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Diagnosis of Herpes Symptoms, Causes and Lab Test

Herpes is a common infection that takes place due to the Herpes Simplex Virus. There are two types of Herpes virus – Herpes Simplex Virus 1 (HSV- 1) and 2 (HSV-2). HSV-1 is also known as oral herpes, and HSV-2 is commonly called genital herpes. Herpes can be diagnosed by laboratory testing and examination of sores during an outbreak.

This article provides information on the various ways you can test for herpes.


Herpes outbreaks occur as blisters that can break open to form sores – in the mouth for oral herpes and in the genitals for genital herpes. For HSV-1, there may be pain, tingling, and bumps in the mouth or on the tongue.

Pain in the genitals during sexual activity or urination, swelling, sores in and around the genitals, and redness are all symptoms of genital herpes or HSV-2.

HSV-1 and HSV-2 are both characterised by visible sores on the mouth or genitals during an outbreak. These sores can also lead to other illnesses. You should see a doctor when you experience any of these symptoms, especially if you notice them for the first time.

You should also see your doctor if the symptoms are worse or different from previous outbreaks that you have experienced.

Lab tests

If you experience symptoms of either HSV 1 or 2, your doctor will take a swab of the sores for further examination if they are present or do a physical examination to confirm that the infection is caused by the virus. A Blood Test London clinic can also be visited to diagnose the infections when there are no visible sores.

Herpes Swab test

A swab is gently taken from the area of the skin affected by the lesions or the fluid from the lesions. This swab is used for a viral culture test or a nucleic acid amplification test (NAAT).

The viral culture test allows the growth of the virus in a laboratory setting while the NAAT identifies the genetic material of the virus in the swab sample. These tests are very reliable, especially if the swabs are taken during an outbreak.

Herpes blood test

 Herpes blood test London clinic can detect asymptomatic herpes infections. This test identifies antibodies produced by the body in defence against the virus. When the virus invades the body, the body produces antibodies to fight against the infection. Antibodies can last for years and in most cases for a lifetime. The body produces antibodies for herpes virus within 2 weeks of contracting the virus.

 The downside of the herpes blood test is that it is not helpful in the detection of reinfection because once the body produces the antibodies during the first infection, the antibodies remain even when the virus becomes dormant.

There are two types of herpes blood test

  1. General herpes blood tests – this test does not identify the specific type of herpes a person has. It only looks for the general antibodies produced to fight against the virus.
  2. Type-specific herpes blood tests – it identifies if the antibodies are produced to fight against either HSV- 1 or HSV-2.

There are different blood tests available for the detection of viral antibodies. Each one has its advantage and disadvantage.

The general downside of herpes blood testing is that there is a latency period between contracting the virus, and the antibodies being detectable via blood testing.

Generally, it takes about 2 weeks for an outbreak to occur after contracting the virus. The median time of some HSV- 2 blood test brands are

  • Kalon ELISA – approximately 120 days.
  • HerpeSelect ELISA – 3 – 4 weeks.
  • Focus ELISA – 21 days.
  • Western blot – 3 – 4 weeks.

When lesions are absent, a swab test becomes impossible and it is advisable to wait for a month or 2 before getting a blood test. Within this time, the antibodies will have been produced.

Getting a blood test before the antibodies are formed can give a false-negative result. You can test for the virus after six months to be sure you do not have it if the first test returns a negative result.

Diagnosis in new-borns

Herpes can be passed from an infected mother to her child during childbirth. Diagnosis of herpes in newborns can be challenging, especially if it is encephalitis (herpes infection of the brain). This requires a more specific test like a lumbar puncture. If the baby has visible lesions in or around the mouth, a swab would be taken for a swab test at a blood test London clinic.

Differential diagnosis

Some other conditions have symptoms that may be confused with herpes. Most of these conditions are very serious and need immediate medical attention. This is one of the reasons why self-diagnosis may not be safe. Medical examinations by doctors and laboratory tests can easily distinguish these symptoms.

Other medical conditions with similar symptoms to herpes include

Syphilis – a sexually transmitted disease characterised by genital sores similar to HSV-2. Blood tests for syphilis detect the presence of Treponemapallidum, the virus that causes syphilis. Your doctor can also distinguish the two infections by examination of the sores.

Cancer/pre-cancer – cancer can also cause lesions in and around the genitals. A needle biopsy or swab test can easily identify if the lesions are caused by cancer or herpes simplex virus.

Canker sores – canker sores are found in the mouth; they are red, raised, raw, with a whitish pit in the centre and painful during the initial period of the infection. Canker sores are a result of oral trauma. Visit a blood test London clinic to be sure of what you are treating.

Medication reaction – some medications can cause allergies and sensitive reactions, which leads to rash around the mouth and lips. The rashes may look like cold sores common to HSV-

Concurrent HSV-1 and HSV- 2 – HSV-1 and HSV-2 are two different viruses. You can be infected with only one or the two. If you have already been diagnosed with one and you discover lesions in a new area of your body, it is important to see your doctor at a blood test London clinic. This may be as a result of infection with another type of herpes virus or an entirely new infection.

Diagnosis of herpes is important because early treatment when diagnosed, can help reduce the number and intensity of outbreaks. It can also reduce the virus to a point where it cannot be transmitted even when a person is still infected.

Visit a blood test London clinic today to get tested. Health is wealth.