What prophylaxis is recommended for individuals exposed to flood waters?

Flood Water Exposure Prophylaxis

Routine antibiotic prophylaxis is not recommended for all individuals exposed to flood water; instead, focus on immediate thorough decontamination with soap and water, wound care, and targeted doxycycline prophylaxis only in high-risk scenarios where leptospirosis attack rates exceed 10 cases per 100 person-years or for individuals with open wounds and unavoidable prolonged flood water contact. 1, 2

Immediate Decontamination Protocol

The priority is aggressive skin decontamination to prevent infectious complications:

• Wash all exposed skin thoroughly with soap and water as soon as possible to remove contaminated material and reduce pathogen load 1
• Remove all contaminated clothing immediately to prevent continued exposure 1
• If eyes were exposed, irrigate with copious amounts of clean water for at least 15 minutes 1
• For visibly soiled hands or skin with organic material, use soap and bottled water (if municipal water is compromised); if hands are not visibly soiled, alcohol-based hand rub is acceptable 1

Wound Assessment and Management

Any break in skin integrity dramatically increases infection risk and requires specific attention:

• Inspect all skin carefully for open wounds, abrasions, or breaks in skin integrity 1
• Any open wounds exposed to flood water require copious irrigation with clean water and documentation of extent and location 1
• Wounds are at high risk for polymicrobial infections, particularly gram-negative bacteria including Vibrio vulnificus, Aeromonas, and atypical mycobacteria 3

Antibiotic Prophylaxis: When to Use It

Prophylaxis should be reserved for specific high-risk situations, not given universally:

Leptospirosis Prophylaxis Indications

• Doxycycline prophylaxis is justified only when attack rates exceed 10 cases per 100 person-years in the affected area 2
• Consider prophylaxis for individuals with laceration wounds and unavoidable prolonged flood water contact, as this population shows increased protective efficacy 2
• Single dose of 200 mg doxycycline orally provides 76.8% protective efficacy against leptospiral infection and 86.3% against clinical leptospirosis 2

Dosing for Leptospirosis Prophylaxis

For adults: 200 mg doxycycline orally as a single dose 2, 4

For children over 8 years: 2 mg/kg body weight (up to adult dose) 4

Critical contraindication: Tetracyclines including doxycycline are contraindicated in children under 8 years due to risk of permanent tooth discoloration and enamel hypoplasia 2

Surveillance for Infectious Complications

Maintain heightened vigilance over the following 2-4 weeks for development of:

• Bacterial skin infections: Cellulitis and wound infections from Staphylococcus, Streptococcus, Aeromonas, or Vibrio species 1
• Atypical mycobacterial infections that may present with indolent cutaneous infections and sporotrichoid spread 1, 3
• Leptospirosis: Can present as Fort Bragg fever with distinctive erythematous papular rash on shins, or as nonspecific febrile illness 3
• Vibrio vulnificus: May present as necrotizing fasciitis with hemorrhagic bullae, particularly in immunocompromised or cirrhotic patients 3
• Melioidosis: Particularly in Southeast Asia and Australia, can remain latent for years 3

Common Pitfalls to Avoid

Do not prescribe universal prophylaxis: The evidence does not support blanket antibiotic prophylaxis for all flood-exposed individuals, as this increases antibiotic resistance without clear benefit 2

Do not use doxycycline in children under 8 years: This is an absolute contraindication due to permanent dental effects 2

Do not delay wound care: Immediate copious irrigation is more important than prophylactic antibiotics for most exposures 1

Do not ignore protective equipment: For ongoing exposure during cleanup, use boots, gloves, and protective clothing to prevent contact 2

Prevention Measures During Cleanup

For individuals involved in flood remediation:

• Avoid contact with contaminated water whenever possible, especially if cuts or abrasions are present 2
• Use protective equipment including boots and gloves during high-risk activities 2
• Relocate from affected areas during cleanup procedures when feasible 5
• Ensure proper hand hygiene: Use alcohol-based hand rub when hands are not visibly soiled, or soap and bottled water when visibly contaminated 5

Environmental Remediation Considerations

For healthcare facilities or buildings requiring decontamination:

• Ensure sewage system is fully functional before beginning remediation 5
• Dry hard-surfaced equipment, floors, and walls within 72 hours and clean with detergent 5
• Remove wet, absorbent structural items (carpeting, wallboard, wallpaper) if they cannot be cleaned and dried within 72 hours to prevent mold growth 5