STI Tests using Blood Tests

Testing for sexually transmitted infections is primarily done through one of three main techniques: Blood, urine, and genital swabs. In this article we look at the blood test, how it is performed, and what conditions it can test for.

How are blood tests for STIs performed?

STI blood tests are the same for both men and women, and will involve extracting a small sample of blood for study. This sample is extracted using sterilized equipment to prevent any infection, and the actual process will generally just involve a small pinching sensation as the needle punctures your skin.

The sample is then delivered to a specialist laboratory where the equipment necessary for the detection of signs of illness is housed.

What do STI blood tests look for?

STI blood tests look for one of two things: Either the bacteria or fungi causing an infection or antibodies your body produces against them. For the former type of test, you blood sample will be treated by means of a process called ‘culturing’. This basically involves keeping the sample in conditions that allow an infecting pathogen to grow until it can be accurately detected.

The second involves testing for the presence of antibodies, these are disease-specific components of your body’s defensive immune system. Each antibody is unique to a particular condition, and therefore they provide a great way of detecting the presence of n STI.

What conditions do STI blood tests detect?

STI blood tests are most often used to detect conditions like Herpes Simplex and Syphilis. Blood tests are not used as much for most other conditions because swabbing or urine testing is a more convenient, and sometimes more reliable, method of detecting STIs.

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