中医疫病的历史回顾

历代中医疫病基本认识

中医疫病的学术流派

中医人痘接种的历史

Retrospection of TCM History on Plague

The basic understanding of Plague by TCM

The schools of TCM on Plague understanding and treatment

Variolation in China: Pioneer of Modern vaccination

 

中医疫病的历史回顾

Retrospection on History of TCM Epidemiology

According to studies in Wuhan Hubei China, where COVID- 19 was first discovered, TCM has been used successfully in more than 92% of all patients suffering from COVID- 19. Good therapeutic effects totaling more than 91% have been found in the following aspects:

 

• TCM herbal prescriptions have been found to be effective in alleviating fever, shortness of breath and phlegm accumulation.
• Formulas improve general conditions, treat fatigue, headache, body aches etc.
• Formulas have been shown to have anti-viral, anti- inflammatory, and antitoxin properties.
• Formulas have also been found to improve immunity against the disease.
• TCM formulas have been found to be effective at improving microcirculation at the capillary level, they have anti-coagulation and anti-shock mechanisms, they stimulate protective responses of internal organs, they have been shown to prevent organ failure, as well as preventing disease progression and decreasing mortality rates.
• TCM formulas have been found to be effective at increasing the likelihood of a poor prognosis, reducing disease rebound and preventing the development of chronicity.
• TCM formulas have been found to be effective at treating sequelae such as pulmonary fibrosis, arrhythmias etc.
• TCM treatment has also been found to be effective at reducing the need for ventilators, ECMO, artificial blood exchange and lung transplants; thereby saving medical resources.
• TCM treatment may also reduce the incidence in affected areas by increasing immunity via the use of immune boosting herbs and by sanitizing the area via the use of herbal air disinfectants.

Beginning with protocols developed in Wu Han, the Chinese government listed TCM in the National COVID-19 Prevention and Treatment Protocol, Edition1-8, to apply TCM treatment for millions of people nationwide.

The outcomes of these various protocols, trials and treatment plans also give rise to the questions of why and how Traditional Chinese Medicine works on COVID-19. We have researched and studied the long history of TCM, and we have found that TCM’s effectiveness in treating COVID-19 is no coincidence. It is wisdom taken from thousands of years of medical practice and people’s struggle with epidemics that helped us in solving COVID-19 in China. In addition, this wisdom may help us to deal with future epidemics and so called X-diseases. This is the initial purpose and significance that inspired us to write this book.

Epidemic and infectious diseases have been on the earth far well before human beings. It is known that early humans and their microscopic counterparts have been battling as long as they have coexisted. In medical science, infectious diseases, especially epidemic diseases, have always been prevalent and ubiquitous. It is not an exaggeration to say that much of the medical knowledge scientists and doctors have garnered through history has come through the careful analysis of epidemic events.

Ancient TCM calls epidemics Wen Bing(温病Warmth induced disorder).  When epidemics or  pandemic happens, they’re called Wen Yi (瘟疫Plague). As early as the Shang dynasty(BCE 1250), plagues were recorded on oracle bones (甲骨文). The earliest known form of Chinese writing used on oracle bones (animal bones or turtle shells) read “sick, no enter”, meaning not to approach the sick, because of contagiousness.  After studying the oracle bone scripts and inscriptions on ancient bronze ware(钟鼎文), archaeologists believe that there was a strong understanding of contagiousness and of epidemics.  People in the Shang and Zhou dynasty (BCE1046-256) took measures to separate themselves from people that were showing signs of sickness. At that time, the lines between medicine and magic were thinly drawn and oftentimes there was considerable overlap. People generally believed that disease was caused by supernatural beings, therefore when epidemics happened, patients were separated from healthy people in the community and the ill were treated with combinations of dance, prayer, sacrifice and medicine.

周朝开始实行医官防疫官制度.《周礼•天官•冢宰》记载：“疾医掌养万民之疾病，四时皆有疠疾。”《周礼》记载了周王室定期举行“以索室驱疫”的时傩活动以及负责“四时变国火，以救时疫”的官员烧槐木大火以消毒救疫情。

During the Zhou dynasty there were already epidemic prevention officers monitoring people’s health. All year long they would set large fires to expel plagues in the city. Periodically they would empty the king’s family home to clear epidemics. These activities were recorded in the Zhou Ceremony Regulation officer’s book (周礼•天官•冢宰).

