ELISA method is very accurate in detecting HIV. In China, HIV antibody testing is the gold standard for the diagnosis of HIV infection, and the majority of hospitals will use the ELISA method for HIV antibody testing, which can reach a sensitivity of more than 99%. Therefore, there may be false positive results, that is, the patient is not infected with HIV, but the test is too sensitive, resulting in a positive test result, and then a confirmatory test should also be performed by protein blotting assay. If the protein blot test is negative, the patient is not infected with HIV and the result is a false positive. If the protein blot test is positive, the patient is infected with HIV.