Can a Patient Contract Infectious Mononucleosis (Mono) Twice?
No, a patient typically cannot contract infectious mononucleosis twice because once infected with Epstein-Barr virus (EBV), antibodies develop that provide lifelong immunity against primary infection. 1
Understanding EBV Infection and Immunity
- After primary EBV infection, antibodies to Epstein-Barr nuclear antigen (EBNA) develop within one to two months and remain detectable for life in approximately 90-95% of infected individuals 1
- Over 90% of the adult population worldwide has IgG class antibodies to viral capsid antigen (VCA) and EBNA antigens, indicating previous infection and developed immunity 1
- EBV serologic testing shows that the presence of EBNA antibodies indicates infection occurred more than 6 weeks prior, confirming past infection rather than a new one 1
Diagnostic Markers of EBV Infection Status
- Primary EBV infection is diagnosed by detecting IgM and IgG antibodies against viral capsid antigen (VCA) with negative EBNA IgG 1
- The presence of EBNA antibodies indicates infection occurred more than 6 weeks from the time of testing, making it unlikely that current symptoms are due to a new EBV infection 1
- Approximately 5-10% of patients who have been infected with EBV fail to develop antibodies to the EBNA antigen, which could potentially affect immunity assessment 1
What Can Be Mistaken for Recurrent Mono
1. Reactivation of Latent EBV
- After primary infection, EBV establishes latency in B lymphocytes and can reactivate under certain conditions, especially in immunocompromised individuals 1
- Reactivation may cause symptoms similar to the primary infection but is not considered a second case of infectious mononucleosis 1
2. Chronic Active EBV Infection (CAEBV)
- Some patients develop chronic active EBV infection with persistent symptoms including fever, lymphadenopathy, and hepatosplenomegaly 1
- CAEBV is characterized by high antibody titers against EBV VCA (1:640) and EA (1:160), and/or increased viral load in tissues 1
- This condition represents a failure to control the virus rather than a new infection 1
3. Co-infection with Multiple EBV Strains
- Research has shown that patients can be infected with multiple EBV strains simultaneously during primary infection 2
- While this represents infection with different viral strains, it occurs during the initial infection rather than as a separate second infection 2
4. Other Mononucleosis-like Illnesses
- Symptoms similar to infectious mononucleosis can be caused by other pathogens such as cytomegalovirus (CMV), adenovirus, HIV, or Toxoplasma gondii 1
- These infections may be mistaken for recurrent mono but are actually different infections 1
Special Considerations
Immunocompromised Patients
- Patients with immunosuppression may experience more severe or prolonged EBV infections 1
- Immunocompromised individuals are at higher risk for EBV-associated lymphoproliferative disease rather than classic infectious mononucleosis 1
Persistent Symptoms Following Mononucleosis
- Some patients experience persistent symptoms for months or years after infectious mononucleosis 3
- This persistence may be associated with defects in EBV-specific immunity rather than reinfection 3
- These patients may have reduced or absent antibodies to EBNA despite normal levels of other EBV-specific antibodies 3
Clinical Implications
- When evaluating a patient with recurrent mononucleosis-like symptoms, clinicians should consider: