One of the most interesting aspects of this course for me was discovering the societal changes made by the emergence of diseases. In “Artifact 5: Tuskegee Syphilis Study and Ethics of Diseases” I examined the response and long-term impact of syphilis on the US. In 1932, desperate to learn more about the disease and its effects, scientists began a study on over 400 African-American men in Macon County, Alabama, telling them vaguely that they were being treated for “bad blood”. Despite the passage of time beyond the project’s initial ending and the development of ethics codes after the Nuremberg Trials, doctors did not tell their patients what condition they had and kept up the pretense of treating them while truly studying the effects of untreated syphilis. To this day, effects of the study persist in that many African-Americans are hesitant to approach doctors for help or trust government programs. This continues to cause problems today with the modern HIV/AIDS epidemic and was not the only study of its kind. One of the doctors involved in the Tuskegee Syphilis Study proceeded to do a study of various sexually transmitted diseases on Guatemalan prisoners with their informed consent. These and other studies (along with even the Nazi experiments that prompted the Nuremberg Trials) were conducted “for the greater good” with the promise of progressing science, but really show the impact of disease on the scientific community: pressure to learn more about diseases made them willing to sacrifice people’s lives in the name of knowledge.

While society is directly impacted by disease, it also has an impact on disease itself. Diseases that are zoonotic (ie originally exist in animals, then pass to humans) are often transmitted to humans as a result of human encroachment and development in previously wild areas. Some examples of this are the Nipah virus (from bat contamination of date palm sap in India), or Ebola in Africa (from consumption of bushmeat). Furthermore, as I discussed in “Artifact 3: Historical and Contemporary Effects of Yersinia pestis”, human actions, such as allowing the accumulation of waste in cities during the Middle Ages, allowed for the spread and progression of the Black Plague. Health and sanitary decisions on the part of societies and individuals made them more susceptible to diseases, and in the case of Y. pestis it was poverty and poor living conditions for serfs that offered plenty of weak hosts for the disease to enter and spread, or mutate to create a stronger strain. In the modern world, continued deforestation and human development in previously wild areas often leads to new outbreaks of disease.

Contemporary society is still negatively impacted by emerging/re-emerging disease, particularly the present HIV/AIDS epidemic I discussed in “Artifact 9: HIV/AIDS in the Modern US”. Just as ancient response to disease was fear and distrust, so it is today. Stigma surrounding HIV originates in the 1980s, when the disease was first identified and people were afraid it could be spread through handshakes, toilet seats, or even breathing the same air. People who are diagnosed are often afraid to share their diagnosis with friends and coworkers, for fear that they will become outcasts. Bogus folk remedies claim to prevent, treat, or cure the disease quickly. Fortunately for HIV there are preventative PrEP and PEP treatments, as well as antiretroviral therapy (ART) which can make a person noncontagious after a significant treatment period. In general, modern science seems to have become capable of treating diseases as they emerge. The challenge has become identifying diseases, developing treatment fast enough to prevent extensive spread, and supplying treatment/prevention to those who need it, particularly in rural areas and underdeveloped nations.

One example of a disease whose re-emergence has been promoted by human action is cholera, as I discussed in “Artifact 8: Cholera, the Motivation for Modern Sanitation and Infrastructure”. After infrastructure in Haiti was destroyed by an earthquake, Nepalese UN workers housed upstream from the local population unintentionally introduced cholera into the water supply. This most recent cholera outbreak is caused by the El Tor strain, which is especially water resistant and produces more mild symptoms in some, making it spread more easily with less detection. The ability of human science to wipe out the more obvious strains made the El Tor strain relatively successful (since it produced mostly milder symptoms), and when a hurricane followed the earthquake in Haiti, the death count increased to over 10,000 for 2016 alone. Oral vaccines have been successfully distributed by health officials in Haiti since 2012, though re-emergence has occurred in Iraq and Yemen following airstrikes in recent years. Doctors hope that sufficient vaccination can protect other members of affected communities via “herd immunity”, though prevention of disease in the long-term requires consist infrastructure and hygiene standards often not met in areas affected by natural disasters or armed conflicts.

