Contained in such a tight space for months at a time, ISS astronauts are reporting higher cases of dormant viruses, such as ‘space herpes’, resurfacing.
Mars might be a tough place to raise a kid, according to the famous Elton John song, but the International Space Station (ISS) appears to be great at sustaining viruses that lie dormant in the bodies of astronauts.
Recent findings published to Frontiers in Microbiology have showed that the herpes virus reactivates in more than half of the crew aboard Space Shuttle and ISS missions, due in large part to the numerous stresses of space travel. This includes months of exposure to microgravity and cosmic radiation, in addition to the extreme G-forces experienced during take-off and re-entry.
To determine the health of the astronauts, researchers analysed saliva, blood and urine samples collected before, during and after spaceflight.
“During spaceflight there is a rise in secretion of stress hormones like cortisol and adrenaline, which are known to suppress the immune system,” said senior author Dr Satish K Mehta.
“In keeping with this, we find that astronauts’ immune cells – particularly those that normally suppress and eliminate viruses – become less effective during spaceflight and sometimes for up to 60 days after.”
This resulted in 47 out of 89 astronauts (53pc) during short trips and 14 out of 23 (61pc) astronauts on longer ISS missions showing herpes in their returned samples, noticeably higher than in samples from before and after their experience in space.
Only six of the astronauts developed any symptoms from the reactivated herpes virus – of which all were minor – but the findings show the challenges posed by viral reactivation in space, notable for when humans eventually travel to Mars and beyond.
Preventing their spread and development would typically be done through vaccinations, but so far the only available one is for shingles, one of the eight known human herpes viruses.
“Trials of other herpes virus vaccines show little promise, so our present focus is on developing targeted treatment regimens for individuals suffering the consequences of viral reactivation,” said Mehta.
Another solution to stop the spread of viruses through the touching of objects has also been proposed in Frontiers in Microbiology – more specifically, a new silver- and ruthenium-based antimicrobial coating that has been shown to dramatically reduce the number of bacteria on contamination-prone surfaces.
Dubbed AGXX, the coating was tested on board the toilet door of the ISS, and is designed to kill all kinds of bacteria as well as certain fungi, yeasts and viruses. After six months of exposure, no bacteria was reported on surfaces with the AGXX coating. Even at 12 and 19 months, just 12 bacteria were recovered – a reduction of 80pc compared to bare steel.