Genital herpes (HSV): recurrence, testing and treatment in Taichung

In short

• Genital herpes and shingles are not the same illness. They are caused by different viruses, and the shingles vaccine does not prevent genital herpes.
• It cannot be eradicated. The virus stays in the nerve ganglia (clusters of nerve cells). Medication can shorten an episode and reduce how often episodes return, but it cannot clear the virus.
• Most transmission is by asymptomatic shedding. On days with no blister and no sensation at all, the virus can still be released.
• Test while a lesion (a blister, sore or ulcer on the skin) is there. Routine HSV antibody screening is not advised for adults without symptoms. A blood test for HSV DNA is of almost no help for genital herpes, unless the infection may have spread through the body.
• Suppressive therapy is one option: taking an antiviral medicine every day to reduce how often episodes return. Whether long-term use suits you is assessed by a doctor, based on how often episodes occur and your partner’s situation.

First, which herpes are you looking for?

The word “herpes” covers several different conditions, so it is easy to read about the wrong one.

HSV-1 is now a common cause of genital herpes, mainly through oral sex. So “my partner only gets something on the lip” is not a reason to feel safe.

A first episode and a recurrence are very different

The first episode

This is usually the most severe one:

• Groups of small blisters. When they break, they form ulcers that hurt. This is the opposite of the syphilis ulcer, called a chancre, which is painless.
• Fever, tiredness, and swollen, tender lymph nodes in the groin may come with it.
• Passing urine can be very painful. Some people avoid urinating because of it.
• The episode can last two to three weeks.

A recurrence

A recurrence is usually milder. It covers a smaller area and lasts a shorter time:

• There is often a warning sensation first (the medical term is the prodrome): tingling, burning, itching or numbness at the same spot, a few hours to one or two days before the lesion appears.
• There are fewer lesions, and they heal faster.
• Common triggers include tiredness, stress, a cold or fever, menstruation, and local friction.
• It usually appears in the same place, because the virus stays in one nerve ganglion and becomes active again in the area that nerve supplies.

That warning sensation matters. If you can recognise it, you may be able to start treatment before the lesion appears, and you know which days to avoid sexual contact.

The part most often missed: asymptomatic shedding

Most transmission of genital herpes does not happen when a lesion can be seen. It happens on days with no symptoms at all: the virus can still be released from the skin and the mucous membrane, and the person feels nothing. This is called asymptomatic shedding.

It explains two things that confuse many people. First, why a partner who has never had a visible lesion can still pass the virus on. Second, why avoiding sex only during an episode is not enough.

Condoms lower the risk but do not remove it, because lesions and shedding can occur outside the area a condom covers. This is not a reason to stop using condoms. It is a reason to set the expectation correctly: the risk goes down, but it is not blocked completely.

How the diagnosis is confirmed

The most reliable moment to confirm genital herpes is while the lesion is still there. A swab taken from the lesion for a nucleic acid amplification test (NAAT, a PCR-type test) is the most direct method. It confirms whether HSV is present, and separates HSV-1 from HSV-2. Once the lesion has crusted over or healed, the test is much less likely to find the virus.

So if you are having an episode now, do not wait until it has healed. A common problem is that people keep getting lesions but only come after they have healed, so a firm diagnosis is never made. Come during an episode, or as soon as the warning sensation starts. If you are not sure whether to come, message us on LINE to arrange a visit.

Why routine antibody testing is not advised

Screening panels, including the one at this clinic, often include HSV-1 / HSV-2 IgG antibodies. This result is easy to misread.

Because it cannot answer the questions that matter, the US CDC treatment guidelines do not recommend routine HSV antibody screening for general adults who have no symptoms. It helps when blisters keep coming back but sampling is never done in time (its most valuable use), when your partner is known to have genital herpes, and in pregnancy-related assessment.

If this test was in your screening panel and the result is positive, there is no need to panic. First look at whether you have symptoms or a history of episodes; the doctor explains this when going through the report.

Four tests with “herpes” in the name, and what each one answers

More than one test has “herpes” in its name. Each uses a different sample and answers a different question, so a test with the right name can still be the wrong test for your question.

This is general information about test methods, not advice for a particular person. Whether to test, and which test, is decided by a doctor at a face-to-face consultation. Guidelines can change; the latest version applies. Costs are explained at the consultation.

Why a blood test for HSV DNA does not help here

This test is sometimes done on serum, plasma or whole blood, and “testing the DNA” sounds more direct than testing antibodies. The problem is where the virus is. Genital herpes is a local infection of the skin and mucous membrane. The virus stays in the lesion and in the nerve ganglion that supplies it, not in the blood in a stable way.

One study looked at 164 adults with a confirmed first episode of genital HSV infection. HSV DNA was found in the plasma of only 40 (24%), more often early in the illness and more often in women. So even in a first episode, the test did not find HSV DNA in the blood of about three in four people. No study of this blood test in people with recurrent genital herpes was found, so there are no data on how often it would be positive.

This 24% figure has two more limits. A negative result does not exclude infection, and a positive result does not mean severe illness. Severity is judged by signs such as fever, liver function and the level of consciousness, not by this number.

Blood tests for HSV DNA do have uses, but elsewhere. One is a newborn whose mother had a first episode at delivery (a negative result cannot exclude infection, and the test may need repeating). Another is hospital patients with suspected disseminated infection. In one study of hospital patients, those with HSV DNA in the blood most often had hepatitis, fever, altered consciousness or sepsis (a severe whole-body reaction to infection). For HSV encephalitis (brain infection), the test uses cerebrospinal fluid (the fluid around the brain and spinal cord), not blood. None of these supports a blood test for an adult with blisters seen in a clinic. When there is no lesion, the useful blood test is the type-specific antibody test (test 2), in the situations listed above.

