Comprehensive Glossary for NCCID Terms

Microorganisms, chemical substances, or forms of radiation that can cause illness.

A chain of infection refers to the conditions or process that allow a virus to spread from one person to another.

Infectious diseases are illnesses caused by germs (such as bacteria, viruses and fungi) that spread from person to person, are transmitted by insects or other animals, or are present in the air, water, food, or soil.  A communicable disease is spread from person to person, or from animal to person (e.g., through body fluids or droplets). All communicable diseases are infectious.  But not all infectious diseases are communicable (e.g., tetanus is infectious but not communicable).

We have provided separate definitions for each, we can also combine them if you prefer.
 
Determinants of health are any factors that influence the health of people or groups of people. These factors are often beyond the control of the individual or group, and help explain why some people or groups are healthy, and others not. Determinants of health can be biological, social, or structural (see below). 

Biological determinants of health: are inherited factors, such as biological sex and genetics.

Social determinants of health are the circumstances into which people are born, grow up, live, work and age. It is usually a combination of these and other social factors that influence the health of people or groups of people.
 
Structural determinants of health are economic, legal, or political systems that create or perpetuate health inequalities by limiting access to wealth or power. These systems can be related to geography (where someone is born or lives), or even history (such as residential schools).

A disaster response refers to activities or actions undertaken during or after a disaster. It can include risk assessment and planning, as well as immediate relief, rehabilitation, and reconstruction.

The transmission of disease is the way in which infectious agents spread from a source or reservoir to a person.

Health disparities are preventable differences in the burden of disease, injury, violence, or opportunities to achieve optimal health that are experienced by populations that have been disadvantaged by their social or economic status, geographic location, environment, or factors such as gender, sexual orientation, race, or ethnicity among others.

Eradication of disease is achieved when, through deliberate efforts, there are no more cases of an infection and interventions are no longer needed. Elimination is when the disease is no longer present in a large geographical area. Extinction means the disease no longer exists (not even in a lab).

A disease is endemic when it is always present in a geographical area or a population group.

When the number of cases is greater than what we normally expect, we say there is an outbreak, an epidemic, or a pandemic. An outbreak is limited to a specific area (like a school) within a certain time period; an epidemic occurs when an outbreak spreads to an even larger area (a country, for example), while a pandemic is when an epidemic spreads across borders, even the entire world.

Ethics in public health (also called “applied ethics”) seeks to guide practitioners in their decision-making process by setting out moral principles such as solidarity and social justice which can be applied to practical situations. See social justice.