Inkubaatioaika

Inkubaatioaika, in epidemiology often referred to as the incubation period, is the interval between exposure to a pathogenic agent and the onset of clinical symptoms. It describes how long after infection symptoms may appear and can vary widely depending on the disease and individual factors.

Several factors influence the length of the inkubaatioaika, including the infectious dose, route of entry, characteristics of the pathogen, and host factors such as age, immune status, and comorbidities. The incubation period is distinct from the latent period (time to becoming infectious) and from the overall infectious period.

Typical ranges for common diseases vary widely. Influenza generally has an incubation of 1–4 days, while SARS-CoV-2 infections commonly show symptoms after about 2–14 days. Measles has around 10–12 days, and varicella-zoster about 10–21 days. Norovirus infections often present within 12–48 hours, whereas tuberculosis can have an incubation of 2–12 weeks, and syphilis 10–90 days. Incubation periods are often right-skewed and modeled using distributions such as the log-normal; reporting often focuses on medians and percentiles for risk assessment.

Applications of the inkubaatioaika include planning quarantine and surveillance, and guiding outbreak investigations. Limitations arise from uncertainties in the timing of exposure, multiple exposures, and asymptomatic infections, which can complicate estimation and public health decision-making.