Laboratory Test Directory


Code

Name



Human Immunodeficiency Virus (HIV) Test

2017-03-28 06:00:00


Test Overview

 

A human immunodeficiency virus (HIV) test detects antibodies to HIV or the genetic material (DNA or RNA) of HIV in the blood or another type of sample. This determines whether an HIV infection is present (HIV-positive). HIV infects white blood cells called CD4+ cells, which are part of the body's immune system that help fight infections. HIV can progress to acquired immunodeficiency syndrome (AIDS).

 

After the original infection, it takes between 2 weeks and 6 months for antibodies to HIV to appear in the blood. The period between becoming infected with HIV and the point at which antibodies to HIV can be detected in the blood is called the seroconversion or "window" period. During this period, an HIV-infected person can still spread the disease, even though a test will not detect any antibodies in his or her blood.

 

Several tests can find antibodies to or genetic material (RNA) of the HIV virus. These tests include:

 

Enzyme-linked immunosorbent assay (ELISA). This test is usually the first one used to detect infection with HIV. If antibodies to HIV are present (positive), the test is usually repeated to confirm the diagnosis. If ELISA is negative, other tests are not usually needed. This test has a low chance of having a false result after the first few weeks that a person is infected.

Western blot. This test is more difficult than the ELISA to perform, but it is done to confirm the results of two positive ELISA tests.

Polymerase chain reaction (PCR). This test finds either the RNA of the HIV virus or the HIV DNA in white blood cells infected with the virus. PCR testing is not done as frequently as antibody testing, because it requires technical skill and expensive equipment. This test may be done in the days or weeks after exposure to the virus. Genetic material may be found even if other tests are negative for the virus. The PCR test is very useful to find a very recent infection, determine if an HIV infection is present when antibody test results were uncertain, and screen blood or organs for HIV before donation.

Indirect fluorescent antibody (IFA). This test detects HIV antibodies using a special fluorescent dye and a microscope. This test may be used to confirm the results of an ELISA test.

Testing is often done at 6 weeks, 3 months, and 6 months after exposure to find out if a person is infected with HIV.

 

Why It Is Done

 

A test for the human immunodeficiency virus (HIV) is done to:

 

Detect an HIV infection.

Screen blood, blood products, and organ donors to prevent the spread of HIV.

Screen pregnant women for HIV infection. Pregnant women who are infected with HIV and receive treatment are less likely to pass the infection on to their babies than are women who do not receive treatment.

Find out if a baby born to an HIV-positive woman also is infected with HIV. A PCR test is often done in this case because the baby may get antibodies against HIV from the mother and yet not be infected.

The Centers for Disease Control and Prevention (CDC) recommend HIV screening as part of routine blood testing.

 

The U.S. Preventive Services Task Force (USPSTF) recommends HIV testing:1

 

As part of regular medical care for people 15 to 65 years old.

For all pregnant women.

For people younger than 15 and older than 65 if they have a high risk for HIV, such as for people who engage in high-risk behavior.

You and your doctor can decide if testing is right for you.

 

This test is not done to determine if a person has AIDS. A diagnosis of AIDS means a person is HIV-positive and other problems are present.

 

How To Prepare

 

You do not need to do anything before you have this test.

 

A test for HIV infection can't be done without your consent. Most doctors offer counseling before and after the test to discuss:

 

How the test is done, what the results mean, and any other tests that may be done.

How the diagnosis of an HIV infection may affect your social, emotional, professional, and financial outlooks.

The benefits of early diagnosis and treatment.

Before the test, it is important to tell your doctor how and where to contact you when your test results are ready. If your doctor has not contacted you within 1 to 2 weeks of your test, call and ask for your results.

 

How It Is Done

 

The health professional drawing blood will:

 

Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.

Clean the needle site with alcohol.

Put the needle into the vein. More than one needle stick may be needed.

Attach a tube to the needle to fill it with blood.

Remove the band from your arm when enough blood is collected.

Apply a gauze pad or cotton ball over the needle site as the needle is removed.

Apply pressure to the site and then a bandage.

 

How It Feels

 

You may feel nothing at all from the needle puncture, or you may feel a brief sting or pinch as the needle goes through the skin. Some people feel a stinging pain while the needle is in the vein. But many people do not feel any pain (or have only minor discomfort) once the needle is positioned in the vein. The amount of pain you feel depends on the skill of the health professional drawing the blood, the condition of your veins, and your sensitivity to pain.

 

Risks

 

There is very little risk of complications from having blood drawn from a vein.

 

You may develop a small bruise at the puncture site. You can reduce the risk of bruising by keeping pressure on the site for several minutes after the needle is withdrawn.

