Topic and Speakers
“A comparison of cholera epidemics in 19th -century London and Tokyo: Usage of rivers, canals, and water in everyday life”
　• Akihito Suzuki (Professor, Tokyo University Graduate School of Humanities and Sociology)
　• Naoki Odanaka (Professor, Tohoku University Graduate School of Economics and Management)

“Comments from the perspective of Japanese history: Using Sendai as an example”
　• Atsushi Kawauchi (Associate Professor, Tohoku University International Research Institute of Disaster Science)
　• Kazuo Takehara (Assistant Professor, Tohoku University Center for Northeast Asian Studies)

●“A comparison of cholera epidemics in 19th -century London and Tokyo: Usage of rivers, canals, and water in everyday life”
Akihito Suzuki (Professor, Tokyo University Graduate School of Humanities and Sociology)

〇Introduction
A Key Feature of Medical History: “Old Medical History” and “New Medical History”
　“Old Medical History” mainly studied prominent physicians, especially in Germany, since the start of the 20th century and the field of study provided many valuable insights. Those works became an important foundation for the establishment of “New Medical History.”
　A key feature of “New Medical History,” established in the 1970s, is that it does not simply analyze the history of medicine and medical science, but takes into consideration the broader social and cultural context. This field has developed closely with the field of general and social history. One important concept is the “Hippocratic triangle,” which states that medicine is structured upon the interrelationship between disease, patient, and medical personnel. The elements that lie behind those three factors include law, policy, economics, science, technology, environment, thought, and culture: all of which contribute to forming the holistic perspective of “New Medical History.”

〇The Historical Background of Cholera
　Cholera is an acute oral infection caused by Vibrio cholerae, discovered by Robert Koch in 1884, transmitted through water and food. Although it was originally endemic around the Ganges River, it spread globally via British soldiers in 1817, with the seventh wave of the epidemic continuing to this day.
　During the 19th and early 20th centuries, many regions, including Europe, the US, and Japan experienced and overcame the cholera epidemic. That was when socioeconomic transition occurred, including revolution; introduction of democracy; industrial revolution; formation of nation-states; and colonial policies, all of which affected cholera epidemics and countermeasures.
　In the early 20th century, a mild type of cholera was identified in El Tur, Egypt. The outbreak was related to religious factors, such as El Tur’s being a pilgrimage site, and economic factors due to its proximity to the Suez Canal.
　The cholera epidemic and its control in the 19th century have been studied from multiple perspectives, resulting in a vast amount of valuable knowledge. Epidemiologically, although the cholera epidemic is not considered the most significant infectious disease in history, it is an epidemic that deserves special attention upon analyzing the history of infectious diseases in the 19th century.

〇Cholera and Public Heath in 19th Century London
　London experienced recurring cholera epidemics between 1831 and 1866. The 1831 epidemic resulted in many deaths, with approximately 10,000 victims between 1853 and 1854, and about 5,600 in 1866.
　A geographical feature of London is the wetland of the eastern part of the River Thames coast. In the 18th-19th centuries, flooding frequently occurred and unsanitary conditions prevailed. According to statistics from 1887 to 1900, about 70% of all floods in eastern England occurred in London. However, London overcame this issue in the 20th century.
　The flooding of the River Thames was associated with rapid population growth. London's population, originally 1 million in 1800, reached 3 million in 1850 and 6.5 million in 1900. This growth was due to the migration from the countryside as a result of the Industrial Revolution. Subsequently, factory effluent and waste polluted the river.
　With the advancement of statistics in the 18-19th century, diseases and urban issues came to be quantitatively analyzed. Politicians, physicians, and civil engineers cooperated to improve urban sanitation. In 1854, Dr. John Snow (1813-1858) statistically analyzed a cholera epidemic in Soho district and showed that differences in water companies had an impact on death tolls. He showed that contaminated water was the cause of cholera and advised improving water supply systems.
　To improve urban hygiene during “The Great Stink” of the River Thames in 1858, the civil engineer Joseph Bazalgette (1819-1891) took the initiative to improve sewerage utilizing water-pumping technology. As such, “water” played an important role in spreading and suppressing the cholera epidemic.
While the development of water pumping technology improved water-associated issues through improvements in sewerage systems, it also encouraged the construction of high-rise buildings and increased the risk of massive fires. In London, high-rise buildings caused major disasters, including the 1903 Mental Hospital fire to the 2017 Grenfell Tower fire. Thus, while water-pumping technology improved urban sanitation, it also created new challenges.

