Can Someone Without Active EBV Infection Transmit the Virus?
Yes, individuals without active EBV infection can transmit the virus through asymptomatic viral shedding in saliva, which occurs intermittently throughout life after primary infection.
Transmission Mechanisms in Non-Active Infection
Asymptomatic Viral Shedding
- EBV is transmitted primarily through saliva, even in individuals who have no symptoms of active infection 1, 2.
- After primary EBV infection (whether symptomatic or asymptomatic), the virus can be shed in saliva for a prolonged period of time 3.
- At least 90% of adults worldwide are seropositive for EBV, meaning they carry the virus and can potentially shed it 2.
Chronic Latent Infection with Reactivation
- EBV has the ability to cause chronic relapsing/reactivating infections by switching between latent and lytic life cycles 1.
- The virus shuttles between different cell types (primarily B cells and epithelial cells), allowing for periodic reactivation and viral shedding even without clinical symptoms 1.
- Individuals with past EBV infection can experience intermittent viral reactivation and salivary shedding without any signs of active disease 3.
Clinical Implications for Transmission Risk
When Transmission is Most Likely
- Transmission occurs most efficiently during primary infection, when viral loads are highest, but asymptomatic carriers can also transmit 2, 4.
- Individuals with asymptomatic primary infections can have very high circulating viral loads similar to those in symptomatic infectious mononucleosis patients 4.
- Even without fever, lymphadenopathy, or other symptoms, these individuals can shed infectious virus 4.
Important Caveats
- The absence of symptoms does NOT mean absence of transmissibility - this is a critical clinical pitfall 3, 4.
- Transmission through saliva is the primary route, but rare transmission through blood products and organ transplantation can also occur 1, 2.
- The virus is spread through intimate contact, including kissing and sharing utensils, even when the source individual feels completely well 2.
Distinguishing from Chronic Active EBV (CAEBV)
It's important to differentiate asymptomatic shedding from CAEBV:
- CAEBV is characterized by persistent or recurrent infectious mononucleosis-like symptoms with high antibody titers (VCA ≥1:640, EA ≥1:160) and viral loads >10^2.5 copies/μg DNA 5, 6.
- Asymptomatic carriers do not have these clinical features or laboratory abnormalities, but can still transmit the virus 3, 4.