What infections can be contracted from drinking stream water?

Infections That Can Be Contracted from Drinking Stream Water

Drinking water directly from streams, lakes, or rivers poses significant health risks due to potential contamination with various infectious pathogens that can cause serious illnesses and should be avoided. 1

Common Waterborne Pathogens in Stream Water

Parasitic Infections

• Cryptosporidium

  • Most common cause of waterborne gastrointestinal illness 2
  • Highly resistant to chlorine and can survive for extended periods in water
  • Can cause severe, prolonged diarrhea, especially dangerous in immunocompromised individuals
  • Can be transmitted through very low infectious doses (as few as 10 oocysts)

• Giardia intestinalis

  • Second most common cause of waterborne gastrointestinal illness 2
  • Causes giardiasis with symptoms including diarrhea, abdominal cramps, bloating, and nausea
  • Partially resistant to chlorine disinfection

Bacterial Infections

• Campylobacter

  • Causes the highest waterborne disease burden in terms of disability-adjusted life years 3
  • Symptoms include diarrhea (often bloody), abdominal pain, fever
  • Can lead to serious complications including Guillain-Barré syndrome

• Salmonella species

  • Causes nontyphoidal salmonellosis
  • Symptoms include diarrhea, fever, and abdominal cramps

• Pathogenic E. coli (including E. coli O157:H7)

  • Can cause severe bloody diarrhea and potentially life-threatening complications
  • May be present in water contaminated by animal feces 4

• Leptospira species

  • Causes leptospirosis
  • Can enter through cuts or mucous membranes during water exposure
  • Symptoms range from mild flu-like illness to severe disease with kidney and liver failure 5

Viral Infections

• Norovirus

  • Most common viral cause of waterborne illness 3
  • Highly contagious with low infectious dose
  • Causes acute gastroenteritis with vomiting and diarrhea

• Hepatitis A and E viruses

  • Can cause liver inflammation and jaundice
  • Transmitted through fecal-oral route in contaminated water 4

Risk Factors and Considerations

• Environmental factors that increase risk:

  • Proximity to agricultural areas (animal waste runoff)
  • Proximity to human sewage discharge
  • Heavy rainfall events that increase contamination
  • Warm water temperatures that promote microbial growth

• Host factors that increase risk:

  • Immunocompromised status (HIV infection, transplant recipients, cancer patients)
  • Very young or elderly individuals
  • Pregnancy
  • Underlying chronic diseases

Prevention Strategies

1. Avoid drinking untreated water directly from streams, lakes, or rivers 1

2. Water treatment methods when in wilderness settings:

   • Boiling water for at least 1 minute (3 minutes at high elevations) - most effective method 1
   • Filtration using submicron personal-use water filters that can remove parasites
   • Chemical disinfection with iodine or chlorine (less effective against Cryptosporidium)
   • UV light treatment devices designed for outdoor use

3. Additional precautions:

   • Avoid swallowing water during recreational activities in potentially contaminated water 1
   • Be aware that ice made from contaminated water poses the same risks 1
   • Fountain beverages and drinks made with tap water in areas with contaminated water supplies may also pose risks 1

Special Considerations for Immunocompromised Individuals

Immunocompromised individuals, particularly those with HIV infection, are at significantly higher risk for severe and prolonged illness from waterborne pathogens. These individuals should:

• Take extra precautions to avoid exposure to potentially contaminated water
• Consider using bottled water or personal water filters even in non-outbreak settings
• Be particularly vigilant about avoiding swallowing water during recreational activities 1

When to Seek Medical Attention

Seek medical care promptly if experiencing:

• Persistent diarrhea (>3 days)
• Bloody diarrhea
• Severe abdominal pain
• Signs of dehydration (decreased urination, dizziness, extreme thirst)
• Fever >101.5°F (38.6°C)
• Symptoms in high-risk individuals (immunocompromised, pregnant, very young or elderly)

Key Takeaway

The safest approach is to avoid drinking untreated water from natural sources. When in wilderness settings where treated water is unavailable, boiling water for at least 1 minute is the most reliable method to kill or inactivate most waterborne pathogens.