〇Cholera and Public Health in 19th Century Edo (Tokyo)
　Edo was artificially created at the end of the 16th century, with the west side being a plateau and the east side being a wetland. The wetlands were reclaimed and merchants lived in the downtown area, while samurai lived on the plateau.
　Kanda Josui and Tamagawa Josui were the most famous water supplies in Edo. Since wetland water was not suitable for drinking, water was drawn from ponds and springs in the plateau. On the contrary, four water supplies constructed later on (Senkawa, Aoyama, Mita, and Kameari Josui) were closed after the Great Edo Fire. This closure was because Murohatosu, a Confucian scholar, advised Shogun Yoshimune that water supply systems promoted fires.
　Unlike the cholera control measures in London, the industrial revolution did not exist in Edo, and water-pumping relied on manpower. Merchants kept quantity records, but there were limited advances in statistical knowledge. However, after the Meiji Restoration, European forms of public health were rapidly adopted, and after 1876, death tolls and patient numbers for legally contagious diseases became published by prefecture.
　Although there were several major cholera outbreaks in Edo, starting with a major epidemic in 1858, there was a considerable downward trend in the 1900s. Information dissemination through newspapers was thought to have played an important role in this decline. Newspapers printed in early Meiji quickly and (most probably) accurately reported details of the town-by-town infection status. The Yomiuri Shimbun recorded epidemics by town, which enabled the identification of outbreak regions.
　In the massive 1886 outbreak, the disease notably prevailed in the wetlands and downtown area, especially in Nihonbashi and Kanda, with areas near the riverbanks most affected. Riverbanks were centers of commerce and transportation but also places that were at constant risk of waterborne disease.
Relatively wealthy merchants and craftsmen lived in the front tenements of Edo, while the poor lived in the back. In the back tenements, dishwashing, laundry, face-washing, and defecation took place in very small, shared water spaces; thus, infectious diseases may have spread via usage of common water sources.
　Since the 1890s, Japan promoted waterwork-reforms based on European water supply systems. In Yodobashi, water-pumping facilities, sedimentation and filtration basins, water supply pools were installed and water pipes were converted to iron. Tap water was first supplied in 1898 and by the 1900s, it spread to central Tokyo, putting an end to a major cholera epidemic.
　In the meantime, sewerage system construction began in 1922, but progress was slow and could not keep up with Tokyo's rapid development. As the Sumida River became more polluted, dysentery cases continued to rise. Water pollution became a long-term issue, with fireworks festivals suspended due to stenches from the river.

〇Conclusion: Comparison of Cholera Control Measures in London and Edo
　In London and Edo, cholera death toll ranged from 5,000 to over 10,000.
　London successfully controlled cholera in the late 1860s, owing to discoveries by John Snow and the large-scale construction of sewerage systems. In Edo, on the other hand, waterworks reforms during the Meiji period greatly suppressed cholera infection in the 1900s.
　The commonality between the two cities was that rivers and shared water sources were deeply involved in the spread of infection, and cholera control was achieved through improvements in public health centered on waterworks development.

●Commentary 1
• Professor Naoki Odanaka (Professor, Tohoku University Graduate School of Economics and Management)

〇Background behind the commonalities/differences in the London and Edo cholera control measures
　Both cities are similar in that water supply construction played a central role in controlling cholera. This is a natural result in a way, since Japan followed the European approach to cholera control.
　In Tokyo (Edo), data for each town was disclosed through Yomiuri Shimbun. This disclosure may have triggered a change in people's behavior. In London, however, the main tactic was to carry out urban transformation, such as sewerage projects, to control nature with technology. These differences may be associated with the differing views of nature and disease in Japan and Europe, and it would be interesting to further discuss the topic from this perspective.
　Furthermore, in Edo, water supply construction progressed rapidly while sewerage construction lagged. In London, on the other hand, sewerage construction was crucial to infection control. This difference may be due to technological, social, political, and economic factors, but further study is required.

