Can you be a carrier of chlamydia and test negative?

Chlamydia is the most common sexually transmitted infection in the UK and is easily passed from one person to another during sex or sexual contact. One of the reasons it’s passed on so easily is because many people show no symptoms and therefore don’t realise they are infectious. In this blog we look at chlamydia testing and a number of different scenarios to answer the question of whether you can carry chlamydia, whilst still testing negative.

How to know if you have chlamydia

Chlamydia is incredibly difficult to diagnose due to its symptomless nature for 70% of women and 50% of men. The only certain way to know that you have chlamydia is to get tested. If you do have symptoms then you will still need to be tested to effectively diagnose that the symptoms are caused by chlamydia. If you’re sexually active, you should get tested regularly whether you have symptoms or not.

What is a chlamydia carrier?

Whenever we talk about a “carrier” in medical terms, we are effectively talking about someone who can infect others with an infectious condition. Anyone with chlamydia is carrying the Chlamydia trachomatis bacteria in their body. This bacteria is easily passed on through unprotected sex whether the person has physical symptoms or not.

Can you test negative for chlamydia and still be a carrier?

Modern medical testing is incredibly accurate and this includes STD tests. However, no medical testing method is 100% accurate and there can be a very small number of false negative test results. A false negative is where a person has a condition, despite the medical test saying they are all clear. As well as these small amounts of false negatives there are a number of scenarios that can cause a person to have chlamydia and still test negative.

Testing before the incubation period

Every STD test has an advised date from which a test becomes accurate. This is because the bacteria needs enough time to multiply within your body in order for it to reach a detectable level when taking a chlamydia test. For chlamydia this is often 14 days. If you test before that 14 days is over, you may test negative, but you could still pass the bacteria on following your test.

Testing following medication

If you receive treatment to get rid of chlamydia, you will still be able to pass the bacteria on for up to two weeks following the completion of treatment. If you have sex whilst you’re on treatment and retrospectively have a test, the test could be negative but you could still have passed the infection on during the sexual encounter. Just because you no longer have the STD, doesn’t mean you didn’t have in the days before your test.

Incorrect Testing Procedure

It’s important that any chlamydia test follows the instructions set out by the laboratory completing your test. Incorrect collection of a sample could lead to false negative results, whereby the sample collected isn’t sufficient or is collected in the wrong way. Many tests will still be accurate in these circumstances, but the accuracy rates would still be diminished.

Incorrect Test Type

Another way that you can test negative, whilst still being a carrier is if you only take a test sample from an area of the body that isn’t infected, whilst still having an infection in another area. This could happen if you have had anal or oral sex, but fail to take a sample from either of these parts of the body and only collect a urine sample. If you have had separate sexual encounters that involved anal or oral sex, then you should test these separately.

If you have anal, oral and vaginal sex with the same person then you will likely only need to test one area, unless there was a long time between these encounters and there’s a chance that chlamydia may have entered the relationship in between. If you have a sexual encounter involving just anal or oral sex, then you should test a rectal and throat swab for chlamydia infection.

Do I need to get tested even without symptoms?

If you are sexually active you should still get tested for chlamydia regularly even if you don’t have symptoms. Chlamydia can lay dormant for a number of years, so you may not know that you even have it. Find out more in our recent article: How long can chlamydia lay dormant?

Passing on chlamydia can make any relationship or sexual encounter extremely awkward and can also have serious repercussions for the other person’s health.

Even without symptoms chlamydia can cause pelvic inflammatory disease in women which can seriously hard reproductive health. It can also cause fertility problems for men. Testing regularly is the most straightforward way to protect both your health and the health of your future sexual partners.

If you’ve been diagnosed with chlamydia, you might find our recent article helpful: What to do if you have chlamydia