_________ _________ are microorganisms that are present in an animal for a short time without causing a disease.

True Pathogen - are capable of causing disease in healthy persons with normal immune defenses. ex. influenza virus, plague bacillus, and ect.

Opportunistic pathogen - cause disease when the host's defenses are compromised or when they grow in part of the body that is not natural to them.

1. The same pathogen must be present in every case of the disease
2. The pathogen must be isolated from the diseased host and grown in pure culture.
3. The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, suscptible laboratory animal.
4. The pathogen must be isolated from the inoculated animal and must be shown to be the orginal organism.

A specific infectious disease is associated with a specific microbe.

Exceptions - Some infectious diseases can be caused by several different pathogens, all of which causing the same signs and symptoms. Others cause several disease conditions.

Any disease that spreads from one host to another, either directly or indirectly, is said to be a __________ ______.

Example: Chickenpox, measles, genital herpes, typhoid fever, and tuberculosis.

_______________ _____ is not spread from one host to another.

Example: Skin Cancer, Diabetes Type 2

__________ _______ is a disease that is easily spread from one person to another.

Example: Chickenpos and Measles.

The ________ of a disease is the number of people in a population who develop a disease during a particular time period.

ie: The ________ of AIDS in the US in 2007 was 56,300 vs 1,185,000 cases up to that point.

The _______ of a disease is the number of people in a population who develop a disease at a specified time, regardless of when it first appeared.

Taking into account both old and new cases.

A _______ _____ is a particular disease tha only occurs occasionally.

ie: typhoid fever

A disease constantly present in a population is called an _____ _____.

ie: common cold, malaria, colora

If many people in a given area acquire a certain disease in a relatively short period, it is called a/an ________ _______.

ie: influenza, AIDS

An epidemic disease that occurs worldwide is called a _______ ______.

ie: influenza, AIDs

____ _______ is when many immune people are present in a community.

ie: Chickenpox, Measles

An _____ ______ is one that develops rapidly but last only a short time.

ie: influenza

A ______ _____ develops more slowly, and the body's reactions may be less sever, but the disease is likely to continue or recur for long periods.

ie: Hepatitis B, tuberculosis, and infectious mononucleosis

A ______ ______ is one in which the causative agent remains inactive for a time but then becomes active to produce symptoms of the disease;

ie: shingles, one of the disease caused by varicella virus.

A _____ ______ is one in which the invading microorganisms are limited to a relatively small area of the body.

ie: boils, abscesses, acne

In a ______ ______, microorganisms or their products are spread throughout the body by the blood or lymph.

ie: Measles, septicemia

The presence of toxins in the blood is called _______.

______ ______ is an accute infection that causes the initial illness.

1. Incubation Period
2. Prodromal Period
3. Period of Illness
4. Peck of Illness
5. Period of Decline
6. Period of Convalescence

The ________ _____ is the interval between the initial infection and the first appearance of any signs or symptoms. Patient is highly contagious.

During this period the disease is most severe. Patient shows the most severe signs and symptoms and white blood cells may increase or decrease. Patient is also contagious.

The recovery period or ______ __ __________, is when the body returns to its prediseased state. Patient becomes a chronic reservior and is the most contagious.

Gender - Females have a higher incidence of urinary track infections than males

Genes - Sickle Cell disease is a severe, life-threatening form of anemia that occurs when the genes for the disease are inherited from both parents.

Climent and Weather - In temperate regions, the incidence of respiratory disease increases during the winter. Due to close contact indoors which spread respiratory pathogens.

Others - Nutrition, fatigue, age, environment, habits, lifestyle, occupation, preexisting illness, chemotherapy, and emotional disturbances.

This is a continual source of infection.

ie: human, animal, or nonliving.

These are people that harbor pathogens and transmit them to others without exhibiting any signs of illness. They are important living resevoirs of infection.

ie. incubation period, convalescent period, Typhoid Mary, AIDs

Diseases that occur primarily in wild and domestic animals and can be transmitted to humans are called ________.

ie. rabies (bats, skunks, foxes, dogs, coyotes), lyme disease (field mice)

1. Soil - harbors such pathogens as ringworm, Clostridium Botulinum (causing botulism), C. tetani (causing tetanus).

2. Water - Feces contaminate the water, causing gastrointestinal diseases. Vibrio cholerae, causing cholera, and Salmonella Typhi causing typhoid fever.

1. Contact Transmission

2. Vehicle Transmission

3. Vector Transmission

_______ ________ is the spread of an agent of disease by direct contact, indirect contact, or droplet transmission.

ie: Influenza, Rabies

Also knon as personn-to-person transmission, is the direct transmission of an agent by physical contact between its source and a susceptible host; no intermediate object is involved.

ie: touching, kissing, and sexual intercourse. Hep A, Influenza, staphylococcal.

_______ _______ ____________ occurs when the agent of disease is transmitted from its reservoir to a susceptible host by means of a nonliving object.

ie; tissues, handkerchiefs, towels, bedding, diapers, drinking cups, eating utensils, toys, mone, etc..

Transmission in which microbes are spread in droplet nuclei (mucus droplets) that travel only short distances.

ie: coughing, sneezing, laughing, or talking and travel less than 1 meter from the reservoir to the host.Influenza, pneumonia, whooping cough.

This is the transmission of disease agents by a medium, such as water, food, or air.

ie:

Water - water contaminated with untreated or poorly treated sewage. Cholera, waterborn shigellosis, and leptospirosis.

Food - incompletely cooked, poorly refrigerated, or prepared under unsanitary conditions. (food poisoning and tapeworm infestation)

Air - Travel more then 1 meter, Measles/Tuberculosis, dust particles (Staphylococci), Spores.

Also known as Arthropods, are animals that carry pathogens from one host to another.

ie: yellow fever, dengue fever, plague, rocky mountain spotted fever, (table 14.3)

Active process, arthropod gets infected, it reproduces in the vector then retransmitted.

Pass through feces, salivary glands

Passive transport of pathogens, insect body parts, (typhoid fever)

A ______ ______ does not show any evidence of being present or incubating at the time of admission to a hospital; it is acquired as a result of a hospital stay. (antibody resistant)

ie; UTI, Surgical site infections, lower respiratory infections. (table 14.5)

_____ _____ _____ are ones that are new or changing, showing an increase in incidence in the recent past, or a potential to increase in the near future.

ie; HIV, West Nile virus, SARS (table 14.6)

__________ are any disease that is required by law to be reported to government authorities.

ie; HIV, anthrax, cholera, measles, lyme disease, (table 14.7)

Descriptive Epidemoilogy

Analytical Epidemiology

Experimental Epidemiology