ask sword 2

Chapter 55 Malaria
control variable?

All the people present were elites who had received the preparatory education of the school, and they just frowned and thought for a while, and quickly understood the general meaning of Li Ang.

"Mosquitoes, not evil spirits, cause malaria?"

Song Shaoyuan and Zhai Yiming widened their eyes and muttered to themselves,

Ji Linglang was thoughtful,
Yang Yu looked at Li Ang curiously. Regardless of whether he was right or not, the theory that larvae caused malaria is a novel theory other than evil spirits, malaria ghosts, and infidelity.

The servant standing at the door still maintained a stern and respectful stance, but there was no movement.
He just moved his ears, as if he heard an order from the next room, and asked respectfully, "Then, Xiao Langjun, do you have any evidence?"

"Evidence, it can also be obtained by controlling variables."

Li Ang thought for a while and said, "If your master has leisure time, you can send someone to visit and inquire about each square city, look at the topographical conditions of each square city, and summarize the number of residents who have suffered from malaria and died of malaria in the square city.

A residential area with high terrain, no water, no grass and few mosquitoes around.

A residential area with high terrain and surrounded by water, grass and mosquitoes.

A low-lying residential area with no water, no grass and few mosquitoes around.

A low-lying residential area surrounded by water, grass and mosquitoes.

As long as there are enough towns visited and the sample of people is large enough,

It's easy to find out if and how malaria is linked to aquatic plant mosquitoes. "

"This"

The servant frowned and said, "Isn't it too troublesome? One hundred and eight squares in Chang'an, with a population of 300 million."

"Your master asks, and I'm just giving a suggestion."

Li Ang said casually: "There are also ways to get results faster.

When I visited Chang'an just now, I noticed that there are drainage ditches and small bridges on one or both sides of the streets of Chang'an.

These ditches are about ten feet wide, and they are all open ditches exposed to the sun.
Coupled with the slow flow of water, mosquitoes can easily lay eggs in the trenches, hatch larvae, and produce more mosquitoes.

In order to prescribe the right medicine, we must first select a large area of ​​Fangshi, cover the drainage ditch of Fangshi with bluestone slabs, and turn the open ditch into a dark ditch.
And in the underdrain, a hollow wire baffle is set at intervals, and between the baffle and the baffle, the fork-tailed betta from Lingnan Road is raised.

No fork-tailed betta, mosquito-eating fish like herring will do.

Pedestrian fishing was banned.

Thereby reducing the mosquito breeding due to the canal.

Mosquito nets and mugwort and artemisia annua were then distributed to the local residents.

Mosquito nets are hung in the bedrooms of adults and children, especially children under the age of five, when sleeping at night,

Mugwort and Artemisia annua are used to smoke and kill adult mosquitoes.

In addition, dispatch people to eradicate low-lying pools and weeds that breed mosquitoes in the markets.

A whole set of processes is completed, and finally, when the malaria disease in summer and autumn appears, compare this square market with other square markets that have not set up underdrains and have not killed mosquitoes.
See which side of the city has a lower chance of malaria.

It is natural to know the link between malaria and mosquitoes.

It is June now, and the initial results will be seen in about three or four months. "

Li Ang spoke calmly, "By the way, in the final summary, we must exclude the monks' residences in the market."

The servant asked in surprise, "Why?"

"Because the cultivator breathes and breathes, it automatically drives away the mosquitoes flying around, and rarely gets sick, so it is a factor that will interfere with the results."

Li Ang said lightly, picked up the chopsticks again, and put a piece of vinegar and celery for Chai Cuiqiao.

In fact, it is only half a month away from the first exam of the Academy. It is really troublesome to find high-end residences with higher terrain in the north of Chang'an City.
But as a doctor, the more deeply Li Ang understands the disease, the more in awe and fear of the disease.

Malaria is one of the diseases that kills the most people in the history of the different world. It can be said that the history of mankind is the history of malaria.

Some mosquitoes carry a single cell called Plasmodium. When a mosquito bites a human body, the Plasmodium enters the human body, infects the liver, produces thousands of new parasites in the liver, and then begins to invade and infect blood. Red blood cells further divide, multiply, and degenerate.