HR: Artifact 5: Tuskegee Syphilis Study and Ethics of Diseases, Artifact 3: Historical and Contemporary Effects of Yersinia pestis, Artifact 9: HIV/AIDS in the Modern US, Artifact 8: Cholera, the Motivation for Modern Sanitation and Infrastructure, class discussion, Microsoft Work for spelling/grammar check

When HIV first appeared in the US, it was completely unknown. The CDC MMWR report from June 1982 examined in class offers no solid explanation for the sudden series of Kaposi’s Sarcoma (KS) and Pneumocystis carinii Pneumonia (PCP) in previously healthy homosexual men. This was so unusual because KS and PCP normally only affect those with weakened immune systems. In 1985 it was announced that the HIV virus had been discovered, through the efforts of American Robert Gallo and Frenchman Luc Montangier. According to the textbook (Power of Plagues by Irwin Sherman, copyright 2017), each man discovered the virus independently before they announced them to be the same, and regardless of the announcement the French and US governments squabbled for priority in disease research and treatment.

Meanwhile, the US public descended into fear and terror of contracting HIV. People believed it could be shared through simple hand contact, toilet seats, or even through the air. As shown in the film during class, government failed to properly reassure the public. Even though the disease had been proved to only spread through bodily fluids, President Reagan said in a press conference that nothing had yet been confirmed and that people should proceed with caution regarding their children’s safety. Furthermore, since the disease was originally thought to occur in gay men (called gay-related immune deficiency or GRID), a stigma developed against homosexuals (for being the “source” of the disease) and against those who had the disease (assuming that they were homosexual or somehow unclean). As discussed in class, this stigma remains common today, despite the advances in understanding and treatment of HIV/AIDS.

Despite the original HIV outbreak in the US being in San Francisco, the south is now the center of the HIV/AIDS epidemic in the US. A 2019 New York Times article by Charlene Flash explains that Southerners often have trouble finding transportation and covering the costs of medication, and that demographic shifts have led to higher numbers of African-Americans and Hispanics, much higher-risk groups for HIV. Sufficient treatment does exist for HIV, most notably in the form of antiretroviral therapy (ART), which can reduce virus levels to eliminate the chance of transmission (as described in a 2019 Journal of the American Medical Association article). For those HIV-negative but at a high risk, there is PrEP (pre-exposure prophylaxis) to lower the risk of getting the infection, and PEP (post-exposure prophylaxis) to reduce the risk of contracting it after an exposure. According to the WHO website there is also an HIV vaccine being developed, though it has not been fully tested or approved by the CDC or FDA. Following President Trump’s mention of eliminating AIDS in March 2019, Flash’s New York Times article suggests that the key to conquering HIV/AIDS in the US is better logistics: ensuring that treatment is easily available and affordable to those who need it, since current technology and medicine provides all the tools necessary (in Flash’s opinion) to eliminate the disease.

HR: References as listed in text, class discussion, Microsoft Word

Cholera (Vibrio cholerae) was originally found only in India, according to the textbook (Power of Plagues by Irwin Sherman, copyright 2017). Its initial spread beyond the subcontinent to Sri Lanka, Burma, Thailand, and Singapore was due to colonization efforts by the British. After that, trade routes brought it to China and areas of the Middle East and Russia. At times the sickness appeared to stop and disappear, only to reemerge later and then pass into a new area, creating a new pandemic. Seven pandemics of cholera have occurred to date, though trade and sometimes fighting troops, such as Russian soldiers in Turkey in the early 19th century. Urbanization facilitated the spread of cholera as well, since many people could be infected by a single source. One example is the Broad Street pump during the 1854 breakout, as shown in the film in class. John Snow studied the distribution of cases and determined that contaminated water was the source of the breakout, assisted by the Reverend Henry Whitehead in gaining the trust of the locals and convincing them to remove the handle of the contaminated pump. Filippo Pacini was the first one to identify the cholera bacterium in 1854, though Robert Koch was the first to publicly identify and name it in 1882. The most recent pandemic of cholera is characterized by the El Tor strain, which is characterized by its increased ability to survive in aquatic environments and mild symptoms in some people (allowing further unnoticed spread) compared to previous strains of the bacteria.

