The term ‘brain-eating amoeba’ is relatively rare and terrifying because the general concept of amoeba is a tiny, harmless microbe. Can this little body really eat the human brain?
The brain-eating amoeba is in headlines again after was recently identified in Florida. Unlike other infections, it cannot spread through people but a freshwater source. Summer is here, and the coronavirus lockdown has been lifted in many parts of the world. People are now heading towards beaches, lakes, and diving sites utterly clueless about what could be waiting for them. What to know about this deadly brain-eating ameba and how to prevent yourself from catching it? Continue reading to find all the answers.
Is brain-eating amoeba real?
Unfortunately, the stories circulating on media regarding this microscopic body that lives on the human brain are genuine and 100% authentic. It may sound weird, but this amoeba exists, and it has infected people before. However, the incidence of this infection is infrequent, which explains why people believe it’s a myth.
This amoeba is named Naegleria, and it doesn’t truly eat the brain. It causes severe swelling in the brain and damages brain cells that eventually cause death. The name given to this condition is “primary amebic meningoencephalitis” or PAM in short.
The Centers for Disease Control and Prevention (CDC) explains the common sources of a brain-eating amoeba as follows.
- Warm saltwater lakes and rivers
- Geothermal water sources
- Warm water effluents from industrial units
- Geothermal drinkable water reservoirs
- Unclean swimming pools
- Commercial water heaters
Biology of the brain-eating amoeba
The scientific name of this brain-eating ameba is Naegleria fowleri. It freely lives in freshwater and causes a deadly brain infection termed primary amebic meningoencephalitis (PAM). The most common habitats of this amoeba are rivers, lakes, and even hot springs. It sometimes lives in the soil as well.
The only way that this bacteria can enter into a human body is through contaminated water entering the nasal cavity. Once it reaches here, it can travel all the way to the brain and start the infection.
The infection is much common if someone prefers to swim or dive in moderately warm freshwater sources. This amoeba rarely lives in another water source than natural water resources i.e., swimming pools with ill-treated water, hot tap water, etc. Not to forget, no one can become infected after drinking the contaminated water.
How often do people get Naegleria infections?
The U.S Centers for Disease Control (CDC) reports only 34 cases from 2008 to 2017. But it also reports that the mortality rate of naegleria infection is 97% in this infection, where only 4 out of 143 infected people survived this ameba disease between 1962 to 2016.
Surprisingly, the naegleria specie is extremely common, but it rarely causes disease. Primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri is an unusual medical condition that may only occur between July to September.
Some studies show that people can develop antibodies against N. fowleri like other common viral and bacterial strains. It implies that these people were infected with the brain-eating amoeba, but their strong immunity saved their life, and the body is keeping a record of this pathogen.
There is no clear information if Naegleria always initiates PAM and leads to death or not. But according to CDC, the exposure to this amoeba is a lot more common than the occurrence of PAM, suggesting there could be either unreported or undiagnosed cases.
How does brain-eating amoeba infect a person?
The amoeba makes its entry through the nose and gets to the nasal cavity. From here, it can easily travel to the brain. Once it reaches in the brain, it starts swelling that initiates primary amoebic meningoencephalitis (PAM).
The infection risk is highest when someone swims in a warm freshwater source i..e lake or river. But it is also possible to get it from other water sources in summer, especially in improperly chlorinated water.
It appears that this amoeba loves heat and lives in warm waters or sometimes in hot springs too. This infection risk is highest in summer, and it declines as the weather begins to cool.
Common symptoms of Naegleria infection
After exposure to the brain-eating amoeba, the symptoms don’t immediately show up. It may take up to 14 days to show its signs. The early symptoms of naegleria infection somehow look like meningitis. These include;
- A high fever
- Severe headache
- Nausea, diarrhea and vomiting
Once these symptoms show up, the ameba disease rapidly progresses and show up as;
- Feeling stiffness in the neck
- Extreme sensitivity to light
- Fatigue and confusion
- Inability to maintain body balance
- Hallucinations and seizures
It may take one to fifteen days for the symptoms to appear after exposure to the amoeba. If untreated, the patient can die within three to seven days of experiencing symptoms. Medical experts believe that the average death rate for primary amoebic meningoencephalitis (PAM) is 5 to 6 days. Only a few people have survived this infection so far.
How to diagnose it?
Anyone who suspects having a Naegleria infection after exposure to a freshwater source should immediately visit his nearest healthcare provider. Based on the primary symptoms, the doctor will take the cerebrospinal fluid (CSF) sample to test Naegleria. This cerebrospinal fluid sample is found in the brain and spinal cord, and the testing takes place through a lumbar puncture. It is an extremely painful technique when the doctor inserts a needle in the lower back, between the two vertebrae to collect CFS.
A detailed examination of this CFS sample can reveal if the patient has Naegleria in his body or not. Those who have this brain-eating amoeba present in their bodies and are on the verge of PAM have an abnormal blood cell and body protein level. It is also possible to see the living Naegleria amoeba in this CSF sample under a microscope. Additionally, the doctor may like to conduct a CT scan or MRI of the head to get a clearer picture of the brain damage.
Treatment for Naegleria infection
As this infection is atypical, there is not much research and clinical data available on it. There is no such treatment of PAM caused by Naegleria amoeba, but amphotericin B, a conventional antifungal medicine, has shown promising results in naegleria patients. The doctors give it intravenously or directly inject it into the spinal cord. In addition to this, Miltefosine is another medicine that also helps in these infections.
After evaluating the patient’s condition, the doctor may prescribe any of the following medicine.
- Antifungal- fluconazole
- Antibiotics- azithromycin and rifampin
Who is at higher risk?
Naegleria infection mostly infects kids who are 13 years old or younger. It is more common in men than in women. In the US, nearly 60% of the infections were observed in children, and 80% of the total cases were male patients. There is no explanation of why this brain-eating amoeba infects men and underage children more. One assumption is that these groups are probably more interested in water-related activities, which brings them at higher risk. Yet, there is no scientific evidence of this possibility.
How to prevent brain-eating amoeba infection?
The chances to get this ameba disease are very less but following precautions while spending time in freshwater can reduce the risk to zero. Here are a few ways to avoid this brain-eating parasite.
- Avoid direct exposure to the freshwater.
Although summer is the only time of the year to enjoy water-based activities, the rivers, lakes, and streams are full this season. But it is better to avoid swimming or to jump directly into the water, easing the amoeba’s entry through the nose.
- Swim with your head up
Even if you have to swim, make sure that your head is above the water level. It is better to use nose clips or simply hold the nostrils, shutting the nasal passage while jumping into the water.
- Don’t play with the sediments.
Avoid going into the deep water, especially around sediments. There are high chances that these sediments contain the brain-eating ameba.
- Disinfect the swimming pools
For indoor swimming, make sure that your pool is clean, chlorinated, and disinfected. Additionally, you can use nose clips and earplugs to swim in rivers and lakes.
- Use full-face masks while diving
There are specific swimming gadgets that prevent the water from touching the face. For example, you can use a full face snorkel while swimming or diving in freshwater lakes and rivers.
- Avoid hot springs
Do not expose your head directly to a hot spring or any other untreated thermally heated water.
- Clean the water heaters
The domestic and commercial water heaters require proper cleaning, so that no pathogen, including the brain-eating bacteria, can reside.
The final word
Primary amebic meningoencephalitis caused by Naegleria fowleri is a fatal condition common in people exposed to freshwater lakes and rivers. This tiny amoeba is common in warm water and is most likely to enter the human body through the nose. Those who love to spend time in warm water should be extra careful and follow all the necessary precautions, especially protecting the nose to reduce the risk.