تويت
السلام عليكم ورحمة الله وبركاته
أخواني الاعزاء زبدة الكلام في المصدر الاساسي للدكاترة في العالم أجمع وليس للدكاتره في هذا المنتدى وهو مركز السيطرة على الامراض في امريكا
وخلاصة الكلام :
بعد كم من التعرض للاصابة يمكن الانتظار حتى يمكننى عمل تحليل الاتش اي فيه
97% بعد ثلاثة أشهر والباقي في حالات نادرة جدا حتى ستة شهور
يعني كل الناس في خلال من 2 إلى 8 أسابيع الى ثلاثة شهور وحالات نادرة الى ستة شهور لا غير
والمصدر الثاني وتحديث جديد جدا في شهر سبتمبر 2008 من ولاية نيويورك مرفق في الاسفل
من النادر جدا أن لا تتكون الاجسام المضادة لدى معظم الناس في ثلاثة شهور ومن قام بعمل فحص بعد ثلاثة شهور لا يحتاج لاعادة الفحص مرة أخرى
هذا مذكور في أخر تحديث
وللعلم يا أخواني هذي المصادر هي المصادر التي يأخذ منه العالم أجمع المعلومات وهي مركز السيطرة على الامراض في أمريكا
كما أحب أن أشير الى أن هذه المراكز لا تقوم بوضع هذا الكلام الا بعد أبحاث ودراسات على مرضى لسنوات عدة والله أعلم وليس كما هو موجود في الوطن العربي
اسئل الله الرحمن الرحيم أن يفرج هم وغم كل مكروب ومهموم من المسلمين
وجزاكم الله خيرا ولا تنسونا من صالح دعائكم بظهر الغيب
How long after a possible exposure should I wait to get tested for HIV?
Most HIV tests are antibody tests that measure the antibodies your body makes against HIV. It can take some time for the immune system to produce enough antibodies for the antibody test to detect, and this time period can vary from person to person. This time period is commonly referred to as the “window period.” Most people will develop detectable antibodies within 2 to 8 weeks (the average is 25 days). Even so, there is a chance that some individuals will take longer to develop detectable antibodies. Therefore, if the initial negative HIV test was conducted within the first 3 months after possible exposure, repeat testing should be considered >3 months after the exposure occurred to account for the possibility of a false-negative result. Ninety-seven percent of persons will develop antibodies in the first 3 months following the time of their infection. In very rare cases, it can take up to 6 months to develop antibodies to HIV.
Another type of test is an RNA test, which detects the HIV virus directly. The time between HIV infection and RNA detection is 9–11 days. These tests, which are more costly and used less often than antibody tests, are used in some parts of the United States.
For information on HIV testing, you can talk to your health care provider or you can find the location of the HIV testing site nearest to you by visiting the National HIV Testing Resources Web site at http://www.hivtest.org or call CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348 (TTY), in English, en Español. Both of these resources are confidential.
If you would like more information or have personal concerns, call CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348 (TTY), in English, en Español.
Back to top
Last Modified: January 22, 2007
Last Reviewed: January 22, 2007
Content Source:
Divisions of HIV/AIDS Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
هذا مصدر ولاية نيويورك في شهر سبتمبر 2008
Update on the Window Period
September 2008
1. What is the Window Period?
The window period is the length of time after infection that it takes for a person to develop enough specific antibodies to be detected by our current testing methods. If an individual engages in unsafe sex or shares drug injection equipment and becomes infected, the body will make antibodies to fight HIV. When enough antibodies are developed, the HIV antibody test will come back positive. Each person's body responds to HIV infection a little differently, so the window period varies slightly from person to person. HIV is most commonly diagnosed in adolescents and adults through HIV antibody testing. However, there are also tests that diagnose HIV infection by detecting certain parts of the genetic material of HIV. PCR tests (polymerase chain reaction, often the same tests used to monitor the ‘viral load’ response to HIV therapy) are used to diagnose HIV infection in infants and to make the diagnosis of acute HIV infection. These HIV PCR tests are used when the clinical suspicion is high for acute HIV infection, the standard screening antibody tests are negative, and the confirmatory Western blot tests are either negative or indeterminant. Viral culture may also be performed in certain circumstances to diagnose HIV, but this method is now rarely ever used.
