Confinement in small spaces, separation from family and friends cited
| CNN – The longer astronauts spend in space, the more likely they are to have viruses like herpes, chickenpox and shingles reactivate, according to new NASA research.
The reason may be the same for viral reactivation on Earth: stress.
Samples of blood, urine and saliva were collected from astronauts before, during and after short space shuttle flights and long-term International Space Station missions.
Herpes viruses reactivated in more than half of the astronauts. The study published last week in the journal Frontiers in Microbiology.
“To date, 47 out of 89 (53%) astronauts on short space shuttle flights, and 14 out of 23 (61%) on longer ISS missions shed herpes viruses in their saliva or urine samples,” said lead study author Satish K. Mehta at Johnson Space Center.
“These frequencies — as well as the quantity — of viral shedding are markedly higher than in samples from before or after flight, or from matched healthy controls.”
Shedding is when a virus successfully reactivates.
On both short and long-term spaceflight missions, astronauts undergo exposure to zero gravity, cosmic radiation and extreme G forces during take-off and re-entry.
Added to this is confinement in small spaces, social separation from family and friends and an altered sleep cycle, the researchers said.
Spaceflight creates a stressful environment for the astronauts, awakening dormant viruses.
Four of the eight human herpes viruses were detected, including oral and genital herpes, chickenpox and shingles. Because the herpes viruses take up residence in nerve and immune cells, they’re never really gone, so they can “wake up.”
But luckily for the astronauts, the reactivation of the viruses doesn’t necessarily mean that the symptoms return.
“Only six astronauts developed any symptoms due to viral reactivation,” Mehta said. “All were minor.”
But the implication for infecting others when the astronauts return to Earth is very real, especially those with compromised immune systems or newborns. Read more.