Dr. Leonard Mermel, Brown University – Germs and Spaceflight

Apr 16, 2013

In today’s Academic Minute, Dr. Leonard Mermel of Brown University reveals why small germs can cause big problems for astronauts on long-term missions.

Leonard Mermel is a professor of medicine in the Warren Alpert Medical School of Brown University. His research seeks to understand the pathogenesis, epidemiology, and prevention of hospital-acquired infections. His work has been published in a number of peer-review journals and book chapter.

About Dr. Mermel

Dr. Leonard Mermel – Germs and Spaceflight

Mars is no place to develop an infection, so we have to focus on prevention.  Prolonged human space flight introduces risks to astronauts and private space tourists because of suppression of the human immune system in microgravity, increased virulence of bacteria in or on their bodies or on environmental surfaces, and confinement in a small habitable space.  A mission to Mars will take at least 520 days with a 20 minute one-way communication delay on the Red Planet.  There may be no way to return before the mission is completed.  

Pre-flight strategies include: vaccination and screening for several microbial pathogens; HEPA filtration of the air and prevention of excess humidity; Infection control education for the astronauts should include hand hygiene, cough and sneeze etiquette, environmental disinfection and aseptic insertion of devices such as catheters.

In-flight mitigation strategies include point-of-use filters for potable water outlets and catalytic oxidation or pasteurization of portable water.  An astronaut with symptoms suggestive of a respiratory infection should practice cough etiquette and consider wearing a surgical mask.  A waterless hand-hygiene product should be used during space travel with design and location of dispensers based on input from human factors engineers. Germicidal wipes for environmental disinfection should be used. Astronauts should take vitamin D, use a powered toothbrush and floss teeth daily.  

A number of unanswered questions remain.  In microgravity, why do humans become immunosuppressed and bacteria develop increased virulence?  Is there a substantive change in the human microbiome in microgravity?  What are ideal agents that can be safely used for hand hygiene and environmental disinfection during space travel?  Answers to these and other question may help us to mitigate risks in future human missions in deep space and allow us to better understand human and microbial evolution on earth.

Production support for the Academic Minute comes from Newman’s Own, giving all profits to charity and pursuing the common good for over 30 years, and from Mount Holyoke College.