In Jin Yong's long martial arts novel "Smiling Rivers and Lakes", in order to better control his subordinates, Dongfang Undefeated specially made a poison called the Three Corpse Brain Divine Pill, and the person who took this poison must obtain an antidote from him every once in a while, otherwise the corpse worm will transfer to the brain, making the poisoner miserable and irrational.
It is not known whether Jin Yong had a realistic reference when he invented this poison, but in any case, a rare amoeba that originated in the United States has a similar effect.
After a person is infected by this amoeba, the worm will gradually transfer to the head of the infected person, consuming astrocytes and neurons in the brain, so it is often called "brain-eating amoeba";
Photo by Kateryna Con / Shutterstock.com
In addition, it has another similarity with the Three Corpse Brain Divine Pill, the infected person will not have any abnormal manifestations in the first 5 days or so, and then a series of brain-related problems including headache, fever, nausea, vomiting, hallucinations, loss of appetite and so on will appear.
When infected people develop these abnormalities, they are almost always fatal, and for a number of reasons, the brain-eating amoeba is spreading in the United States, with cases reported everywhere.
How do brain-eating amoebas infect humans?
The scientific name of the brain-eating amoeba is Naegleria fowleri, which was discovered in Australia in the 60s of the last century and named after Australian pathologist Malcolm Fowler, and because it belongs to a species of the genus Naegler, it is the only one known to infect humans.
Amoebas are proto-single-celled animals that live in water and survive by devouring nutrients such as bacteria, and the way to proliferate is simple binary division.
The same is true of Negritus fowleri, but it is a thermophilic amoeba with water temperatures of 42 degrees Celsius as their optimal survival and reproduction temperature, and can survive normally up to 46 degrees Celsius.
They are most commonly found in warm and hot freshwater ponds, lakes and rivers, do not like seawater, and have three biological phases, namely cysts, trophozoites, and flagellar forms (which again reminds me of the Three Corpse Brain Pill).
Cysts are a membrane wall secreted by many lower plants and protozoa to adapt to changes in external environmental conditions, and for Negrie Fuchi amoebas, this state occurs when the water temperature is below 10 degrees Celsius or other unfavorable factors, wrapping itself into a sphere.
The cysts of Negritos fowlerii float in the air in search of suitable habitat with the wind, so they can actually spread through the air and infect people.
Pictured: Three biological phases of Negrita fowleri
However, after ingesting cysts, humans are not directly infected, but transformed into trophozoites - this is the only stage in which Negrellia fouchi infects humans.
Trophozoites take on an irregular, changeable shape and are the stages at which they can actively eat and proliferate. At this stage, as soon as people inhale them through the nose (it's okay to swallow them in the mouth), they are likely to stick to the nasal passages and enter the brain through the sieve plate.
In the brain, they engulf some of the brain's tissue cells to survive and release cell-lytic substances or destroy brain tissue by using cell-lytic membrane proteins, allowing infected people to develop meningitis, or Negritosis.
©Katerynakon
During the trophozoite stage, they grow flagella to help them move, and this stage can also enter the nasal cavity through water, but like the cyst, after entering the nasal cavity it transforms into a trophozoite within a few hours and reinfects humans.
When a foreign body invades the body, the immune system kills the invader in the form of fever, but in the case of Negri Fuchi amoeba this seems to be exactly what it wants, quickly completing the proliferation in the brain.
Although Negree fowleri was first detected in Australia, researchers believe they evolved in the United States, which is currently the country with the highest number of infections in the world.
Source: Wikimedia Commons
From 1962 to the present, 154 cases of infection have been reported in the United States, of which only 4 survived; Worldwide, the number of reported infections is almost twice that of the United States, with only 7 surviving, a fatality rate of about 97%. We have also reported several cases in China, but none of them have been cured.
Brain-eating amoeba infections have similar symptoms to many bacterial infections, so they are very easy to misjudge, and many infected people may not be reported at all.
So this infection, while rare, is certainly much more than it really is, and most importantly, researchers haven't fully figured out on what basis it infects humans, and maybe some animals will be infected, just ignored by us.
Negri Fuchi infection occurs mostly at low latitudes, but in recent years, its infection has spread more and more northward, and it has reached an all-time high, and it has spread almost all over the country in the United States, even Alaska.
The amoeba © katerynakon is often present in tap water
Why is it spreading?
There are two main reasons why brain-eating amoeba spread north: global warming and heat pollution.
This amoeba is a thermophilic microorganism, and the heat pollution created by our current lifestyle provides them with a good living environment.
Artificial hot springs, the use of water heaters, and the discharge of warm water from industry or power plants are all very easy to breed this amoeba.
On the other hand, heat contamination also kills those heat-sensitive microbes, in the sense that it also reduces amoeba competitors, who can get more food and thus proliferate rapidly.
When the water temperature conditions are ideal, they can become cysts, wrap themselves in water and wind to transfer, and when ingested by the human nose, they can become a wave of trophozoite proliferation.
In addition, with global warming, higher latitudes are getting hotter, which makes it possible for them to survive farther north.
Most importantly, global warming promotes the emergence of extreme heat weather, which is as good for their survival and proliferation as heat pollution, and infection with Negri Fuchi is highly correlated with hot weather.
At last:
The way humans live today, and the changing direction of the climate, may be detrimental to most organisms, but many organisms also benefit from it.
Two of the most obvious are rats and cockroaches, both animals that reached their peak in the Anthropocene.
Of course, there are many more hard-to-find creatures poised to take off, and Negri Folleri may be one of them.
However, you will find that many times these outbreaks of species are not necessarily good for humans.