That's right, merozoites transformed by Plasmodium will differentiate into male and female, and can survive in the human body for 60 days.
Once the male and female merozoites are re-inhaled by the mosquitoes, they will multiply in the mosquitoes to form "gametes", and the gametes will become "kinetic zygotes", enter the mosquito's stomach wall to form oocysts, and finally reproduce asexually. It forms "sporozoites" and actively enters the saliva of mosquitoes to start the next round of infection.

The whole process is incomparably cumbersome and complicated, which can be called strange and exquisite.

For humans, the rubbish released by the malaria parasite in the body will cause the body's immune response, resulting in alternating hot and cold, continuous sweating, and anemia, splenomegaly, and organ failure after repeated attacks.

'Even if calculated according to the most optimistic 1% malaria incidence rate, with a total population of 400 million people in Yu State, [-] million people suffer from malaria every year, and a large part of them are under five years old and have not developed sufficient immunity child. '

Li Ang thought silently: "Without effective treatment, the mortality rate of falciparum malaria is as high as 40%.

And even if it is not malaria, mosquito bites may also spread Japanese encephalitis, dengue fever, filariasis, yellow fever - Chang'an City, Wan Guoli,

Traders, livestock, and beasts from all over the world may become the source of disease. "

Before becoming a monk and possessing basic disease resistance, Li Ang didn't want to detect his resistance to influenza diseases at all.

Seeing what Li Ang said was orderly, the servant standing at the door became more and more respectful and said, "My master said, "In winter, you will suffer from cold, but in spring, you will be febrile. In summer, you will suffer from heat.

Autumn is coming soon, there may not be so much time,

I would like to ask Xiao Langjun if there is a faster way to detect the association between malaria and mosquitoes. "

"A little faster?"

Li Ang raised his brows, thought about it, and said, "Then spend a lot of money, ask the monks in the Tingyu realm and the cloud patrol realm who specialize in Talisman Dao to write down the Qingfeng Talisman.

Distributed to local residents.

The Breeze Talisman can summon the breeze and drive away mosquitoes, and it can also have the effect of preventing mosquitoes. "

The servant still maintained a respectful attitude, "Is there a faster way?"

"Ok?"

Song Shaoyuan frowned and said, "How can your master make such an inch?

We were just chatting in private, so you can knock on the door to disturb you.

Now my classmates have given two strategies, but you are still aggressive. This is a bit inappropriate, right? "

Although Song Shaoyuan has a loyal personality, he is not stupid.
The identity of the other party was unknown, and he rationally did not name Li Ang, but only called Li Ang a "classmate".

Zhai Yiming hesitated for a while, and followed suit.

Although he is usually a little jealous of Li Ang, he is still a classmate from the same town, and he can't watch his own people being bullied under the eyes of outsiders.

"."

Li Ang looked at the servant, his eyes quickly turned cold, and said indifferently: "Since your master already knows the answer, why do you need to ask?

Let me just remind you that people are doing it, and God is watching.

Please come back. "

After that, Li Ang flicked his sleeves and stopped looking at the servant.

The other party also bowed very respectfully to the end, turned and left.

"Ok?"

This time, it was Song Shaoyuan's turn to be puzzled, and subconsciously asked Li Ang: "What do you mean by saying to that servant that his master already knows the answer?"

"What else could it mean,"

Li Ang said indifferently: "I want to figure out the connection between malaria and mosquitoes as quickly as possible, even before the arrival of autumn and the outbreak of malaria in the city.
There is only one way."

"Direct proof."

Ji Linglang elegantly picked up a piece of vinegar and celery, and added the next sentence to Li Ang, "Prove the relationship between malaria and mosquitoes with that method of controlling variables."

----

In the next room, Qiu Jian, the medical officer of the Imperial Physician's Office, looked angrily at his friend across the table, patted the table and shouted, "Tantai Leshan!"

Xue Gong Siye, named Tantai Leshan, sat on the spot and calmly accepted his friend's anger, "Why is Qiuxiong angry?"

On the wall of the private room, a [soundproof talisman] has been pasted, which can isolate the sound of the conversation between the two, so Qiu Jian did not suppress his voice, and shouted sharply: "What the hell are you trying to do?!"

(End of this chapter)