According to new research by NASA, four human herpesviruses have been shown to be reactivated by astronauts in Space Shuttle missions and the International Space Station.
The study, published in the Frontiers in Microbiology magazine last month, revealed that these viruses were capable of exploding due to the high level of stress that astronauts experience during a space flight. He also found that the longer the mission, the higher the reactivation rates.
Although the results do not show any serious danger for current flights, longer missions, such as a Mars mission, could be affected by the potential of the herpes viruses that will develop.
“NASA astronauts endure weeks or months of exposure to microgravity and cosmic radiation, not to mention the extreme G forces of take-off and reentry,” said Dr. Satish K. Mehta of KBR Wyle at the Center. Johnson space and author Main study, he says.
“This physical challenge is made up of more well-known stressors, such as social separation, isolation, and a modified sleep-wake cycle,” Mehta added.
The researchers studied samples of saliva, blood and urine from astronauts before, during and after spaceflight. They discovered that stress hormones increased during the trip and latent viruses reappeared.
Scientists have discovered four of eight known human herpes viruses: oral and genital herpes, chickenpox and shingles, cytomegalovirus (CMV) and Epstein-Barr virus (EBV). CMV and EBV are known to cause different monkey strains.
“During spaceflight, there is an increase in the secretion of stress hormones such as cortisol and adrenaline, which are known to suppress the immune system.” As a result, we find that the immune cells of astronauts, especially those that normally suppress and eliminate viruses, become less effective. “During spaceflights and sometimes up to 60 days later,” said Mehta.
Mehta added that 53% of astronauts performing shorter space shuttle flights and 61% of longer missions on the International Space Station had traces of herpes virus in their saliva or urine samples, which is higher frequency and quantity than in the samples before or after the space flight. However, only six astronauts developed real symptoms of viral reactivation and even these symptoms were minor.
“The magnitude, frequency and duration of viral propagation [reactivation] increase with the duration of the space flight,” said Mehta.
This could affect the way NASA is preparing to send humans into space, beyond the moon and Mars. “The ideal countermeasure is the vaccination of astronauts, but so far it is only available against VZV [the virus responsible for chickenpox and shingles],” said Mehta, adding that Since other herpes vaccines are not promising, we are currently focusing on the development of targeted treatment regimens for people suffering from the consequences of viral reactivation. ”