Following the Zhou dynasty were the Spring and Autumn Period and the Warring States Period (475-221BCE). The struggle between witchcraft and medicine reached its peak during this time. The writings of the legendary TCM doctor Bian Que (407-310BCE) were recorded around this period and this famous doctor refused to treat any patient who believed in witchcraft. Bian Que is largely considered to be China’s first physician. Many myths and stories are told about his life and practices. The publishing of the Yellow Emperor’s Inner Classic (黄帝内经) marked a significant historical event in TCM history, rooting their medical system in empirical thought and practice, while leaving the magic behind.

The Yellow Emperor’s Inner Classic written between the Warring States Period and the Han Dynasty (206BCE-220CE) is the first comprehensive and earliest TCM theory book, also the first book to explore an epidemic’s etiology, pathogenesis and treatment principle, as well as  formulas prescribed for disease patterns.

The Yellow Emperor’s Inner Classic contributed much to the understanding of how to diagnose and treat epidemic diseases, the characteristics of epidemic diseases. It described their onset, rapid spread, pattern of symptoms, and mortality rates. The Inner Classic explained how epidemic diseases often began with animals and insects living in rivers and seas.

The Inner Classic identified external factors such as wind, cold, heat, and dampness as mechanisms of epidemic diseases. Discussions between the Yellow Emperor and his chief physician Qi Bo also focused on concepts of immunity and prevention. Moreover, they discussed how to isolate sick patients to prevent the spread of disease. Much of their discourse remains relevant to the problems we currently face in the handling of modern epidemic diseases.

Not long after in the Eastern Han Dynasty, Zhang Zhongjing (150-219 A.D.) wrote his book the  Shang Han Za Bing Lun (Treatise on Cold Pathogenic and Miscellaneous Diseases). It is a monument to the understanding and treatment of infectious diseases, especially epidemics.  The book explored the concepts of onset and the transitions of cold induced diseases.  Cold induced disorders were the most common in Northern China during autumn and winter, mostly influenza, but other epidemics diseases such as acute gastroenteritis and dysentery were prevalent as well.

The Shang Han Lun described how epidemics can move through six stages. They begin in the Tai Yang superficial stage, then to the Shao Yang. They then move to the interior during the Yang Ming stage and, if unchecked, will eventually move into the three yin meridian stages Tai Yin, Shao Yin, and Jue Yin. It is when infectious diseases reach these yin stages that they become deadly.

The Shang Han Lun discussed many modern disorders such as Acute Bronchitis, Pneumonia, and Bronchial Asthma. The book also discussed more severe illnesses like Acute Nephritis, Myocarditis, Pericarditis, Reactive Thoracicitis, and Toxic Intestinal Obstruction. It went on to describe even fatal diseases such as Acute Kidney Failure, Shock, Heart Failure and Respiratory Failure.

The Shang Han Lun established one of the earliest diagnostic methods of TCM. The Six Meridian Differentiation of Syndromes system became a great tool to analyze and understand epidemics. It embodied the most predominate characteristics of TCM. At the time, it was an incredibly advanced system which differentiated TCM from other Medical science systems. Because of this Zhang Zhongjing is considered the father of TCM diagnosis and differentiation of epidemic diseases.

The Shang Han Lun created and recorded many effective formulas as standardized treatment for epidemic diseases.  Unlike his predecessors and peers, who commonly used single herb formulas, Zhang Zhongjing started to advocate the use of combined formula, which is more effective and has much less side effects. Proven by almost two thousand years of clinical practice on millions of people, his formulas, 314 in total, are considered classic formulas.

It was Zhang Zhongjing who definitively fingered out that febrile diseases, especially epidemics, are the most important diseases in mainstream Medical science. He described other diseases as miscellaneous and advocated that elite doctors study the most advanced compounded formulas in order to fight coming epidemics. Finally he created the Shang Han school, becoming the most predominate figure in TCM history, and being called a Medical Sage.

For two thousand years, his formulas have not only been held as secret in folk medicine, but they are also kept in a golden cabinet in the Emperor’s Forbidden Palace as the state’s most precious medical documents.  Later on, this information spread to many Asian countries, and were repeatedly re-edited and published in China and abroad as text books by the National Health Administrations of Korea, Japan and Vietnam. Because of Zhang Zhongjing’s work, TCM became integral in protecting people in East Asia from diseases like influenza. Formulas like Ma Huang Tang, Gui Zhi Tang and Xiao Chai Hu Tang were for the first time in medical science history using natural anti-virals, antipyretics and analgesic compound formulas to treat epidemic diseases.

