Final answer:
The primary symptom of Herpes simplex virus type 1 (HSV-1) is cold sores or fever blisters around the lips. It is highly contagious through direct oral contact and can cause genital sores. The virus can lie dormant and reactivate under certain conditions.
Step-by-step explanation:
The symptom of Herpes simplex virus (HSV) type 1 is primarily cold sores or fever blisters, usually found on or around the lips. HSV-1 is highly contagious and can be transmitted through direct oral contact. This virus can be dormant within the body, residing in nerve ganglia, and can reactivate due to triggers like stress or environmental changes. Though HSV-1 traditionally affects the oral region, it can also cause genital sores through oral-genital contact. It's important to note that genital herpes is typically associated with HSV-2 but can also be caused by HSV-1.
During active phases, the HSV-1 lesions may blister, break open, and crust over before healing. Infection rates are quite high, with many individuals being asymptomatic carriers of the virus. HSV-1 can spread even when there are no visible symptoms due to asymptomatic viral shedding.