HIV Saliva Test Vs. Blood Test
There are two major types of tests used to diagnose HIV infection: blood tests and saliva tests. Though many locales use saliva tests merely as a screening method, modern saliva tests can be quite accurate.-
Saliva Testing
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A saliva test uses an absorbent sponge or a device that can scrape the inside of the cheek to collect a saliva sample. The presence of certain proteins in the saliva indicates likely HIV infection. A result can be delivered in as soon as 20 minutes.
Blood Testing
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A sample of blood is taken and sent to be tested using either the ELISA or Western Blot antibody tests. These tests look for antibodies that are produced during HIV infection and are often used in conjunction with each other to confirm a diagnosis. Testing can take up to two weeks.
Accuracy
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Both saliva and blood tests can be highly accurate, up to 99.8% according to the National Institutes of Health. The accuracy can be affected by the time since infection, however, as it can take up to six months for the virus to replicate itself enough to cause a positive result on either test.
Testing Type Based on Location of Clinic
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Rural areas may be more likely to use blood tests because they can be processed in a central location, and the number of tests performed may not justify keeping saliva tests on hand. Urban areas are more likely to use saliva tests as a preliminary diagnosis technique because of the speed involved and the larger number of tests performed.
Pediatrics
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Saliva tests are commonly used for diagnosis of HIV infection in infants and children because of the ease of administering the test without the need for needles and blood work. As children can progress into late-stage HIV infection faster than adults, the faster saliva tests can also help to start treatment earlier.
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