Can a 4th gen combo hiv test miss an infection if the test was taken 24 weeks after sexual exposure? i had a negative std panel at 3 months and a combo hiv test again at 24 weeks all negative. is it possible that the test missed infections?

With your results you did not get HIV from sex 24 weeks ago, however, HIV is only one of the STDs. A condom may not protect against HPV, Herpes, LGV, syphilis, pubic lice etc. It would be prudent to see your doctor for an evaluation. Visit this site for information: https://www.cdc.gov/std/default.htm Wish you good health!

The HIV AgAb (combo) tesS ARE conclusive any time 6 weeks or more after infection. There is no possibility they missed HIV acquired 3 months and ~5 months after exposure.