When we get infected with any cold virus, it takes a while for the virus to replicate enough to cause symptoms. This period of being infected before symptoms show up is called the incubation period. The incubation time for chicken pox prior to the onset of the cold symptoms can be up to 24 days.

The average incubation period for mumps is 16-18 days, with a range of 12-25 days. Fever may persist for 3-4 days and parotitis, when present, usually lasts 7-10 days. Persons with mumps are usually considered infectious from 3 days before until 5 days after onset of parotitis.

In experimentally infected cats, signs were seen as early as 2 days after inoculation. In a single report describing a naturally infected cat, signs were observed 5 days after the cat ate the carcass of an infected pigeon.

The incubation period between exposure to infection and the development of symptoms appears to range from 2-10 days, with 3-5 days being more common.

For the red "bull's-eye" rash (erythema migrans), usually 7 to 14 days following tick exposure. Some patients present with later manifestations without having had early signs of disease. Most people feel weak or tired about 10 days to two weeks after being bitten.

The book, "Laboratory Testing for BOD and CBOD", by Brake and Raynovic, is the only reference (until recently) that discusses an absolute definition (± 2 hours). Both EPA and older editions of Standard Methods are silent on the issue. The 21st Ed. of Standard Methods says + 6 hours. We believe that you should strive to stay as close to the actual 5 day incubation period as you can, but certainly stay within 5 days ± 4-6 hours.

A person usually becomes ill with bubonic plague 2 to 6 days after being infected. When bubonic plague is left untreated, plague bacteria invade the bloodstream. When plague bacteria multiply in the bloodstream, they spread rapidly throughout the body and cause a severe and often fatal condition. Infection of the lungs with the plague bacterium causes the pneumonic form of plague, a severe respiratory illness.

A SARS carrier does not usually show clinical manifestations. The illness usually begins with a fever (temperature greater than 100.4°F). The fever is sometimes associated with chills or flu-like symptoms, including headache, general feeling of discomfort, and body aches 4.

The incubation period is usually 12 days following contact, although the incubation range is 7 to 17 days. Initial symptoms include high fever, weakness, head and backache. A rash appears in 2-3 days on the mouth, face, arms, and legs. The rash starts with flat red lesions. Lesions become pus-filled after a few days and then scab early in the second week. Scabs then separate and fall off after 3-4 weeks. Approximately 70% of people that get smallpox recover while 30% of the cases are fatal.