Of all the infections that one can get from living a so-called ordinary life, this one is about as lethal as any I’ve come across in the past. The disease is called primary amoebic meningoencephalitis, or PAM for short. Fortunately, it’s rare and only 128 cases have been reported in the United States between 1962 and 2012.
The bad news is that of those 128 cases, there was only one survivor. PAM is a devastating infection of the brain caused by the free-living Naegleria fowleri organism. It’s been called the “brain-eating amoeba” in the media because the organism enters the body through the nose and travels up the olfactory nerve to the brain. It then causes the usually fatal PAM.
Before proceeding, however, let me clarify that although the spelling of “amoeba” is used almost exclusively around the world, it’s sometimes spelled as “ameba” in North America. Therefore, in some references you may see this spelling alternative.
The Naegleria fowleri amoeba is commonly found in warm freshwater (such as lakes, streams and hot springs) and the infection occurs when people go swimming or diving in these waters. In rare instances, PAM can occur from inadequately chlorinated swimming pools. Infections can even result from contaminated tap water if an individual uses the water to flush out the nose, as in using a neti pot for sinus irrigation.
Most infections occur in southern-tier states, with more than half of the occurrences in Texas and Florida. And cases have been identified in Louisiana after the hurricane Katrina hit the area. Aside from such a natural disaster, the PAM infection disproportionately affects males and children, probably as a result of their more aggressive water sports activities.
The infection presents much like bacterial meningitis. Symptoms include severe headache, fever, vomiting, neck stiffness and seizures. The most important medical clue leading to a proper diagnosis of PAM is if the patient presents with the above-mentioned symptoms and, in the two weeks prior to symptom onset, the patient swam in a freshwater lake, river or stream.
The only certain way to prevent this amoebic infection is to refrain from swimming in warm freshwater. Barring that, there are several preventive measures one can take to reduce the risk of contracting this disease. Hold your nose shut or use nose clips when swimming or diving into freshwater, or keep your head above water at all times when enjoying outdoor water sports. And never put your head under water when soaking in natural hot spring pools.
Additional advice is to not dig in or stir up the sediment in shallow freshwater. The sediment is a perfect breeding ground for such amoeba. And when irrigating the sinuses with tap water, be sure to first boil the water for at least one minute—or for three minutes at elevations higher than 6,500 feet. And always allow the water to cool before use.
These measures may seem drastic but a PAM infection is nearly ALWAYS FATAL, so act cautiously to ensure your safety against this lethal organism.
Thoughts? Comments? I’d love to hear them!