplet spread by sneezing, coughing or talking; Indirect can be by vector (insect), vehicle (water, biologic product, fomites) or airborne.

Triad of Analysis

Person, place and time; Agent, host, environment

Epi-Curve

A histogram that shows the course of an outbreak by plotting the number of cases according to the time of onset.

Epi-Curve, Point Source

Occurs when people are exposed to the same exposure over a limited, well defined period of time. The shape of the curve commonly rises rapidly, contains a peak, followed by a gradual decline.

Epi-Curve, Continuous Common Source

Occurs when exposure to the source is prolonged over an extended period of time and may occur over more than one incubation period. The down slope of the curve may be very sharp if the common source is removed or gradual if outbreak exhausts itself.

Epi-Curve, Propagated (Progressive source)

Occurs when a case of disease serves later as a source of infection for subsequent cases and those subsequent cases in turn serve as sources for later cases. Shape of curve usually contains successively higher peaks. Person-Person contact.

Sensitivity

1. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 2. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 3. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.

Specificity

The proportion of persons without a disease who are correctly identified by a test. The specificity is the number of true negative results divided by the sum of the numbers of true negative plus false positive results.

R-0

Susceptible population divided by the Threshold Population; average number of infections per infected person.

infectivity

the ability of an infectious agent to cause infection, measured as the proportion of persons exposed to an infectious agent who become infected.

pathogenicity

ability to cause disease; the ability of an organism to cause disease (ie, harm the host). This ability represents a genetic component of the pathogen and the overt damage done to the host is a property of the host-pathogen interactions

virulence

degree of pathogenicity; The ability of any agent of infection to produce disease. The virulence of a microorganism (such as a bacterium or virus) is a measure of the severity of the disease it is capable of causing.

temporality

cause / exposure must precede the effect / outcome

natality

the ratio of births to the general population, birth rate.

etiology

the study of all factors that may be involved in the development of a disease, including the susceptibility of the patient, the nature of the disease agent, and the way in which the patient's body is invaded by the agent; the cause of a disease.

risk

the probability that an event will occur. In epidemiology, it is most often used to express the probability that a particular outcome will occur following a particular exposure.

Case Fatality Rate (CDC)

The proportion of persons with a particular condition (cases) who die from that condition. The denominator is the number of incident cases; the numerator is the number of cause-specific deaths among those cases. (Note: For longer periods of time, a more specific term may be used: e.g. 5-year survival rate)

Epidemiology

Epidemiology is the study (or the science of the study) of the patterns, causes, and effects of health and disease conditions in defined populations. It is the cornerstone of public health, and informs policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive medicine. Epidemiologists help with study design, collection and statistical analysis of data, and interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies and, to a lesser extent, basic research in the biological sciences.

outbreak

(localized epidemic) - more cases of a particular disease than expected in a given area or among a specialized group of people over a particular period of time.

pandemic

An epidemic occurring over a very wide area (several countries or continents) and usually affecting a large proportion of the population.

Public Health Surveillance

the systematic collection, analysis, interpretation, and dissemination of health data to gain knowledge of the pattern of disease occurrence in order to control and prevent disease in the community.

cluster

an aggregation of cases over a particular period esp. cancer & birth defects closely grouped in time and space regardless of whether the number is more than the expected number. (often the expected number of cases is not known.)

Relative risk

estimates the extent of the association between an exposure and a disease. It estimates the likelihood of developing the disease in the exposed group as compared to the unexposed group. Relative risk is not expressed in negative numbers.

A relative risk \>1.0

indicates a positive association or an increased risk. This risk increases in strength as the magnitude of the relative risk increases.

A relative risk \= 1.0

indicates that the incidence rates of disease in the exposed group is equal to the incidence rates in unexposed group. Therefore the data does not provide evidence for an association.

zoonosis

An infectious disease that is transmissible from animals to humans.

reservoir

An organism that is the host for a parasitic pathogen or that directly or indirectly transmits a pathogen to which it is immune.

vector

an animate intermediary in the indirect transmission of an agent that carries the agent from a reservoir to a susceptible host. An organism that transmits the infection as a mosquito transmits the malaria protozoans

animals

Definition in terms of infectious agents

prevalence

In epidemiology, the prevalence or prevalence proportion is the proportion of a population found to have a condition (typically a disease or a risk factor such as smoking or seat-belt use).

fomite

a physical object that serves to transmit an infectious agent from person to person.

acquired immune deficiency syndrome (AIDS)

Infectious disease syndrome that is caused by the human immunodeficiency virus (HIV). Characterized by the loss of a normal immune response and increased susceptibility to opportunistic infections and some cancers.

acquired immunity

Specific immunity that develops after exposure to a particular antigen or after antibodies are transferred from one individual to another.

acyclovir

Synthetic drug with antiviral activity against herpes simplex virus. Often used to treat genital herpes.

aerobe

Organism that can grow in the presence of atmospheric oxygen.

airborne transmission

Transmission of an infectious organism in which the organism is truly suspended in the air and travels a meter or more from the source to the host. Chicken pox, flu, measles, and polio are examples of diseases that are caused by airborne agents.

allergen

Substance that can induce an allergic reaction or specific susceptibility.

amantadine

Antiviral compound sometimes used to treat influenza type A infections.

amebiasis

Infection with amoebae. Usually refers to an infection by Entamoeba histolytica. Symptoms are highly variable, ranging from an asymptomatic infection to severe dysentery.

amphotericin B

Antibiotic used to treat systemic fungal infections and also used topically to treat candidiasis.

anaerobe

Organism that can grow in the absence of atmospheric oxygen.

anthrax

Infectious disease of animals caused by ingesting the spores of Bacillus anthracis. Can occur in humans.

antibiotic

Microbial product, or its derivative, that kills or inhibits the growth of susceptible microorganisms.

antibody

Glycoprotein produced in response to an antigen. Antibodies have the ability to combine with the antigen that stimulated their production.

antibody-mediated immunity

Immunity that results from the presence of antibodies in blood and lymph.

antigen

Foreign (nonself) substance to which lymphocytes respond.

antimicrobial agent

Agent that kills or inhibits the growth of microorganisms.

antiseptic

Chemical applied to tissue to prevent infection by killing or inhibiting the growth of pathogens.

antitoxin

Antibody to a microbial toxin. An antitoxin binds specifically with the toxin, neutralizing it.

arenavirus

Type of RNA virus. Lassa fever is caused by an arenavirus.

autogenous infection

Infection that results from a patient's own microflora.

B-cell

Type of lymphocyte derived from bone marrow stem cells that matures into an immunologically competent cell under the influence of the bone marrow. Following interaction with an antigen, a B-cell becomes a plasma cell, which synthesizes antibodies.

bacillus

Rod-shaped bacterium.

bactericide

Agent that kills bacteria.

binary fission

Asexual reproduction in which a cell separates into two cells.

biologic transmission

Disease transmission in which an infectious organism undergoes some morphologic or physiologic change during its passage through the vector.

botulism

Form of food poisoning caused by a neurotoxin produced by Clostridium botulinum. Sometimes found in improperly canned or preserved food.

broad-spectrum drug

Chemotherapeutic agent that is effective across a wide range of different types of pathogens.