Acute Gastroenteritis Outbreak Among Colorado River Rafters and Backpackers in the Grand Canyon, 2022

Details

• Alternative Title:
  Wilderness Environ Med
• Personal Author:
  Miko, Shanna ; Calderwood, Laura ; Dale, Ariella P. ; King, Ronan F. ; Maurer, Matthew B. ; Said, Maria A. ; Gebhardt, Marette ; Dyer, Laurie P. ; Maurer, Wendy ; Wikswo, Mary E. ; Mirza, Sara A.
• Description:
  Objectives:
  
  During April 1-May 31, 2022, Grand Canyon National Park received increased acute gastroenteritis reports. Pooled portable toilet specimens identified norovirus genogroups I and II. We sought to determine outbreak transmission contributors and individual risk factors while rafting or backpacking in the park.
  
  Methods:
  
  Grand Canyon rafters and backpackers were surveyed online during June 13–July 8, 2022 and a Cox proportional hazards model was used to identify predictors associated with illness and adjusted for potential confounding factors.
  
  Results:
  
  Among 762 surveys, 119 cases and 505 well persons had complete survey data. Illness among rafters was associated with interaction with ill persons during the trip (adjusted hazard ratio [adjHR]= 3.4 [95%CI 2.3–5.0]) and lack of any hand hygiene (1.2 [0.7–1.9]) or use of only sanitizer or water (1.6 [1.04–2.6]) before snacks. Younger rafters had higher illness rates compared to those ≥60 years (1.5 [1.2–1.8] for ages 40–59 and 2.2 [1.4–3.5] for ages <40 years).
  
  Conclusion:
  
  Person-to-person transmission likely accounted for the widespread outbreak. Future outbreak mitigation efforts on river trips could focus on symptom screening before trip start, prompt separation of ill and well passengers, strict adherence to hand hygiene with soap and water, minimizing social interactions among rafting groups, and widespread outbreak notices and education to all park users.
  
  
• Subjects:
  Adolescent Adult Aged Caliciviridae Infections Colorado Disease Outbreaks Female Gastroenteritis Humans Male Middle Aged Norovirus Parks, Recreational Risk Factors Swimming Young Adult

  More +
• Keywords:
  Gastroenteritis Grand Canyon Outbreak Recreational Water River Rafter Secondary Transmission
• Source:
  Wilderness Environ Med. 35(2):173-182
• Pubmed ID:
  38613339
• Pubmed Central ID:
  PMC11073894
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Volume:
  35
• Issue:
  2
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:286640fa76a9f7950e48a728ef9c68254d1c8a2285e39995b35adc2c3e697d9c063a1ba6e75782c53dc9cd0cc2a28be980a150b5938c085d79c4af60181193ae
• Download URL:
  https://stacks.cdc.gov/view/cdc/155549/cdc_155549_DS1.pdf
• File Type:
  [PDF - 219.32 KB ]