This article is very complete and long, it includes the history of malaria, treatment, symptoms, pathogenesis and some modern antimalarial drug introduction, the whole article is more than 4300 words. Although it may bring "fear" to friends who are not used to reading long texts, it can still gain a lot if you look closely.
Although malaria seems to be less common in China, it has been raging in China. Moreover, there will be nearly a thousand cases in China every year.
Worldwide, malaria kills an astonishing number of people, killing hundreds of thousands of people every year.
The mosquitoes that transmit malaria are also known as the "deadliest animals" on the planet!
< h1 class= "pgc-h-arrow-right" > history of malaria</h1>
Malaria is a very old disease that may have appeared on this earth even before late Homo sapiens (us).
Malaria is thought to have originated in Africa and spread as humans migrated across the globe.
As early as the Yin Dynasty in China, there were already records of diseases such as "malaria" in the oracle bones.
The ancient Greeks called it "swamp fever."
The lethality of malaria is staggering.
The Book of the Later Han Dynasty says that during the conquest of ancient Vietnam, there was an outbreak of malaria in the army, "Nanzhou is warm and hot, with miasma, until the dead, ten must be four or five." ”
In other words, malaria at that time directly caused the Han army to lose nearly half of its soldiers.
In the Western Roman era, due to the long-term malaria epidemic, the Romans were weak and the land was deserted, which to some extent also led to the weakening of the Roman Empire.
Far from it, malaria claimed 100 million lives between 1900 and 1950 alone.
According to some researchers, nearly half of all humans have died from malaria since there were humans.
If you follow the demographer Karl Herb estimates that a total of 100 billion people on Earth have survived on Earth, in other words, malaria has claimed 50 billion lives.
This data is very surprising, and many people have difficulty accepting it.
However, in 2016 alone, malaria was still endemic in more than 90 countries around the world, with 216 million new cases and about 445 000 deaths from malaria.
Therefore, the lethality of malaria cannot be underestimated.
China has made remarkable achievements in eliminating malaria globally, for example, in 2017, the number of malaria cases in China was 2697 and the number of deaths was 6. And you know, China has a population of 1.4 billion.
<h1 class= "pgc-h-arrow-right" > cinchona bark and malaria</h1>
Before the discovery of the golden rooster, humans were basically helpless against malaria.
Therefore, if a patient has malaria, whether he can survive or not depends entirely on luck.
In fact, the situation may be worse than this, because the medical science at that time was simply too far from the science of principles.
For example, if you lived in ancient Europe and you had malaria, you might have to endure a series of "blind" operations such as enemas and bloodletting.
Doctors will toss you to death before malaria kills you.
Especially bloodletting, they will take a knife and bleed directly from your large blood vessels until you are in a trance, unconscious and die.
And the appearance of cinchona bark is actually a gift from God.
Cinchona is a plant that grows in the Peruvian Andes Mountains in South America.
Cinchona tree
Local Indians often use its bark to treat malaria, but how the Indians discovered that it could cure malaria is still a mystery.
The missionary who had been preaching in South America had the misfortune of contracting malaria, and the friendly local Indians treated him with this drug.
So the missionaries brought the drug back to Europe and used it as one of the pressure-out drugs when missionaries went around the world.
Kangxi, who contracted malaria in 1693 and was helpless with numerous imperial physicians, decided to try the cinchona bark carried by a Portuguese missionary.
Kangxi first ordered healthy people to eat it to see if it was poisonous, and after confirming that nothing was wrong, he tried it, and the result was surprisingly good, and he was cured.
Since then, this medicine has become a necessary medicine for the Qing Emperor's life-saving medicine list.
Cinchona bark cures malaria because it can effectively kill the fissiles of malaria parasites in the blood.
In 1820, P.J. Péltier and J.B. Cabondo extracted the active ingredient from the bark of cinchona, a theobromine and 4-methoxyquinoline antimalarial, and "quinine" was born, commonly known as rheumatogena.
Quinine is an important antimalarial drug against the endocytic protozoa of falciparum malaria that inhibits its reproduction or kills it.
However, the side effects of quinine are also very large, can inhibit myocardial contraction, and a little carelessness may be poisoned by taking it.
<h1 class="pgc-h-arrow-right" > findings of Anopheles mosquitoes and malaria transmission</h1>
For a long time, it was not clear how malaria occurs.
Although it has long been clearly known in experience that malaria is associated with swamps and rainforests, the specific causes and transmission routes of malaria were not understood until the end of the 19th century.
Three great scientists accomplished this feat: the French physician Ravelland, the British pioneer of tropical medicine Manson, and the microbiologist Ross.
