Incubation Period

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incubation period

[‚iŋ·kyə′bā·shən ‚pir·ē·əd]
The period of time required for the development of symptoms of a disease after infection, or of altered reactivity after exposure to an allergen.
(vertebrate zoology)
The brooding period required to bring an egg to hatching.

Incubation Period


(or incubation), the time interval from the moment of infection to the appearance of the clinical symptoms of a disease.

For each infectious disease, the incubation period has a characteristic length, although the length may vary depending on the number of microbes that entered the body, their pathogenicity, the physical condition of the body itself (previous traumas and illnesses, malnutrition, vitamin deficiency), and the site of entry of the infection. Vaccination, seroprophylaxis, and chemotherapy prolong the incubation period.

Table 1. Length of incubation periods of some infectious diseases
 Length of incubation period (in days)
Most frequent “average”MinimumMaximum
Rabies . . . . . . .40123-6 months (rarely up to 1 year)
Botulism . . . . . .12-24 hours1-2 hours1 (rarely more)
Brucellosis . . . . .14720-30
Typhoid fever . . .143–421
Chicken pox . . . .11–141021
Influenza . . . . . .2a few hours3
Dysentery . . . . .32 hours7
Diphtheria . . . . .527–10
Whooping cough .7–9214–15
Measles . . . . . .8–10717 and 21 (with injection of serum)
Malaria . . . . . . .10–15631 (in tertian malaria, sometimes 7–11 months)
Epidemic parotitis (mumps) . . . . . .11921
Poliomyelitis . . . . .7–14335
Scarlet fever . . .3–6a few hours7–12
Tetanus . . . . . . .7–14140 (sometimes upon removal of splinters, a few years)
Typhus . . . . . . .12–14620
Tularemia . . . . . . .8121
Epidemic cerebrospinal meningitis2–3a few hours7
Foot-and-mouth disease . . . . .426

In some infectious diseases (such as measles and diphtheria) causative agents are discharged into the environment during the incubation period; this leads to the infection of other persons. The length of the incubation period is important in discovering the source of infection and sometimes also for establishing a diagnosis.


References in periodicals archive ?
Distinct prion proteins in short and long scrapie incubation period mice.
A second Australian case, with a long incubation period.
If the incubation period is 10 years, then we are in the middle of the epidemic.
For case-patients with [greater than or equal to] 2 exposure days (n = 18), and for case-patients with a single exposure day (n = 6), the overall median incubation period was longer for those who had visited a wet poultry market than for those who were exposed to sick or dead poultry, but the difference was not significant.
Throughout the ensuing risk incubation period of stage two, therefore, it's essential that managers take a disciplined approach that applies both hindsight and foresight techniques to detect possible problems.
Speaking exclusively to Gulf News from the UK, John Oxford, Professor of Virology at the University of London, said that the nine- to 10-day incubation period of Mers makes it easier for public health interventions.
Our incubation period analyses included data for 453 patients (infected with a total of 11 strains) from 19 studies (Table 1); data for 6 of the patients were excluded because of highly outlying covariate patterns (online Technical Appendix, wwwnc.
For example, factors affecting the onset of incubation and quantitative contributions of male and female to incubation period are poorly recognized.
Experts have found the incubation period of variant CJD may depend on a victim's genetic make-up.
The egg and incubation period of the Peruvian Antpitta (Grallaricula peruviana).
The incubation period is between three and five years and symptoms range from whitening of the skin to massive nodules and ulcers.
Since vCJD has an unknown, albeit lengthy, incubation period that is asymptomatic, there is no way to know how many people already have the disease and how many could have already transmitted it via blood transfusion.