"A few decades ago, I could occasionally see such a group of patients, who were yellow-faced and thin, and obviously malnourished. However, in that era, the standard of living was generally not good, and it was not uncommon for patients to be emaciated. But when I saw their elephant-like legs dragging the ground, I knew I would never easily forget that scene in my life...
In 2007, the Chinese health department informed the World Health Organization that China had eliminated filariasis.
Since then, filariasis has become history in the land of China!
But if you go back decades, including in the early days after the founding of the People's Republic, filariasis is still very common.
Globally, filariae that can parasitize humans can be divided into 8 categories.
The sites where these filaria parasitize vary, but in China, banscher nematode and Malayan blue nematode are the main ones.
Both filaria are also common parasites that can parasitize tissues such as the lymphatic system.
Especially common in the lower limbs, scrotum, arms and other parts.
According to historical records, Ben's filaria has existed in ancient tropical regions as early as ancient times.
For example, many ancient Greek and Roman scholars, Celsus, Galen, etc., can find a record of a disease called elephantiasis.
And elephantiasis is to a large extent what we call filariasis.
Gallian
Because after the filaria infect the lymphatic system and other tissues, they can "eat, drink" and "multiply" inside, eventually stimulating local skin hyperplasia and blocking the lymphatic vessels, resulting in swelling.
So, from a distance, these infected skins are as thick as elephant skins.
However, it is worth mentioning that in history, leprosy and filariasis have also easily confused with each other.
Because leprosy can cause granulomatous inflammation locally in the skin, it stimulates local skin hyperplasia and causes similar elephant skin symptoms.
However, leprosy rarely causes swelling of the lower legs and scrotum in the human body, while Benn's filariasis is much more common.
Scholar B.R. Laurence believes that Ben's filariasis should originate in the rainforests of Southeast Asia.
As people migrated in the region, it subsequently spread to the South Pacific islands and Africa.
Eventually, the disease spread across the globe.
Interestingly, in order to survive, filariae have adapted to the favorable living environment in these areas in favor of mosquito vectors.
This explains why Ban's Vulcoidiasis has both daytime and nocturnal species.
Over the past 400 years, continued migration and the opening of trade in the tropics, coupled with the strong adaptability of banscher vulans to various mosquito vectors, has led to the spread of the parasite throughout the tropics, including China and India.
Filariasis in the Americas may be the result of the african slave trade.
The slave trade brought filariasis to the Americas
As a result of this trade run by white Europeans, slave incarcerations in the West Indies were concentrated in infected black Africans and then trafficked to regions such as North and South America.
The black slaves bit each other through mosquitoes, and eventually carried the silk worm across the ocean to the American continent.
For a long time, little was known about filariasis. It is also difficult to distinguish between diseases.
The real scientific understanding of filariasis began in the 17th century and reached maturity in the 19th century.
Europeans at that time began to establish colonies in various parts of the world.
When the colonists came to the New World and encountered a variety of indigenous peoples, they were quickly attracted by the huge calves and scrotums of some filariasis patients (indeed, this was even more visually striking).
Although, europeans at that time already knew that the lesions of this disease were in the lymphatic vessels.
There are even scholars who have tracked the entire process of the development of filariasis in detail, from lymphangitis and lymphadenitis to the gradual swelling of limbs and scrotums.
Manifestations of the onset of filariasis in various stages
But no one knows why they get this disease.
It was not until the late 19th century, with the invention and widespread use of the microscope, that the face of filariasis was truly revealed.
In 1862, the French physician Jean Nicolas de Marquez (Jean Blanc) Nicolas· Demarquay) extracted the chyloid fluid from the swollen scrotum fluid of the local Cuban natives, but he did not study the liquid further at the time.
Ban's Ngocet nematode
The following year, when he extracted the liquid again, he put it in a microscope and finally saw: "What attracts attention is the longer and cylindrical creatures, doing extremely fast curling and stretching movements." ”
Since then, many scholars have successively discovered this worm in the affected part of patients with filariasis.
In 1877, Patrick Manson, who had been studying filaria for a long time in China, was killed in a book. Manson), published a paper in which he published an important point: mosquitoes are vectors of filariasis!
Mosquitoes are the second host of filariasis
First, Manson argues that filarial larvae cannot grow, mature, and enter the bloodstream when they are not absolutely overwhelming in number over their human hosts.
Although we now know that this is the result of the immune system suppressing and killing these protozoa, he was able to draw this empirical understanding in that era.
Why did Manson think of the possible role of mosquitoes in transmitting filariasis?
Because Manson himself has a rich and excellent knowledge of animal parasites and life history.
He proposed and eventually confirmed that mosquitoes are hosts for filarial larvae!
Manson believes that mosquitoes swallow filariasis while sucking blood, and their larvae develop and grow in this second host.
And when it bites, it can complete the transmission of filariasis.
Parasitic cycle of filariasis
Manson also believes that mosquitoes carrying filaria usually die in flowing water after death, while filaria can enter the water.
When humans drink this already contaminated water, they ingest filaria.
Prior to this, some scholars believed that drinking water was the main way to cause filariae infection.
Manson's explanation can be a good proof of it.
Now we know all about filariasis.
Filariasis caused by Benseziasis and Malayan Bruceworm is also known as weevilia or weeperosis.
This is because these two filaria can parasitize the subcutaneous tissue, lymphatic system, abdominal cavity or chest cavity of the skin of the legs, scrotum, arms and other skin of the person, and then secrete factors to stimulate the thickening of the skin and block the lymphatic vessels, resulting in lymphadenopathy, and eventually forming tissue as thick as elephant skin.
The vicious nematodes are adult worms, linear, white, coiled in the human lymph nodes and lymphatic vessels, and "eat and drink" for up to 10-18 years.
Benn's filariasis is transmitted only by mosquitoes.
Mosquitoes can carry infected filarial larvae after sucking the blood of patients with filariasis.
When it bites the next person, the filarial larvae can enter his skin through the mouthpiece.
The larvae will find the path of the lymphatic vessels, where they will eventually "rest" for about 1 year, and mature and mate, producing a steady stream of larvae.
In fact, only filaria parasitize the lymphatic vessels can cause elephantiasis.
Now people have been able to completely cure filariasis, and there are also special drugs.
For example, pyrimethamine is a very effective anti-filariasis drug!
Pyrimethamine is effective in killing filarial microfilariae and preventing it from multiplying in the body.
However, a few decades ago, this was just a luxury!