infektime

InfekTime is a term used in epidemiological modeling to denote the estimated time of infection for an individual within a transmission chain. It is an inferred latent variable distinct from the onset of symptoms or from a positive test date.

Definition: InfekTime for person i is the time point when the infection occurred, usually represented as a probability distribution reflecting uncertainty.

Calculation: InfekTime is inferred from data such as exposure windows, contact networks, dates of symptom onset, and testing results. Methods include back-calculation, Bayesian inference, Markov chain Monte Carlo, and particle filtering. The result is a posterior distribution or point estimate with uncertainty.

Applications: It supports reconstruction of transmission trees, estimation of generation time, assessment of intervention timing, and validation of outbreak simulations.

Relationship to other concepts: It is related to, but distinct from, the incubation period (infection to symptoms) and the latent period (infection to infectiousness).

Limitations: Estimation relies on accurate data and explicit model assumptions; results carry substantial uncertainty, especially with incomplete exposure information or asymptomatic cases.

Notes: In some literature, infection timing is referred to more generically; InfekTime is a name used in certain modeling frameworks or discussions to emphasize the probabilistic nature of the estimate.

See also: incubation period; latent period; generation time; serial interval; back-calculation; transmission tree.