Explore Our Glossary

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.

To vaccinate is the act of administering a vaccine, usually by injection.

Population health is a way of understanding why some groups of people are healthier than others.

Public health is what society does to keep people healthy, prevent or reduce the effects of illness or injury, and prolong life. This includes policies, programs, and services.

In most cases, when an individual is susceptible they are more likely to get a disease because of lack of protection or poor resistance to it, or because of other health determinants.

The number of new cases of a disease, injury or other health issue, in a specific population over a given period of time. Compare with prevalence. Incidence is the number of new cases (of a disease, injury or other health issue) over a period of time, while prevalence is the proportion of a population affected…

Zoonoses (plural) are infectious diseases that have jumped from animals to humans. Rabies is an example of a zoonosis (singular form).

Social justice addresses issues related to fairness in public health: a better distribution of opportunities and resources (such as money) among groups that have historically been at a disadvantage.

Prevalence generally refers to the proportion of a population affected by a disease at a given time, usually expressed as a rate or percentage. Compare with incidence. Incidence is the number of new cases (of a disease, injury or other health issue) over a period of time, while prevalence is the proportion of a population…

Pre-exposure prophylaxis (or PrEP) is medicine taken to prevent getting HIV (link).

Post-exposure prophylaxis means taking medicine after possible exposure to a disease, usually HIV.

A pandemic is when an epidemic spreads across borders, even the entire world. Compare with “epidemic”.