Herpes simplex virus type 2 (HSV-2) is a common infection spread via sexual contact which manifests with a rash in the genital area.
Historically, herpes simplex virus type 2 (HSV-2) infection has been considered a sexually transmitted infection and the cause of genital herpes, although in recent years herpes simplex virus type 1 has also been recognized as a causative factor of genital herpes. Nevertheless, HSV-2 remains the main germ associated with rash and ulceration in the genital area.
What is the virus like?
Herpes simplex virus 2 belongs to the alpha herpesvirus group. HSV possesses an internal core with linear double-stranded DNA. The capsid of herpes viruses consists of 162 consumers. The virus is wrapped in a lipid envelope with viral glycoproteins on the surface. Its molecular weight is approximately 100×106 units and a diameter of approximately 160 nm.
HSV-2 more commonly affects females than males. Moreover, usually, HSV-2 infection is associated with the commencement of the sexual activity. The global prevalence of HSV-2 was estimated at about 11,3% as of 2012 and around 23 million new cases of HSV-2 are detected worldwide every year which makes it less common than HSV-1.
HSV-2 infection is considered a sexually transmitted disease and hence is transmitted often during sexual intercourse through direct contact with mucosal surfaces. Unlike bacterial sexually transmitted diseases, HSV-2 is more likely to be transmitted within long-term couples rather than accidental sexual relationships. It is important to understand that herpes simplex virus infection may be asymptomatic and hence infected individuals may spread the virus without realizing it.
HSV-2 infection acquisition is associated with a wide range of risk factors including:
- Sexually active lifestyle;
- Female sex;
- Negroid race;
- A big number of sexual partners;
- Poverty or low income;
Primary genital infection develops within 2 to 12 days following exposure to the virus. The disease itself lasts from 10 to 12 days when the infection occurs for the first time. The first episode of genital herpes starts with fever, headache, general malaise, and muscular pain. A person may feel pain and itching in the genital area before the rash appears. Other symptoms also include pain while peeing (dysuria), increased vaginal and urethral discharge, and the painful enlargement of the glands in the groin. These symptoms are especially prominent in the first week of the disease. The typical rash appears as widely spaced nodes on the genitalia. The painful lesions quickly become ulcers covered with a grey-white exudate. Later on, the lesions crust on healing and disappear without scarring afterward. These lesions persist for approximately 21 days. HSV-2 may also affect the pharynx, causing ulcers or lesions of the pharynx or the tonsils.
Primary herpes genitalis in males appears as a cluster of vesicles on the red surface of the skin on the tip of the penis. In women, lesions appear on two sides of the vulva. HSV-2 infection may also cause inflammation of the cervix (cervicitis) which is characterized by purulent or bloody vaginal discharge. During the examination, cervical ulceration or necrosis is observed.
The virus is known to cause meningitis as a complication of genital herpes, especially in women, which develops on average within a week following the occurrence of genital rash. In individuals with adequate immunity, meningitis has a self-limiting character and resolves spontaneously in 2-4 days.
Genital herpes infection tends to recur especially in the first 12 months following primary infection, over time recurrence rate decreases and occurs less often. When the disease recurs it is typically not as severe as the first bout of infection and has a shorter duration.
The diagnosis is made based on clinical features but laboratory tests to detect viral DNA via PCR method are ordered if there is any doubt regarding the disease’s cause.
Acyclovir, valacyclovir, or famciclovir may be used in the treatment of genital herpes, especially the first episode. Treatment should be initiated as soon as possible, ideally within 72 hours of rash occurrence.
For recurrent infections, a shorter course of antiviral treatment is recommended. Daily administration of acyclovir was reported to prevent genital herpes recurrence. However, long-term application of antiviral medications is used only in individuals with the severely suppressed immune system.
Knowledge of a partner’s infection, diagnosis, and treatment reduce the risk of HSV-2 transmission. Chemoprophylaxis with antiviral medications and consistent condom use are known to decrease the transmission rates as well. Male circumcision was shown to decrease both HIV-1 and HSV-2 acquisition risk in males but does not affect the transmission rates among females.