Genital herpes is a genital infection caused by the herpes simplex virus (HSV). Most individuals carrying herpes are unaware they have been infected and many will never suffer an outbreak, which involves blisters similar to cold sores. While there is no cure for herpes, over time symptoms are increasingly mild and outbreaks are decreasingly frequent. When symptomatic, the typical manifestation of a primary infection is clusters of genital sores consisting of inflamed papules and vesicles on the outer surface of the genitals, resembling cold sores. These usually appear 4–7 days after sexual exposure to HSV for the first time. Genital HSV-1 infection recurs at rate of about one sixth of that of genital HSV-2.

HSV has been classified into two distinct categories, HSV-1 and HSV-2. Although genital herpes was previously caused primarily by HSV-2, genital HSV-1 infections are increasing and now cause up to 80% of infections.

In 2013 about 1.1 billion people (15.9%) had asymptomatic genital herpes and 47 million new cases of genital herpes occurred. A 1998 study indicated it was the most common sexually transmitted infection by the number of cases.

Signs and symptoms


Genital herpes in a male
In males, the lesions occur on the glans penis, shaft of the penis or other parts of the genital region, on the inner thigh, buttocks, or anus. In females, lesions appear on or near the pubis, clitoris or other parts of the vulva, buttocks or anus.

Other common symptoms include pain, itching, and burning. Less frequent, yet still common, symptoms include discharge from the penis or vagina, fever, headache, muscle pain (myalgia), swollen and enlarged lymph nodes and malaise. Women often experience additional symptoms that include painful urination (dysuria) and cervicitis. Herpetic proctitis (inflammation of the anus and rectum) is common for individuals participating in anal intercourse.

After 2–3 weeks, existing lesions progress into ulcers and then crust and heal, although lesions on mucosal surfaces may never form crusts. In rare cases, involvement of the sacral region of the spinal cord can cause acute urinary retention and one-sided symptoms and signs of myeloradiculitis (a combination of myelitis and radiculitis): pain, sensory loss, abnormal sensations (paresthesia) and rash. Historically, this has been termed Elsberg syndrome, although this entity is not clearly defined.

After approximately 80% of first episodes of herpes genitalis caused by HSV-2, there will be at least one recurrence, while the recurrence rate for herpes genitalis caused by HSV-1 is approximately 50%. Herpes genitalis caused by HSV-2 recurs on average four to six times per year, while that of HSV-1 infection occurs only about once per year.

People with recurrent genital herpes may be treated with suppressive therapy, which consists of daily antiviral treatment using acyclovir, valacyclovir or famciclovir. Suppressive therapy may be useful in those who have at least four recurrences per year but the quality of the evidence is poor. People with lower rates of recurrence will probably also have fewer recurrences with suppressive therapy. Suppressive therapy should be discontinued after a maximum of one year to reassess recurrence frequency.

Treatment

As of November 2015, genital herpes cannot be cured. Moreover, genital herpes can be transmitted by viral shedding prior to and following the visual signs of symptoms. There are, however, some drugs that can shorten outbreaks. Among these drugs are acyclovir, valacyclovir, and famciclovir.

Acyclovir is an antiviral drug used against herpes viruses, varicella zoster viruses, and Epstein–Barr viruses. This drug reduces the pain and the number of lesions in the initial case of genital herpes. Furthermore, it decreases the frequency and severity of recurrent infections. It comes in capsules, tablets, suspension, injection, powder for injection, and ointment. The ointment is used topically and it decreases pain, reduces healing time, and limits the spread of the infection.

Valacyclovir is also used to treat herpes virus infections. Once in the body, it is converted to acyclovir. It helps relieve the pain and discomfort and the sores heal faster. It only comes in caplets and its advantage is that it has a longer duration of action than acyclovir. An example usage is 1000 mg by oral administration twice per day for 10 days for primary lesion, and 500 mg orally twice per day for 3 days for a recurrent episode.

Famciclovir is another antiviral drug that belongs to the same class as acyclovir and valacyclovir. Famciclovir is a prodrug that is converted to penciclovir in the body. The latter is the one active against the viruses. This drug has a longer duration of action than acyclovir and it only comes in tablets.

Epidemiology

About 16 percent of Americans between the ages of 14 and 49 are infected with genital herpes, making it one of the most common sexually transmitted diseases. More than 80% of those infected are unaware of their infection. Annually, 776,000 people in the United States get new herpes infections.

Tests for herpes are not routinely included among STD screenings. Performers in the pornography industry are screened for HIV, chlamydia, and gonorrhea with an optional panel of tests for hepatitis B, hepatitis C and syphilis, but not herpes. Testing for herpes is controversial since the results are not always accurate or helpful. Most sex workers and performers will contract herpes at some point in their careers whether they use protection or not.

History

Early 20th century public health legislation in the United Kingdom required compulsory treatment for sexually transmitted diseases but did not include herpes because it was not serious enough. As late as 1975, nursing textbooks did not include herpes as it was considered no worse than a common cold. After the development of acyclovir in the 1970s, the drug company Burroughs Wellcome launched an extensive marketing campaign that publicized the illness, including creating victim's support groups.

Research

Main article: Herpes simplex research
There are efforts to develop a vaccine, but the results so far has not been able to cure herpes or eliminate transmission.

Vaccine Company Lead Researcher Vaccine Type Status
HSV-2 ICP0‾ HSV-2 0ΔNLS Rational Vaccines RVX William Halford Live, Attenuated Looking for Volunteers
dl5-29 / ACAM-529 / HSV-529 Sanofi Pastuer David Knipe ? Phase I
Admedus Admedus Ian Frazier Sub Unit Phase II
HerpV Agenus ? ? ?
Gen-003 Genocea ? Sub Unit Phase II
Vical Vical ? ? Phase II
Einstein Einstein Med College William Jacobs Jr ? Preclinical
GV2207 GenVec ? ? ?
Mymetics Mymetics ? ? ?
AIC316 AICuris ? ? ?
Vitaherpavac & Herpovax ? ? ? ?
NE-HSV2 NanoBio ? ? Preclinical
Profectus BioSciences ? ? ? ?
Biomedical Research Models ? ? ? ?
Tomegavax ? ? ? ?
Herpevac ? ? ? Discontinued
PaxVax ? ? ? ?
Amgen BioVex ? ? ? ?
AuRX ? ? Live, Attenuated Inactive
Zostavax (VZV, shingles) Merck ? Live, Attenuated In Production
Varicella (C.Pox) Merck ? Live, Attenuated In Production

source - Wikipedia