Chlamydia testing in Taichung: why most infections have no symptoms
Chlamydia is one of the quietest sexually transmitted infections. Most people who have it feel nothing. That is why it keeps passing between partners.
Explained by Dr. Chao-An Chen, urologist, at 昭安泌尿科診所 (Morning Urology Clinic), West District, Taichung.
In short
- Most infected people have no symptoms. When symptoms do appear, they are milder than in gonorrhoea: a little clear discharge, or slight discomfort at the opening of the urethra.
- An untreated infection can move upwards. It can cause epididymitis in men and pelvic inflammatory disease in women. Both are linked with fertility problems.
- Taiwan has no national case count for chlamydia, because it is not a notifiable disease here. It is still the commonest cause of urethritis that is not caused by gonorrhoea.
- Testing is by nucleic acid amplification test (NAAT, a PCR-type test), on urine or a swab. With symptoms, test the same day. Without symptoms, test about 1 to 2 weeks after the exposure.
- Test again about 3 months after treatment to check for reinfection. Being cured does not make you immune.
A common infection that never reaches the news
One thing is rarely said clearly: chlamydia is not a notifiable disease in Taiwan. Syphilis and gonorrhoea are category 3 notifiable diseases, which doctors must report to the health authority, so the Taiwan Centers for Disease Control (Taiwan CDC) publishes a figure every year: 9,738 syphilis cases and 7,607 gonorrhoea cases in 2024. Chlamydia trachomatis is not on that list, so Taiwan has no national statistic for it, even though it is one of the bacterial sexually transmitted infections found most often in clinic.
No numbers, no news, and no symptoms. Those three things together are why it keeps circulating. So this page answers three questions: how it affects you, when to test, and what to do after the result.
Symptoms: most people have none, and the rest have very few
The main feature of chlamydia is that the symptoms are unclear, or absent altogether. When they do appear, they are milder than in gonorrhoea:
- Discharge that is clear or white, and small in amount. Sometimes you can only see it before the first urine of the morning.
- Slight stinging when you pass urine. People often describe it as a little strange rather than painful.
- Itching at the opening of the urethra. Very common, and the sign most often ignored.
The problem is not that these symptoms are severe. It is that they are not severe enough to make anyone see a doctor. People wait for them to pass, and they often do.
Symptoms going away is not the same as being cured. Chlamydia can stay in the body with no symptoms at all, it can still be passed to other people, and it can still move upwards. Gonorrhoea usually forces you to see a doctor; chlamydia does not.
In men: epididymitis, and the link with fertility
An untreated infection of the urethra can travel up the vas deferens, the tube that carries sperm, and cause epididymitis, an infection of the coiled tube behind the testicle. It causes swelling and pain on one side of the scrotum, sometimes with fever. In a sexually active young man with acute epididymitis, chlamydia and gonorrhoea are the first causes to consider.
Sudden severe pain on one side of the scrotum should not be watched at home. Acute epididymitis has to be told apart from testicular torsion, an emergency with a time limit: late treatment affects the survival of the testicle.
The link with fertility
Repeated or untreated infection and inflammation of the genital tract may affect the structure of the ducts that carry sperm, and may affect sperm quality. This is why doctors ask about past infections when they assess infertility. If you are planning a pregnancy, or a semen analysis gave a poor result, say so at the consultation.
This link is an explanation of the mechanism and one factor in an assessment. It does not mean that one infection must lead to infertility.
In women: pelvic inflammatory disease and what follows
The proportion of women with no symptoms is even higher. What may appear is more discharge, bleeding after sex, discomfort when passing urine, or a dull ache in the lower abdomen. All of these are easy to explain as something else.
An untreated infection may move upwards and cause pelvic inflammatory disease, an inflammation of the womb, the fallopian tubes and the organs around them. It is linked with later chronic pelvic pain, fertility problems involving the fallopian tubes, and ectopic pregnancy, a pregnancy that grows outside the womb. Hence a simple rule: if a man tests positive, his female partner should be tested as well. She may feel nothing, and the effect on her may be greater.
Female urology is a subspecialty within urology, so urinary symptoms in women can also be assessed here. If treatment for pelvic inflammatory disease is needed, the clinic will help arrange the right specialty.
Throat and rectum: two completely silent sites
Oral sex can lead to infection of the throat. Anal sex can lead to infection of the rectum. Chlamydia at these two sites almost never causes symptoms, and a urine test alone cannot find it.
One rectal situation is worth knowing about: lymphogranuloma venereum (LGV). It is caused by particular types of the chlamydia bacterium and is reported from time to time among men who have sex with men. It may show as pain in the rectum, a constant urge to pass stool, discharge or bleeding, and the course of treatment is much longer. Please tell the doctor if you have these symptoms, because the management is different.
This is why the consultation asks whether you have oral sex, or receptive anal sex. Those questions have one purpose: to decide where the swab goes.
How and when to test
The nucleic acid amplification test (NAAT, a PCR-type test) is the standard method. The sample can be urine or a swab, and the test also works on samples from the throat and the rectum.
Two terms are often mixed up. A window period is the time a test needs before it can detect an infection. An incubation period is the time before symptoms appear. The table below is about the window period.
| Your situation | When to test |
|---|---|
| You already have symptoms | The same day. There is no need to wait out a window period. |
| No symptoms, but you want to check one exposure | About 1 to 2 weeks after the exposure. |
| Your partner has tested positive | As soon as possible. Do not wait for your own symptoms. |
| After treatment | About 3 months later, to check for reinfection. |
Where the sample is taken matters more than how many tests you have. Oral sex means the throat needs its own sample; anal sex means the rectum does. Giving only a urine sample checks about one third of the picture.
