URETHRITIS AND STI CARE
Urethritis and Sexually Transmitted Infections: Testing and Treatment
For pain on urination, urethral discharge, genital itching or sores, or concern about infection. STIs may cause no symptoms. Testing should match the exposure and its timing, rather than relying on symptoms alone.
Medically reviewed by Koshiro Nishimoto, MD, PhD (Director; specialist in urology)Updated September 23, 2026
Urethritis
What is urethritis?
Urethritis is inflammation of the tube that carries urine out of the body. Symptoms may include:
- Pain or burning when urinating
- Clear, white or yellow discharge or pus from the urethra
- Itching or discomfort at the urethral opening
Common causes include gonorrhea, chlamydia, Mycoplasma genitalium and Trichomonas vaginalis. Inflammation can also have non-infectious causes.
The severity of pain or appearance of discharge cannot identify the organism. Even gonorrhea may cause few symptoms, so testing is important.
Four organisms tested at our clinic
Different organisms need different medicines, and more than one infection can be present. For patients diagnosed with urethritis, our policy is generally to test for the following four organisms at the first visit.
| Organism | Features |
|---|---|
| Gonorrhea | May cause severe pain on urination and pus, but symptoms can also be mild. |
| Chlamydia | Symptoms are often relatively mild, and infection may go unnoticed. |
| Mycoplasma genitalium | Can cause urethritis that persists because of antibiotic resistance. |
| Trichomonas vaginalis | A protozoan infection that may cause few symptoms in men. |
In men, we usually collect first-catch urine (the first part of the urine stream) for nucleic acid amplification testing, which looks for the organism’s genetic material. Samples are sent to an external laboratory, so results are explained at a later date. The tests and eligibility for insurance coverage are assessed during the consultation.
Oral sex can transmit infection to the throat. Urine testing alone cannot detect a throat infection. Depending on the exposure, we may advise testing from the throat or other sites and blood tests for syphilis, HIV or hepatitis B.
Testing soon after exposure may miss an infection. Please tell us when the contact occurred.
Treatment according to the cause
Treatment uses oral medicine or injections according to the result and infection site. Depending on symptoms and examination findings, treatment may start before the results are available. The following are example adult prescriptions used in Japan. Medicines and doses are adjusted for kidney function, pregnancy, allergies and other individual factors.
Gonorrhea
At our clinic, we use Rocephin (ceftriaxone), 1 g by intravenous infusion as a single dose, to treat urethral and throat gonorrhea.
Chlamydia
Zithromac 250 mg tablets (azithromycin hydrate): four tablets, totaling 1 g, taken orally once. A different medicine may be selected according to the infection site and test results.
Mycoplasma genitalium
An example is Gracevit 50 mg tablets (sitafloxacin hydrate): two tablets (100 mg) orally twice daily for 7 days. Drug resistance is common, so treatment depends on test results and previous treatment. Use against this organism is off-label under the Japanese product information; we assess and explain the need for it.
Trichomonas vaginalis
Flagyl 250 mg tablets (metronidazole): one tablet orally twice daily for 10 days.
If more than one organism is found, each infection needs appropriate treatment.
An infection may remain after symptoms improve. Follow-up testing is arranged according to the infection and site.
Testing and treatment for partners
Partners may be infected without symptoms. Treating only one person can lead to reinfection. Depending on the diagnosed infection, current or recent partners may also need testing and treatment.
Male partners can receive assessment and necessary testing at our clinic. Female partners are generally referred to obstetrics and gynecology for vaginal or cervical testing and assessment of possible uterine or fallopian tube inflammation and pregnancy-related concerns.
Avoid sexual contact until you and the relevant partners have completed treatment and your clinician says it is safe to resume.
Syphilis
Syphilis is caused by the bacterium Treponema pallidum.
Early infection may cause a relatively painless lump or sore on the genitals, mouth or anus, or swollen lymph nodes in the groin. A rash may later appear over the body, including the palms and soles.
Symptoms disappearing on their own does not mean the infection is cured. It can progress without symptoms.
Syphilis during pregnancy can infect the baby and cause miscarriage, stillbirth or illness in the baby. If you are pregnant or may be pregnant, consult your regular obstetrician promptly.
Blood tests for syphilis: TP antibodies and RPR
Blood tests for syphilis check two types of antibodies with different roles. We assess the results together with your symptoms, the timing of possible exposure and any previous treatment.
