Herpes simplex virus

ALSO KNOWN AS: HSV, HSV-1, HSV-2

RELATED CONDITION: Gingivostomatitis

DEFINITION: Herpes simplex virus is an enveloped, double-stranded, deoxyribonucleic acid (DNA) virus that causes skin ulcers in infected persons. Herpes simplex virus 1 (HSV-1) commonly affects the lips, the face, and the skin above the waist. Herpes simplex virus 2 (HSV-2), sexually transmitted, affects the genitalia and the skin below the waist. Complications of HSV infection include inflammation of the brain lining and eye infections.

Risk factors: Sexually active adolescents and adults are at risk of infection with HSV-2. People with weakened immune systems, such as cancer patients, are at an increased risk of recurring HSV infection and disease.

Etiology and the disease process: Once infected, the virus spreads to the nerve cells and remains in the body (in a latent form) for life.

The lesions in the genital area first look like red bumps but then turn into watery blisters that may open up, ooze fluid, or bleed. Some heal in seven to ten days but may take up to four weeks. The lesions may reappear, usually after periods of stress, fever, or overexposure to sunlight.

Cancer, human immunodeficiency virus (HIV), acquired immunodeficiency syndrome (AIDS), and the use of medications (corticosteroids) that weaken the immune system may also trigger the reappearance of symptoms. Individuals with HSV-2 are more likely to contract and transmit HIV.

Some studies suggest that women infected with herpes simplex virus and a high-risk type of human papillomavirus (HPV) have a greater likelihood of developing cervical cancer than women who have only the HPV infection. However, HSV infection need not be present for cervical cancer to develop.

Incidence: HSV infections are ubiquitous and transmitted between people whether or not they have symptoms. Most children will acquire an HSV-1 infection during their first few years of life, usually through contact with infected saliva. Globally, around 3.7 billion people younger than fifty have HSV-1, which mainly causes oral herpes, and around 491 million individuals between fifteen and forty-nine have HSV-2, which causes genital herpes.

Symptoms: HSV infections in children beyond the neonatal (newborn) period, adolescents, and adults usually have no symptoms. HSV-1 may cause fever (especially during the first episode), mouth sores (fever blisters), and enlarged lymph nodes in the neck or groin. HSV-2 may cause genital lesions with a burning and tingling sensation, muscle pain, vaginal discharge, and trouble urinating.

Screening and diagnosis: HSV infections can be diagnosed by the physical appearance of the skin lesions. However, laboratory tests are available to diagnose herpes simplex virus infections, including blood and cell culture tests. Other available tests include:

• Tzanck test: The sore on the skin is scraped, and the sample is stained for examination under a microscope.
• Direct fluorescent (DFA) test: This uses a fluorescent antibody to detect the presence of the virus.

Treatment and therapy: Mild cases of the disease may not require treatment. For more severe cases, two types of therapies are usually recommended: episodic and suppressive therapy. Episodic therapy consists of taking medication at the first sign of recurrence to accelerate the healing process of the lesions. The medication is taken for a few days until the lesions disappear. Suppressive therapy consists of taking medication daily to eliminate or reduce recurrence. Suppressive therapy is usually recommended for people who have six or more recurrences per year.

Cancer patients with severe cases and frequent infections may be treated with antiviral drugs, such as acyclovir (Zovirax), famciclovir (Famvir), and valacyclovir (Valtrex). Acyclovir is available in ointment and pill forms. Valacyclovir uses acyclovir as its active ingredient but is adsorbed better by the body than acyclovir, thus requiring fewer daily doses. Famciclovir stops the virus from replicating, using the active ingredient penciclovir. Like valacyclovir, it is well absorbed by the body.

Prognosis, prevention, and outcomes: Herpes has no cure. Recurrences, however, may be milder over time. HSV skin lesions usually heal in seven to ten days, but they may take longer in people with weakened immune systems. People with genital herpes may feel ashamed or guilty and may think that they can no longer have sex. Herpes can be treated, and transmission can be prevented. Using condoms can help prevent genital HSV infection, but they do not always cover the whole infected area, and infection may occur.

There is no licensed vaccine against herpes simplex virus, but several candidate vaccines have been studied.

Bibliography

American Academy of Pediatrics. “Varicella-Zoster Virus Infections.” Red Book: 2021-2024 Report of the Committee on Infectious Diseases. Kimberlin, David W., et al. 32nd ed. American Academy of Pediatrics, 2021. doi.org/10.1542/9781610025782-S3‗156.

Bradley, H., et al. "Seroprevalence of Herpes Simplex Virus Types 1 and 2—United States, 1999–2010." Journal of Infectious Diseases, vol. 209, no. 3, 2014, pp. 325–33.

"Cervical Cancer Prevention (PDQ®)–Health Professional Version." Naional Cancer Institute, 6 Mar. 2024, www.cancer.gov/types/cervical/hp/cervical-prevention-pdq. Accessed 10 July 2024.

Ebel, Charles. Managing Herpes: How to Live and Love with a Chronic STD. Rev. ed., American Social Health Assn., 2002.

"Herpes Simplex: Overview." American Academy of Dermatology, www.aad.org/public/diseases/a-z/herpes-simplex-overview. Accessed 10 July 2024.

"Herpes Simplex Virus" World Health Organization, 23 Apr. 2023, www.who.int/news-room/fact-sheets/detail/herpes-simplex-virus. Accessed 10 July 2024.

"Infections in People with Cancer." American Cancer Society, www.cancer.org/cancer/managing-cancer/side-effects/infections.html. Accessed 10 July 2024.

Stanberry, Lawrence. Understanding Herpes. 2nd ed., UP of Mississippi, 2006.