What Are Hiv Tests Used For
An HIV test kit is used to determine if you have contracted HIV. HIV is the virus that causes AIDS . Most people with HIV do not have AIDS. Cells and are at risk for life-threatening diseases, including dangerous infections, severe pneumonia, and certain cancers. If HIV is detected early, you can get medications that will help you protect your immune system. HIV medication can prevent you from getting AIDS.
Is Hiv Testing Necessary For Pregnant Women
HIV testing is critically important for pregnant women. HIV testing is recommended at the beginning of each pregnancy during prenatal care. If any HIV risk factors are present or there is a high incidence of HIV in the population, testing should be repeated in the third trimester. There have been enormous advances in the treatment of HIV-infected pregnant women. With proper management, the probability of transmitting the virus to the fetus is less than 2%. Without proper management, the risk of transmission is as high as 33%. Because undiagnosed HIV is so common, it is necessary to test all pregnant women. It is strongly recommended that all children born to women with HIV also be tested.
What Do The Results Mean
If your result is negative, it can mean you don’t have HIV. A negative result may also mean you have HIV but it’s too soon to tell. It can take a few weeks for HIV antibodies and antigens to show up in your body. If your result is negative, your health care provider may order additional HIV tests at a later date.
If your result is positive, you will get a follow-up test to confirm the diagnosis. If both tests are positive, it means you have HIV. It does not mean you have AIDS. While there is no cure for HIV, the disease can be effectively controlled with medicine. The medicine used to treat HIV is called antiretroviral therapy . ART can significantly reduce the amount of HIV in the blood. People with HIV who take ART before the disease gets too advanced can live long, healthy lives. If you are living with HIV, it’s important to see your health care provider regularly.
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Which Test Is Which
Figure 11 lists commonly used HIV tests and shows what type of test they are.
Your testing centre should tell you this information for the test that they use.
Sometimes testing centres give the tests explained above different names like ELISA or Western blot without explaining what kind of test they are and what it is they are looking for.
ELI, MEIA, ELFA, ECLIA use similar technology to ELISA tests.
UK guidelines recommend using 4th generation tests but 5% of clinics still use 3rd generation tests.
Ask your clinic for more detailed information about the type of test that they use.
Are These Figures Always Accurate
In some situations, these figures should be interpreted with caution:
- When tests are done with samples of fingerprick blood or oral fluid , their window periods are likely to be longer.
- Individuals who are taking pre-exposure prophylaxis or post-exposure prophylaxis may have a delayed antibody response, extending the window period.;
- The data are based on individuals with HIV-1 subtype B and its possible that tests are less sensitive to other subtypes.
British HIV Association, British Association for Sexual Health and HIV and British Infection Association. Adult HIV Testing Guidelines 2020.
Delaney KP et al. Time from HIV infection to earliest detection for 4 FDA-approved point-of-care tests. Conference on Retroviruses and Opportunistic Infections, abstract 565, 2018.
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What Do Hiv Test Results Mean
If an HIV antibody test is negative, no antibodies were detected. A negative test can indicate that a person is not infected with HIV , or that s/he has been exposed but their immune system has not had time to produce antibodies. Antibodies to HIV may take up to six months to develop after the initial exposure.
A positive HIV antibody test means that the body has been exposed to HIV .; A person with a positive HIV test will need to have further testing done to confirm this diagnosis. When a person has a positive HIV test, it does not mean that the person has AIDS or that the person will have AIDS in a certain amount of time–it only means that the person is infected with HIV.
How Long Are The Window Periods Of Different Hiv Tests
Basic information on testing
It is hard to say exactly how long the window period lasts, as there are variations between individuals and it is a difficult topic to research .
Nonetheless, a study by Dr Kevin Delaney and colleagues calculated window periods for a range of HIV testing assays. All these analyses were based on plasma samples. Window periods are likely to be several days longer when testing samples of fingerprick blood or of oral fluid, as will be normal when using rapid, point-of-care tests and self-testing devices. Unfortunately, precise figures for how much longer the window periods are have not yet been published.
The researchers analysis confirms that fourth-generation laboratory tests detect HIV infections between one and three weeks earlier than older antibody-only tests. Moreover, their data suggest that some countries guidelines which recommend retesting 90 days after a possible exposure to HIV are more cautious than they need to be.
Afourth-generation laboratory testis recommended in UK and US guidelines. It uses a sample of blood plasma or serum and can detect immunoglobulin G antibodies, immunoglobulin M antibodies and p24 viral antigen . Commonly used tests of this type include Abbott Architect HIV Ag/Ab, GS Combo Ag/Ab EIA and Siemens Combo HIV Ag-Ab.
- The median window period is 18 days . This indicates that half of all infections would be detected between 13 and 24 days after exposure.