We always say that Traditional Chinese Medicine grew to maturity by struggling with plagues. Zhang Zhongjing’s Six Meridian Syndrome Differentiation system is still the most important method to analyze and understand the treatment of epidemics. It has been applied for diseases such as Measles, Scarflet Fever, Influenza including H1N1.SARS. And this system has been currently applied to the treatment of COVID-19. All have significant efficacy and have been officially recommended in the China National Protocol of Prevention and Treatment of COVID-19 (1^st-8^th editions). TCM epidemiologists believe that Shang Han Theory will be effective in treating for X-diseases in the future.

Studies have shown that a total of more than 352 recorded plagues have occurred in more than two thousand years of China’s history.  Many were caused by wars between kingdoms which caused mass migration and hunger. Ethnic integration and commercial exchanges during peace time resulted in growing concentration of populations and the urbanization process.  This was noted between the domestic and foreign exchanges of the northern nomads and the southern farming civilizations.

During the Jin Dynasty, Dr.Ge Hong(283AD-343AD) wrote A Handbook of Formulas for Emergencies 肘后救卒方. He created the concept of first aid in TCM, recorded cases of smallpox from captives of the Hun people.  The Hun people had struck terror into east Europe and spread this horrible plague. He also recorded methods of applying rabid dog’s brain tissues onto the wounds of patient in order to treat rabies, and using single sweet wormwood for malaria treatment. Based on these TCM methods, Dr.Tu,Youyou of China successfully developed an Artemisinin injection, which remains the only effective anti-malaria drug now. She won the 2015 Noble Prize in Physiology or Medicine.

Sun Simiao (581AD-682AD), the emperor’s family doctor during the Sui and Tang dynasty, pointed out “plague and miasma come from heaven and earth, they can be prevented and treated by products of nature. He created a lot of effective formulas for epidemics which were recorded in his book Prescriptions worth thousand gold for emergency 备急千金要方 and the Tang Goverment Materia Medica 唐本草, the first pharmacopeia in history.  He was considered China’s King of Medicine for his significant contributions to Chinese Medicine and tremendous care to patients at all social levels

The Song dynasty was the most prosperous imperial dynasty of China (960AD-1279AD). The imperial publishing house re-edited the Treatise on Cold Pathogenic and Miscellaneous Diseases which had been lost for hundreds of years. The health administration issued The Formulas Pharmacopoeia便民和剂局方, 圣济总录, This contained several formulas for plague, like Three Treasure Formulas for Unconsciousness due to Brain Damage, the Peace Palace bezoar pill, and the Blue Snow Pill and Top Treasure Pill安宫牛黄丸,紫雪丹,至宝丹.

 

Liu,Wansu, one of the four most predominate TCM doctors, stated “all evil qi will eventually transform into interior fire, we should clear interior heat and fire with cool and cold herbs”. This concept deepened the understanding of how cold-induced disease mechanisms behaved and offered a strong platform of understanding for subsequent doctors who created and abided in the theories of the so-called Wen Bing or warm-induced schools of thought.

During the Ming Dynasty (1368-1644), the greatest pharmacologist in TCM history Li Shizhen (1518-1593AD) developed air sanitization methods by steaming vinegar, and he created methods for disinfecting surfaces by cooking in water, earlier than pasteurization which was created in France in 1862.

Unlike the Song dynasty, at end of the Ming dynasty and at the beginning of the Qing Dynasty, doctors started to challenge the Shang Han School theory which focused on cold-induced plagues. After the Qing dynasty, the Manchu conquered China which resulted in a growing concentration of population and urbanization. In particular, the northern nomads and the southern farming civilizations had integrated. More people lived in southern China in large cities along the Yangtze River where the weather is hot.  China’s population was 150 million at end of the Ming Dynasty. During Emperor Qian Long’s reign, the population reached 200 million, and finally reached 400 million in 1833. These increases in population created more frequent commercial exchanges, and along with the warm climate, came more warm-induced plagues.

