Window period is defined as the time taken from:

Ans. b. Exposure to laboratory detection of disease (Ref: Park 23/e p99, 22./e p95)Window period is defined as the time taken from Exposure to laboratory detection of disease."Window Period: Time between first infection & when the test can reliably detect that infection." Disease Transmission: DefinitionsWindow period* Time between first infection & when the test can reliably detect that infection* In antibody-based testing, the window period is dependent on the time taken for seroconversionIncubation periodQ* Time interval between invasion by an infectious agent and appearance of the first sign or symptom of the disease in questionMedian incubation periodQ* Time required for 50% of cases to occur following exposureGeneration timeQ* Time taken for a person from receipt of infection to develop maximum infectivity* Roughly equal to the incubation period of the diseaseLatent periodQ* Period from disease initiation to disease detection,* Used in non-infectious diseases as equivalent of incubation periodSerial intervalQ* Gap in onset between primary case (first case in the community) and secondary case (case devetoping through infection from the primary case)* By collecting information on series of secondary cases with serial intervals, one can guess the incubation period of a diseasePeriod of communicabilityQ* Time during which an infectious agent may be transferred directly/indirectly from an infected person to another person, from infected animal to man or from an infected person to animal, including arthropods* An important measure of communicability is secondary attack rate