〇Examining the characteristics of the 19th century from various perspectives
　It is worth noting that there are both positive and negative aspects to controlling infectious diseases. In London, some pointed out that the development of water-pumping technology enabled the construction of taller buildings which also increased the risk of massive fires.
　On the contrary, “developogenic diseases,” in which infectious diseases spread as national development advances, have been under discussion in India. This is an example of how modernization negatively affected infectious disease control. Furthermore, the fact that cholera, originally endemic around India, turned into a pandemic with the intervention of the British military could be considered a negative aspect of colonization that emerged through infectious disease control.
　Behind infectious disease control in the 19th century lies the historical context such as industrialization, nation-state formation, imperialism, and colonization. We must examine both positive and negative aspects that these factors brought forth. In addition, we should also consider the underlying views toward disease and nature, and what significance they have in society. It is also important to analyze how they differ between the East and the West.

●Commentary 2: “Comments from the perspective of Japanese History: Using Sendai as an example”
Associate Professor Atsushi Kawauchi (Tohoku University International Research Institute of Disaster Science)

〇The Process of Water Supply and Sewerage Development in Sendai City
　Sendai is a smaller city than Tokyo, and between the end of the Edo period to the early Meiji period, it had a population of approximately 50,000. Despite its size, however, Sendai was one of the top 10 largest cities in Japan at the time, and it faced challenges similar to those in Tokyo.
　In Edo, while water-supply such as Tamagawa Josui was successfully constructed, sewerage construction was delayed. In Sendai, on the contrary, sewerage system development took the lead and its construction, which completed in 1912, was the third to be completed in Japan, following Tokyo and Osaka. In contrast, the construction of the water supply system was not completed until the Taisho period, and water supply to the city began approximately 10 years later.
　The following factors were listed in the document on “Rationales for budget proposal for water-supply survey,” submitted to the Sendai City Assembly in 1891:

1. Sanitary Issues Associated with Road Repairs
2. Frequent Flood Damage
3. Lack of Water for Extinguishing Fires
4. Irrigation Development for the Promotion of Modern Industry

〇Sendai’s Yotsuya Irrigation System
　The Yotsuya Irrigation System, which drew water from Hirose River and supplied it to the castle town, had been constructed in Sendai since the Edo period. That irrigation canal was used as water for daily life, fire prevention, and drainage, while water from wells were used for drinking. The town community, “Suika-Juhachimachi,” was responsible for cleaning and managing the water systems.
　 However, following the Meiji Restoration, as urban remodeling progressed, the Yotsuya water supply was downsized. Its management by the town community became inadequate and water became polluted. As a result, cases of house flooding during heavy rain increased and water pollution deteriorated hygiene. These issues arose during the transition from premodern to modern cities and were an example of how sanitary conditions deteriorated when the flow of water was redirected from the “front” to the “back” of the city in order to hide it.

〇Transformation of the Modern City and its Infectious Disease Response
　What the case of Sendai reveals is the importance of associating the process of infectious disease response with the spatial and social transformation of a modern city–based on industrialization and modernization of transportation–when analyzing infectious disease issues in Japanese cities during the Meiji period. Some research on urban history, especially the establishment and development of cities, require analysis from the perspective of medical history. For example, a “sanitary association” was formed in Kobe. There are studies that found that during the Edo period, sanitation management shifted from individual efforts by “householders” to the city government. Such social transformation is an essential perspective in considering the history of infectious disease response.

〇 A General View of “Modernity” and the Perspective of “Japanese Modernity”
　Infectious disease response in the modern era must not only be considered a general “modern” issue but must also be considered from the perspective of the unique nature of “Japanese modernity.” Japanese modernity was established on the basis of a premodern society. By examining its process of transformation, it may be possible to uncover Japan’s unique infectious disease model and its formation process, which largely differs from that of the West. Upon deepening this discussion, a comparison of London and Edo is extremely useful and thus, further discussion is expected.