Ravelán, a military doctor, suspected that the malaria pathogen should be a parasite and then used a microscope to find the malaria parasite.
But Ravelán has always wondered how it entered the human body. He never found the reason.
Charles Luis Alphonse Ravelland
Manson and Rose solve the puzzle.
Manson was the first to suspect that mosquitoes might be hosts of malaria parasite disease transmission, but the mosquitoes he experimented with at the time were Culex and Aedes mosquitoes.
So he failed to find the malaria parasite in experimental mosquitoes that bit malaria patients.
Patrick Manson
Ross was lucky enough to repeat the experiment with Anopheles mosquitoes and found the malaria parasite in his body.
Later, Manson repeated Ross's experiment to further confirm the phenomenon.
As a result, people learned that the transmission route of malaria was actually caused by the bite of "mosquitoes".
For this, Ross was awarded the 1902 Nobel Prize in Physiology or Medicine, and Ravelland was later awarded the 1907 Nobel Prize in Physiology or Medicine for the fact that protozoa can also cause disease.
Ronald Ross
Later, successive studies showed that there were four species of malaria parasites parasitic in humans, namely Plasmodium vivax Grassi & Feletti (1890), Plasmodium malariae Laveran (1881), Plasmodium falciparum Welch,1897) and Plasmodium plasmodium (Plasmodium). ovale Stephens，1922）
In China, plasmodium vivax and plasmodium falciparum are mainly the two species; the other two are rare, and in recent years, some cases imported from abroad have occasionally been seen.
Different plasmodiums cause vivax, three-day malaria, falciparum malaria and ovate malaria.
< h1 class= "pgc-h-arrow-right" > malaria</h1>
Among the four malaria parasites mentioned above, the most dangerous is Plasmodium falciparum, and the other three malaria parasites do not have a high fatality rate.
If a person is bitten by Anopheles mosquitoes with the malaria parasite, the first thing is not immediately onset, but first enters an incubation period.
latent period
The so-called incubation period refers to the time it takes for the malaria parasite to multiply in the body's liver cells and red blood cells.
For example, the incubation period for vivax and ovate malaria is generally 14 days, falciparum malaria is only 12 days, and the longest time for three-day malaria is generally 30 days.
Of course, some cases do have incubation periods of up to six months to one year, but this is rare.
The fetus can also have a shorter incubation period due to the mother's infection.
Chilling period
When the incubation period has passed, the infected person begins to show symptoms.
At this time, it will enter a chilling period. The patient first feels chills at the ends of the limbs, then chills on the back and all over the body.
Goosebumps began to appear all over the body, purple lips, pale face, and sore joint muscles throughout the body.
Then the whole body began to tremble involuntarily, the teeth trembled, and the cold sensation could not be stopped by covering several beds of quilts, often lasting about 10 minutes, and then the chills naturally stopped.
Febrile period
After the manifestations of chills and chills, the patient begins to turn rosy, the lips turn purple and disappear, and the body temperature rises rapidly, reaching more than 40 degrees Celsius.
During high fevers, the patient is in extreme pain, tossing and turning, and moaning incessantly. Sometimes there are hallucinations, convulsions, spasms, coma and other manifestations.
It can also be accompanied by a series of manifestations such as severe headache and non-stop vomiting.
This period tends to last for several hours.
Sweating period
At the end of the fever period, the face and palms begin to sweat slightly. However, it soon turned into a period of sweating.
After 2-3 hours, the body temperature begins to decrease, and the patient begins to feel comfortable, but is very tired and can often sleep peacefully.
Wake up refreshed, have an appetite, and work as usual.
However, this is not a complete improvement, but only a transition to the next incubation period of malaria parasite reproduction.
If the malaria parasite in the body is not removed, the next outbreak will strike, and eventually the patient will experience life and death in the "cold-heat exchange".
< h1 class="pgc-h-arrow-right" > pathogenesis of malaria</h1>
The reproductive cycle of the malaria parasite is done by exchanging mosquitoes and humans.
The life of the malaria parasite can be divided into three forms: trophozoites, fissures, and gametophytes.
Malaria parasites mainly reproduce sexually in mosquitoes, and when mosquitoes suck the blood of malaria patients, the malaria parasites of each stage enter the gastrointestinal tract of mosquitoes.
In the gastrointestinal tract of mosquitoes, only gametophytes can survive, so the male and female gametophytes of the malaria parasite mate with each other, producing a steady stream of plasmodium spores.
When the female mosquito is "pregnant", it will creep up on the person's skin, insert its own mouthparts into the gaps in the skin, and suck blood from it.
The malaria parasite spores "escape" along the digestive tract of mosquitoes and enter the human body.