2. How Has Our Understanding of the Window Period Changed Over the Years?
Early in the epidemic, our testing methods were not as sensitive as they are today. Doctors and public health officials wanted to make sure that people who engaged in risk behaviors for HIV were tested long enough after their risk to be sure that anyone who was actually infected would test positive. The Centers for Disease Control currently states that people with possible exposure to HIV, who test negative, should be re-tested 6 months after the possible exposure to ensure that sufficient time has elapsed to make antibodies. Improvements in HIV testing technology, increasing laboratory experience with testing and the ability to better monitor early infection through PCR testing have contributed greatly to our understanding of the window period and have provided increased confidence that virtually all cases of HIV infection can be detected by the standard antibody screening tests 3 months after the possible exposure.
3. What is the best time for the first HIV test after a possible exposure to HIV?
Most people infected with HIV will develop enough antibodies to be detected by our current HIV antibody tests 4 weeks after the exposure. This means that, for example, if a person had unsafe sex and became infected on January 1, it is likely that he/she will have enough antibodies to test positive 4 weeks later. If the person tests positive, this early testing is beneficial because the person can begin receiving medical care very early in the course of the infection. Recent advances in care and treatment for HIV infection have increased the advantages of early identification and treatment. Therefore, especially when HIV infection is highly suspected, the first HIV test should take place 4 weeks after the exposure. In cases of occupational exposure or exposure through sexual assault, an HIV test is also recommended immediately after the exposure to establish baseline HIV status. The protocol for testing following occupational exposure recommends testing at baseline, 1 month, 3 months, and 6 months post-exposure. See HIV Prophylaxis Following Occupational Exposure.
4. How long after a possible exposure to HIV does the person have to wait to be tested to be sure he/she is not infected?
It is possible that someone who tests negative 4 weeks after an exposure may be infected but his/her body has not had sufficient time to develop antibodies. Therefore, to rule out HIV infection, it is important to re-test 3 months after the exposure. If symptoms suggestive of HIV acute seroconversion syndrome (e.g., fever, fatigue or malaise, joint pain, headache, loss of appetite, rash, night sweats, myalgias, nausea or diarrhea, pharyngitis) develop, medical evaluation should occur immediately. A plasma HIV RNA assay should be used in conjunction with an HIV-1 antibody test to diagnose acute HIV infection. It is extremely rare for an HIV-infected individual to not develop antibodies by 3 months. An individual who tests negative 3 months after an exposure does not require further testing unless he/she may has had repeated exposures or if their antibody test results are incompatible with their clinical history.
5. What is the recommendation for testing individuals who engage in on-going risk behavior?
The primary focus of our work with individuals who place themselves at ongoing risk for HIV infection must be continued education, behavioral counseling and harm reduction, such as education about safer injection practices and referral to syringe exchange programs and drug rehabilitation services. HIV testing offers no "protection" from HIV infection. When an individual is engaging in ongoing risk behavior, it is not possible to develop a timeline for re-testing based on a single exposure. An individual with a negative HIV test who engages in on-going risk behavior should be offered testing every 3 months and counseled to avoid risk behavior. In these cases, the function of testing is to ensure early access to care in the event that the individual becomes HIV positive.
For more information about the window period, consult the following articles:
Bartlett JG. Serology and baseline laboratory studies for human immunodeficiency virus infection. Infect Dis Clin Pract 1995;4:334-342.
Busch W, Lee LL, Satten GA, et al. Time course of defection of viral and serologic markers preceding human immunodeficiency virus type I seroconversion: Implications for screening of blood and tissue donors. Transfusion 1995;35:91-97.
Lackritz EK, Satten GA, Aberle-Grasse, et al. Estimated risk of the human immunodeficiency virus by screened blood in the United States. N Engl J Med 1995;333:1721-1725.
Patel P, Klausner JD, Bacon OM, et al. Detection of acute HIV infections in high-risk patients in California. J Acquir Immune Defic Syndr 2006;42:75-79.
