Incubation period
Say it: in-kyuh-BAY-shun PEER-ee-ud
The incubation period is the time between infection with a pathogen and the first appearance of signs or symptoms of the disease it causes.
Also: incubation periods
Definition
What is the incubation period?
The incubation period is the interval from the moment a pathogen enters the body to the onset of the first signs or symptoms. During this stage the microbe multiplies and spreads, but there are not yet enough organisms, or enough tissue damage, to cause illness, so the person usually feels well. For noninfectious causes, such as radiation or a cancer-causing chemical, the equivalent stretch is usually called the latency period.
Each infection has a typical range rather than a fixed length. It can be under two days for Salmonella food poisoning or influenza, about two weeks for chickenpox and two to three months for hepatitis B. The infecting dose, the route and site of entry, the strength of the pathogen and the host's immune defenses all affect where in that range an individual case falls.
The incubation period matters in public health. It sets how long exposed contacts are monitored or quarantined, helps investigators work back from the first cases to the likely time and source of an outbreak, and explains why people can travel or spread an infection before they know they are ill, since many infections become contagious late in the incubation period.
Word parts
Where does the term “incubation period” come from?
- in-
- on, uponLatin in
- -cub-
- to lie down (incubare: to lie on, as a bird on eggs)Latin cubare
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Terms that go with it
- PathogenA pathogen is a microbe or other agent, such as a virus, bacterium, fungus, parasite or prion, that can cause disease in a host.
- QuarantineQuarantine is the separation and restricted movement of people or animals exposed to a contagious disease who are not yet sick, in case they become ill.
- EpidemicAn epidemic is a rise in cases of a disease, often sudden, above the level normally expected in a given population, area and time.
- Communicable diseaseA communicable disease is an infection that can pass from one person or animal to another, directly or through air, water, food, objects or vectors.
- VirusA virus is a tiny infectious particle of DNA or RNA inside a protein coat that can multiply only by taking over the machinery of a living host cell.
- EpidemiologyEpidemiology is the study of how often diseases and other health events occur in populations, what causes them and how they can be controlled.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- CDC Principles of Epidemiology, Lesson 1 Section 9: Natural History and Spectrum of Disease
- OpenStax Microbiology, 15.1 Characteristics of Infectious Disease
- NCBI MeSH: Infectious Disease Incubation Period
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