Incidence of Epstein-Barr virus in astronaut saliva during spaceflight

Background: Astronauts experience psychological and physical stresses that may result in reactivation of latent viruses during spaceflight, potentiall y increasing the risk of disease among crewmembers. Hypothesis: The sheddin g of Epstein-Barr virus (EBV) in the saliva of astronauts will increase dur ing spaceflight. Methods: A total of 534 saliva specimens were collected fr om 11 EBV-seropositive astronauts before, during, and after four space shut tle missions. The presence of EBV DNA in saliva, assessed by polymerase cha in reaction (PCR), was used to determine shedding patterns before, during, and after spaceflight. Results: EBV DNA was detected more frequently before flight than during (p < 0.001) or after (p < 0.01) flight. No significant difference between the inflight and postflight periods was detected in the frequency of occurrence of EBV DNA. Conclusions: The increased frequency of shedding of EBV before flight suggests that stress levels may be greater b efore launch than during or after spaceflight.