There are two blood tests done for HSV, the Eliza and the Western Blot.
The Eliza test is the one offered by the BCCDC Provincial lab. The Western Blot, done by the national microbiology lab, is only offered to pregnant women who may have had an exposure to HSV.
With the Eliza test, there is some cross-reactivity between HSV 1 and HSV 2. That means if your test result is positive for HSV 1 you could actually have HSV 2, or vice versa. The reason for cross-reactivity is because the proteins and structure of HSV 1 and 2 are very similar.
Because of cross reactivity the lab states that the HSV Eliza test is not definitive, but there is a likelihood of HSV infection. The best way to test is to swab a sore or lesion.
Another thing to consider is the window period. The window period is the time between infection with HSV and when the virus shows up in a blood test. Most HSV blood test results are accurate after 4 months.
Its also important to remember that no test is 100% accurate, including the HSV test. Accuracy of testing is not changed when a person has symptoms or not.
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