Homo sapiens evolved in Africa, emerging from that continent between 150,000 and 200,000 years ago. The earliest humans migrated through the Middle East before splitting up and venturing into Asia and Europe. According to findings recently published in PLOS ONE by three University of Wisconsin researchers, humanity’s oldest viral enemy migrated out of Africa and evolved alongside its hosts. The virus they tracked across ancient soils was HSV-1, or Type 1 herpes, the virus that causes the cold sore.
About 90 percent of the world’s adults test positive for HSV-1. The virus presents dangers for infants and for others that have compromised immune systems, such as people with AIDS, cancer, severe burns or other conditions requiring immunosuppressant drugs. For most people, HSV-1 just causes annoying sores around the mouth. However, doctors estimate that 25 percent of genital herpes cases are now caused by HSV-1.
Lurking Under the Surface
Once a person acquires HSV-1, it never goes away. The virus enters the body through the mucus membranes of the oral area or the eye. It begins to replicate itself in the skin cells but soon burrows into the nerve cells.
After invading the nerve cells, it sheds its outer membrane, hiding within the nerve cells to evade the immune system. It injects itself into the nerve cell nucleus, where it lives in dormant form until activated. Eventually, HSV-1 works its way into the trigeminal ganglion, or the flattened nerve roots of the facial nerves that lie within the skull. Some researchers believe that people can harbor latent HSV-1 within the brain itself.
HSV-1 occasionally travels from the ganglion to the skin, where it causes blisters to form. These blisters can transmit HSV-1 to uninfected individuals through skin-to-skin contact. Sometimes, the herpes virus sheds at the skin’s surface without producing blisters or other symptoms. When this happens, someone that has herpes can transmit the virus without knowing that it’s active.
Today’s antiviral medications for HSV-1 work by blocking enzyme activity within the host cell while others alter the virus genetic material. The medications can’t expel herpes from the body, but they can minimize symptoms and discomfort. Some antivirals like valacyclovir can be taken orally. Other antivirals like acyclovir, famciclovir and penciclovir are applied as topical creams. Generally, oral antiviral meds are the most effective in fighting HSV-1.
Patients with frequent cold sore outbreaks can take oral valacyclovir daily to prevent viral shedding. The dosage should be discussed with a physician. An over-the-counter cream called Abreva is FDA-approved for cold-sore treatment. Other treatments include lip balms that contain lemon oil and lysine supplements.
A Note About Oral Sex
A person that has cold sores can transmit HSV-1 to a partner’s genital area when giving oral sex, where it can cause outbreaks of genital herpes. Likewise, a person that has genital herpes can transmit HSV-1 to a partner’s oral area when receiving oral genital stimulation.
Never perform oral sex on a partner when you have a visible cold sore. Non-lubricated condoms and dental dams provide some additional protection as does a daily dose of oral valacylovir. However, because HSV-1 can shed without producing symptoms, the virus may be transmitted to a partner’s genitals even without the presence of a visible cold sore.
An Old Enemy
HSV-1 has traveled with us since the dawn of humanity and will continue to evolve as human beings evolve. With treatment, anyone with herpes can corral or at least minimize the effects caused by this hitchhiker from mankind’s earliest days.
Found an error in this article? Please contact us!
Last updated November 2013
Image courtesy of Renjith Krishnan / FreeDigitalPhotos.net