<unk>  (also known as the latent<unk>  or latency<unk>  is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, the<unk>  signifies the<unk>  taken by the multiplying organism to reach a threshold necessary to produce symptoms in the host. In some diseases, as depicted in this diagram, the latency<unk>  is shorter than the<unk> . After the latency<unk>  (but prior to clinical infection) the infected person can transmit the disease without signs of any symptoms. Such infection is called subclinical infection. While latent or latency<unk>  may be synonymous, a distinction is sometimes made whereby the latent<unk>  is defined as the time from infection to infectiousness. Which<unk>  is shorter depends on the disease. A person may carry disease, such as Streptococcus in the throat, without exhibiting any symptoms. Depending on the disease, the person may or may not be contagious during the<unk> . During latency, an infection is subclinical. With respect to viral infections, in<unk>  the virus is replicating. This is in contrast to viral latency, a form of dormancy in which the virus does not replicate. An example of latency is HIV infection. HIV may at first have no symptoms and show no signs of AIDS, despite HIV replicating in the lymphatic system and rapidly accumulating a large viral load. People with HIV in this stage may be infectious.
Incubation period
Benefit period
Risk factor
Vaccine efficacy
Epidemic curve
Disease cluster
Median lethal dose
Risk of mortality