Improvements in hygiene, sanitation, and infrastructure have greatly reduced instances of cholera in the modern world, though it continues to be an issue in places with poor infrastructure, especially in the wake of natural disasters such as the 2010 earthquake in Haiti. Following the earthquake, Nepalese UN workers arrived at the site and were housed in an area upriver from the local living site. Latrines were not properly-made and wastewater contaminated the drinking source, leading to widespread outbreak among the locals. According to the PowerPoint shown in class, as of 2016 the epidemic in Haiti had killed 10,000 and sickened more than 800,000 people in Haiti. In 2012 an oral vaccine began being distributed in Haiti, then in Iraq in 2015 and Yemen in 2017. The outbreak in Yemen followed airstrikes which destroyed local infrastructure, and according to the article “Vaccines Blocked As Deadly Cholera Raged Across Yemen” by Maggie Michael, UN workers struggle to transport and administer vaccines in areas heavily affected by conflict. Areas suffering the most destruction due to conflict are also the most likely to suffer outbreaks, and despite a brief lull near the end of 2018, 150,000 cases have been reported in the first half of 2019 alone. If the vaccine is widespread enough, scientists hope that “herd immunity” may keep others from getting sick. Vaccines and oral rehydration salts (ORS) for treatment, along with education on cholera and its prevention, are the key resources that UN health workers continue to distribute among the locals in affected areas.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check

In the textbook The Power of Plagues (copyright 2017), Irwin Sherman describes tuberculosis (Mycobacterium tuberculosis) as most likely having originated in cows. A similar bovine parasite, Mycobacterium bovis is also capable of being transmitted to humans, though it is not transmitted through the air and does not thrive in oxygen-rich environments as pulmonary tuberculosis does. Ancient Egyptian mummies have been found infected with tuberculosis in the vertebrae of the spine, suggesting that the disease spread from M. bovis in cattle after domestication and then developed in pulmonary form. In mummies dated after 4000 B.C.E. pulmonary tuberculosis had been discovered, and the disease is believed to have spread by nomadic Indo-European tribes to the Middle East, Greece, and India through. Despite being endemic in much of the known world (including most of Europe during the Middle Ages), tuberculosis was not suspected to be infectious until 1772 with the observations of Benjamin Marten.

With the emergence and development of large cities and towns by 1780, a new wave of tuberculosis hit England, followed through the years by many cities across Eastern Europe and North America. The closer proximity of people and their dairy cows to the community center meant more transmission of tuberculosis between people, as well as between cows and across the two species. During the nineteenth century there was a large influx of immigrants (including refugees of the potato blight, as discussed in the previous artifact) to the US, and tightly packed tenement housing facilitated the spread of the disease. Lack of ventilation in the tenements, especially during cold winter months when windows remained shut, meant very little fresh air and high likelihood for previously healthy individuals to contract the disease. Aside from being housed close together, poor immigrants were often malnourished, weakening immune systems’ ability to fight off the bacteria.

In 1882, physician Robert Koch was able to identify M. tuberculosis despite its colorless cells and difficulty to stain (the waxy cell walls were later discovered to retain dye with the help of an acid wash and the cells are Gram positive). In 1890 the extract used in the modern PPD test for tuberculosis was developed. During the twentieth century the disease was romanticized in books and movies, such as the 1936 movie Camille. As discussed in class, the pale and wasted look of the sick was considered beautiful and even associated with increased creativity and artistic work.

Due to its ability to be spread through simple inhalation, tuberculosis infections often go unnoticed or dismissed as a simple cold. According to the textbook (p. 337), in 85-90% of cases the infection goes no further than division of the bacilli throughout the body and formation of visible tubercles in the lung, calcified by the immune response and therefore making the disease latent (ie not actively harming the infected person or infecting other people). The danger of this is that the infection can be later reactivated (some 5-10% of cases becoming active at a later date). Penicillin was completely ineffective against tuberculosis, and strains of TB quickly became resistant to the newly-discovered streptomycin. Other drugs such as para-aminosalicylic acid (PAS) and isoniazid were developed, followed by others to form the veritable cocktail of drugs used today to treat tuberculosis while minimizing resistance.

