Evaluation of Incidental CMV IgG Positivity in a 28-Year-Old Female
No further evaluation is needed for an incidental finding of CMV IgG positivity in an immunocompetent 28-year-old female with URTI. 1, 2
Understanding CMV Serology Results
In immunocompetent individuals, CMV serology interpretation follows these principles:
- CMV IgG positive only: Indicates past exposure to CMV with no active infection 1
- CMV IgG + IgM positive: Suggests recent infection, though false positive IgM can occur with EBV or other immune system activations 1
- CMV IgG negative + IgM negative: No previous CMV exposure or infection
Algorithm for Evaluation Based on Patient Status
For Immunocompetent Adults (like this patient)
Isolated CMV IgG positive:
- No further testing required
- Represents past infection with immunity
- No clinical significance in healthy individuals
If symptoms of active CMV infection present (not applicable in this case):
- Test for CMV IgM
- Consider IgG avidity testing if IgM positive
- PCR for CMV DNA only if clinically indicated by symptoms
Special Circumstances Requiring Further Evaluation (not applicable in this case)
- Pregnancy: CMV screening is relevant due to risk of congenital infection 1, 3
- Immunocompromised status: Would require viral load monitoring 1, 2
- Pre-transplant evaluation: Would need comprehensive CMV status assessment 1
Key Points About CMV Infection
- CMV infection is extremely common worldwide, with seroprevalence of 58% in US women aged 12-49 years 4
- In immunocompetent individuals, primary CMV infection is typically asymptomatic or causes mild mononucleosis-like symptoms
- CMV IgG positivity indicates past infection and lifelong immunity, though the virus remains latent
- The virus can reactivate during periods of immunosuppression
Common Pitfalls to Avoid
- Overinterpreting isolated CMV IgG positivity: This is an extremely common finding and represents past infection only
- Unnecessary testing: In immunocompetent individuals with isolated CMV IgG positivity, additional testing (IgM, PCR, avidity) provides no clinical benefit
- Failure to recognize when further testing is needed: In pregnancy or immunocompromised states, additional evaluation would be warranted
In this case of an incidental finding in an immunocompetent young adult with URTI, the positive CMV IgG simply indicates prior infection and requires no further evaluation or management.