Stekler J, Maenza J, Stevens CE, et al. Screening for acute HIV infection: Lessons learned. Clin Infect Dis 2007;44:459-461
أخواني الاعزاء زبدة الكلام في المصدر الاساسي للدكاترة في العالم أجمع وليس للدكاتره في هذا المنتدى وهو مركز السيطرة على الامراض في امريكا
وخلاصة الكلام :
بعد كم من التعرض للاصابة يمكن الانتظار حتى يمكننى عمل تحليل الاتش اي فيه
97% بعد ثلاثة أشهر والباقي في حالات نادرة جدا حتى ستة شهور
يعني كل الناس في خلال من 2 إلى 8 أسابيع الى ثلاثة شهور وحالات نادرة الى ستة شهور لا غير
والمصدر الثاني وتحديث جديد جدا في شهر سبتمبر 2008 من ولاية نيويورك مرفق في الاسفل
من النادر جدا أن لا تتكون الاجسام المضادة لدى معظم الناس في ثلاثة شهور ومن قام بعمل فحص بعد ثلاثة شهور لا يحتاج لاعادة الفحص مرة أخرى
هذا مذكور في أخر تحديث
وللعلم يا أخواني هذي المصادر هي المصادر التي يأخذ منه العالم أجمع المعلومات وهي مركز السيطرة على الامراض في أمريكا
كما أحب أن أشير الى أن هذه المراكز لا تقوم بوضع هذا الكلام الا بعد أبحاث ودراسات على مرضى لسنوات عدة والله أعلم وليس كما هو موجود في الوطن العربي
اسئل الله الرحمن الرحيم أن يفرج هم وغم كل مكروب ومهموم من المسلمين
وجزاكم الله خيرا ولا تنسونا من صالح دعائكم بظهر الغيب
How long after a possible exposure should I wait to get tested for HIV?
Most HIV tests are antibody tests that measure the antibodies your body makes against HIV. It can take some time for the immune system to produce enough antibodies for the antibody test to detect, and this time period can vary from person to person. This time period is commonly referred to as the “window period.” Most people will develop detectable antibodies within 2 to 8 weeks (the average is 25 days). Even so, there is a chance that some individuals will take longer to develop detectable antibodies. Therefore, if the initial negative HIV test was conducted within the first 3 months after possible exposure, repeat testing should be considered >3 months after the exposure occurred to account for the possibility of a false-negative result. Ninety-seven percent of persons will develop antibodies in the first 3 months following the time of their infection. In very rare cases, it can take up to 6 months to develop antibodies to HIV.
Another type of test is an RNA test, which detects the HIV virus directly. The time between HIV infection and RNA detection is 9–11 days. These tests, which are more costly and used less often than antibody tests, are used in some parts of the United States.
For information on HIV testing, you can talk to your health care provider or you can find the location of the HIV testing site nearest to you by visiting the National HIV Testing Resources Web site at http://www.hivtest.org or call CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348 (TTY), in English, en Español. Both of these resources are confidential.
If you would like more information or have personal concerns, call CDC-INFO 24 Hours/Day at 1-800-CDC-INFO (232-4636), 1-888-232-6348 (TTY), in English, en Español.
Back to top
Last Modified: January 22, 2007
Last Reviewed: January 22, 2007
Content Source:
Divisions of HIV/AIDS Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
هذا مصدر ولاية نيويورك في شهر سبتمبر 2008
Update on the Window Period
September 2008
1. What is the Window Period?
The window period is the length of time after infection that it takes for a person to develop enough specific antibodies to be detected by our current testing methods. If an individual engages in unsafe sex or shares drug injection equipment and becomes infected, the body will make antibodies to fight HIV. When enough antibodies are developed, the HIV antibody test will come back positive. Each person's body responds to HIV infection a little differently, so the window period varies slightly from person to person. HIV is most commonly diagnosed in adolescents and adults through HIV antibody testing. However, there are also tests that diagnose HIV infection by detecting certain parts of the genetic material of HIV. PCR tests (polymerase chain reaction, often the same tests used to monitor the ‘viral load’ response to HIV therapy) are used to diagnose HIV infection in infants and to make the diagnosis of acute HIV infection. These HIV PCR tests are used when the clinical suspicion is high for acute HIV infection, the standard screening antibody tests are negative, and the confirmatory Western blot tests are either negative or indeterminant. Viral culture may also be performed in certain circumstances to diagnose HIV, but this method is now rarely ever used.
