Astronauts who travel into space could come home suffering from a very unwelcome bout of herpes, Nasa has revealed.
Half of the people who travel outside Earth’s atmosphere aboard the Space Shuttle or International Space Station suffer from the ‘reactivation’ of herpes viruses, according to new research.
It’s believed conditions in space play havoc with the immune system.
‘Nasa astronauts endure weeks or even months exposed to microgravity and cosmic radiation – not to mention the extreme G forces of take-off and re-entry,’ said D. Satish K. Mehta of the Johnson Space Center.
‘This physical challenge is compounded by more familiar stressors like social separation, confinement and an altered sleep-wake cycle.
‘During spaceflight, there is a rise in the secretion of stress hormones like cortisol and adrenaline, which are known to suppress the immune system.
‘In keeping with this, we find that astronaut’s immune cells – particularly those that normally suppress and eliminate viruses – become less effective during spaceflight and sometimes for up to 60 days after.’
The process of reactivation does not necessarily cause sores to form or viruses to once again attack the human body.
It’s generally ‘asymptomatic’, with just six of the astronauts analysed in the study suffering symptoms as the viruses in their bodies became active again.
However, once back on Earth the viruses could infect other people, with vulnerable newborn babies particularly at risk.
‘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,’ reported Mehta.
‘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.’
Last year, scientists discovered a thriving ecosystem of ‘infectious organisms’ aboard the International Space Station.
A Nasa team found five different varieties of Enterobacter, which are similar to bugs found in hospitals down here on Earth.
The toilet of the orbiting space base was one of the main sites of infection along with the exercise area.
Researchers calculated that there is a ‘79% probability that they may potentially cause disease’, although analysis has only been carried out on dead samples at this stage so this risk could prove to be higher or lower following further research.
