Epstein-Barr Virus Shedding by Astronauts During Space Flight

Patterns of Epstein-Barr virus (EBV) reactivation in 32 astronauts and 18 healthy age-matched control subjects were characterized by quantifying EBV shedding. Saliva samples were collected from astronauts before, during, and after 10 space shuttle missions of 5 to 14 d duration. Samples were collected on a similar schedule from control subjects. At one time point or another, EBV was detected in saliva from each of the astronauts. Of 1398 saliva specimens from 32 astronauts, polymerase chain reaction analysis showed that 314 (23%) were positive for EBV DNA. Examination by flight phase showed that 29% of the saliva specimens collected before flight were positive for EBV DNA, as were 16% of those collected during flight and 16% of those collected after flight. The mean number of copies of EBV DNA from samples taken during the flights was 417 plus or minus 31, significantly greater (p less than 0.05) than the number of copies from the preflight (40 plus or minus 2) and postflight (44 plus or minus 5) phases. In contrast, the control subjects shed EBV DNA with a frequency of 3.7% and a mean number of EBV DNA copies of 40 plus or minus 2 per mL of saliva. Ten days before flight and on landing day, titers of antibody to EBV viral capsid antigen were significantly (p less than 0.05) greater than baseline levels. On landing day, urinary levels of cortisol and catecholamines, and plasma levels of substance P and other neuropeptides, were increased over their preflight values. Increases in the number of viral copies and in the amount of EBV-specific antibody were consistent with the occurrence of EBV reactivation before, during, and after space flight.