What is Herpes Simplex Virus?
Infection with herpes simplex virus, commonly known as herpes, can be due to either herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2). HSV-1 is mainly transmitted by oral-to-oral contact to cause infection in or around the mouth (oral herpes).
However, HSV-1 can also be transmitted through oral-genital contact to cause infection in or around the genital area (genital herpes). HSV-2 is almost exclusively transmitted through genital-to-genital contact during sex, causing infection in the genital or anal area (genital herpes).
Both oral herpes infections and genital herpes infections are mostly asymptomatic or unrecognized but can cause symptoms of painful blisters or ulcers at the site of infection, ranging from mild to severe.
Herpes simplex virus type 1 (HSV-1)
HSV-1 is a highly contagious infection, that is common and endemic throughout the world. Most HSV-1 infections are acquired during childhood, and infection is lifelong. Most HSV-1 infections are oral herpes (infections in or around the mouth, sometimes called orolabial, oral-labial or oral-facial herpes), but a proportion of HSV-1 infections are genital herpes (infections in the genital or anal area).
What are the symptoms?
Oral herpes infection is mostly asymptomatic, and most people with HSV-1 infection are unaware they are infected. Symptoms of oral herpes include painful blisters or open sores called ulcers in or around the mouth. Sores on the lips are commonly referred to as “cold sores.” Infected persons will often experience a tingling, itching or burning sensation around their mouth, before the appearance of sores.
After initial infection, the blisters or ulcers can periodically recur. The frequency of recurrences varies from person to person. Genital herpes caused by HSV-1 can be asymptomatic or can have mild symptoms that go unrecognized. When symptoms do occur, genital herpes is characterized by 1 one or more genital or anal blisters or ulcers. After an initial genital herpes episode, which can be severe, symptoms may recur. However, genital herpes caused by HSV1 typically does not recur frequently, unlike genital herpes caused by herpes simplex virus type 2 (HSV-2).
How do people get HSV-1?
HSV-1 is mainly transmitted by oral-to-oral contact to cause oral herpes infection, via contact with the HSV-1 virus in sores, saliva, and surfaces in or around the mouth. However, HSV-1 can also be transmitted to the genital area through oral-genital contact to cause genital herpes. HSV-1 can be transmitted from oral or skin surfaces that appear normal and when there are no symptoms present.
However, the greatest risk of transmission is when there are active sores. Individuals who already have HSV-1 oral herpes infection are unlikely to be subsequently infected with HSV-1 in the genital area. In rare circumstances, HSV-1 infection can be transmitted from a mother with genital HSV-1 infection to her infant during delivery to cause neonatal herpes.
Is there a cure or treatment for HSV-1?
Antiviral medications are the most effective medications available for people infected with HSV. These can help to reduce the severity and frequency of symptoms but cannot cure the infection.
What are the complications of HSV-1?
In immunocompromised people, such as those with advanced HIV infection, HSV-1 can have more severe symptoms and more frequent recurrences. Rarely, HSV-1 infection can also lead to more severe complications such as encephalitis (brain infection) or keratitis (eye infection).
Recurrent symptoms of oral herpes may be uncomfortable and can lead to some social stigma and psychological distress. With genital herpes, these factors can have an important impact on quality of life and sexual relationships. However, in time, most people with either kind of herpes adjust to living with the infection.
How can HSV-1 be prevented?
HSV-1 is most contagious during an outbreak of symptomatic oral herpes but can also be transmitted when no symptoms are felt or visible. People with active symptoms of oral herpes should avoid oral contact with others and sharing objects that have contact with saliva. They should also abstain from oral sex, to avoid transmitting herpes to the genitals of a sexual partner. People who already have HSV-1 infection are not at risk of getting it again, but they are still at risk of acquiring herpes simplex virus type 2 (HSV-2) genital infection.
Herpes simplex virus type 2 (HSV-2)
HSV-2 infection is widespread throughout the world and is almost exclusively sexually transmitted, causing genital herpes. HSV-2 is the main cause of genital herpes, which can also be caused by herpes simplex virus type 1 (HSV-1). Infection with HSV-2 is lifelong and incurable.
What are the symptoms?
Genital herpes infections often have no symptoms, or mild symptoms that go unrecognized. Most infected people are unaware that they have the infection. When symptoms do occur, genital herpes is characterized by one or more genital or anal blisters or open sores called ulcers. In addition to genital ulcers, symptoms of new genital herpes infections often include fever, body aches, and swollen lymph nodes.
After an initial genital herpes infection with HSV-2, recurrent symptoms are common but often less severe than the first outbreak. The frequency of outbreaks tends to decrease over time but can occur for many years. People infected with HSV-2 may experience sensations of mild tingling or shooting pain in the legs, hips, and buttocks before the appearance of genital ulcers.
How do people get HSV-2?
HSV-2 is mainly transmitted during sex, through contact with genital surfaces, skin, sores, or fluids of someone infected with the virus. HSV-2 can be transmitted from skin in the genital or anal area that looks normal and is often transmitted in the absence of symptoms. In rare circumstances, HSV-2 infection can be transmitted from a mother to her infant during delivery to cause neonatal herpes.
Is there a cure or treatment for HSV-2?
Antiviral medications are the most effective medications available for people infected with HSV. These can help to reduce the severity and frequency of symptoms but cannot cure the infection.
What are the complications of HSV-2?
HSV-2 and HIV have been shown to influence each other. HSV-2 infection increases the risk of acquiring a new HIV infection by approximately three-fold. In addition, people with both HIV and HSV-2 infection are more likely to spread HIV to others. Recurrent symptoms of genital herpes may be painful, and the infection can lead to social stigma and psychological distress. These factors can have an important impact on quality of life and sexual relationships. However, in time, most people with herpes adjust to living with the infection.
How can HSV-2 be prevented?
Individuals with genital HSV infection should abstain from sexual activity whilst experiencing symptoms of genital herpes. HSV-2 is most contagious during an outbreak of sores but can also be transmitted when no symptoms are felt or visible. The consistent and correct use of condoms can help reduce the risk of spreading genital herpes. However, condoms only provide partial protection, as HSV can be found in areas not covered by a condom. Medical male circumcision can provide men life-long partial protection against HSV-2, in addition to HIV and human papillomavirus (HPV)