Wu Youke (1582-1652) figured out that epidemic plagues are not caused by wind, cold, or anything else but by evil qi戾气, and each disease is caused by a particular evil qi.  These evil qi affect human beings and animals differently. He also figured that disease vectors enter the human body through the nose and mouth. His academic viewpoints are the closest to modern medical science. Two hundred years later, with Antonie van Leeuwenhoek’s invention of the microscope in 1828, German scientist Christian Ehrenberg identified bacteria and other microbes as disease causing agents. While is was understood that viruses were involved in causing diseases in humand well before, viruses as a distinct entity came to light only during the late 1800s.

His book Warm plague treatise瘟疫论 is a milestone within the Wen Bing School and his formulas like Da Yuan Yin have been popular, even for COVID-19 it is very effective.

During the Qing Dynasty in southern China, the Wen Bing school grew rapidly. Some key figureheads are Ye Tianshi (1667-1747), Xue Shengbai (1681-1770), Wu Jutong (1758-1836), Wang Mengying(1808-1863).  These four masters of the Wen Bing school discovered the concept that epidemics often occur during the spring or summer season and they include Influenza, Epidemic Meningitis, Encephalitis, Epidemic Hemorrhagic Fever, Measles, Chickenpox, Scarlet fever etc. They formed the Wei,Qi Ying,Xue Syndrome Differentiation and Treatment System as well as the Three Jiao Differentiation and Treatment system, the core theories systems of Wen Bing School.

Titled as the Number One Master of Wen Bing, Ye,Tianshi’s books Febrile disease treatise 温热论, and Clinic Guidance From Cases 临证指南医案 contain the Wen Bing School’s fundamental theories. He demonstrated the Wen Bing School’s common aetiology, pathogenesis, routine of contact, location, transmission and prognosis, and principle of treatment. He pointed out that warm evil qi first attacks the lung in the upper part of the body through the mouth and nose, initially at Wei Level. Then it enters the Qi level, recovery with desirable prognosis for many cases is expected. However, for seniors or people with poor constitution, disease may  then enter the Ying level and eventually the blood level. There will be apparent bleeding, then obstruction syndrome and collapse syndrome and an adverse prognosis. This theory very clearly describes the linear progression of epidemics through onset, develop, and then complications of Disseminate Intravenous Coagulation (DIC). The treatment of DIC includes cooling the blood, moving blood, breaking clots, and improving capillary blood circulation. Even from today’s perspective, this theory is still very advanced, especially for critical cases of epidemics.

Xue,shengbai’s Dampness-Heat Disease Chapter 湿热病篇systematically recorded damp-heat epidemics’ manifestations and characteristics of pulse and tongue in detail. It also includes treatment formulas. Wu,Jutong officially created the Three Jiao Syndrome Differentiation and Treatment System. He discovered that epidemics caused by damp-heat always began in the upper Jiao lung, then Middle Jiao spleen and stomach, then Lower Jiao liver and kidney may be damaged. He created several formulas which correspond to the patterns. His book Detailed analysis on febrile diseases 温病条辨became one of most remarkable documents of the Wen Bing School, also because of his most popular formulas like Ying Qiao San, Sang Ju Yin, Qing Ying Tang, Xi Jiao Di Huang Tang Etc.

Early TCM Epidemiology tended to be quite rigid and needed to mature. Cold-induced disease were treated using the concepts in the Shang Han School of Six Meridian Syndrome Differentiation and Treatment system, while warm-induced disease were treated with the Wen Bing School theories and the Wei, Qi, Ying, Xue and Three Jiao systems. Those systems became standardized tools used to analyze and treat different epidemics.  In later generations, Wang Mengying was the first doctor who integrated the Shang Han and Wen Bing Schools’ theories, he used Shang Han theory as longitude, Wen Bing theory as Latitude. In the spirit of integration he wrote his book Longitude and Latitude of Febrile diseases 温热经纬. His ideas contributed greatly to TCM, especially for epidemics. Doctors of later generations all followed his laws and from there considered cold and warm theory as one.

From the Ming and Qing Dynasties, medical science in Europe which has been called Western Medicine was developing rapidly. Religious missionaries brought the knowledge into China. After bacteria was discovered, antibiotics like sulfas and penicillin were developed as well as vaccines. Scientist had a much better understanding of epidemic diseases like dysentery, tuberculosis, smallpox. These diseases that disturbed human beings for thousands of years were now totally under control, they became treatable and curable, Western Medicine spread all over China, people believed blindly and optimistically that all problems could be resolved.

