In order to understand which of these tests is more accurate, you need to understand how both the positive culture and the negative blood tests work. You can then, with the help of your health-care provider, take a call as to which test is more suited for you.
Doctors generally recommend that you go in for a Blood culture test when you exhibit some symptoms of herpes. The first 48 hours is the best time to take a swab from the symptoms once a lesion appears. You will then get the results in a week or so. Doing a culture has its advantages such as the accuracy of the test in diagnosing positive results and the ability of the test to ascertain if HSV-1 or HSV-2 has caused the infection. On the other hand the culture test has a rate of false negatives that is high. This generally happens because the lesion may be small or already healing as a result of which the virus may not be sufficiently present to give you accurate results. So if the swab is collected beyond 48 hours of the symptoms being seen, you might receive a false negative test result. The results for viral culture may also not be accurate if there is a reoccurrence.
Blood tests on the other hand could be utilized to find out when a person is worried about the fact that he has herpes but has no visible symptoms. So what happens is that the blood tests help you detect the antibodies in the blood and not the virus. Some of the older blood tests in the market sometimes are not as effective in distinguishing between type-1 and type-2 herpes. Some other limitations of these older blood tests can sometimes give results that are deceptive and can also be misleading about the when and how the person acquired herpes. There is a cross-reaction of this test with some viruses from the same family. These are viruses which are responsible for causing chicken pox and other such conditions. Thus if you are actually HSV-1 positive, chances are that you may be diagnosed wrongly as HSV-2 positive.
There are some newer tests in the market that provide accurate tests in the case of herpes. However they cannot help in determining if the infection site is oral or if the infection site is genital. It therefore becomes important to check with your health care provider as to what type of blood tests are available. You could also check if these tests are FDA-approved or not.
Submitted by M T on April 14, 2010 at 01:44