Herpes is a very common family of viruses that lead to painful rashes and even nerve damage. The various viruses in this family include chicken pox, cytomegalovirus, and simplex 1 and 2, to name a few. There are several others to consider but for the purpose of this article, I will discuss herpes simplex and how to understand the various lab tests available to diagnose it. In brief, the herpes family of viruses tend to lie dormant in the body and can travel along nerve cells, which is also why they are so painful. The virus tends to present as a blistering rash in various parts of the body. Chicken pox, or varicella, can spread throughout the body and then hibernate, only to appear years later as shingles. A common theme to the family of herpes virus is that the virus can spread before lesions appear and symptoms can start as tingling, burning and pain in the area that the lesion will form.
Specifically, I will address Herpes Simplex in this article and hopefully clarify the importance of testing. The two main types of simplex are 1 and 2. The first causes very common cold sores or fever blisters in the mouth and lips. The blisters can cause painful swelling of the mouth and out breaks can occur at any time. Fortunately, this can be treated with a one day anti-viral treatment. Simplex type 2 causes genital lesion and will be the focus of the rest of the article. While type 2 does tend to infect the genital area and is sexually transmitted, it can also appear in other areas of the body if that part comes into contact with the virus. For example, simple type 2 can infect the mouth, eyes and other openings if exposed.
This virus is spread through contact with bodily fluids of an infected individual. The first can be present in secretions for several days prior to any lesions forming. The infected person can be without any symptoms but still very contagious. The symptoms can start as general malaise, fatigue, and sometimes fever with progression to pressure in the genital area and the development of tingling, burning and blistering of the skin and genitals. The fluid filled blisters contain virus and are very contagious. Avoiding contact with the lesions is the first step in preventing the spread of the virus. In addition to the pain associated with the infection, it can also lead to severe complications if it infects the eye, the brain or other body systems. It is especially detrimental in pregnancy as the virus can infect the newborn and be potentially fatal for the fetus.
In order to understand the different tests for herpes, it is necessary to have some understanding of how the immune system works. When the body encounters an infection, it will generate different antibodies to attack the invader. The first antibody is known as IgM. This is an early antibody that develops in response to acute infection. Once the infection resolves, the body will produce IgG antibodies to always remember the infection and know how to respond to it when encountering the infection again. The IgG antibody stays positive in the blood even when the infection is gone. Think of the IgM as the shock troops sent out to destroy the invader and the IgG as the reserve unit that responds to a repeat threat.
To test for herpes infection, a patient can either test for the virus itself or the body’s response to the virus. If active lesions are present, the fluid can be sampled and a test can be run to detect active virus. A culture of fluid can be done to grow out the virus but this tends to have a low yield. A different test known as PCR (polymerase chain reaction) can be done to reveal the presence of virus. It is more accurate then culture. Since it is not always easy to sample the fluid and it is important to detect infected persons before the virus is spread, blood tests need to be done. As noted earlier, IgM and IgG antibodies can be detected in the blood to distinguish between acute and chronic infection. The antibody test can also distinguish between type 1 and 2. If the IgM test is positive then it is likely to be an active infection. If the IgG is positive, the individual has been infected in the past and may or may not develop symptoms in the future. Having a positive IgG does not mean an outbreak will always occur but it does mean the patient has been infected in the past and could get an outbreak. A person with a positive IgG should inform any prospective partners of his or her status and practice safer sex with barrier protection, such as condoms. Once the IgG is positive, it will always test positive and does not need to be repeated. In summary, a person can test for the virus itself or the bodies response. The test for the virus only occurs during an actual outbreak while the body’s response can be tested at any time. The blood test can distinguish between type of herpes and shows new or old infection. To be clear, herpes testing can be done at any time without any lesions present No one should wait until a problem occurs before finding out the status of infection. Testing should be done well in advance of any sexual encounter to prevent infection. Antiviral medications can be used to treat acute outbreaks or can be used to suppress future outbreaks by daily use of such medications.
Hopefully this article helped to elucidate some of the issues with testing for herpes simplex. HSV is a concerning STD that can be spread from person to person before symptoms develop. While treatment is available, it can not be cured and the best course of action is prevention. Engaging in frequent sexual activity is a risk for infection and the lesions cause damage to the membranes which increase the risk of other infections. It is just as important to test for HSV as it is to test for any of the other STDs. A doctor should be sought for any questions or concerns regarding testing and treatment of HSV.