HIV positive in screening test

Dear Ask The Doctor: Good day doc! last january i was exposed in hiv, i developed toncillitis after 3 weeks. i under gone 3 screening test and its all reactive to anti bodies. it is possible to appear in western blot assay test as negative? the screening test was conducted two months after the exposure.

Dear Alex: The HIV Western blot is not standardised and thus around the world different combinations of bands are considered positive. Hence a positive test in one country is not positive in another. A positive Western blot confirms an HIV infection. A negative Western blot test means the ELISA test was a false positive test. The Western blot test can also be unclear, in which case more testing is done. Also, people with early HIV infection (termed acute HIV infection or primary HIV infection) often have a negative test result.