Herpes simplex virus type 2 (HSV-2) is a common viral infection that often causes genital herpes. The virus establishes a lifelong presence in the body, characterized by periods of dormancy and reactivation. Understanding how frequently the virus is released from the body, a process known as shedding, is important.
What is HSV-2 Shedding?
HSV-2 shedding refers to the release of infectious viral particles from infected cells onto the skin or mucous membranes. This process allows the virus to be transmitted to others. Shedding can occur symptomatically or asymptomatically. Symptomatic shedding happens when there are visible signs or symptoms of an outbreak, such as blisters or sores. Asymptomatic shedding occurs when the virus is present on the skin or mucosal surfaces without any noticeable lesions or discomfort. Asymptomatic shedding is common and often goes unnoticed, making it a significant aspect of the virus’s spread.
Frequency of Viral Shedding
HSV-2 shedding is a frequent occurrence for infected individuals, even daily for many. During the first six months following infection, shedding can happen on 20% to 40% of days. For those with longer-term infections, shedding may occur on 5% to 20% of days. Studies using highly sensitive detection methods, such as PCR, have shown that asymptomatic shedding occurs on approximately 20% of days with daily sampling. Shedding can vary significantly from person to person and is not always predictable. It can also happen from multiple genital sites.
Factors Affecting Shedding
Several factors can influence how often and for how long HSV-2 shedding occurs. The duration of the infection plays a role, with shedding rates generally decreasing over time. For example, total HSV shedding occurred on 33.6% of days within the first year of infection, decreasing to 20.6% for those infected for 1-9 years, and 16.7% for those infected for 10 years or more. An individual’s immune status also impacts shedding. Those with compromised immune systems, such as those with HIV infection, tend to experience increased HSV shedding. Antiviral medications can significantly reduce the frequency and amount of viral shedding. Other triggers that may influence shedding include stress, general illness, and hormonal changes.
Shedding and Transmission
Understanding viral shedding is important because HSV-2 can be transmitted even when no symptoms are present. Most new HSV-2 infections are attributed to asymptomatic shedding, accounting for up to 70% of transmissions. This means individuals can transmit the virus without being aware they are shedding it. The presence of HSV-2 on the genital mucosal surface, whether through clinically recognized outbreaks, subclinical episodes, or asymptomatic shedding, can lead to transmission. While avoidance of sexual contact during visible lesions offers some protection, most transmissions occur during asymptomatic reactivation.