●Commentary 3
Assistant Professor Kazuo Takehara (Tohoku University Center for Northeast Asian Studies)

〇Infectious Disease Control in Different Regions
　The point that topographical characteristics such as wetlands, plateaus, and riverbanks make a significant difference in the number of patients was striking. This demonstrates the importance of considering regional characteristics in infectious disease control.
　During the Meiji Era, following the cholera epidemic, sanitation policies in Japan rapidly developed. In 1877, Nagayo Sensai, known as the “father of sanitation,” submitted his “Opinion on Sanitation.” Sensai stated that sanitation measures should be tailored to local climate and culture, and that the national government should be responsible for overseeing all measures, while simultaneously taking measures in accordance with regional characteristics. This opinion relates in some ways to the debate over the balance between centralization of power and local autonomy.
　The system of “sanitary associations” mentioned by Professor Kawauchi is germane to this discussion as well. In 1887, the government recommended the establishment of sanitary associations, but the spread of such associations was challenging. Nonetheless, efforts to improve sanitation by local residents cooperating in cleaning and disinfection gradually spread, and the system functioned as a that based on cooperation and monitoring. Thus, efforts at the national level and efforts tailored to local characteristics is essential in the fight against infectious diseases.

〇The Significance of Irrigation Systems and Other Measures
　The prioritization of low-cost infectious disease measures such as quarantine, disinfection, delays in waterworks during the Japanese modernization process have received some criticism. Indeed, while waterworks development was effective in combating cholera, it was limited for typhoid fever and dysentery. This difference insists that measures limited to waterwork construction was inadequate, but a multi-layer approach was essential, including quarantine; disinfection; sanitation; and the dissemination of sanitary knowledge. Furthermore, the difference in the mortality rates between cholera, typhoid, and dysentery also influenced the difference in their transmission rates. Back then, the cholera mortality rate was as high as 60~70%, while that of dysentery was about 20~30%. Given the low mortality rate of dysentery, there was a tendency for its patients to conceal their infection, which became a reason for its spread. The difference in mortality rates was a key factor that significantly affected infectious disease control measures and public awareness of diseases.

●Discussion

〇Distinct Transmission Routes between Cholera, Typhoid, and Dysentery
　Professor Takehara spoke of the difference between typhoid fever and dysentery from the perspective of transmission routes. Since cholera is a waterborne infection spread through water, waterwork construction is an effective measure. On the other hand, typhoid fever is transmitted mainly through food. As in the case of Typhoid Mary, an infected person may continuously transmit the bacteria. Dysentery is mainly transmitted via fecal-oral transmission and can spread especially among households if handwashing is inadequate. Even with improved water systems, typhoid fever and dysentery will spread unless the overall hygiene is improved. These differences in transmission routes explain why cholera cases have decreased with improved water supply, as opposed to typhoid fever and dysentery.

〇The Endless 7th Cholera Pandemic
　Cholera was contained among the developed countries after the 1900s but continues to be a serious issue in middle- and under-developed countries, especially in Africa and Asia. In Kolkata (Calcutta), India, which is considered the epicenter of cholera, the annual death toll is estimated to be around 100,000even today. Lusaka, Zambia has also been experiencing annual epidemics of cholera, and its infrastructure construction has not caught up with the rapid urban population growth. Indeed, the seventh pandemic that began in 1961 is thought to be continuing to this day.

〇Water Environment of Edo and Cholera: Shallow Wells and Infection Spread Risks
　Fresh water supply in Edo relied on outside water sources such as Tamagawa Josui, provided through shallow wells, since Edo was a reclaimed area where fresh and sea water mixed. The water quality was particularly poor in the Fukagawa (downtown) area. However, in Shinjuku and Yamanote (uptown), groundwater filtered through Kanto District’s loamy layer was available, so people had access to naturally filtered water. This difference in water access impacted the sanitary environment of each region in Japan.
　In areas with many shallow wells and low-quality water, wastewater from bathrooms mixed with groundwater. The resulting unhygienic water environment is thought to have contributed to high cholera transmission.
　The Sumida River water level changes at high tide and waterways nearby Fukagawa are brackish. These brackish waters were endemic to cholera and increased risks of cholera transmission in highly populated areas.
　Overall, Edo and modern middle- and under-developed countries shared common water conditions which impacted the spread of cholera.

〇The Reality of “Sanitary Associations”
　The establishment of Sanitary Associations was recommended as an autonomous effort to improve sanitary conditions through the cooperation of local residents. However, in the 19th century, there were many cases where the system failed to function. Some believe the association did not provide a place where local residents could enjoy and actively participate in the activities. Rather, the association may have been perceived as a mandatory activity similar to community association board member activities.
　In castle and port towns where community association frameworks were clear and sanitary associations functioned to a certain extent, smaller-scaled organizations did not emerge. On the other hand, in rural areas, sanitary associations may have formed but its details are not well understood.