Subsequently, the scabies spores enter the blood vessels and "swim" in the human body along the blood flow!
The liver is an extremely abundant organ of the human blood flow, and the spores of the malaria parasite will come here sooner or later. As a result, the scabies spores are sought out in the veins of the liver tissue.
When it finds a Kupffer cell, it burrows into the liver cell through it.
Probably to get rid of the screening of immune cells, it does not immediately multiply in liver cells close to blood vessels. It will "weirdly" run into the liver cells that are further inward.
It eventually rests inside the "deep" liver cells, while the peripheral liver cells begin to die because of its "penetration".
Subsequently, plasmodium spores begin to undergo "asexual reproduction" within liver cells. They grow little by little until they are large enough that the liver cells rupture, releasing more offspring.
Subsequently, a steady stream of early offspring of the parasite is released into the bloodstream.
They will begin to have new infection mechanisms. They can invade red blood cells.
To circumvent the scrutiny of immune cells, they burrow into red blood cells.
Over the next few hours, through various stages such as trophozoites, many fissures are produced.
Infected red blood cells follow the bloodstream and "walk" along with other red blood cells.
However, because it is too heavy to float in the plasma, it is deposited on the walls of blood vessels.
Eventually, in a "rupture", mature fissures, spores, gametophytes, trophozoites and other components are released.
And these "bad guys" can infect more red blood cells.
< h1 class= "pgc-h-arrow-right" > the causal relationship between Plasmodium malaria and malaria symptoms</h1>
Why does malaria cause chills?
One theory is that when the parasite parasitizes the body, the body's immune cells will eventually find it and begin to kill it. i
In order to inhibit the reproduction of pathogens, the body will deliberately raise the body's body temperature.
Because after the body temperature rises, the activity of proteases decreases, and the reproduction of pathogens is inhibited.
Of course, the body temperature rises, and our own normal cells are also "uncomfortable".
The reason why the body can raise body temperature is because information about pathogens is presented to the hypothalamus through immune cells, which is the body's thermoregulatory center.
After the hypothalamus receives the relevant information, it will raise the body's body temperature adjustment point. For example, the original setting was 37 degrees Celsius, and now it is set at 40 degrees Celsius.
As a result, the human body will use 40 degrees Celsius as its "standard" body temperature.
In fact, at this time, the temperature of the person cannot reach the temperature, so the body thinks that it is "hypothermia".
Desperately raise your body temperature by shivering, getting goosebumps, seeking warmth, etc.
Why do my lips turn purple during malaria?
Purple lips are actually due to anemia and hypoxia symptoms caused by the destruction of red blood cells in the body by the malaria parasite.
What is the reason for fever?
The fever period is located after the chilling period, when the human body continues to produce heat through the chilling period, reaching or even exceeding the set problem.
Malaria parasites and the like are very likely to die in large numbers due to environmental discomfort.
As a result, information from the malaria parasite infection can be captured by the hypothalamus, and gradually begin to downregulate the temperature setting point.
However, at this time, the temperature of people is actually very high, and suddenly people feel extremely "hot and dry".
And in order to alleviate this "heat", I began to sweat continuously to cool down.
< h1 class="pgc-h-arrow-right" > artemisinin and malaria</h1>
Quinine was the first anti-malarial drug in history, but the side effects of quinine are also enormous.
To this end, scientists have developed a series of more efficient antimalarial drugs such as ethrime, chloroquine, and primaquine, with fewer side effects.
In 1971, Tu Youyou, a scientist from China, based on the records of traditional Chinese medicine texts, used modern technology to extract its antimalarial active ingredient in Artemisia annua and named it artemisinin.
Artemisinin is the most effective antimalarial drug after the above antimalarial drugs.
Especially in the long-term killing of malaria, the malaria parasite gradually has the characteristics of chloroquine resistance, and artemisinin can compensate for this resistance.
It is also fast-acting and low-toxic, and has been called "the only effective malaria treatment drug in the world" by the World Health Organization.
In September 2011, tu youyou developed artemisinin to save millions of malaria patients, and won the Lasker Prize, known as the "wind vane" of the Nobel Prize.
In October 2015, Tu Youyou, a native with no doctorate, a foreign background and the title of academician, won the Nobel Prize in Physiology or Medicine that year, becoming the first Nobel Laureate in China.
Regardless of other emotional colors, the extraction of artemisinin may not be technically difficult, but artemisinin's treatment of malaria is definitely a very great innovation.
Moreover, looking at the world, the achievements of artemisinin are very great, and Tu Youyou is of great significance in promoting the development of human health, and she is undoubtedly great.
But it's not great because of the Nobel Prize!