In rare cases, the vein may become inflamed after the blood sample is taken. This condition is called phlebitis and is usually treated with a warm compress applied several times daily.

Continued bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can also make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your health professional before your blood is drawn.

 

Results

 

A human immunodeficiency virus (HIV) test detects antibodies to HIV or the genetic material (DNA or RNA) of HIV in blood or another type of sample. This determines whether an HIV infection is present (HIV-positive). ELISA results are usually available in 2 to 4 days. Results of the other tests, such as the Western blot or IFA, take 1 to 2 weeks.

 

What Affects the Test

 

Reasons you may not be able to have the test or why the results may not be helpful include:

 

Using corticosteroids.

Having an antibody test done before a detectable amount of antibodies is present (during the seroconversion period).

<>Having an autoimmune disease, leukemia, or syphilis.

Drinking too much alcohol.

What To Think About

 

A rapid test (HIV-1/2 Ag/Ab Combo test) that can detect both HIV antibodies and HIV antigens is available. This test can detect an HIV infection earlier than other tests available. It also can tell whether an HIV infection is new or is established.

After initial testing, it is important for your doctor to contact you with the results of your test. Be sure to tell your doctor how and where to contact you. If your doctor has not contacted you within 1 to 2 weeks of your test, call and ask for your results.

The ELISA is a good screening test, because it is usually positive when an HIV infection is present. But the ELISA test results can indicate HIV is present when it is not (false-positive). So the ELISA alone cannot be used to make a definite diagnosis of HIV infection. No one is considered HIV-positive until he or she has a positive Western blot, IFA, or PCR test.

Detecting HIV in a newborn infant is difficult. Until about 18 months of age, even a baby who is not infected may still have HIV antibodies received from his or her HIV-positive mother. A PCR test may be done to see if HIV genetic material (RNA or DNA) is present in the baby.

To be certain that an HIV infection is not present, a person must test negative for the virus at least 6 months after the last possible exposure to HIV. Testing is often done at 6 weeks, 3 months, and 6 months to find out whether a person is infected.

Two types of home test kits for HIV have been approved by the U.S. Food and Drug Administration (FDA). If the results from a home test kit show that you have an HIV infection, talk to a doctor. And keep in mind that these test kits sometimes may show that you have HIV when you don't (false-positive result) or may show that you don't have HIV when you do (false-negative result).

One test kit (called OraQuick) gives you the results right away. For this test, you rub your gums with a swab supplied by the kit. Then you place the swab into a vial of liquid. The test strip on the swab indicates if you have HIV or not.

Another type of test kit for HIV is a home blood test kit. This kit provides instructions and materials for collecting a small blood sample by sticking your finger with a lancet. The blood is placed onto a special card that is then sent to a lab for analysis. You can find out your results over the phone by using an anonymous code number. Counseling is also available over the phone for people who use the test kit.

If you have a positive test result, contact your sex partners to inform them. They may want to be tested. You may be able to get help from your local health department to do this.

A screening test for HIV infection may also be done on urine or saliva. An oral HIV test finds antibodies to HIV. Urine testing is rarely done.

Oral test kits that find HIV-1 and HIV-2 in saliva have been approved by the United States Food and Drug Administration (FDA). The test results are provided the same day. Test results that show an HIV infection need to be confirmed by a Western blot test.

Most states require health professionals, clinics, and hospitals to report confirmed cases of HIV infection to the state health department. Some states allow anonymous reporting (the person's name or other identifying information is not provided). Other states require confidential reporting (identifying information is provided but only to authorized public health officials). All states must report the numbers of cases of AIDS, without names or other identifying information, to the Centers for Disease Control and Prevention (CDC).

After an HIV infection is present, other tests are done to determine when to treat the infection and how treatment is working. These tests include a CD4+ count and the viral load.

CD4+ Count

Viral Load Measurement

Two types of HIV have been identified.

HIV-1 causes almost all of the cases of AIDS worldwide.

HIV-2 is found mostly in West Africa.

U.S. Preventive Services Task Force (2013). Screening for HIV: U.S. Preventive Services Task Force recommendation statement. Available online: http://www.uspreventiveservicestaskforce.org/uspstf/uspshivi.htm.

 

Other Works Consulted

 

Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.

 

Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.

 

U.S. Department of Health and Human Services Panel on Antiretroviral Guidelines for Adults and Adolescents (2015). Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. U.S. Department of Health and Human Services. http://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf. Accessed May 5, 2015.

