What is the herpes simplex virus?

What is herpes simplex?

Herpes simplex is a very common virus known as HSV. The virus causes herpes which most commonly affects the mouth and the genitals. It can cause outbreaks of sores along with other symptoms.

Herpes simplex is a contagious virus that is transmitted through direct contact with an infected person. Once infected, the virus remains with a person for the rest of their lives.

There are two types of herpes simplex virus:

HSV-1

This form of herpes is contracted from interacting with another infected person in ways that will pass the virus on such as sharing eating utensils, kissing and sharing lip balm. When the sufferer is having an outbreak the infection is more contagious. HSV-1 can also be transmitted to the genital area during oral sex. HSV-1 can be contracted even when the infected person is asymptomatic. An estimated 67% of people under 50 years are infected by HSV-1 globally.

Symptoms: People who carry HSV-1 do not, on the whole, exhibit symptoms and so are unaware they are carrying the virus. During an outbreak, there will be painful blisters or sores around the mouth(also known as cold sores). Preceding the appearance of these sores the sufferer may experience tingling, itching or burning around the area. Outbreaks tend to be intermittent but the frequency of outbreaks varies from person to person.
Complications: In some cases, HSV-1 can cause severe complications. For example, a person whose immune system is seriously compromised such as somebody suffering from advanced HIV infection can experience more severe symptoms and have more frequent recurrences. In rare cases, HSV-1 can lead to encephalitis (infection of the brain) or keratitis (infection of the eye)

When a child is born it may come into contact with herpes simplex virus (either HSV-1 or HSV-2) during the delivery process. Neonatal herpes however is very rare occurring in an estimated 10 out of 100,000 births worldwide. It is a very serious condition that can lead to disability or even death. If a mother has genital herpes prior to becoming pregnant the risk to the child is very small but this risk increases if the infection is contracted in late pregnancy. This is because there greater levels of the virus in the genital tract soon after infection.

HSV-2

This form of herpes is contracted through sexual contact with a person who is infected with HSV-2. This form of herpes simplex is spread through contact with a herpes sore. An estimated 13% of people aged 15-49 are infected with HSV-2 worldwide.

Symptoms: Genital herpes can often go undetected due to being asymptomatic or having only mild symptoms. When symptoms do occur, genital herpes manifests as genital or anal blisters. In addition to this, in the case of a new infection, the sufferer may experience fever, aching body and swollen lymph nodes. After the initial infection symptoms may recur but less severe than the initial outbreak and as time goes on outbreaks tend to become less and less frequent but can occur for many years. It may be that a person experiences mild tingling or shooting pain in the legs, buttocks or hips before the outbreak of blisters.
Complications: There is a marked connection between HSV-2 and HIV. This is because the risk of contracting HIV is trebled when the person is already infected with HSV-2. In addition, if a person is infected with both HIV and HSV-2 they have a greater chance of passing HIV to other people. HSV-2 is extremely common in people living with HIV, occurring in 60 - 90% of people suffering from HIV.

In these cases, HSV-2 can present in a more severe form and with more recurrent outbreaks. If the HIV is advanced then the HSV-2 can lead to very serious complications such as meningoencephalitis, oesophagitis, hepatitis, pneumonitis, retinal necrosis or disseminated infection

Treatment for herpes simplex virus infection

Antiviral drugs are available such as acyclovir, famciclovir and valacyclovir. These drugs can be effective in treating the symptoms or severity of outbreaks but it is important to remember that HSV is a lifelong infection that cannot be cured.