The Most Common Infections You Can Get in an Emergency or Disaster

By the Jase Medical Team

When most people picture getting an infection after a hurricane or flood, they imagine contaminated floodwater, a cut on the leg, and some unusual bacteria they’ve been warned about on the news.

But oftentimes, it’s the invisible outbreaks that happen when communities are displaced.

It’s a gym floor lined with 200 cots and a stomach bug moving through the room in 48 hours.

When you look at documented outbreaks after real U.S. disasters, the infections people actually encounter are almost the reverse of how they’re often presented in preparedness content.

The most common threats aren’t necessarily rare bacteria lurking in floodwater. They’re the same highly contagious viruses that spread anywhere people are suddenly living close together.

And for those infections, soap, distance, screening, and good sanitation can matter more than anything in your medicine cabinet.

#1: Stomach Bugs Like Norovirus

If you evacuate to a crowded shelter, one of the biggest infectious-disease concerns is gastrointestinal illness—particularly norovirus.

Norovirus spreads extremely easily through contaminated hands, surfaces, food, and close contact. A shelter gives it plenty of opportunities: shared bathrooms, communal meals, frequently touched surfaces, and hundreds of people living in close quarters.

We’ve seen this play out repeatedly.

During the 2025 Eaton Fire response in Pasadena, shelter surveillance identified 104 cases of norovirus. During the 2018 Camp Fire, an outbreak across eight shelters involved 292 cases, with an estimated attack rate of about 27%. The median age of patients in that outbreak was 63.

What brought these outbreaks under control?

Not antibiotics.

Public-health teams screened people for symptoms, separated those who were sick, intensified cleaning and disinfection, and emphasized handwashing and infection-control measures.

That’s an important preparedness lesson: sometimes the best tool for preventing an infection isn’t a medication.

If you’re staying in a shelter, wash your hands thoroughly with soap and water, pay attention to sanitation around shared spaces, and follow shelter instructions if you develop vomiting or diarrhea. If you’re sick, limiting contact with others helps protect the people around you too.

#2: Respiratory Viruses

Crowded shelters also create ideal conditions for respiratory illnesses to spread.

During the Eaton Fire shelter response, surveillance identified 56 cases of COVID-19, 29 cases of influenza, and another 30 cases of other respiratory illness.

Again, these were viral illnesses—not bacterial infections that could be solved with an antibiotic.

The same basic principles that reduce respiratory transmission elsewhere still matter during an evacuation: give sick people space when possible, wash your hands, cover coughs and sneezes, improve ventilation when circumstances allow, and follow public-health guidance in the shelter.

If you develop significant symptoms or you’re concerned about your individual risk, seek medical guidance. Depending on the illness and the person, a clinician may recommend testing or specific treatment.

But reaching automatically for an antibiotic isn’t the answer to a viral respiratory infection.

#3: Skin and Wound Infections

This is where the more familiar post-hurricane picture starts to become relevant.

Floodwater can contain sewage, debris, microorganisms, and other contaminants. At the same time, cleanup work creates plenty of opportunities for cuts, punctures, scrapes, and other injuries.

That combination can lead to skin and wound infections.

Prevention starts before infection does: avoid floodwater when possible, cover existing wounds, wear protective footwear and gloves during cleanup, and clean new wounds appropriately.

Then pay attention to what happens afterward.

Increasing redness, warmth, swelling, drainage, worsening pain, fever, or redness that appears to be spreading away from a wound deserves medical attention.

This is also one of the narrower situations where a prescribed oral antibiotic may have a role when an ordinary wound infection develops and begins spreading.

But “I was exposed to floodwater” doesn’t automatically equal “I need antibiotics.” The wound, symptoms, exposure, and severity all matter.

What About the Scary Floodwater Infections?

There are bacterial infections associated with floodwater that deserve to be taken seriously. They simply shouldn’t be presented as though they’re more common than norovirus or respiratory viruses.

Leptospirosis is one example. The bacteria can spread through water or soil contaminated by the urine of infected animals. Following Hurricane Fiona, Puerto Rico recorded 156 leptospirosis cases over a 15-week period, and 72% of those patients were hospitalized.

Certain Vibrio infections are another serious concern, particularly when a wound is exposed to coastal or brackish water.