 

Credits

 

ByHealthwise Staff 

Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine 

Specialist Medical ReviewerPeter Shalit, MD, PhD - Internal Medicine

 

Source: http://www.webmd.com/hiv-aids/human-immunodeficiency-virus-hiv-test#1



Make a Payment

To make our medical lab services easier to use we now offer a secure online payment service.

Home Visit Requisition Form

To request a home care services or to obtain more information on Accu reference medical lab, please complete an Home Visit Requisition Form

Career Opportunities

We are always interested in expanding our professional team. If you'd like to be considered for a position, send us your resume

E-Forms

This section contains e-forms. The forms may be printed and mailed or faxed.


Find a Location

East Orange Patient Service Center
108 South Munn Ave, East Orange, NJ 07018
Phone: (862) 233-6611
Hours:

10:00 AM-5:00 PM


Glassboro Patient Service Center
359 N Main Street, Glassboro, NJ 08028
Phone: (856) 881-5320
Hours:

7:30 AM-3:30 PM


Irvington Patient Service Center
40 Union Avenue, Suite 205, Irvington, NJ 07111
Phone: (862) 231-6223
Hours:

9:00 AM - 6:00 PM
CLOSED THURSDAYS AND WEEKENDS


Jersey City Patient Service Center
709 Newark Ave 2nd Floor, Jersey City, NJ 07036
Phone: (201) 222-0178
Hours:

9:00 AM - 5:00 PM


Linden Patient Service Center
1901 East Linden Avenue, Unit 25, Linden, NJ 07036
Phone: (908) 474-1004
Hours:

8:00 AM - 2:00 PM
CLOSED WEEKENDS


Somerset Patient Service Center
1553 Rt.27, Somerset, NJ 08873
Phone: (609) 528-9199
Hours:

9:00 AM - 6:00 PM
CLOSED WEEKENDS



Stamford Patient Service Center
111 High Ridge Road, First Floor, Stamford, CT 06905
Phone: (908) 583-6607
Fax: (908)224-9700
Hours:

9:00 AM - 3:00 PM

CLOSED WEDNESDAY, WEEKENDS



Baltimore Patient Service Center
3455 Wilkins Avenue, Suite L10-A, Baltimore, MD 21229
Phone: (410) 644-0075
Hours:

9:00 AM-3:39 PM


Brooklyn Patient Service Center
5908 5th Avenue, Suite 6, Brooklyn, NY 11220
Phone: (718) 439-8200
Hours:

9:00 AM-5:00 PM


Chappaqua Service Center
175 King Street, Chappaqua, NY 10514
Phone: (914)861-2439
Fax: (914)861-2440
Hours:

Monday, Wednesday 8:00 AM - 12:00 PM

Thursday, Friday       8:00 AM - 4:00 PM

CLOSED TUESDAY, WEEKENDS

 


New Hyde Park Patient Service Center
1575 Hillside Avenue, New Hyde Park, NY 11040
Phone: (516) 500-1047
Hours:

7:30 AM-4:00 PM



Medical Drive Patient Service Center
1314 Medical drive, Suite 101, Fayetteville, NC 28304
Phone: N/A
Hours:

8:30 AM-4:30 PM


Payetteville Patient Service Center I
1905 Skibo Road, Suite 101, Fayetteville, NC 28314
Phone: (910) 867-7071
Hours:

9:00 AM-6:00 PM


Walter Reed Patient Service Center
1220 Walter Reed Road, Suite A, Fayetteville, NC 28304
Phone: (910) 491-1956
Hours:

7:00 AM - 4:00 PM



Bangor Patient Service Center
225 Erdman Avenue, Bangor, PA 18013
Phone: (610) 452-9174
Hours:

7:00 AM- 3:00 PM


Hazelton Patient Service Center
101 South Church Street, Hazelton, PA 18704
Phone: (570) 455-0747
Hours:

8:00 AM - 4:00 PM


Kingston Patient Service Center
517 Pierce Street, Kingston, PA 18704
Phone: (570) 283-0674
Hours:

7:00 AM - 3:00 PM


Nanticoke Patient Service Center
233 South Prospect Street, Nanticoke, PA 18634
Phone: (570) 735-2626
Hours:

7:00 AM - 1:00 PM



Conlin Patient Service Center
4420 Conlin Street, Ste#100, Metairie, LA 70006
Phone: (504) 302-2035
Hours:

8:00 AM - 5:00 PM


Saxon Patient Service Center
4213 Saxon Street, Metairie, LA 70006
Phone: (504) 779-8163
Hours:

7:00 AM - 4:00 PM


West Bank Patient Service Center
1799 Stumpf blvd, Gretna, LA 70056
Phone: (504) 301-1817
Hours:

N/A



Have questions or need assistance? Call (877) 733-4522