Infection
Types of Carriers
Modes of Transmission
Prevention
Case Concepts
100

An organism or substance such as bacteria, viruses, fungi, mold, or parasites that is capable of producing disease.

What is a Pathogen?

100

An individual who has been exposed to and harbors a pathogen and who can spread the disease at different places or intervals.

What is an Intermittent Carrier?

100

The transfer of a disease to a human by a vector.

What is Vector-Borne Transmission?

100

The effort to prevent a disease or disorder before it happens.

What is Primary Prevention?
100
The first disease case in the population.

What is a Primary Case?

200

The place  where pathogens or other disease-causing agents enter the body of a susceptible host.

What is the Portal of Entry?

200

An individual who has been exposed to an harbors a pathogen but has not become ill or shown any symptoms of the disease.

What is a Healthy or Passive Carrier?

200

The transfer of a disease via a particular vehicle.

What is Vehicle-Borne Transmission?

200

The efforts to limit disability by providing rehabilitation where disease, injury, or a disorder has already occurred and caused damage. 

What is Tertiary Prevention?
200

A person in a population who has been identified as having a particular disease, disorder, injury, or condition.

What is a Case?

300
The place where pathogens leave the reservoir and are spread.

What is the Portal of Exit?

300

An individual who has been exposed to and harbors a pathogen, and has done so for some time, even though they may have recovered from the disease.

What is an Active Carrier?

300

The process of spreading disease through a physical transfer process.

What is Mechanical Transmission?

300

It does not require behavior change on the part of the individual to prevent disease or disorder from occurring.

What is Passive Primary Prevention?

300

A person who becomes infected from contact with the primary case after the disease has been introduced into the population.

What is a Secondary Case?

400

The process through which infectious disease transmission occurs.

What is the Chain of Infection?

400

An individual who has been exposed to and harbors a pathogen; who is beginning to show symptoms and is in the beginning stages of the disease; who still has the ability to transmit the disease.

What is an Incubatory Carrier?

400

The transfer of bacteria or viruses on dust particles or on small respiratory droplets that may become aerosolized when individuals sneeze, cough, laugh, or exhale.

What is Airborne Transmission?

400

The activities aimed at health screening and early detection to improve the likelihood of cure and reduce the chance of disability or death.

What is Secondary Prevention?

400

An individual or group who have all the signs and symptoms of a disease or condition but have not been diagnosed as having the disease or had the cause of the symptoms connected to a suspected pathogen.

What is Suspect Case?

500

An infected person or animal that contains, spreads, or harbors an infectious organism.

What is a Carrier?

500

An individual who harbors a pathogen and who is still infectious even though they are in the recovery phase of the course of the disease.

What is a Convalescent Carrier?

500

The process in which a pathogen reproduces and transfers to a susceptible host by a vector.

What is Biological Transmission?

500
The behavior change on the part of the individual that prevents a disease or disorder before it happens.

What is Active Primary Prevention?

500

The first disease case brought to the attention of the epidemiologist.

What is Index Case?