window period

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window period

1. a critical interval of time.
See also: window (2).
See also: incubation period.
2. the interval that elapses between infection or inoculation with a pathogen and the onset of symptoms or of detectability of infection by laboratory testing.
See also: incubation period.
3. the time between infection with a bloodborne virus and the appearance of specific laboratory evidence of infection in a specimen of blood obtained from the asymptomatic host for the purpose of diagnostic screening, or in blood or blood products donated by the host.

In clinical medicine and blood banking, the window period (sense 3 above) refers to the earlier part of the incubation period of an infectious disease, during which the host is or may be infectious to others, but where the presence of infection has not yet caused symptoms and cannot be detected by laboratory testing. Bloodborne viral infections, particularly those due to human immunodeficiency virus (HIV-1) and hepatitis C virus (HCV), can be transmitted sexually, by sharing of needles among intravenous drug abusers, from mother to fetus, by transfusion of blood or blood products, and by accidental needlestick injuries among health care workers. The window periods of these infections are of critical importance in the early detection of transmissible infection in asymptomatic people and in the screening of donor blood. Because those harboring these viruses typically become infectious well before the end of the window period, the challenge is to shorten the period as much as possible by the use of maximally sensitive tests. An important limitation in determining the window period is the difficulty of fixing its beginning, which requires precise knowledge of the time when infection was acquired-often not available except in cases of accidental exposure to body fluids in health care workers, as in needlestick injuries. The definition of the window period has evolved with the emergence of increasingly sensitive tests to detect infection. Early definitions were based on the interval between infection and the appearance of detectable antibody to virus. The development of tests for the presence of viral antigen in plasma shortened the window period, permitting detection of viral material and infectivity before the occurrence of an immune response. Nucleic acid testing, involving detection of viral DNA or RNA after amplification of the specimen by polymerase chain reaction, has reduced the window period for detection of HCV from 82-25 days and of HIV from 22-12 days.

Infectious disease The period during which a pathogen can be detected in a patient specimen by nucleic acid testing, but not by serology, as the patient’s immune system has not yet responded to the pathogen by producing measurable levels of antibodies
Toxicology The period which corresponds to the interval between ingestion of lethal quantities of a drug or toxin, and development of irreversible organ damage

window period

AIDS An interval between initial infection of HIV and development of anti-HIV-1 antibodies, usually 3–6 months Immunology An interval between the time of inoculation or exposure to a microorganism, usually viral, and the ability to detect its presence by serologic assays which detect the production of antibodies by the host, or the presence of the pathogen's antigens

win·dow pe·ri·od

(windō pērē-ŏd)
1. Critical time interval.
2. Time between infection with a bloodborne virus and the appearance of specific laboratory evidence of infection in a specimen of blood obtained from the asymptomatic host for the purpose of diagnostic screening, or in blood or blood products donated by the host.

window period,

n the period between when a party is exposed to an infectious organism and when that organism becomes detectable via a serum marker. See incubation period.
References in periodicals archive ?
All business plans received by the Commonwealth during the two 2015 open window periods will receive equal consideration for the RACP funding available in this round.
Despite the relief the two window periods can provide, however, neither window period is available if the method for the item being changed is an issue under consideration as part of a controlling shareholder's exam (see, e.
There are a total of 15 open windows (approximately 3 per year), and submissions may occur at any time during those open window periods.
Firstly, we experienced a great end to the footy season, and the drama is set to continue in what should prove to be one of the most exciting transfer window periods ever, especially after Ol' Winky himself has finally decided to cash in his chips and go and live the cushy life out in Madrid.
Between me and OM (Marseille), it is always the same trite news story, which reappears during transfer window periods.
Germany and Italy have already been allowed to extend their open window periods with England and France hoping to follow suit.
Sturgis Bancorp executives and board members have a limited number of window periods in which to purchase or sell Sturgis Bancorp stock.
92-20, including modifications of general filing requirements, window periods, rulers for taxpayers under examination, and terms and conditions -- most important, the elimination of the Category A and B distinction and the provision of a uniform four-year section 481(a) adjustment.
Any trade by members of the Group Executive will only occur during open window periods and in compliance with RBC policies and regulatory and governance requirements.
Any transfer restrictions imposed on A's sales (or other trading) by the referenced agreements were "lapse restrictions"--demonstrated by both their tolling (the underwriter's agreement and the lock-up agreements) and the window periods (the insider trading compliance program).
Furthermore, the rules provide various window periods within which voluntary accounting method changes may be secured, following contact for examination but before a compulsory change imposed by the Commissioner.
The plan covers only options that are due to expire in September 2008, and allows the officer to sell Sensient stock acquired as a result of exercising the options during two window periods starting in April 2008 and ending in August 2008.