title: Incidence of clinical symptoms during long-duration orbital spaceflight.
abstract: BACKGROUND
  The environment of spaceflight may elevate an astronaut's clinical risk for specific diseases. The purpose of this study was to derive, as accurately as currently possible, an assessment of in-flight clinical "incidence" data, based on observed clinical symptoms in astronauts on board the International Space Station (ISS).
  
  
  METHODS
  Electronic medical records were examined from 46 long-duration ISS crew members, each serving approximately a 6-month mission on board the ISS, constituting 20.57 total flight years. Incidence for immunological-related adverse health events or relevant clinical symptoms was tabulated in a non-identifiable fashion. Event categories included infectious diseases, allergies, and rashes/hypersensitivities. A subsequent re-evaluation of more notable events, either of prolonged duration or unresponsive to treatment, was performed.
  
  
  RESULTS
  For the disease/symptom categories used in this evaluation, the ISS incidence rate was 3.40 events per flight year. Skin rashes were the most reported event (1.12/flight year) followed by upper respiratory symptoms (0.97/flight year) and various other (non-respiratory) infectious processes. During flight, 46% of crew members reported an event deemed "notable". Among the notable events, 40% were classified as rashes/hypersensitivities. Characterization of on-orbit rashes manifested as redness with irritation, and could present on a variety of body locations.
  
  
  CONCLUSIONS
  Based on reported symptoms, astronauts experience adverse medical events of varying severity during long-duration spaceflights. The data suggests caution, from both a vehicle design and biomedical countermeasures perspective, as space agencies plan for prolonged deep space exploration missions.
authors.affiliation: Biomedical Research and Environmental Sciences Division, NASA-Johnson Space Center.
authors.forename: Brian
authors.initials: B
authors.lastname: Crucian
authors.affiliation: Epidemiology/Lifetime Surveillance of Astronaut Health, KBR-Wyle, Houston, TX, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Babiak-Vazquez
authors.affiliation: Biomedical Research and Environmental Sciences Division, NASA-Johnson Space Center.
authors.forename: Smith
authors.initials: S
authors.lastname: Johnston
authors.affiliation: Biomedical Research and Environmental Sciences Division, NASA-Johnson Space Center.
authors.forename: Duane L
authors.initials: DL
authors.lastname: Pierson
authors.affiliation: Biomedical Research and Environmental Sciences Division, NASA-Johnson Space Center.
authors.forename: C Mark
authors.initials: CM
authors.lastname: Ott
authors.affiliation: Biomedical Research and Environmental Sciences Division, NASA-Johnson Space Center.
authors.forename: Clarence
authors.initials: C
authors.lastname: Sams
keywords: astronauts; clinical incidence; clinical risk; disease; gravity; immunity; spaceflight