Herpes Simplex
Herpes simplex is an infection that primarily affects the mouth or genital area.
Causes, incidence, and risk factors
There are two different strains of herpes simplex viruses:
- Herpes simplex virus type 1 (HSV-1) is usually associated with infections of the lips, mouth, and face. It is the most common herpes simplex virus and is usually acquired in childhood. HSV-1 often causes lesions inside the mouth such as cold sores (fever blisters) and is transmitted by contact with infected saliva. By adulthood, up to 90% of individuals will have antibodies to HSV-1.
- Herpes simplex virus 2 (HSV-2) is sexually transmitted. Symptoms include genital ulcers or sores. In addition to oral and genital lesions, the virus can also lead to complications such as meningoencephalitis (infection of the lining of the brain and the brain itself) or cause infection of the eye -- in particular the conjunctiva, and cornea. However, some people have HSV-2 but do not display symptoms. Up to 30% of U.S. adults have antibodies against HSV-2. Cross-infection of type 1 and 2 viruses may occur from oral-genital contact.
A herpes virus can infect the fetus and cause congenital abnormalities. It may also be transmitted to a newborn during vaginal delivery in mothers infected with herpes viruses, particularly if the mother has active infection at the time.
However, the virus may be transmitted even in the absence of symptoms or visible lesions.
Symptoms
- Mouth sores
- Genital lesions (male) -- may be preceded by burning or tingling sensation
- Genital lesions (female) -- may be preceded by burning or tingling sensation
- Blisters or ulcers -- most frequent on the mouth, lips and gums or genitalia
- Fever blisters
- Fever -- may be present especially during the first episode
- Enlargement of lymph nodes in the neck or groin.
Some cases are relatively mild and may not require treatment.
In severe or prolonged cases, or in individuals who are immunosuppressed or who have frequent recurrences, antiviral medications such as acyclovir may be used.
In individuals with more than 6 recurrences of genital herpes per year, chronic antiviral medications may be offered to reduce recurrences.
Prevention
Prevention is difficult since the virus can be spread to others when an infected person has no evidence of an active outbreak.
Avoiding direct contact with an open lesion will lower the risk of infection.
People with genital herpes should avoid sexual contact when active lesions are present. Safer sex behaviors, including the use of condom, may also lower the risk of infection.
Individuals with active herpetic lesions should also avoid contact with newborns, children with eczema, or immunosuppressed individuals as these groups are at higher risk for more severe disease.
To decrease the risk of infecting the newborn, a cesarean delivery (C-section) is recommended for pregnant women who have active herpes simplex infection at the time of delivery.
Credit: National Institute of Health.