NASA: Viruses like herpes are reactivated in astronauts while traveling in space

Space missions could be even more complicated for astronauts, as some latent viruses, such as herpes, are reactivated during flights, according to a new NASA study published in Frontiers in Microbiology. Although astronauts only develop a small percentage of the symptoms, the duration of the space flight increases the rate of reactivation of the virus, which could present more difficulties for missions such as an expedition on Mars or at the same time. -of the.

"During spaceflights, the secretion of stress hormones increases cortisol and adrenaline, which suppress the immune system. We have discovered that the immune cells of astronauts, especially those that normally suppress and eliminate viruses, become less effective during spaceflights and sometimes until 60 days later, "said Satish K. Mehta, Lead author of the study Johnson Space Center (USA), in a statement.

Stress is the culprit

Mehta and his colleagues discovered that the urine and saliva of astronauts contain more herpes samples than before or after a trip in space. The researchers suspect one of the culprits is the stress caused by space missions.

NASA astronauts endure weeks or months exposed to microgravity and cosmic radiation, not to mention the extreme forces of take-off and reentry, "said Mehta. This physical challenge is compounded by more known stressors, such as social separation, isolation and a modified sleep-wake cycle. "

"To date, 47 of the 89 astronauts (53%) conducting short flights in space shuttles and 14 of 23 (61%) participating in longer missions of the International Space Station (ISS) have the virus. herpes in their saliva samples or urine, "according to the authors of the study.

A threat to the inhabitants of the Earth

The reactivation of the herpes virus in astronauts is not only a threat to them, but also to the people with whom they come into contact on Earth. According to research, people with reactivated virus still expel infectious substances in their body fluids until 30 days after the return of the ISS.

Fortunately, this viral shedding is usually asymptomatic. The six astronauts who developed the symptoms due to reactivation presented only minor symptoms. However, the fact that the duration of space flights can affect the reactivation of viruses is not a good sign for future missions. The duration, frequency and extent of viral propagation increase with the duration of space flight.