Herpes simplex is the most common sexually transmitted infection which is caused by the herpes simplex viruses. The two types of herpes simplex virus are : 1 and 2.
The herpes simplex virus 1 causes oral herpes and is also responsible for the formation of the fever blisters and cold sores around the mouth and on the face of the infected person.
<u>Therefore, cold sores are associated with the herpes simplex virus.</u>