〇The Impact of Newspapers and Migration Desires
　During the Meiji Period, newspapers reported in detail the names of the wards and towns where infected people lived, which sparked people’s interest and desire to move to other regions. During the Edo period, residential areas were determined by social status, but in the Meiji period, people could freely migrate. For example, there are records of wealthy people living in Nihonbashi and Kyobashi wishing to emigrate. This suggests that information from newspapers triggered people to consider moving to new areas, leading to a major change in residential patterns as areas previously occupied by samurai and feudal lords became available and their residences were sold off.
　Such a change in settlement patterns within the city (“horizontal migration”) likely produced desires to migrate from the dangerous and poor environment of the wetlands and along the riverbanks to safer and more comfortable neighborhoods. Thus, information provided by newspapers had a significant impact on people's migration decisions.

〇Changes in Information Disclosure regarding Infectious Disease Measures
　The fact that data published at the town-level in the Yomiuri Shimbun influenced people's behavior, including migration, is full of implications. In the 1800s, the Ministry of Home Affairs produced detailed maps of cholera, and Tokyo city government published data by ward. Thus, the differences in mortality rates between downtown and uptown Tokyo were relatively well known.
　If one asks whether the situation faced during the cholera epidemic matches that of COVID-19, it does not necessarily seem to be the case. For example, in early modern Japan, detailed maps and patient information were recorded in what are known as “disease notes,” and information was widely disclosed in a way that would be considered problematic today in terms of privacy.
　In contrast, in the case of COVID-19, there in an impression g that detailed reports on disease transmission differences by region were restrained . Japanese media reported more carefully than the West, where newspapers have reported every regional difference in patient outbreaks within cities, prompting people to change their behavior. The transition in information disclosure regarding infectious disease measures in modern and contemporary Japan is intriguing.

〇Infectious Diseases during Edo
　Unlike 14-18th century Europe where infectious diseases such as plague recurred, Japan did not experience those types of infectious diseases during the Edo period. While news about measle outbreaks spread through their depiction in “Nishiki-e” and “Hanga” (woodblock printing), such cases have not been confirmed before the 17th century. While quarantine was sometimes implemented on a regional basis for highly contagious diseases such as smallpox, the concept of infection was not widely shared for other diseases. Although the plague epidemic in Europe triggered the development of public health measures, Japan had no such experience, and there was probably little recognition of infectious diseases as a communal crisis.
　The uniqueness in the concept of “epidemics” in modern Japan lies in the point that both famine and infectious diseases were co-existent in the concept of “epidemics.” Thus, it was highly likely that not only infectious diseases such as measles and smallpox, but also deaths due to starvation were treated as “epidemics.”
　Historical records and gravestones are important sources for studying the causes of mortality in the Edo period. Since gravestones were only built for certain social classes, they limit our understanding of the general picture. The gravestones nevertheless confirmed that child mortality increased during the famine period, suggesting that starvation was a major cause of mortality.
　Measles have been known to exist from before the Edo period. As for smallpox, there are records that they were introduced to Japan around the 6th century. However, an article in Science published in 2020 pointed out that the virulence of the smallpox virus increased dramatically around the 17th century, and that the disease may not have been fatal before that time. Genetic analyses of smallpox virus extracted from bones from the Viking-era also suggest that the virus was not highly pathogenic at that time.
　Records concerning pandemic influenza are debatable. As for the 1889 pandemic, there is no definitive evidence as to whether it was caused by influenza or by a coronavirus. It is difficult to identify the disease from the records of the time, and it has been suggested that a coronavirus of bovine origin, HCoV-OC43, may have spread to humans. Furthermore, a study by the University of Paris noted that the age distribution of deaths during this period was different from that of conventional influenza, but further research is required.
　In fact, some point out that the concept of influenza was gradually established after the 1890s, when physicians began to utilize statistics to document infectious diseases.
　Scientific understanding of infectious diseases was extremely limited globally until the beginning of the 19th century. Prior to Robert Koch's identification of the cholera bacteria, miasma and pathogen theories were mainly discussed and no concrete measures were taken, even at the International Congress of Hygiene in 1851. It was not until the late 19th century that Koch's work advanced scientific understanding of infectious diseases and made the implementation of concrete measures possible.

