My STI panel in Korea came back positive. Does that mean I have a sexually transmitted infection?

A multiplex PCR panel looks for a set of organisms at once — commonly twelve — from a single sample. It is fast, it is widely available in Korea, and it is often ordered as a package. The problem is not the test. It is that the result is handed over as a list of positives and negatives, and a positive is easy to read as a diagnosis.

How often these panels come back positive#

A nationwide analysis published in 2025 examined 1,399,431 of these tests carried out in Korea between 2021 and 2024 — 902,713 in women and 496,718 in men. It is the largest description of what these panels actually find in this country.

That figure is the context a result arrives without. Two in three people who have this panel are told something was found. If a positive line meant an infection, two thirds of everyone tested would have one.

What is being found#

The organisms driving that number are not the ones the test is usually taken to look for.

• Gardnerella vaginalis, 64.70 percent.
• Ureaplasma parvum, 41.37 percent.
• Candida albicans, 18.07 percent, falling with age from 32.17 percent in the teens to 6.45 percent in the eighties.

These are organisms that live in the genital tract of large numbers of people who have no symptoms and no disease. The study's own description of the co-infection pattern is that it is “predominantly commensal-driven” — that is, the pairs of organisms turning up together are mostly normal inhabitants, not transmitted infections.

Which results do mean something#

The distinction is not between important and unimportant results in general. It is between organisms that are sexually transmitted and organisms that are not. Six on the standard panel are unambiguously the former: Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, Treponema pallidum and herpes simplex virus 2. In the four-year Korean series, positivity for these declined significantly over the period.

Chlamydia deserves separate attention because it is the one that tends to be found without having announced itself. The Korean guidelines describe symptoms as mostly absent or mild, and untreated infection in women as capable of leading to pelvic inflammatory disease, chronic pelvic pain and infertility through narrowing of the fallopian tubes. Among Koreans aged 15 to 24, chlamydia was the largest single share of sexually transmitted infection cases at 21.8 percent, with gonorrhoea next at 18.5 percent.

Co-infection between two genuine sexually transmitted organisms was uncommon across the whole dataset but clustered in the youngest patients: chlamydia together with gonorrhoea reached 4.25 percent among males in their teens. That is the pattern that argues for testing young patients properly rather than for testing everyone repeatedly.

What to establish about a positive result#

1. Which organism was found — the name, not simply that the panel was positive.
2. Whether that organism is classified as a sexually transmitted infection or as a commensal in Korean guidelines.
3. Whether the result is being treated because of symptoms, or because it appeared on a list.
4. Whether a partner needs testing, which follows from the first answer rather than from the fact of a positive.

None of this is an argument against being tested. It is an argument for reading the result as the list of organisms it is. A panel that finds Ureaplasma parvum and nothing else has, by Korea's own guidelines, usually found no sexually transmitted infection at all.