How Accurate Is An Hiv Test What Is The Window Period For An Hiv Test
The current testing protocols are highly accurate but not perfect. The probability of a false result on the test depends on the test and on the person’s risk factors for getting infected. The lower the risk of getting HIV, the higher the probability of a false-positive result.
Falsely negative tests occur in people who are truly infected with HIV but have negative tests. Among 1,000 people who are truly infected, rapid tests will be falsely negative in zero to six people, depending on the test. Negative antibody tests in people infected with HIV may occur because antibody concentrations are low or because antibodies have not yet developed. On average, antibodies take about four weeks to reach detectable levels after initial infection, and falsely negative tests may occur during this so-called HIV window period. Individuals with negative tests and who had a high risk for HIV exposure should be retested in two to three months.
How Are Results Reported
Your test centre should clearly explain the results of your test.
If you have questions that were not explained, or that still worry you, ask the test centre first.
Rapid blood tests show two lines if positive or one line if negative, in a similar way as a pregnancy test .
Results from laboratory tests are given as negative, positive or indeterminate.
Negative or non-reactive means you are HIV negative. You do not have HIV .
Positive or reactive means the test shows you are HIV positive and you have HIV infection.
Indeterminate means the test result was unclear and needs to be repeated.
If You Have A Negative Test Result Does That Mean That Your Partner Is Hiv
No. Your HIV test result reveals only your HIV status.
HIV is not necessarily transmitted every time you have sex or share needles, syringes, or other drug injection equipment. And the risk of getting HIV varies depending on the type of exposure or behavior. Therefore, taking an HIV test is not a way to find out if your partner has HIV.
It’s important to be open with your partner and ask them to tell you their HIV status. But keep in mind that your partner may not know or may be wrong about their status, and some may not tell you if they have HIV even if they are aware of their status. Consider getting tested together so you can both know your HIV status and take steps to keep yourselves healthy.
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What You Can Do
If a healthcare provider makes an HIV diagnosis, they will help determine the best treatment. Treatments have become more effective over the years, making the virus more manageable.
Treatment can start right away to reduce or limit the amount of damage to the immune system. Taking medication to suppress the virus to undetectable levels in the blood also makes it virtually impossible to transmit the virus to someone else.
If a person receives a negative test result but isnt sure if its accurate, they should get retested. A healthcare provider can help determine what to do in this situation.
What If Your Hiv Test Result Is Negative
If your HIV test result is negative, it doesn’t necessarily mean you don’t have HIV. That’s because of the window periodthe time between when a person gets HIV and when a test can accurately detect it. The window period varies from person to person and depends on the type of HIV test you take.
Ask your health care provider or testing counselor about the window period for the type of HIV test youre taking. If youre using a self-test, you can find that information in the test package.
If your test result is negative,get tested again after the window period to be sure. If your test result is negative again, and you have had no possible HIV exposure during the window period, then you do not have HIV.
Whats next? Now is a good time to think about your HIV prevention options. If youre sexually active or use needles to inject drugs, continue to take actions to prevent HIV, like taking pre-exposure prophylaxis, or PrEP if youre at high risk or using condoms the right way every time you have sex.
If you have certain risk factors for HIV, you should continue to get tested at least once a year. Learn more about who is at risk for HIV and why they should be tested more often.
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B The Method Of Performing The Hiv Rapid Test
F Management If The First Hiv Rapid Test Is Positive But The Second Is Negative
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Study Design And Population
This cross-sectional study was nested within a larger cluster randomized controlled trial implemented among pregnant women attending antenatal care at three health facilities , Entebbe Hospital and Nakaseke Hospital) in central Uganda. Details about the larger trial have been described elsewhere . In brief, a total of 1514 pregnant women were randomly enrolled into the intervention or the control arm . Intervention arm respondents received at least two HIVST kits while control arm respondents received information on the importance of male partner HIV testing but no HIVST kits were distributed. All respondents were followed for 3 months to assess differences in male partner HIV testing between the intervention and control arms. Intervention arm respondents were asked to return used HIVST kits to compare the results read by the client to the results read by a member of the study team. The main study was conducted between July 2016 and March 2017.
Fig. 1
What Are The Advantages Of A Rapid Hiv Test
The rapid test allows for testing of more individuals. According to the CDC, 1.2 million Americans have HIV, but up to one in eight don’t know it. About 44,000 Americans per year become infected with HIV. This number has decreased recently due, in part, to more testing. Among those who get tested using traditional methods, 31% of those who test positive do not return for their results .
