Ask Sword

  Chapter 55 Malaria

  Control variable?

  All the people present were elite scholars who had received preparatory education in the academy. They just frowned and thought for a while, and quickly understood Li Ang's general meaning.

   "Is it mosquitoes, not evil spirits, that cause malaria?"

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

  Ji Linglang was thoughtful,

  Yang Yu looked at Li Ang curiously. Whether he was right or not, the theory that larvae mosquitoes cause malaria is a novel theory other than evil spirits, malaria ghosts, and disloyalty.

  The servant standing at the door, still maintaining a reserved and respectful posture, did not see any movement,

  Just moved his ears, as if he heard an order from the next room, he cupped his hands respectfully and asked, "So, little man, do you have any evidence?"

  "Evidence 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 each square city to inquire about the terrain conditions of each square city, and summarize the number of residents in the square city who have suffered from malaria and died of malaria.

  Residential areas with high terrain, no water, no grass and few mosquitoes around.

  Residential areas with high terrain, surrounded by water, grass and mosquitoes.

  Residential areas with low terrain, no water, no grass and few mosquitoes around.

  Low-lying residential areas surrounded by water, grass and mosquitoes.

  As long as enough cities are visited and the sample size is large enough,

   It is easy to find out if and how malaria is related to waterweed mosquitoes. "

"this"

   The servant frowned and said, "Isn't it too troublesome? Chang'an has 108 squares, with a population of 3 million."

   "Your master asked, and I was just giving a suggestion."

  Li Ang said casually: "There are also ways to get the result 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 in Chang'an.

  These ditches are about one foot wide, and they are open ditches exposed to the sun.

   Coupled with the slow water flow, mosquitoes can easily lay eggs in the ditch, hatch larvae, and produce more mosquitoes.

  In order to prescribe the right medicine, first select a large square city, and cover the drainage ditch of the square city with bluestone slabs, turning the open ditch into a dark ditch.

  In the dark ditch, a hollow wire baffle is set at intervals, and between the baffles, fork-tailed bettas from Lingnan Road are cultivated.

  There is no fork-tailed betta, and mosquito-eating fish such as herring are also fine.

   Then ordered to prohibit pedestrian fishing.

  Thus reducing the mosquito breeding caused by the drains.

  Then distribute mosquito nets, mugwort and Artemisia annua to the residents.

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

   Mugwort and Artemisia annua are used to fumigate adult mosquitoes,

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

  Completed a whole set of procedures, and finally waited until the malaria disease appeared in summer and autumn, and compared this square city with other square cities that did not set up underground drains and did not kill mosquitoes.

  See which Bianfang city has a lower rate of malaria.

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

  It is now June, and if you act now, you will see initial results in about three to four months. "

  Li Ang talked calmly, "By the way, when summarizing at the end, we must exclude the monks' residences in the market."

  The servant asked in surprise, "Why?"

   "Because the monks breathe and breathe, they automatically drive away the mosquitoes flying around, and rarely get sick, so it can be regarded as a factor that will interfere with the results."

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

  In fact, it’s only half a month before the school exam, so it’s really troublesome to find a high-end residence with a higher terrain in the north of Chang’an City.

  But as a doctor, Li Ang, the more he understands the disease, the more he is in awe and fear of the disease.

  Malaria is one of the diseases that killed the most people in the history of other worlds. It can be said that the history of mankind is the history of malaria.

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

  Yes, the merozoites transformed from 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 mosquito, they will reproduce in the mosquito and form a "gamete", and the gamete will become a "kinetic" and enter the mosquito's stomach wall to form an oocyst, and finally pass asexual reproduction Become "sporozoites", actively enter the mosquito saliva, and start the next round of infection transmission.

  The whole process is extremely cumbersome and complicated, and it can be called weird and exquisite.

  For humans, the garbage 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 40 million people in Yu State, 4 million people suffer from malaria every year, and a large part of them are under five years old and have not developed sufficient immunity of children. '

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

   Even if it is not malaria, mosquito bites may also transmit epidemic Japanese encephalitis, dengue fever, filariasis, and yellow fever—Changan City, Wan Guolai,

  Businessmen, livestock, and wild animals from all over the world may become the source of disease. "

  Before he became a monk and had basic disease resistance, Li Ang didn't want to test his resistance to infectious diseases at all.

   Seeing what Li Ang said was orderly, the servant standing at the door became more respectful, cupped his hands and said: "My master said that if you suffer from cold in winter, you will have febrile disease in spring, you will suffer from heat in summer, and you will suffer from malaria in autumn.

  Autumn is coming soon, maybe there is not so much time,

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

   "Faster?"

  Li Ang raised his eyebrows, thought for a while and said: "Then spend a lot of money, and ask monks who specialize in talisman Taoism to listen to the rain and patrol the clouds to write down the breeze talisman.

  Distributed to ordinary residents.

  The Breeze Talisman can summon the breeze and repel mosquitoes, and it can also have the effect of preventing mosquitoes, but it is costly. As far as I know, asking the monks in the cloud patrol to spend energy writing Zhang Talisman, no matter how you start, you have to start. "

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

"Um?"

  Song Shaoyuan frowned and said, "Why is your master so aggressive?

  We were just chatting privately, so it’s fine if you knock on the door to interrupt,

  Now my classmate has given two strategies, but you are still aggressive. Isn't this a bit inappropriate? "

   Although Song Shaoyuan has a loyal personality, he is not stupid.

  The identity of the other party was unknown, and he sensibly did not say Li Ang's name, and only called Li Ang a "classmate."

  Zhai Yiming hesitated for a moment, and then chimed in.

  Although he is usually a little jealous of Li Ang, but no matter what, he is still a classmate from the same hometown, and he can't watch his own people being bullied under the eyes of outsiders.

  “.”

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

  I just want to remind you that what people are doing is what God is watching.

   Please come back. "

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

  The other party bowed extremely respectfully to the end, then turned and left.

"Um?"

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

   "What else could it mean,"

   Li Ang said indifferently: "If you want to find out the connection between malaria and mosquitoes as quickly as possible, even before autumn comes and malaria breaks out in the city,

  Then there is only one way.”

   "Direct proof."

  Ji Linglang elegantly picked up a piece of vinegar celery, and added the next sentence for Li Ang, "Using the method of controlling variables, prove the relationship between malaria and mosquitoes."

  ——

  In the next room, Qiu Jing, the medical officer of the imperial medical department, looked at his friend across the table with an angry face, slapped the table and shouted: "Tantai Leshan!"

  Scholar Siye named Tantai Leshan sat upright, accepting his friend's anger calmly, "Brother Qiu, why are you angry?"

  On the wall of the box room, a piece of [Soundproofing Symbol] has been pasted, which can isolate the sound of the conversation between the two, so Qiu Jing didn't suppress his voice, and directly shouted: "What the **** are you trying to do?!"

  (end of this chapter)