HIV when we can know that we are infected of not?

10. How long should I wait to test and what is the 'window period' ?

We know approximately how long it may take a person to produce antibodies to HIV based on years of data, research and advancements in testing.

A person who has contracted HIV may show up positive as early as two weeks after the time they were infected. According to page 11 of the Module 6 Training Manual from the U.S. Centers for Disease Control and Prevention, the vast majority of those who contract HIV will show up positive between 4—6 weeks after infection.

To obtain a reliable test result, it is recommended that you wait at least six weeks after your last exposure. A tiny number of people may not test positive for three months. These are generally people with pre-existing immune disorders such as chemotherapy patients or recent organ transplant recipients who must take immune system-suppressing drugs. For this reason, many agencies will suggest a uniform three month test to cover everyone.

Testing beyond three months is completely unnecessary.

Here is a chart with approximate accuracy of HIV antibody testing:

Time Accuracy

2 weeks……………&# 8230;…………50%

3 weeks……………&# 8230;…………75%

4 weeks……………&# 8230;…………95%

6 weeks……………&# 8230;…………99%

3 months……………& #8230;…….100%


11. Why do some places say to wait 3 months, 6 months, etc. to test?
Science (even medical science) is not perfect, and cannot account for every situation a person may have going on with their bodies. For this reason, not everyone will have enough antibodies to test at the same time. Those with weak immune systems can take longer to develop HIV antibodies.

Many resources lump everyone together to give one recommendation (for the U.S. Centers for Disease Control and Prevention this is 3 months). Some places suggest longer window periods because the staff may not be eeucated with regard to updates in testing procedures. Still, others may use the longer window period as an effective scare tactic for behavior modification. Overall though, six months is far more than anyone needs to wait.

Ultimately, a person can only educate themselves by using resources like infectious disease medical professionals, state HIV hotlines, and local AIDS service prevention and education organizations to gather information and make the decisions that work for them. There are websites where questions can be asked and answered about HIV transmission, and that is the purpose of those sites. It's not the purpose of this one. This is a site for people affected by HIV to congregate and find support.