People give a variety of reasons for not returning for their test results. The frequency of each response depends on the population being tested. The most commonly given reasons include the following:
- Fear of a positive result
- Lack of transportation
- Relocating to a new city
- Belief that they are at low risk for HIV and therefore the result will be negative
- Fear that their HIV status will be disclosed to someone else
Significant benefits of the rapid HIV test include the following:
Once important difference between the conventional laboratory test and rapid tests is the ability to detect very early or acute HIV infection. This is done with the addition of an HIV RNA PCR or NAT test. HIV RNA appears in the blood within the first few days of infection. If the antibody test is negative but the NAT is positive, this may indicate that the patient is very newly infected. NAT testing is also used to confirm a positive result of the third- or fourth-generation test. Western Blot testing is no longer routinely used.
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Integrating Rapid Hiv Testing Into Fast
Kevin Armington, MDClinical Director of HIV ServicesCallen-Lorde Community Health CenterSummary by Tim HornEdited by Bernard M. Branson, MD, and Susan Forlenza, MD, MPH
Reprinted from The PRN Notebook® | June 2005 | Dr. James F. Braun, Editor-in-Chief Tim Horn, Executive Editor | Published in New York City by the Physicians Research Network, Inc.® | John Graham Brown, Executive Director | All rights reserved. ©June 2005
When it comes to HIV infection, the need for improved diagnostic care couldnt be more evident. According to the U.S. Centers for Disease Control , 29% of HIV-infected persons in this country are unaware of their HIV status. CDC surveillance data also indicate that 37% of persons who test positive for HIV develop AIDS within a year after their diagnosis, meaning that many individuals likely remain unaware of their infection for several years, potentially putting their own healthand the health of othersin jeopardy. New York City Department of Health and Mental Hygiene statistics mirror those of the CDC: approximately 25% of HIV-positive New Yorkers learn that they are infected with HIV at the time of an AIDS diagnosis.
Another central concern is the fact that between 27,000 and 30,000 of blood tests conducted annually at publicly funded testing sites are positive for HIV antibodies. However, approximately 31% of those who test positive do not return to anonymous testing sites to receive their results.
Finding The Cause Of A False
Since there are various reasons for false-positive results, individuals should speak with a doctor about the probable cause. Some may be due to human error, such as a technical or clerical oversight.
However, a false-positive result can also result from another condition, such as an STI or an autoimmune disorder. Autoimmune disorders that may cause false-positive results include lupus and rheumatoid arthritis.
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How Is Hiv Diagnosed
Healthcare providers typically use an enzyme-linked immunosorbent assay, or ELISA test, to test for HIV. This test detects and measures HIV antibodies in the blood. A blood sample via a finger prick can provide rapid test results in less than 30 minutes. A blood sample through a syringe will most likely be sent to a lab for testing. It generally takes longer to receive results through this process.
It usually takes several weeks for the body to produce antibodies to the virus once it enters the body. The body typically generates these antibodies three to six weeks after exposure to the virus. This means that an antibody test may not detect anything during this period. This is sometimes called the window period.
Receiving a positive ELISA result doesnt mean that a person is HIV-positive. A small percentage of people may receive a false-positive result. This means the result says they have the virus when they dont have it. This can happen if the test picks up on other antibodies in the immune system.
All positive results are confirmed with a second test. Several confirmation tests are available. Typically, a positive result must be confirmed with a test called a differentiation assay. This is a more sensitive antibody test.
Do I Have To Tell My Sexual Partner
It is difficult to decide if, when, and how to tell people that you have HIV .
It is important to understand the law around sharing your status where you live. In some countries you must tell your sexual partners you have HIV.
Sharing your status can be hard, and help is available. Speak to your healthcare professional.
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About Rapid Hiv Testing Top Of Page
There are four rapid HIV tests approved by the U.S. Food and Drug Administration. Two of these assays are designed to be POC tests, in both medical and non-medical settings. They can also be performed in separate laboratories after a specimen has been obtained.
