Sexually transmitted infections (STIs) can be caused by bacteria (e.g. Treponema pallidum, Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma), viruses (e.g. HSV) or parasites (Trichomonas vaginalis), which are transmitted from person to person by vaginal, anal or oral sex. The course, symptoms and consequences of STIs can differ significantly depending on the causative pathogen. In many cases, the infection is asymptomatic, so that it remains undiscovered for a long time and is only diagnosed when it has become chronic. Infections with these pathogens often cause inflammation of the urogenital tract, which may ascend and lead to e.g. infertility.
In addition to the consequences for the patient, infections with most of the mentioned pathogens can also lead to intrauterine foetal loss, preterm birth or damage to the unborn child. Moreover, many pathogens can be transmitted to the newborn during birth, causing severe postnatal infections.
The commonly used detection methods for STI are direct methods, in which the pathogen is detected by PCR or culture, and indirect methods, i.e. detection of pathogen-specific antibodies. Since detection by culturing is especially time-consuming and difficult for Chlamydia, Mycoplasma, Ureaplasma and Treponema, other detection methods, e.g. PCR-based and/or serological procedures, are generally recommended or required for these pathogens.