By Dr Ananya Mandal, MD
Herpes simplex is a viral infection that has been known to mankind for centuries. Genital herpes infection is one of the most well known types of herpes and is therefore usually called "herpes" instead of herpes genitalis.
Another common type of herpes is orofacial herpes which affects the face and mouth and often leads to cold sores. Other herpes disorders such as ocular or eye herpes, herpetic whitlow (causes lesions on finger or thumb), and herpes simplex encephalitis (herpes infecting the central nervous system) are less common.
Neonatal herpes is a serious infection, usually passed on by a mother who has been recently exposed (during the pregnancy) to the virus and has passed it onto the baby through infected secretions in the birth canal during childbirth.
Before the 1960's, herpes infections were largely untreated, but it was during this decade that new experimental antiviral drugs were developed. These drugs interfered with the replication of the DNA material inside the virus, preventing its multiplication. These drugs were called DNA replication inhibitors and were used for the severe and more life threatening infections such as herpes encephalitis, herpes keratitis or to treat those with immune suppression due to HIV, an organ transplant, chemotherapy or radiation therapy.
Initially, the medications used for herpes infections were 5-iodo-2'-deoxyuridine, idoxuridine and 1-β-D-arabinofuranosylcytosine or ara-C. Others examples included trifluorothymidine, ribivarin, interferon and 5-methoxymethyl-2'-deoxyuridine.
In the 1970's, the drug 9-(2-hydroxyethoxymethyl) guanine or acyclovir was developed, which had a lower toxicity and better efficacy and was declared the drug of choice in herpes simplex infection by the FDA in 1998. It could also be used to treat herpes in newborns.
Reviewed by Sally Robertson, BSc