Improved sanitation measures such as cleaner cities, elimination of tubercular cows, better nutrition, and higher standards of living also led to a decline in TB by the 1940s. Unfortunately, with the rise of HIV and subsequent weakened immune systems, incidences of TB have risen in slums and other poverty-stricken areas, particularly in India, Indonesia, and China. Multidrug and extremely drug resistant cases of TB have emerged, and according to a recent Healthline News article (“Why Tuberculosis Has Been So Difficult to Eradicate”) TB prevention is made more difficult by the fact that existing vaccines don’t work well in adults and render the current test for latent TB ineffective. To eliminate the so-called People’s Plague, especially now that the world is faced with HIV that weakens so many immune systems, it is important that research continue to develop more effective medicines and vaccines, while public health and sanitation in poverty-stricken countries be improved to minimize the spread.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check

By the year 1840, Ireland’s population had grown to 8 million. According to the PowerPoint shown in class, over half of Ireland’s huge population in 1840 was entirely dependent on the potato. Its nutrition content is such that people were able to survive on potatoes for all meals, perhaps with the occasional bit of milk. Most of the best products were forcibly exported to England, and thus landowners were forced to work their laborers harder to keep themselves financially afloat under such requirements. Poverty skyrocketed, and those in poverty were forced to live in crowded, slum-like conditions. To make matters worse, potato production focused on one or two high-yielding varieties. Though it may have at first seemed to maximize production and profit, this monoculture made the plants highly susceptible to disease.

Starting in 1845, the potato blight struck: a fungus-like organism called Phytophthora infestans, resulting in shrunken, corky, and rotted potatoes. Somewhere between a third and a half of potato crops were lost in 1845, and three-quarters of crops in 1846. In the years that followed, much of the seed potatoes (ie those able to sprout new potato plants and thereby revive potato production) were damaged and unable to assist in Ireland’s recovery. As described in the PowerPoint from class, P. infestans is believed to have originated in Mexico, spread to North America, and then crossed the Atlantic in potatoes used as provisions for the long voyage. The strain which caused blight (HERB-1) continued to spread until the 1970s, after which it died out and has since been replaced by the US-1 strain, a descendant the same original P. infestans strain from Mexico.

Irish people were forced into further poverty and malnutrition by the blight. Diseases listed in the PowerPoint such as measles, tuberculosis, diarrhea, whooping cough, and respiratory infections became common as a result of malnutrition, and cholera struck Ireland in 1849. Over a million people died, and another million (amounting to 20-25% population loss overall) emigrated from Ireland in hopes of escaping the blight. The United States was a common destination for refugees from the blight, and they brought many of the above listed diseases to the US on so-called “coffin ships” where few people survived to see the New World. As a result, Irish slums in the US became more prevalent and filled with disease.

Today, potatoes can be genetically engineered against blight (as described in the article “EPA, FDA approve 3 types of genetically engineered potatoes” by Keith Rogers in 2017). Still, many people are not fond of the idea of altering nature to create such GMOs (Genetically Modified Organisms). Another contemporary example of the GMO controversy is described in the 2019 NPR article by Rob Stein (“Scientists Release Controversial Genetically Modified Mosquitoes In High-Security Lab”). Stein explains that scientists have genetically modified some female mosquitos to have male mouthparts and deformed sexual organs, a characteristic that will be passed on to all offspring. The hope for this genetically modified mosquito is that it can greatly decrease mosquito populations and stop the transmission of malaria in Africa. Regardless, critics worry about unexpected ecological effects such as changes in pollinator populations or potential emergence of mosquitoes carrying other diseases. For now, the new “gene-drive” mosquitoes are simply being studied in Italy, a climate in which they would not be able to survive even if they escaped the lab. With more study and perhaps a few adjustments, scientists hope they can gain approval to release the mosquitoes in malaria-stricken areas.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check

The Tuskegee Syphilis Study is the most well-known US case of unethical medical treatment. As described in the Tuskegee study film, 400 African-American men were offered “free treatment” for a disease vaguely termed “bad blood”. Officially, the experiment began for the purpose of finding out whether syphilis in African-Americans was the same and/or had the same series of symptoms and effects as that in Caucasians. However, patients were never told the actual sickness or offered consistent treatment, even after informed consent became required in experimental research. Instead, patients were given fake tonics and pills as “treatment” and subjected to routine medical exams as their health slowly worsened from the effects of syphilis. The continual deception and withholding proper medical treatment from patients without their knowledge are what makes the Tuskegee study so unethical. In the video, physician Dr. Culter attempts to rationalize it by saying that the result of the research would save so many African-American lives as to be worth the subjects’ lives. It was later discovered that Dr. Culter was involved in a similar experiment affecting (according to a current Encyclopedia Britannica online article by Kara Rogers) over 1,000 Guatemalans. Prisoners, soldiers, and sex workers were purposely infected with STDs to test potential alternatives for the widely-used penicillin without their informed consent.