Treatment, and what comes after it
Chlamydia is treated with oral antibiotics. The main option in Taiwanese and international guidelines is doxycycline, which is approved in Taiwan for infections caused by Chlamydia trachomatis. The medicine, the dose and the length of the course are decided by the doctor, based on the site of infection, pregnancy, drug allergy and test results.
- Finish the whole course. Stopping the medicine when the symptoms go is the commonest reason treatment fails.
- Avoid every form of sex, including oral and anal sex, until both partners have completed treatment.
A further test about 3 months later is advised. The purpose is not to confirm that the last treatment worked, but to check for reinfection, which is not rare when the partner was not treated at the same time.
Being cured does not make you immune. After one infection, you can get it again.
Your partner has to be handled at the same time
Chlamydia is the clearest example of an infection where the partner must be treated too. The reason is simple: the other person usually has no symptoms, so they will not go for a test on their own. Recent sexual partners should be tested and assessed for treatment. If you do not know how to raise the subject, the clinic can give you a written testing recommendation to hand over.
When only one side is treated, the infection usually comes back within weeks to months. This is not about willpower; the chain of transmission has not been broken.
Prevention: where Doxy-PEP fits
Doxy-PEP is a single dose of the antibiotic doxycycline, taken after a risk exposure. Taiwan's 2025 guidelines on syphilis and gonorrhoea in adults place it as a measure to prevent syphilis, for men who have sex with men and transgender women who are at risk of syphilis and chlamydia (recommendation: strong; evidence: high). For cisgender women and heterosexual men there is no recommendation at present. For preventing gonorrhoea it is not recommended in Taiwan: Taiwan CDC surveillance in 2024 showed nearly 80% of gonococcal strains in Taiwan were already resistant to tetracycline-class antibiotics.
Medication disclosure
This use differs from the treatment dosage in the doxycycline product information, so it is off-label use. The dose, the time limit, what it can and cannot do, and known side effects such as stomach upset and sensitivity to sunlight are explained before it is prescribed, and you decide whether to use it. It is not a replacement for regular screening.
The other measures still apply: condoms, including during oral sex; regular screening matched to your own risk; and treating partners at the same time after a diagnosis.
Getting tested in Taichung
昭安泌尿科診所 (Morning Urology Clinic) is listed on two registers published by the Taiwan CDC, under medical institution code 3503241524. Both can be downloaded from the Taiwan CDC page on anonymous counselling and screening, so you can check them.
- Register of anonymous HIV screening institutions. This is an HIV rapid blood test. For this service we do not check your National Health Insurance card or any identity document, so it is open to you regardless of nationality. There is no charge for it. No formal report can be issued, because no identifying information is recorded.
- Anonymous syphilis screening for young people aged 24 or under and for students. A separate service with its own rapid test. People in those two groups are not charged, and the service depends on test kits allocated by the Taiwan CDC.
Chlamydia is not covered by either service: those two test for HIV and syphilis. For chlamydia you book an ordinary consultation and have a NAAT, with the sampling site decided by the type of sex you have. Both can be done on the same day: the tests that carry no charge first, then the tests for infections that cause discharge.
Costs are explained at the consultation. Please bring your passport or resident certificate; it is needed to create the medical record. If you are not enrolled in Taiwan's National Health Insurance, the consultation and tests are self-paid. We are required by law to report certain infections to the health authority. Your personal information is protected by the Communicable Disease Control Act, Article 10. The clinic uses separate consultation rooms and a separated patient flow, so you do not have to explain why you are here in the waiting area.
If you are not sure whether you need a test, book online or message us on LINE. Say when the last exposure was and what type of sex it was. That is enough to decide whether to test, and where to take the samples.
Common questions
I have no symptoms. Do I still need a test?
A test is advised if you have a new partner, sex without a condom, more than one partner, or a partner who has tested positive. Chlamydia does not warn you through symptoms, and an untreated infection can move upwards.
Can I get chlamydia from oral sex only?
Yes. The throat can be infected, it almost never causes symptoms, and a urine test will not find it. A separate throat sample is needed.
My partner has no symptoms. Should they be tested too?
Yes. They will not go for a test on their own, and when only one side is treated the infection usually comes back within weeks to months.
Related pages
Appointments and access
Consultations are conducted in Mandarin, and can also be conducted in English.
昭安泌尿科診所 (Morning Urology Clinic)
No. 98, Boguan 2nd St., West District, Taichung City 403, Taiwan（403 臺中市西區博館二街98號）
Consulting hours: Monday to Saturday (closed Sunday). Online booking is open 24 hours.
This page was produced by 昭安泌尿科診所 (Morning Urology Clinic). Medical content last updated: August 2026 (same as the Traditional Chinese version). English version published: 4 September 2026. Medically reviewed by Dr. Chao-An Chen, urologist.
Sources: Workowski KA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021 (MMWR Recomm Rep 2021;70(4):1-187) / Taiwan CDC and the Infectious Diseases Society of Taiwan, Taiwan Guidelines for the Diagnosis, Treatment and Prevention of Syphilis and Gonorrhoea in Adults, first edition, August 2025 / Taiwan CDC, notifiable disease categories and reporting / World Health Organization, updated treatment recommendations for Neisseria gonorrhoeae, Chlamydia trachomatis and Treponema pallidum, 2024. Medication content follows the Chinese-language product information approved by the Ministry of Health and Welfare; the Doxy-PEP use described here is off-label use recommended by the guidelines.
This page provides general medical information and does not replace an individual diagnosis or treatment plan. The site of infection, sampling sites, choice of medicine, dose, course length and follow-up are decided by a doctor after assessing your history, symptoms and test results.