- Treponema pallidum antibodies (TP antibodies): These are antibodies against Treponema pallidum (TP), the bacterium that causes syphilis. They may remain positive for a long time after treatment. A positive result alone does not establish a current infection or a need for treatment.
- Nontreponemal antibodies detected by the RPR test: RPR (Rapid Plasma Reagin) is the name of a testing method. The result can be positive for reasons other than syphilis, but changes in the quantitative result help assess disease activity and the response to treatment.
Understanding your results
The table below lists TP antibodies first, followed by RPR. ＋ means positive; － means negative.
| TP antibodies | RPR | Possible meaning and next steps |
|---|---|---|
| ＋ | ＋ | This may indicate a current infection or antibodies remaining after treatment. We review quantitative results, symptoms and treatment history. |
| ＋ | － | This may reflect a past infection or previous treatment, but early infection or longstanding untreated syphilis is also possible. We check your treatment history and arrange additional tests if needed. |
| － | ＋ | A positive result unrelated to syphilis (a biological false positive) is possible. Early infection cannot be ruled out, so quantitative results and repeat testing may be needed. |
| － | － | No antibodies have been detected at this time. However, both tests can be negative soon after infection. |
The combination of positive and negative results alone cannot determine the diagnosis or whether treatment is needed.
What we check after a positive result
If either test is positive, we check the quantitative RPR result and, when needed, quantitative TP antibody results or confirmation using a different testing method. If quantitative results are already available, there is no need to duplicate the same test. If you have previously been treated, please bring any records showing when you were treated, the medicines used and your test results.
There is no single RPR value that confirms syphilis in every patient. We interpret the results together with symptoms and treatment history. If early infection is suspected or symptoms do not match the results, testing may be repeated after 2–4 weeks. If you have symptoms, seek medical advice without waiting for the repeat test.
Treatment for syphilis
Syphilis is an infection that can be treated with appropriate antibiotics. Before choosing treatment, we review your symptoms, blood test results, previous treatment and any history of medicine allergies.
Treatment with amoxicillin (originator brand in Japan: Sawacillin)
Prescription example
Amoxicillin is a penicillin antibiotic. The usual oral treatment for adults is 500 mg, taken three times a day for 28 days. Even if your symptoms improve, do not stop taking the medicine on your own.
Treatment for people with a penicillin allergy: minocycline (originator brand in Japan: Minomycin)
Prescription example
If you have a penicillin allergy, we review the details of your previous reaction and your health before considering minocycline. The usual adult regimen is 100 mg, taken twice a day for 28 days.
Blood tests after treatment
We record quantitative results before treatment and use repeat RPR and TP antibody tests, approximately every four weeks after treatment starts, as a guide to follow-up. Treatment response is assessed mainly from falling RPR values and improvement in symptoms. Even when recovery is progressing well, further tests are recommended at around three and six months.
The expected decrease depends on the method: to one-half or less of the pretreatment value with automated testing, or to one-quarter or less with serial dilution testing. Results should be compared using the same method, with continued checks for any subsequent rise. The rate of decline varies between patients. Antibodies remaining positive after treatment do not, by themselves, mean that treatment has failed.
HIV infection
Early infection may cause flu-like symptoms such as fever, sore throat and a rash. A long symptom-free period is also possible. Symptoms alone cannot establish whether HIV is present.
HIV is tested with blood samples. Testing soon after exposure may need to be repeated. A reactive screening result requires confirmation.
If infection is confirmed, we coordinate with specialist services. Ongoing antiretroviral treatment suppresses the virus.
Hepatitis B
Hepatitis B spreads through blood and body fluids, including sexual contact. It may cause no symptoms, or cause fatigue, loss of appetite, nausea, dark urine or yellowing of the skin and eyes (jaundice).
Blood tests such as HBs antigen and liver-function tests are used. Monitoring, treatment or specialist referral depends on whether infection is acute or chronic and on the results.
Vaccination can prevent hepatitis B. Please ask about vaccination.
Genital herpes and cold sores
Genital herpes causes painful blisters or sores on or around the genitals. Pain when urinating, itching and swollen lymph nodes in the groin may also occur.
Cold sores (oral herpes) cause blisters or sores on or around the lips, often preceded by tingling, stinging or itching. Oral herpes can spread through contact with an infected person's saliva or skin around the mouth, including through nonsexual contact.
Both are caused by herpes simplex virus and can recur after symptoms have settled.