Figure 1. Performing an OraQuick Rapid Advance Antibody Test
A sample OraQuick Rapid Advance antibody test is shown here . To collect a specimen for the test, either touch the collection loop to a fingerstick blood droplet or use standard phlebotomy collection procedures for whole blood with the following test tubes: EDTA, Sodium Heparin, Sodium Citrate, or ACD Solution and dip the collection loop into the test tube . Five microliters of whole blood should adhere to and fill a single collection loop . Insert the loop and stir the specimen in the vial of developer solution . The OraQuick device is inserted into the developer vial where it remains until the results are read . Test results must be read no sooner than 20 minutes but no later than 40 minutes after the device is added to the developer solution .
Source:Orasure, Inc. U.S. Centers for Disease Control and Prevention
Any medical office, clinic, or organization that performs a rapid HIV test to provide results to patients is considered to be a laboratory under the Clinical Laboratory Improvement Amendments of 1988 . As a result, all laboratories must comply with the regulations of the CLIA Program and with any applicable state requirements.
What Do Your Hiv Test Results Mean
If youve just had an HIV test, you may be wondering what a positive or negative test result means. If you were tested in a health care providers office, a clinic, or a community setting, the provider or testing counselor will explain what your result means and talk to you about the next steps. If you used a rapid HIV self-test at home or another private location, the package materials will provide this information, along with a phone number you can call.
Below are answers to some of the most common questions.
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Technical Or Clerical Error
Mishandling samples, mislabeling, and mixing up specimens can occur during testing. At-home tests may also be prone to user error. Some testing devices may rely on subjective interpretation when reading a result, leading to incorrect interpretations when results are borderline.
of new HIV transmissions are from people who do not know that they have HIV.
The risk of HIV transmission depends on the behavior or exposure. The CDC measures a specific behaviors likelihood to transmit HIV for every 10,000 exposures.
Blood transfusion has the highest risk of transmitting HIV. Receptive anal sex, or receiving the penis into the anus, also increases transmission risk. A 2010 meta-analysis found a 1.4% risk of transmission, or 1 in every 71 exposures, from unprotected anal sex, regardless of whether the receptive person is male or female.
Needle sharing also carries some risk. A person has a chance of getting HIV when they share a needle with a person with the condition.
Performing An Hiv Test Using The Uni
The procedure for this test is very similar to that used for the KHB and STAT-PAK tests. However, there are some differences. The procedure for the Uni-gold test is outlined below.
First, collect the test items and other necessary laboratory supplies. Remove the Uni-gold device from its packaging, and label it using a code number or a client identification number. The Uni-gold also has a sample port and an area where the control and test lines are read.
Unlike the other tests, blood is collected from the punctured finger using a pipette and then two drops of blood are placed into the sample port of the Uni-gold device . Two drops of running buffer are then also added to the sample port.
µl means microlitre.
Now wait for ten minutes for the test to develop. The control line will be the first to show, and this indicates that the test is working correctly and is valid.
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What Does A Positive Result Mean
You will need a second test to confirm the result. In some countries you will need three tests in total to confirm the result.
If you get a positive result after using a self-test kit you will need to go to a healthcare clinic.
If your final test result is positive, it means you do have HIV. Receiving a positive diagnosis can be a shocking and emotional experience this is completely normal. The healthcare worker will support you and answer any questions that you have.
You can now start treatment straight away which will keep you healthy.
Implementing Rapid Hiv Testing
Six possible results using the OraQuick Advance antibody test. A nonreactive test will yield a line in the control area and no line present in the test area . A nonreactive test result should be interpreted as negative for HIV-1 antibodies. A reactive test will yield a line in the control area and a line in the test area . A reactive test result should be interpreted as a preliminary positive for HIV-1 antibodies and must be confirmed. Also shown here are three examples of invalid test responses , which require that a second test be performed. A weakly reactive test will yield a line in the control area and a weak line present in the test area . Follow-up testing is recommended to confirm an initial weakly active result.
Source:Orasure, Inc. U.S. Centers for Disease Control and Prevention
The successful implementation of rapid HIV testing does not begin with the assay itself, but rather with pre-testing counseling. Everything thats required for standard EIA and Western blot is required for rapid testing, Dr. Armington said. Pre-test counseling still needs to be done.
With the conclusion of the pre-test counseling, the collection of informed consent, and the results of the assay available, its time to deliver the news to the individual receiving the test.
Figure 4. Performing a Uni-Gold Recombigen HIV-1 Antibody Test
Source:Trinity Biotech U.S. Centers for Disease Control and Prevention.
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