2. How Has Our Understanding of the Window Period Changed Over the Years?
Early in the epidemic, our testing methods were not as sensitive as they are today. Doctors and public health officials wanted to make sure that people who engaged in risk behaviors for HIV were tested long enough after their risk to be sure that anyone who was actually infected would test positive. The Centers for Disease Control currently states that people with possible exposure to HIV, who test negative, should be re-tested 6 months after the possible exposure to ensure that sufficient time has elapsed to make antibodies. Improvements in HIV testing technology, increasing laboratory experience with testing and the ability to better monitor early infection through PCR testing have contributed greatly to our understanding of the window period and have provided increased confidence that virtually all cases of HIV infection can be detected by the standard antibody screening tests 3 months after the possible exposure.
3. What is the best time for the first HIV test after a possible exposure to HIV?
Most people infected with HIV will develop enough antibodies to be detected by our current HIV antibody tests 4 weeks after the exposure. This means that, for example, if a person had unsafe sex and became infected on January 1, it is likely that he/she will have enough antibodies to test positive 4 weeks later. If the person tests positive, this early testing is beneficial because the person can begin receiving medical care very early in the course of the infection. Recent advances in care and treatment for HIV infection have increased the advantages of early identification and treatment. Therefore, especially when HIV infection is highly suspected, the first HIV test should take place 4 weeks after the exposure. In cases of occupational exposure or exposure through sexual assault, an HIV test is also recommended immediately after the exposure to establish baseline HIV status. The protocol for testing following occupational exposure recommends testing at baseline, 1 month, 3 months, and 6 months post-exposure. See HIV Prophylaxis Following Occupational Exposure.
4. How long after a possible exposure to HIV does the person have to wait to be tested to be sure he/she is not infected?
It is possible that someone who tests negative 4 weeks after an exposure may be infected but his/her body has not had sufficient time to develop antibodies. Therefore, to rule out HIV infection, it is important to re-test 3 months after the exposure. If symptoms suggestive of HIV acute seroconversion syndrome (e.g., fever, fatigue or malaise, joint pain, headache, loss of appetite, rash, night sweats, myalgias, nausea or diarrhea, pharyngitis) develop, medical evaluation should occur immediately. A plasma HIV RNA assay should be used in conjunction with an HIV-1 antibody test to diagnose acute HIV infection. It is extremely rare for an HIV-infected individual to not develop antibodies by 3 months. An individual who tests negative 3 months after an exposure does not require further testing unless he/she may has had repeated exposures or if their antibody test results are incompatible with their clinical history.
5. What is the recommendation for testing individuals who engage in on-going risk behavior?
The primary focus of our work with individuals who place themselves at ongoing risk for HIV infection must be continued education, behavioral counseling and harm reduction, such as education about safer injection practices and referral to syringe exchange programs and drug rehabilitation services. HIV testing offers no "protection" from HIV infection. When an individual is engaging in ongoing risk behavior, it is not possible to develop a timeline for re-testing based on a single exposure. An individual with a negative HIV test who engages in on-going risk behavior should be offered testing every 3 months and counseled to avoid risk behavior. In these cases, the function of testing is to ensure early access to care in the event that the individual becomes HIV positive.
For more information about the window period, consult the following articles:
Bartlett JG. Serology and baseline laboratory studies for human immunodeficiency virus infection. Infect Dis Clin Pract 1995;4:334-342.
Busch W, Lee LL, Satten GA, et al. Time course of defection of viral and serologic markers preceding human immunodeficiency virus type I seroconversion: Implications for screening of blood and tissue donors. Transfusion 1995;35:91-97.
Lackritz EK, Satten GA, Aberle-Grasse, et al. Estimated risk of the human immunodeficiency virus by screened blood in the United States. N Engl J Med 1995;333:1721-1725.
Patel P, Klausner JD, Bacon OM, et al. Detection of acute HIV infections in high-risk patients in California. J Acquir Immune Defic Syndr 2006;42:75-79.
Stekler J, Maenza J, Stevens CE, et al. Screening for acute HIV infection: Lessons learned. Clin Infect Dis 2007;44:459-461
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