Should Coloradans Worry About the "Brain-Eating Amoeba"?
If you've been anywhere near the news this week, you've probably seen the headlines: a North Carolina teenager critically ill with a "brain-eating amoeba" infection. And if you're anything like my patients who've already texted me about it, your next thought was some version of wait, do I need to worry about this at the reservoir this weekend?
Short answer: no, not really. Slightly longer answer: here's what it actually is, why Colorado isn't North Carolina, and the handful of situations where it's actually worth paying attention.
What is it, actually?
The amoeba is called Naegleria fowleri, and yes, "brain-eating" is a fair description of what it does once it gets where it shouldn't be. It causes a condition called primary amebic meningoencephalitis (PAM) — and I won't sugarcoat it, PAM is about as serious as infections get. Since 1962, the CDC has recorded 167 cases in the US. Four people have survived.
But here's the part that matters most for your peace of mind: fewer than 10 people get infected in the entire country each year. You are, quite literally, more likely to be struck by lightning.
How you actually get it (and how you don't)
This is the detail that gets lost in every scary headline: Naegleria fowleri doesn't infect you by being swallowed. You can drink water with the amoeba in it and be completely fine. The only way it causes harm is if contaminated water gets forced up your nose with enough pressure to reach the brain — think diving, jumping in, water skiing, or dunking your head in warm, stagnant freshwater.
So a pool, a properly chlorinated hot tub, or a glass of tap water? Not a risk. A warm, shallow pond you cannonball into on a 95-degree day? That's the actual scenario.
Why Colorado is lower-risk (but not zero-risk)
The amoeba loves warm water — we're talking water that's been sitting and heating up for a while, usually 80°F and above, most often in the South during a long, hot summer. Most of our reservoirs and lakes here simply don't get that warm, and our recreation season is shorter.
That said, I'd be doing you a disservice if I said "impossible." Shallow, slow-moving, sun-baked water — a warm pond, a stagnant stretch of a slow creek, even parts of a reservoir during a heat wave — can theoretically warm up enough. It's rare here. It's not never.
What to actually do about it
I'm not going to tell you to stay out of the water all summer — that's not proportionate to the risk, and honestly, Colorado summers are too good for that. Instead:
Use nose clips (or just hold your nose) when jumping or diving into warm, shallow freshwater, especially late in the season during a heat wave.
Avoid stirring up sediment in shallow warm water — the amoeba lives in the bottom muck.
Keep your head above water in hot springs.
If you use a neti pot or do nasal rinsing, never use plain tap water. Use distilled, sterile, or previously boiled and cooled water — every time, no exceptions. This one actually matters more than the lake-jumping scenario.
When to actually worry
Symptoms start 1 to 9 days after exposure and hit fast: a severe headache, fever, nausea, and a stiff neck, progressing quickly to confusion, seizures, or worse. If you or your kid develops that kind of headache-plus-stiff-neck combination within a week or so of swimming in warm freshwater, that's not a wait-and-see situation — go to the ER and tell them about the water exposure specifically, so they know to consider it.
For everyone else? Go enjoy the reservoir. I'll see you at your next visit, not the ER.