Diagnosis is based on symptoms and an examination of the affected area. A rapid antigen test (immunochromatography) using a sample from a blister or sore may help support the diagnosis. A negative result does not rule out infection, so symptoms and the course of the illness are considered together.
Treatment when symptoms are present
Oral medicines are the main treatment. A topical medicine may be added when needed. The following are typical adult prescription examples.
Valaciclovir 500 mg tablets (originator brand in Japan: Valtrex)
One tablet (500 mg) twice a day for 5 days.
Arasena-A ointment 3% (vidarabine)
Apply an appropriate amount to the affected area 1–4 times a day.
For a first episode of genital herpes, oral treatment may be extended to up to 10 days. Return for assessment if symptoms do not improve or worsen. The dose and interval are adjusted for kidney function and other individual factors.
Options for recurrent herpes
Depending on how often episodes occur, their effect on daily life and whether you can recognise the early symptoms, we consider daily suppressive therapy for genital herpes or patient-initiated therapy (PIT) for either cold sores or genital herpes.
1. Daily suppressive therapy for genital herpes
Taking medicine every day can reduce recurrences in people with frequent episodes of genital herpes (approximately six or more a year). The following is a typical regimen for adults with normal immune function.
Valaciclovir 500 mg tablets (originator brand in Japan: Valtrex) — daily suppression
One tablet (500 mg) once a day, taken continuously.
We review your progress regularly and reassess the need to continue treatment about one year after starting. The dose and interval are adjusted for kidney function and other individual factors.
2. PIT: starting treatment yourself at the first signs of recurrence
Patient-initiated therapy (PIT) means keeping medicine prescribed in advance and starting it yourself when you recognise the early symptoms of a recurrence. It is an option for recurrent cold sores as well as recurrent genital herpes.
Early symptoms include tingling, stinging, burning or itching before blisters or sores appear. PIT is considered for people with repeated episodes of the same type who can recognise these symptoms themselves.
For adults with normal kidney function, the usual instructions are:
Famciclovir 250 mg tablets (originator brand in Japan: Famvir) — PIT
- First dose: take 1,000 mg (four 250 mg tablets) within 6 hours of the first symptoms.
- Second dose: take another 1,000 mg (four tablets) 12 hours after the first dose.
Two doses, eight tablets in total, complete the medicine course for one recurrence. Do not continue taking extra doses until all symptoms disappear. People with reduced kidney function need an adjusted dose or number of doses.
After taking your PIT medicine
The medicine prescribed in advance is for one future recurrence. After taking it, return for a review of the episode and a prescription for the next recurrence.
Genital warts (condyloma acuminatum)
Human papillomavirus (HPV) causes warts around the genitals or anus. They may cause little pain and increase in size or number unnoticed.
Diagnosis is based on the appearance, location, size and number of lesions. At our clinic, warts are cauterized with an electrosurgical device under local anaesthesia. Several sessions may be needed depending on the number and extent of lesions.
Follow-up checks wound healing and any remaining or recurrent warts. Recurrence is particularly important during the first three months. Return before your scheduled appointment if you notice new or enlarging warts.
Free anonymous syphilis and HIV screening
For people without symptoms, we offer free anonymous syphilis and HIV screening from September 1 through the end of December 2026 under the Miyazaki Prefecture program.
See the dedicated page for eligibility, booking and the screening process.
If you have pain on urination, discharge or a rash, arrange a medical consultation for appropriate testing and treatment rather than using the asymptomatic screening program.
Frequently asked questions
Do I need testing if I have no symptoms?
Infection can be present without symptoms. Please ask if a partner has been diagnosed or you are concerned about an exposure. We advise on whether and when to test based on the exposure and time elapsed.
Can a test immediately after exposure tell me whether I am infected?
Very early testing may miss infection. Tell us the date and site of contact and when symptoms began. Repeat testing may be recommended.
Can urine testing detect every STI?
No. Throat infection needs testing from that site, while syphilis, HIV and hepatitis B require blood tests. Examination of blisters or warts is also important.
Can I stop attending once symptoms settle?
An infection may remain after symptoms improve. Follow-up requirements depend on the infection and site, so follow your clinician’s advice.
Is testing covered by insurance?
Medically necessary tests for a suspected infection may qualify for insurance coverage based on symptoms and examination findings. Conditions apply to individual tests and combinations. Asymptomatic screening may be self-pay; we explain this during the consultation.
References
This page provides general guidance on symptoms, testing and treatment. Your examination determines the appropriate care.
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