From the Guidelines
Herpes Simplex Virus Type 1 (HSV-1) is primarily spread through direct contact with infected bodily fluids, most commonly saliva, and can be transmitted through oral-to-oral contact, such as kissing, or by sharing items that touch the mouth, as noted in a study published in the Journal of Clinical Virology 1. The virus typically transmits through:
- Oral-to-oral contact such as kissing
- Sharing items that touch the mouth like utensils, lip balm, or toothbrushes HSV-1 can also spread to the genitals through oral-genital contact, making it a cause of genital herpes as well, with at least 50% of new cases of herpes genitalis in developed countries now caused by HSV-1, as reported in the Journal of Clinical Virology 1. The virus is most contagious when active sores or blisters are present, but it can still spread even when no symptoms are visible, a process called asymptomatic shedding, as discussed in the 1998 guidelines for treatment of sexually transmitted diseases by the Centers for Disease Control and Prevention 1. People with compromised immune systems face higher transmission risks, and the virus enters the body through tiny breaks in the skin or mucous membranes and, once contracted, remains dormant in nerve cells for life, periodically reactivating to cause outbreaks. To reduce transmission risk, it is recommended to:
- Avoid kissing or oral contact when sores are present
- Not share personal items that touch the mouth
- Practice good hygiene including handwashing after touching sores.
From the Research
Spread of HSV 1
- HSV 1 is usually acquired through direct contact with infected lesions or body fluids, typically saliva 2
- The virus can be spread through mucocutaneous vesicular eruptions, which can occur on the tongue, lips, gingival, buccal mucosa, and the hard and soft palate 2
- Recurrent infections can give rise to vesiculo-ulcerative lesions at mucocutaneous junctions, particularly the lips (herpes labialis) 2
- HSV 1 can also be spread through contact with an infected person's eyes, as the virus can be present in the tears 3
- The virus can remain latent in the ganglia and brains of infected individuals, and can be reactivated by various factors, including UV exposure 3
Factors Influencing Spread
- Socioeconomic background can play a role in the prevalence of HSV 1 infection, with lower socioeconomic backgrounds having a higher seroprevalence 2
- Immunocompromised patients are more susceptible to severe and recurrent HSV 1 infections 2, 4
- The use of antiviral medications, such as acyclovir and valacyclovir, can help reduce the severity and spread of HSV 1 infection 3, 5