Two more traps

• No lesion? Do not have a random genital swab. The US CDC states that without a lesion, genital HSV infection should not be diagnosed with a random or “blind” swab (a swab taken where nothing can be seen): sensitivity is low, and a negative result cannot exclude infection. If you have no symptoms, ask which samples a panel includes.
• A low positive antibody result is not a firm diagnosis. The US CDC notes that commercial type-specific antibody tests can give false positives, especially when the value is low (an index below 3.0; false positives are common between 1.1 and 3.0). It advises confirming with a second method, which not every laboratory adds. Where that is not available, the person should first understand that false positives do happen. The doctor reads the value together with your symptoms and history of episodes.

Treatment: episodic therapy and suppressive therapy

One point has to be clear first: current antiviral medicines cannot clear the virus from the body. It stays in the nerve ganglia. Medication controls episodes and reduces how often they return. Any claim that genital herpes can be eradicated does not match current medical understanding.

1. Episodic therapy

This is a short course of antiviral medicine during an episode, started as early as possible — ideally as soon as the warning sensation appears. The aim is to shorten the episode and reduce symptoms. It suits people who have episodes only occasionally and can recognise the warning sensation. You keep the medicine with you and start it when the sensation begins.

2. Suppressive therapy

This means taking an antiviral medicine every day, to reduce how often episodes return. For the antiviral medicines approved in Taiwan for this use (for example valaciclovir), the approved indication covers herpes zoster, and the prevention and treatment of recurrent genital herpes. It is worth considering when episodes are frequent or severe, when they are a clear source of stress, or when your partner has not been infected and you want to lower the risk of transmission (see the note below).

The medicine, the dose and the length of the course are decided by a doctor, based on how often episodes occur, kidney function, whether you are pregnant, and your own situation. Regular review decides whether to continue.

3. Other measures that help

• Keep the lesions clean and dry, and avoid friction.
• If passing urine is very painful, the clinic can offer ways to ease the discomfort.
• Avoid sexual contact during an episode, including oral sex.

Telling a partner

Genital herpes cannot be eradicated, but recurrences can be reduced. It is also a very common virus, not a moral question. Some practical points:

• Confirm the diagnosis first. Discussing uncertain information only creates misunderstanding.
• Explain asymptomatic shedding. It shows why transmission does not mean that someone was unfaithful. Many people carry the virus for years without knowing.
• Talk about concrete steps, not only about risk. Avoiding contact during an episode, recognising the warning sensation, suppressive therapy where appropriate, and continued condom use are things you can do together.
• If your partner has no symptoms and wants to know their own status, an antibody test is one of the few situations where it is useful.

If you do not know how to start the conversation, the clinic can provide a written explanation for you to give to your partner.

Pregnancy and delivery

If you or your partner have a history of genital herpes, and you are planning a pregnancy or are already pregnant, tell the obstetrician yourself.

Neonatal herpes is uncommon but serious, and the plan for delivery differs according to the mother’s infection status and whether an episode is active. A new infection during pregnancy carries a higher risk than one from the past. The obstetric team manages this, but only if they know. Many people do not mention it because they think it was long ago.

Getting checked in Taichung: your visit

• You have an episode now: come while the lesion is still there. A swab can be taken the same day, and it is the most valuable chance to confirm the diagnosis.
• It has healed, but keeps coming back: an antibody test can be discussed.
• No symptoms, and you want to check your status: the doctor first looks at your history of episodes and your partner’s situation, then decides whether an antibody test is useful. Tests for discharge-type infections, HIV and syphilis can be arranged on the same day.

Book through the online form, on LINE, or by telephone. 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. Costs are explained at the consultation. Episodic or suppressive therapy can be decided afterwards, without rushing. The clinic uses separate consulting rooms and patient routes, so you do not have to explain why you are here in the waiting area.

Free anonymous screening: what it covers

This clinic is on two Taiwan CDC rosters, under medical institution code 3503241524: anonymous HIV screening, and anonymous syphilis screening for young people or students aged 24 or under. Both can be checked on the Taiwan CDC page for anonymous counselling and screening.

The HIV test is a rapid blood test. For it 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. The result is given under a code number. The syphilis rapid test is a separate service for people aged 24 or under or students. It also has no charge, but depends on the test kits Taiwan CDC supplies.

Herpes is not part of these free services. Lesion sampling and antibody testing for herpes need a normal clinic registration. When genital herpes is confirmed, checking HIV and syphilis at the same time is reasonable. These two can be tested free on the same day, if you meet the conditions above.

Related pages

• Syphilis: symptoms and the window period
• Genital warts and HPV
• Full sexually transmitted infection screening
• Anonymous screening routes in Taichung

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: September 2026 (same as the Traditional Chinese version). English version published: 4 September 2026; revised 31 October 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 / Patel R, et al. 2024 European guidelines for the management of genital herpes (IUSTI/EADV). J Eur Acad Dermatol Venereol / British Association for Sexual Health and HIV (BASHH), 2024 UK national guideline for the management of anogenital herpes / Johnston C, et al. Herpes simplex virus viremia during primary genital infection. J Infect Dis 2008;198:31-34 / Taiwan FDA approved product information database, oral valaciclovir preparations (herpes zoster; prevention and treatment of recurrent genital herpes) / World Health Organization, herpes simplex virus. Indications and dosing follow the Chinese-language product information approved by the Ministry of Health and Welfare. This page makes no claim about the effect of antiviral medicines on transmission between partners.

This page provides general medical information and does not replace an individual diagnosis or treatment plan.