Over time, we suddenly find that the frequency of epidemics remains unchanged and have even increased worldwide. New diseases, especially one from viruses keep coming. Traditional Chinese Medicine, as a well accepted medicine, with its wide natural sources, less side effects, and perfect efficacy, has made great contributions and is being used along with Western Medicine. This is called Combination of Chinese Medicine and Western Medicine中西结合 for more than a hundred years, A movement called Modernization of Traditional Chinese Medicine 中医现代化has been active in the last sixty years in China with multitudinous achievements.  One of those is the capillary blood circulation theory and clinic practice. In 1983, Professor Xiu Rijuan discovered in her research that capillary blood circulation was disturbed profusely in serious infectious diseases like Epidemic Hemorrhagic Fever, Meningitis, Encephalitis etc in their critical stages. Anisodamine (654-2), an active ingredient extracted from Chinese Herbal Medicine Yang Jin Hua (Datura Flower) 洋金花 can significantly improve blood flow perfusion by inhibiting platelet gathering and relaxing blood vessel spasms. After extended use of her method, epidemics’ mortality rate due to internal organ failure and acute circulatory shock decreased dramatically.

In over half a century of TCM modernization, thousands of Traditional Chinese Herbal Medicinals have been extracted by modern techniques and have been tested by pharmaceutical researchers. Formulas have been made into modern preparations like injections, many have anti-viral, anti-bacterial and anti-toxicity properties. Many of these have been  applied in the clinical environment to treat infections and/or epidemics effectively for diseases like H1N1, SARS, and COVID-19.

The most representative one is the Artemisinin injection by Dr.Tu Youyou.  Since1965, she has worked at the China Academy of Traditional Chinese Medicine.  After years studying ancient TCM documents and extracting active constituents, she successfully developed an Artemisinin injection. It is one of the only effective anti-malarial drugs after Quinine which was from a plant as well. This injection is extremely effective and has improved millions lives every year worldwide. In 2015 she won the Nobel Prize in Physiology or Medicine for her discoveries concerning a novel therapy against Malaria. At the ceremony at the Royal Swedish Academy of Sciences, she said “this is a gift from Traditional Chinese Medicine to all the world”. People believe that this is a milestone recognizing TCM’s value and the wisdom of thousands of years of practice.

It is worth noting that these are standardized laws developed over thousands of years of clinical practice, whether we are talking about the Six Meridian System, Wei, Qi, Ying, Xue Four Level System or the Three Jiao System. These systems have been created and developed through careful observation, meticulous categorization of research and clinical data, and exhaustive analysis of pathogenesis, treatment strategies, disease combinations, pattern differentiation over a very long time. This is how and why we are able to understand and create treatment strategies for new epidemics and pandemics like H1N1, SARS, MERS, andCOVID-19 or X-diseases in the future.

The so-called classical or experiential formulas were created based on unremitting clinical practice using a vast number of samples on a massive scale used inside human bodies. This is the most reliable evidence-based and logical reason that TCM can be applied in the fight against modern epidemics.

历代中医疫病基本认识

The basic understanding of Epidemics by TCM

Traditional Chinese medicine constantly explores the epidemiological characteristics and treatment methods of epidemics.  All generations of Chinese medicine practitioners have been unrelenting in their exploration of epidemiological characteristics and how to treat them. They formed a set of systematic methods and can be summarized as follows:

 

1. Precondition of plague onset

瘟疫的条件: 战争: 凶年之后必有温疫《老子》,李东垣在《内外伤辩惑论》中记载天兴元年开封大疫: 解围之后, 都人不知受病者, 万无一二. 人口流动: 《景岳全书》瘴气感人,途者十之八九. 盖因: 居者安静, 途者劳伤. 贫困营养不良: 瘴气唯染劳役伤饥之人. 《景岳全书》

自然地理: 天运化疫,地运化疠. 人谓岭南水泉草木地气有毒, 故凡往来岭南之人, 及官而至者, 无不病瘴而至危殆者也. 《景岳全书》

气候条件: 凡时行者,春应暖而复大寒,夏应热而反大凉,秋应凉而反大热《伤寒论》.

Traditional Chinese Medicine realized very early on that the onset of epidemics were related with natural factors. In the Yellow Emperor’s Inner Classic it is said  that Heaven and Earth generate plagues.

