The rates of false negative and false positive chlamydia tests for various types of tests are as follows (see related link):
The chances of a false negative chlamydia test result with the newest test kits may be as high as 10%. The chances of two false negative results are 1%, and of three are one in one thousand. Having a negative result followed by a positive normally means that you were infected with chlamydia between the first and second test.
The chances of a false positive DFA chlamydia test is less than 1%. The chances of a false negative DFA is 15-20%.
A false negative chlamydia test is one that says chlamydia is not present, when the patient is actually infected.
You can have chlamydia if you tested negative six months ago under two circumstances: you were infected in the last six or seven months, or one of the tests is a false result.
You could have a false negative result; but if it is tested for there is a high probability it will show up in a urine test.
If you were tested before 3 weeks after infection, the test could have turned up false.
An estimate, from both tests showing negative, is less than a 2% chance you actually have the infection. The male urethral swab has a false negative rate of 15-20%. The rate of a false negative for the urine test has a false negative rate of 3-5.5%. So the chances of both being false negative, if they were done on separate days, is somewhere between 0.6% and 1.1%. If you had them done one right after the other on the same day, the risk of a false negative result goes up, as they couldn't have been done according to instructions.
The test for chlamydia remains reliable even if someone has been infected for years. Unlike syphilis, long term infection doesn't give a false negative result. However, a certain percentage of people appear to clear chlamydia infection on their own, so it's possible to have chlamydia in the past but test negative now even without taking treatment.
Possibly. You should not rely on a partner's test result to determine if you have an STD. You should get tested yourself. Your partner could have cleared the infection before testing, or could have had a false negative result.
A urine test is much more sensitive and a bit less specific than a culture for diagnosing chlamydia. In other words, it's much less likely to have false negative results, and a little more likely to have a false positive result.
A false chlamydia test result can come from any of these factors:Urination less than a few hours before urine testing.Poor technique for swabsNot disclosing the possible location of infection (e.g. if you only have receptive anal sex, then urethral testing won't find your infection).Recent antibiotics that reduced, but didn't eliminate, chlamydia infectionTesting too soon after infection.
The rates of false negative and false positive chlamydia tests for various types of tests are as follows (see related link):Becton-Dickinson NAAT female urine: 1% false positive; 19.5% false negativeGen Probe NAAT female urine: 1.1% false positive; 5.3% false negative