After 44 days of high-risk behavior, testing with a fourth-generation test will basically confirm infection. For those who use the third-generation test reagents and have a negative result, it is generally necessary to retest after three months, and only when the result is still negative can it be confirmed that the person is not infected.
To detect HIV infection, the third and fourth generation of test reagents are currently used throughout China. The most advanced generation is the fourth-generation test reagent.
The fourth-generation test reagent can generally detect the vast majority of infected people 14 days after high-risk sexual contact, and those who test negative will need to be retested again six weeks (40 days) after high-risk behavior. A retest that is still negative essentially rules out infection.
The window period for the third-generation test reagent is about 21 days after high-risk exposure. Those who test negative still need to be retested after three months, and the test result after three months will prevail.
A hospital check-up 44 days after high-risk behavior using the fourth generation test reagent can basically confirm whether the infection is present. Those who use the third generation test reagent with negative results generally need to be retested in three months, and can only be confirmed as uninfected if they are still negative.
People with high-risk behaviors for HIV should go to a regular hospital or CDC in a timely manner to be tested under the guidance of a doctor.