These infections can become severe quickly.

And that’s precisely why they don’t belong in the category of “keep some antibiotics around and treat it yourself.”

A severe Vibrio wound infection, for example, can require urgent antibiotics, hospital care, and surgical removal of infected or dead tissue. A pill sitting in a medicine cabinet cannot provide that care.

Rare invasive fungal infections can also occur after major disasters and traumatic injuries. They’re serious, but they’re rare—and giving them equal weight with the viral illnesses that routinely spread through crowded shelters distorts what you’re actually most likely to encounter.

The Most Serious Infections Are Often “Get to Care” Problems

This distinction matters when you’re building a medical emergency plan.

There’s a tendency in preparedness conversations to reduce infection planning to one question:

What antibiotics should I have?

But that’s the wrong starting point.

Some of the infections you’re most likely to encounter after a disaster are viral, meaning antibiotics won’t treat them at all.

Some bacterial infections may require prescription treatment after evaluation.

And some of the most dangerous post-disaster infections need capabilities you simply cannot reproduce at home: diagnostic testing, IV medication, wound management, surgery, or hospital-level monitoring.

Appropriate medical preparation means knowing the difference.

A prescription can be incredibly valuable when it’s the right tool. But being prepared also means recognizing when the right response is to get to medical care.

Where Does a JaseCase Fit?

There is a narrower space where having appropriately prescribed contingency medication can matter.

Imagine you’re cleaning up after a hurricane and sustain a cut. Despite cleaning and monitoring it, several days later you develop signs of a routine bacterial skin infection with spreading cellulitis—and local healthcare access is genuinely disrupted.

That’s very different from taking an antibiotic because you stepped in floodwater or developed diarrhea at a shelter.

JaseCase provides physician-prescribed contingency medications for certain common acute illnesses when normal healthcare access isn’t available. Every request is reviewed by a licensed medical provider, who determines whether the medications are appropriate and writes the prescriptions for the individual.

If you become ill during an emergency, you should still try to reach an appropriate healthcare provider first. Your JaseCase is a contingency layer for when that normal access has broken down—not a replacement for clinical care and certainly not a substitute for emergency treatment when symptoms are severe.

Prepare for What Actually Happens

If you’re preparing for a hurricane, wildfire, flood, or evacuation, start with the risks that repeatedly show up in real disasters.

In a crowded shelter: think handwashing, sanitation, respiratory illness, and avoiding close contact when someone is sick.

During cleanup: think gloves, sturdy footwear, wound protection, clean water, and prompt wound care.

If you become sick: know which symptoms can be managed with routine guidance and which ones mean you need to find medical care.

And when medications do have a role, use them for the problems they’re actually designed to treat.

That’s what we mean by appropriate medical preparation. We’re a family team of medical doctors, PAs, and pharmacists, and we’d rather help you understand where the clinical line is than sell past it.

When Communities Need More Than Personal Preparedness

There is another side of disaster medicine that doesn’t fit inside an individual’s emergency kit.

When hurricanes, wildfires, floods, and other disasters disrupt healthcare across an entire community, people may lose access not only to a pharmacy but to clinics, medical supplies, and the healthcare professionals they normally depend on.

That’s where Jase Response, our nonprofit disaster-response organization, comes in.

Jase Response delivers essential medical services to help build resilient communities in times of crisis. Working alongside trusted response partners, the team helps mobilize medications, medical supplies, and medical providers into communities where normal healthcare access has been disrupted.

Because preparedness and response are two sides of resilience.

At home, preparation helps you care for yourself and the people you love. In a disaster zone, response helps make sure communities aren’t left to recover alone.

Support Jase Response today: https://givebutter.com/aQ8pUO

The Jase Medical Team is a family team of medical doctors, PAs, and pharmacists focused on appropriate medical preparation: clinically grounded readiness that complements, rather than replaces, primary care and the healthcare professionals you already trust.

This article was prepared by the Jase Medical content team for informational purposes only and does not constitute medical advice. Prescription requirements, emergency dispensing rules, insurance coverage, and controlled-substance regulations vary by medication, jurisdiction, and individual circumstances. Consult a licensed healthcare provider or pharmacist regarding your specific medications.