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Routine Hiv Testing In Pregnancy
The CDC recommends that all pregnant women receive an HIV test in both their first and third trimester of pregnancy.;The CDC recommends that all pregnant women receive an HIV test in both their first and third trimester of pregnancy.The Illinois Perinatal HIV Prevention Act was enacted in 2003 to ensure that women are screened for HIV as early in pregnancy as possible.;HIV testing protocols for pregnant women should include the following according to the Illinois Perinatal HIV Prevention act:
The 24/7 Illinois Perinatal HIV Hotline serves as a resource for clinicians and medical and social service providers to assist with medical and social services for pregnant, HIV-positive women, to help ensure healthy outcomes for both mothers and their babies.;
Hiv Tests For Screening And Diagnosis
HIV tests are very accurate, but no test can detect the virus immediately after infection. How soon a test can detect HIV depends upon different factors, including the type of test being used. There are three types of HIV diagnostic tests: nucleic acid tests , antigen/antibody tests, and antibody tests.
An initial HIV test;usually will either be an antigen/antibody test or an antibody test. If the initial HIV test is a rapid test or a self-test;and it is positive, the individual should go to a health care provider to get follow-up testing. If the initial HIV test is a laboratory test and it is positive, the laboratory will usually conduct follow-up testing on the same blood sample as the initial test. Although HIV tests are generally very accurate,;follow-up testing;allows the health care provider to be sure the diagnosis is right.
Resources for FDA-approved laboratory tests, self-tests, and testing of self-collected samples are available. Learn more about testing in nonclinical settings and screening in clinical settings.
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The Healthcare Worker There To Help You
Before you test, your healthcare worker will talk to you about your sexual health and why youve decided to test. This is to help them understand your situation so they can offer you the best services and advice.
Remember, the healthcare professional is not there to judge you. There will be nothing you can say that they havent heard before so be honest with them, and ask as many questions as you want. Thats what theyre there for.
You should never feel pressured to test. The results will be completely confidential but you should only go through with it if you want to.
When Is It Ordered
Several organizations recommend routine screening for HIV:
- The Centers for Disease Control , American College of Physicians , and the U.S. Preventive Services Task Force recommend that anyone between the ages of 13 and 64 and pregnant women be screened for HIV at least once.
- The CDC and American College of Obstetricians and Gynecologists recommend that all pregnant women be screened. Repeat testing in the third trimester may be done for women at high risk. A woman who wants to make sure she is not infected with HIV before getting pregnant may opt to get tested
- The American Academy of Pediatrics advises that all sexually active youth be screened, and that youths between 16 and 18 years old who live in high risk areas be offered HIV testing at least once, regardless of sexual history.
For additional details on screening recommendations, see the articles for Teens, Young Adults, Adults, and Adults 50 and Up.
Annual screening is advised for those at high risk for HIV and is recommended when an individual:
- Has had unprotected sex with more than one partner since the last HIV test
- Is a man who has had sex with another man
- Has used street drugs by injection, especially when sharing needles and/or other equipment
- Has exchanged sex for drugs or money
- Has an HIV-positive sex partner
- Has had sex with anyone who falls into one of the categories listed above or is uncertain about their sexual partner’s risk behaviors
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How Confidential Are Hiv Test Results
Your HIV status, like other medical conditions and test results, is protected by the HIPAA Privacy Rule and cannot be shared with friends, family, or employers without your written permission. Your HIV status may be shared with your healthcare providers who have a “need to know” in order to treat you. Also, in order to determine the incidence of HIV and to provide appropriate prevention and care services, all new cases of HIV are reported to state and local health departments.
Certain testing centers provide either anonymous or confidential HIV testing and counseling. The FDA has approved one home testing device that allows you to remain anonymous and to get confidential results. You can also contact your state, county, or city health department to find out where testing may be available.
Other Tests Used In Hiv Treatment
The CD4 T-cell count is not an HIV test, but rather a procedure where the number of CD4 T-cells in the blood is determined.
A CD4 count does not check for the presence of HIV. It is used to monitor immune system function in HIV-positive people. Declining CD4 T-cell counts are considered to be a marker of progression of HIV infection. A normal CD4 count can range from 500 cells/mm3 to 1000 cells/mm3. In HIV-positive people, AIDS is officially diagnosed when the count drops below 200 cells/μL or when certain opportunistic infections occur. This use of a CD4 count as an AIDS criterion was introduced in 1992; the value of 200 was chosen because it corresponded with a greatly increased likelihood of opportunistic infection. Lower CD4 counts in people with AIDS are indicators that prophylaxis against certain types of opportunistic infections should be instituted.
Low CD4 T-cell counts are associated with a variety of conditions, including many viral infections, bacterial infections, parasitic infections, primary immunodeficiency, coccidioidomycosis, burns, trauma, intravenous injections of foreign proteins, malnutrition, over-exercising, pregnancy, normal daily variation, psychological stress, and social isolation.