 

Weather abnormalities: This is the most important factor in TCM. Zhang Zhongjing in his book the Treatise on Shang Han东汉.张仲景.伤寒论 said that seasonal plagues often happen when spring should be warm but is cold,  when summer should be warm but is cool, and when Autumn should be cool but is hot.

 

Geographic factors: In general, cold-induced plagues are far less prevalent than warm-induced plague, therefore in southern China, especially the deep south tropics or subtropical zone, plagues happens much more often. In the Ming Dynasty, Zhang Jinyue described that there is toxic qi among the mountains and water in the deep southern zone. businessmen, traveler even officer travel there actually at risk.

 

Social conflicts:  Wars and population migration are very important factors. “There must be warm plague after an inauspicious year” for example war and/or famine said Li Er in Dao De Jing, and Zhang Jingyue found that eight or nine out of ten people contracting plague are travelers in foreign territory. He stated this in his book Jingyue Comprehensive books 明代.张景岳. 景岳全书.

 

Human body’s weak constitution is always the inner reason: Zhang Jingyue said Miasma Plague can be contagious only due to over-exertion and starvation in his book Jingyue Comprehensive books 明代.张景岳. 景岳全书.

瘴气唯染劳役伤饥之人

 

TCM first discovered Intermediate Hosts, the earliest in Medical Science History. Infectious diseases not only move from person to person, but also from animal to person, even plants to person (unapproved). Many animals are intermediate hosts, and studies have shown that 60-70% of epidemics are common diseases shared between humans and animals, called Zoonosis.

The Yellow Emperor Inner Classic quoted the Upper Classic by Shang Shi which states “Plague could not exist and spread without being hosted by scaled or shelled creatures in rivers and seas, by plume and wing on insects or beast. Bloody jaundice always arrive by contagions from one either in water or on earth”. It clearly pointed out that animals are intermediate hosts of epidemics.

《上经 尚时》曰：瘟之至也，非江海鳞甲之类而不生。疫之至也，非虫兽毛羽而不存。血黄之至，非染于水旱两动而不形。

Traditionally in TCM, there are animal miasmas like birds miasma, Duck miasma, Goose Miasma, Hornet Miasma, even pets like Peacock Miasma.

Zhang Zhongjing said that if domestic fowl die by themselves, most likely due to disease, they become poisonous, so they should not be eaten. He also warned people to not eat wild cats (found to be an intermediate host for SARS), avoid fruits that have fallen on the ground after they have been bitten by insects, because they are poisonous. In the Synopsis Prescriptions Of Golden Chamber, Li Shizheng directly warned us not to eat Bat (widely considered an intermediate host for COVD-19) in his Compendium of Materia Medica本草纲目. In the Ming Dynasty, he advocated eliminating rats, mosquitoes and flies. Later on, he became famous for the Eliminate Four Pests Movement nation-wide at the end of 1957 in China. Knowing that mosquitoes were  such an important intermediate host, mosquito nets and curtains date back to the Han Dynasty.

消灭中间宿主:  汉代:已经有蚊帐.灭鼠蒼蝇蚊子《本草纲目》.

动物传人: 动物瘴(蛇,鸟,孔雀,鸭鹅,蚯蚓,黄蜂)

六禽自死皆疫死,则有毒,不食《金匮.禽兽鱼虫禁忌病治》警告:狸肉漏脯有毒,果子落地经宿,虫蚁食之者,大大忌之. 《本草纲目》告诫不得食用蝙蝠: 蝙蝠性能泻,治病可也,服食不可也.

植物传人: 桂花瘴, 菊花瘴.

Routine of plague transmission: TCM realized very early on that one could get sick by food through the mouth, or the air through breathing, body contact, or sexual transmission. (Ying Yang Yi 阴阳易。伤寒论。Han Dynasty. Shang Han Lun).

As Dr.Wu Youke (Qin Dynasty) said: “Evil Qi enters the body through the mouth and nose smoothly, through the breath”. And Dr. Yuchang (Qin Dynasty) also said: “Dirty Evil Qi easily transfers from one to another by living in the same house and by sleeping together.

邪从口鼻而入…本气适逢亏欠,呼吸之间,外邪因而承之.《温疫论》.

室内传播: 况乎连床并塌,邪秽尤易相亲.(俞昌).

-Dr. Bai Song Zhong