After public outrage over experiments such as the Tuskegee Syphilis Study, the responsible organizations often try to financially reimburse the survivors and families of the deceased. Cultural effects of such experiments, however, are not easily forgotten. In 2016, research about an outbreak of tuberculosis in Alabama led New York Times author Alan Blinder to conclude that residual mistrust from the Tuskegee Syphilis Study was to blame for the people’s unwillingness to seek medical help. His article “Outbreak is Fueled by Mistrust in Alabama” describes the people of Marion, Alabama as being close-lipped about their sickness, while blaming the same authorities for not working to contain and prevent the sickness earlier. Therefore, unethical experiments such as the Tuskegee study affect more than just the current victims and their families. They also create lasting cultures of medical distrust, a source of complications for future attempts to contain or treat disease.

In general, ethical issues surrounding infectious diseases exist also on a personal level. For example, recent news of “anti-vax” support raises the question of whether it is ethical to require each individual to be vaccinated (regardless of their personal preference) for the safety of the larger population. Additionally, historical requirements for quarantine of recently arrived immigrants were questionable, since they assumed that immigrants were already infected and/or likely to spread infectious disease. Minority groups are often viewed as targets for experiments such as the Tuskegee Syphilis Study (discussed in class), most likely because of the expectation that they accustomed to taking orders without full explanation and will follow doctors’ instructions without question. Another example of this, described in the article “The Rationalization of Unethical Research” by Charlotte Paul in 2015, was women in New Zealand used in a study about the development of cervical cancer. The doctor in charge of the experiment received permission to leave carcinoma in situ (CIS) untreated in the women, but never informed the women that their lack of treatment was unusual.

The modern difficulty of doing research in developing countries is that it can be difficult for doctors to communicate the information for informed consent, leaving themselves open to an accusation of unethical practices. Even in the US, good intentions cannot outweigh unethical actions. A final example is the SIU professor William Halford’s attempts (described in a 2017 StatNews article by Marisa Taylor) to create an effective herpes vaccine. He wanted to test the vaccine in 2013 and resorted to a series of hotel-room tests on volunteers who were unaware that the formula was experimental. His good intentions meant nothing against the unethical nature of his actions. Similarly, the Nazi doctors’ beliefs that their experiments would be worth the suffering of patients for future knowledge and health of many did not earn them any leniency when faced with the Nuremburg Trials.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check

Nobody knows exactly when smallpox (Variola) began affecting the human population, though the oldest recorded case was that of the Egyptian Pharoah Ramses V in 1155 B.C.E. By the Middle Ages it was endemic across Asia and Europe, as well as the Middle East and Africa, and after the arrival of Colombus in the New World it was quickly transmitted there as well. According to the smallpox film shown in class, traditional remedies varied from potions of horse dung to bursting the pox with a golden needle. Some of the most popular were bloodletting (“bled to the point of fainting” read some remedies) and heat or red therapies, where patients were placed close to fires and surrounded by the color red (red blankets, food/drinks, even red UV light in more modern quack treatments). Many cultures also had deities, commonly goddesses, who represented smallpox and were prayed to in times of outbreak.

According to the text (Power of Plagues by Sherman, copyright 2017), prevention measures considered effective by modern medicine did not appear until 1675, in a letter from a physician to the king of Denmark and Norway. In 1715 Lady Montague brought to England the method of variolation (rubbing material from the pustule of a sick person into a scratch on a healthy person’s arm) from the Turks, which became popular even in the English colonies with the help of physician Cotton Mather. As discussed in class, the Chinese had their own alternative to variolation in the form of insufflation, which consisted of inhaling powder of dried scabs.

Near the end of the 18th century, physician Edward Jenner observed and tested the rural folk remedy of purposely infecting people with cowpox to confer immunity against smallpox. He was the first to use the term “vaccine”, and from his work the modern smallpox vaccine (using not cowpox, but a similar virus, vaccinae) was developed. By 1801, the use of a vaccine was widely accepted by the scientific community and quickly became compulsory in some European states, though its political association in the US (according to the text) meant that it did not gain widespread popularity there until the 1900s. Though vaccination greatly decreased incidences of smallpox and proved especially useful in times of war (such as for Germany in the Franco-Prussian War, losing a fraction of the men that France did to smallpox), it also led to difficulties about two percent of the time. Furthermore, in the US, there had been outbreaks of the far less fatal Variola minor, leading citizens to believe that smallpox was not a serious disease and ignore the strong suggestion to be vaccinated, despite the established 30% mortality of Variola major.

