Definition Herpes simplex infections are caused by herpes simplex viruses 1 and 2, also called HSV-1 and -2. The infections can involve the mouth, the genital region, the skin, the central nervous system, and the eyes.
What is going on in the body? Humans are the only known source of herpes simplex viruses. The infection is spread by close physical contact and can be passed from mother to infant during pregnancy or childbirth. The infection is chronic and can reactivate throughout life.
HSV-1 usually causes disease above the waist. HSV-2 usually causes disease below the waist, and is usually transmitted sexually. Symptoms of infection with HSV range from none to painful ulcers at the site of infection. HSV-1 is often acquired during childhood and can cause gingivostomatitis, an illness marked by fever and ulcers around the mouth and lips. Reactivation of HSV-1 later in life often causes cold sores.
HSV-2 is usually acquired by adults or young adults through sexual contact. HSV-2 causes painful ulcers in the genital region. Sometimes HSV-2 infection is associated with mild cases of meningitis, which is an inflammation of the brain and spinal cord. For both HSV-1 and HSV-2, reactivation takes the form of single ulcers at the site of the original infection.
The eyes can also be a site of HSV infection. Eye infections can vary in severity and should be treated as soon as possible to avoid complications. An HSV infection can also occur on the finger. This is called a 'herpetic whitlow' and it is usually the result of touching an ulcer at another site.
Infants can acquire HSV-1 or HSV-2 from their mothers during pregnancy or childbirth. This usually happens when the mother is acquiring HSV for the first time. Infection can involve the skin, the eyes, the mouth, the central nervous system, or the internal organs. HSV infection in newborn babies is a serious matter. It can result in the death of the infant or brain damage even when the infant is treated appropriately. Infection in someone with a weakened or damaged immune system can also be severe, and may require prolonged treatment.
What are the causes and risks of the infection? Causes of this infection include:
Close contact with an infected person increases the risk of infection.
Babies born to mothers who have first-time HSV infections during pregnancy are more likely to become infected.
What can be done to prevent the infection? Using condoms during sexual activity helps prevent the spread of the infection. People who are immunocompromised or who have frequent recurrences often take antiviral drugs, such as acyclovir and valacyclovir, to help prevent reactivation. A doctor who specialises in the condition should monitor a pregnancy complicated by HSV infection.
How is the infection diagnosed? HSV can be cultured, or grown in the laboratory, from infected secretions. It can also be detected rapidly in infected specimens by using special stains. Antibodies are chemicals produced by the body against the herpes simplex viruses and can be found in the blood.
What are the long-term effects of the infection? With herpes simplex:
Infection is chronic, and some people will have recurrences of the infection.
Infection in newborn babies and people who are immunocompromised can result in brain damage or death.
What are the risks to others? Herpes infections can be passed from one individual to another through contact.
What are the treatments for the infection? Acyclovir is used to treat HSV in newborn babies and people who are immunocompromised. Acyclovir or famciclovir, can be used to treat HSV in otherwise healthy people.
What are the side effects of the treatments? High doses of acyclovir injected into a vein may cause kidney problems, but all side effects are rare.
What happens after treatment for the infection? Some people will have frequent recurrences of HSV. They sometimes benefit from taking acyclovir as a preventive measure.
Author: Danielle Zerr, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
