NASA has come up with a warning about herpes zoster or shingles being activated among crew aboard the Space Shuttle and the International Space Station missions. The problem was highlighted in a study that appeared in the latest issue of the journal Frontiers in Microbiology.
Varicella zoster virus or varicella-zoster virus (VZV) is one of eight herpesviruses known to infect humans and vertebrates. 3D illustration Credit: Tatiana Shepeleva / Shutterstock
The agency a small number of astronauts have developed symptoms of reawakening of the dormant chicken pox virus called herpes zoster or shingles. In long space flight missions this activated virus could be troublesome they add. Shingles is a painful reactivation of the chicken pox virus in a person who has been previously infected with it. This leads to painful blister like lesions along the course of a nerve - usually seen across the face, forehead or along one side of the trunk.
The virus remains dormant in the nerves of the person who has had chicken pox for life. It gets activated when there is a Dr Satish Mehta, senior author and an academic at the Johnson Space Centre in a statement said, “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. This physical challenge is compounded by more familiar stressors like social separation, confinement and an altered sleep-wake cycle.”
The researchers explain that the NASA keeps a close watch on the physiological effects of space flights on astronaut’s bodies. They do this by monitoring the saliva, blood and urine of the astronauts all along the flight.
The authors write, “During spaceflight there is a rise in secretion of stress hormones like cortisol and adrenaline, which are known to suppress the immune system.” The study adds, “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 team explains that because of the suppression of the immune system the bodies of the astronauts cannot keep the dormant viruses down and thus these are activated. Dr Mehta said, “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. 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.” Dr Mehta said, “Only six astronauts developed any symptoms due to viral reactivation…All were minor.”
Longer flights seem to be reactivating the viruses more said the researchers. “The magnitude, frequency and duration of viral shedding all increase with length of spaceflight,” Mehta said.