〇The Value of Medical History: From the Perspective of Psychiatry and Infectious Disease Research
　Historical research on psychiatry values the document known as the “clinical diary.” Clinical diaries are detailed records of a patient’s medical condition and daily activities recorded by physicians and nurses. It is an extremely valuable information source for in-depth analysis of individual cases and statistical studies. Since the length of hospitalization is often long for patients in psychiatric hospitals, clinical diaries often provide a detailed record of the patient's reasons for hospitalization, background, and personal episodes.
　On the other hand, as for infectious diseases like cholera, since the length of hospitalization was short, there were few continuous records like clinical diaries. Thus, it is difficult to obtain detailed information about the patient’s background and disease progression. However, it is possible that such records were kept at isolation hospitals that treat infectious diseases. To find these documents, we need to carefully investigate medical institutions and archives. For instance, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, which once functioned as an isolation hospital, is one example of a hospital that has detailed records.
　On the contrary, it is true that most medical records have already been discarded, one reason being the lack of space to store the records. This reality is considered a significant loss for the field of medical history. However, there are some hospitals, such as the Second Department of Surgery at Tokyo University School of Medicine that have preserved past records carefully. The department possesses detailed records of about 50 patients hospitalized during the Great Kanto Earthquake. The records provide valuable insight into the actual situation at the time of the disaster.
　Medical records for infectious diseases such as cholera and COVID-19 have also not been adequately analyzed. Collaboration between medical historians and archive specialists to make the most out of underutilized records will be valuable for the development of the field of medical history.

〇Orthodox and Unorthodox Histories in the History of Medicine: A New Historical Perspective
　Cholera control measure-implementation in 19th century London by John Snow has been widely recognized as the origin of modern epidemiology. However, in the book “Maladies of Empire: How Colonialism, Slavery, and War Transformed Medicine” published in 2021, Jim Downs challenges that idea.
　Downs claims that the narrative that epidemiology was established by the 19th century British Empire was formed in later years, and that the argument regarding John Snow is merely a “rewritten history.” According to him, epidemiological statistics and analysis were already performed back then, such as for slave trade, where data were collected on the relationship between the number of people loaded on slave ships and mortality rates. Thus, medical statistics in the imperialistic context may have been the origin of epidemiology. This perspective arouses suspicion that the common belief that John Snow's work is the sole origin of modern epidemiology may be “covering” the historical facts associated with imperialism.
　A similar example where history was reconstructed is research that studied the relationship between tobacco smoking and lung cancer. The first known official study that showed positive association between the two was a follow-up study of UK physicians after World War II. However, researchers of Nazi Germany had in fact discovered the association at an earlier stage through the comparison of the smoking histories of patients with and without lung cancer. This research, conducted as part of Nazi’s health policy, is a fact that is often neglected today.
　What these examples imply is that medical history has been rewritten in certain contexts. History is closely tied to social demands and backgrounds at the time and is interpreted accordingly. If the contextualization of John Snow's work as the origin of modern epidemiology is valid, it is worthwhile to evaluate it. Conversely, an alternative perspective that epidemiological analysis was already underway in the context of imperialism and slavery is also very important for understanding the diversity of history.
　The field of history has developed by continuously reevaluating canons considered “authentic history.” Incorporation of various perspectives upon analyzing history will likely lead us to understanding underlying facts that we do not yet know.

〇How Modernization Made Society Vulnerable to Infectious Diseases
　In pre-modern Japan, drinking water was obtained by each household through a well within their property. This water system contributed to suppressing the spread of infectious diseases in certain regions. In eastern Japan, wells were constructed per house while in western Japan where houses were densely built, some areas shared wells. In areas with abundant groundwater, such as Sendai, a system of separating drinking water and drainage canals were constructed since the Edo period. This system may have suppressed infectious diseases in such areas.
　Famine was the major reason for mass deaths during the Edo period, not infectious diseases. However, urban planning associated with modernization elevated the vulnerability of communities through the contamination of wells, which ultimately led to epidemics such as cholera.
　In the Tohoku region, communal structure of the agricultural area is thought to have contributed to the early decline of cholera. On the other hand, cases of tuberculosis rose dramatically in the 1920-1930s due to increased migratory movements of people to the cities. This is another example where communities were originally protected from infectious diseases through traditional communal structure but became vulnerable to diseases due to modernization.
　Furthermore, in developing countries where traditional, independent lifestyle prevented the spread of infectious diseases, after adopting of a new lifestyle impacted by modernization, some regional environments have become more vulnerable to pandemics.

