How long after exposure can u test for hepatitis ; syphilis, hiv for a retest if the first test was negative ..for repeat test?

STD screening: It depends on the tests. The routine most common tests would be: Syphilis: six weeks after exposure unless a visible sore appears sooner. There are three common Hepatitis viruses. Probably twelve weeks is a good standard for them. HIV is twelve to twenty- four weeks unless you have access to the RNA test and then that is 21 days post exposure.