This test is also used occasionally to estimate immune system function for people whose CD4 T cells are impaired for reasons other than HIV infection, which include several blood diseases, several genetic disorders, and the side effects of many chemotherapy drugs.
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What Are The Elisa Test And The Hiv Differentiation Assay
The enzyme-linked immunosorbent assay , also known as an enzyme immunoassay , detects HIV antibodies and antigens in the blood.
Antibodies are proteins produced by the immune system, which helps your body fight disease. The immune system produces the antibodies in response to the presence of foreign substances, such as viruses. By contrast, antigens are any foreign substance in the body that causes the immune system to respond.
The ELISA test is typically the first test ordered by a healthcare provider. In case of a positive result from this test, the ELISA test was previously followed by a test called a Western blot to confirm the diagnosis. However, the Western blot is no longer used, and today the ELISA test is followed by an HIV differentiation assay to confirm HIV infection. The provider may also order an HIV genetic material detection test.
The ELISA test is recommended if a person has been exposed to HIV or is at risk for contracting HIV. Those at risk for contracting HIV include:
- people who use intravenous drugs
- people who have sex without a condom, especially with someone who has HIV or an unknown HIV status
- people who have had sexually transmitted diseases
- people who had blood transfusions or blood clotting factor injections before 1985
Provides Information To Assist In Interpretation Of The Test Results
Negative results for both HIV-1 and HIV-2 antibodies usually indicate the absence of HIV-1 and HIV-2 infection. However, in patients with reactive initial combined HIV-1/-2 antigen and antibody test results, such negative results do not rule-out acute or early HIV infection. In this situation, the HIQNP / HIV-1 RNA Detection and Quantification, Prenatal, Plasma reflex test will be performed. For patients at risk for HIV-2 infection , testing for HIV-2 DNA/RNA is recommended.
Positive HIV-1 antibody but negative HIV-2 antibody results indicate the presence of HIV-1 infection. Together with reactive initial combined HIV-1/-2 antigen and antibody test results, individuals with such results are presumed to have HIV-1 infection. Verification of a first-time positive test result is recommended for the diagnosis of HIV-1 infection. Additional testing with a newly submitted plasma specimen for HIQNP / HIV-1 RNA Detection and Quantification, Prenatal, Plasma is recommended to verify and confirm the diagnosis of HIV-1 infection prior to initiating antiretroviral treatment.
Indeterminate HIV-1 antibody but negative HIV-2 antibody results suggest either very early HIV-1 infection or the presence of nonspecific cross-reactivity between the patients’ specimens and HIV-1 antigens on the assay strip. In this situation, the HIQNP / HIV-1 RNA Detection and Quantification, Prenatal, Plasma reflex test will be performed.
-Heat-inactivated specimens
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What Do The Test Results Mean
It may take up to 2 weeks to get the test results. Results are only given to you. Some states have to report results to the health department. Talk to your caregiver if you have concerns about how the test is reported in your area.
- A positive test means that you may have the HIV virus. It does not necessarily mean you have AIDS. Once a person is infected with this virus, you will remain infected for life. Some people infected with HIV seem healthy and show no symptoms for several years. Others may get sick with AIDS or have symptoms of an HIV infection. You cannot get rid of the virus and it will not go away. There is no cure for HIV infection. There are medicines to help slow down the infection. There are also medicines to help fight other infections that HIV positive people may get.
- A negative test means that you probably do not have the HIV virus. However, you may need to follow up with repeat tests. These tests are especially important if you have done things during the last year that put you at high-risk to get HIV. Your body takes from 6 to 8 weeks to develop the antibodies to HIV.
Why Should You Have An Hiv Test
- Federal guidelines recommend that everyone ages 13-64 get tested for HIV at least once in their lifetime. People at higher risk, such as people with more than one sex partner in the year, people diagnosed with sexually transmitted infections, sexually active men who have sex with men, and people who inject drugs should get tested at least 1-3 times per year.
- Getting tested for HIV can give you important information and help keep you and others safe. Knowing your HIV status is vital to your health. If you find out you are HIV-positive, you will be linked to medical care immediately that improves your health, prolongs your life, and greatly lowers your chance of spreading HIV to others.
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Importance Of Hiv Testing For Prevention Of Hiv Infection
People with HIV who are aware of their status can get HIV treatment; and remain healthy for many years. Studies show that the sooner people start treatment after diagnosis, the more they benefit from ART. Treatment with ART reduces the amount of HIV in the blood , reduces HIV-related illness, and helps prevent transmission to others. People with HIV who take HIV medicine as prescribed and get and keep an undetectable viral load have effectively no risk of transmitting HIV to HIV-negative sex partners.
People who get tested and learn they dont have HIV can also make decisions about sex, drug use, and health care that can protect them from HIV. For people at risk for HIV, taking HIV medicine called pre-exposure prophylaxis; is highly effective for preventing HIV.