〇Imperialism and Infectious Diseases: The Western Response to Infectious Diseases
　In his book “Infectious Diseases and Society in History [Kansensho wa Bokurano Shakai wo Ikani Kaetekitanoka],” Professor Odanaka refers to a description of the cholera epidemic in London by Masatoshi Miichi, a historian of British history. According to Miichi, in early 19th–century London, there were few large-scale outbreaks of infectious diseases. The first cholera pandemic in Asia that started in 1817 only spread up to the Ottoman Turks. Back then, the British considered cholera to be a disease unique to Asia. However, during the third pandemic, London was also hit by a major epidemic, resulting in many casualties and resulting in a situation they phrased, “they saw Asia within themselves.”
　The 19th century was when nation-state formation, industrialization, and imperialism progressed. Europe was trying to identify and incorporate the “other” into their own country, as well as to other countries. The cholera pandemic is an example of how Asian elements affected European society amid the expansion of imperialism.
　This phenomenon shares similarities with the COVID-19 pandemic. Western countries initially considered infectious diseases as issues in Asia and Africa, neglecting infection risks due to their confidence in their medical system. Unfortunately, the delay in response led to the spread of diseases and high death tolls, which received severe criticism.

〇Concluding Remarks: Comments from speakers as Historians Who Experienced COVID-19
　Through the COVID-19 pandemic, I strongly felt the impact of “routine surveillance,” something unique to Japanese society. For example, the emergence of “self-restraint police,” a form of social pressure, impacted infectious disease control measures, for the better or worse. Such phenomena may have contributed to Japan’s low mortality rate.
　Experiencing COVID-19, the way I examine historical documents have transformed. Although I had previously viewed history from the perspective that “saving lives matters the most,” I realized that economic activities and social factors actually have a significant impact on people's behavior. Given this experience, I strongly felt the necessity of reevaluating people’s historical choices and actions.
　When examining infectious diseases and history, Alfred Crosby's concept of “ecological imperialism,” known for his work on the Spanish flu, is highly thought-provoking. Since the Age of Discovery, human interaction, including the movement of microorganisms, accelerated the global spread of infectious diseases. With COVID-19, the centuries-long “unity of the world” temporarily collapsed, forcing each country to respond as a national unit. Under these circumstances, we must ask how the characteristics of Japan as a country affected its resistance and adaptation to infectious diseases. Simultaneously, we realized that a global perspective alone is insufficient. The impact of infectious diseases needs to be reconsidered at the micro-level, such as towns and districts. In fact, COVID-19 was prevalent mainly in urban areas, an aspect common with cholera, and it provided an opportunity to rethink the vulnerability of infectious diseases brought about by urbanization.
　We also consider the “time lost” by students who experienced COVID-19 as a significant issue. We realized there is a generation-specific lack of experience from the words of a student in the seminar who said, “I have never experienced an imoni [taro and meat soup] party.” We must start reassessing the “meaning of time” from a historical perspective.
　COVID-19 demonstrated the importance of future pandemic preparation. COVID-19 demonstrated the importance of being prepared for the next pandemic. Given the increasing urbanization and the risk of zoonotic viruses, new infectious disease outbreaks are inevitable. In such an event, the ability of each country and individual to respond will be challenged. If the young generations are affected by a future pandemic, the impact on society as a whole will be immeasurable. Understanding pandemics requires not only medical science, but also perspectives from other fields, such as sociology and psychology.
　Another important challenge we must overcome is the method of properly preserving the massive number of COVID-19-related documents and passing them down to future generations. As digitization progresses, there is a need for a system to prevent the dissipation of the large volume of records in various media and to pass them on to the next generation; rather than simply dismissing COVID-19 as a crisis, the question is how to position it in history and draw lessons for the future.