As discussed in class and in the smallpox film, eradication of the smallpox virus was achieved using a method called surveillance and containment. Since smallpox did not have an animal reservoir, doctors were able to travel across the globe and identify cases, then use contact tracers to track down and vaccinate those they interact with. The long incubation period of smallpox (1-2 weeks) greatly assisted in eradication efforts, and in 1980 smallpox was officially declared eradicated by the World Health Organization (WHO). Vaccination was halted, and plans were made to dispose of all remaining stores of the virus. However, after rumors that the Soviet Union was developing the virus to be used as a bioweapon, the stores of the virus have been retained. Particularly since the 9/11 terrorist attack on the US, stores have been retained for research purposes and in case of future bioterrorism.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check

When the Black Plague struck Europe during the Middle Ages, the continent had been experiencing years of poor harvest and famine. As stated in the text (“Power of Plagues” by Sherman, copyright 2017), Yersinia pestis generally resides in rat or other rodent hosts but will move to “less preferred” human hosts when the rodent population drops. Famine likely meant less food for rodents (decreasing population) as well as humans, leading to weakened human immune systems, increased poverty, and armed conflict. Furthermore, the introduction of new Mongol trade routes meant more interaction with the far East and potential introduction of sickness from areas previously untouched by Europeans.

The film “Plague” describes medieval response to the emergence of Y. pestis. Many people believed that the plague was a result of sinners angering God, and as a result sought to increase prayer. Religious movements like the flagellants grew in popularity, practicing self-harm in an imitation of Christ to gain God’s pity. As priests became sick and began refusing last rites to protect themselves, trust in the church hierarchy decreased (though overall religious sentiments remained strong). Scapegoat groups such as Jews were thought to have poisoned wells or rivers, and women believed to be witches were violently persecuted to prevent further plague. Some more scientifically-minded individuals believed that an alignment of planets led to the release of noxious vapors, called miasmas, into the air. Attempts to prevent further spread included fires or strong perfumes to “cleanse” the air, and some cities utilized quarantine, to varying degrees of success. Armed guards were occasionally used in a technique called “cordon sanitaire” to fight against those fleeing the disease.

Also described extensively in the film were the social impacts of the disease. Aside from loss of trust in the church, people lost trust in their doctors, who were often unable or unwilling to try to treat the disease for fear of catching it themselves. Friends and family members refused to take care of each other to protect themselves, and in some cases even committed murder to prevent the disease from taking their loved ones. Fortunately, there were some positive results: better hygiene and corpse treatment/disposal standards were just a few of the public health reforms during that time period. The feudal system crumbled as a result of the high number of deaths. Since there were not enough serfs to do all the farmwork, nobles forced to find other labor or work the land themselves. Once the disease had passed, reduced population meant higher wages and more people able to own land, and the birthrate increased. A 2014 Smithsonian.com article by Beth Griggs, titled “The Black Death Actually Improved Public Health” describes modern scientific skeleton analysis revealing improved living conditions and longer lifespans for 200 years in London following the end of the plague.

Today we know that Y. pestis is usually transmitted by fleas from small rodents, though it is also capable of being spread pneumatically (human-to-human via infected droplets from the lungs). As discussed during class, it is endemic (ie continues to live in animal populations) in the western US, though the average for the entire country is only seven cases per year and treatment is simple with modern antibiotics (provided that the disease is caught quickly enough). The main method of prevention in the US is avoiding contact with small rodents, while treating house pets with flea collars and preventing them from entering areas with known carriers. Madagascar has suffered several outbreaks of Y. pestis since the 1990s, reaching epidemic levels since 2009. This was discussed in class to be primarily a result of poor sanitation and infrastructure, with problems like overflowing landfills and lack of proper waste disposal. Large amounts of waste allow for rodents to breed freely and poverty among humans is extremely high, meaning that many people encounter rodents daily. Children have even been known to play with the dead bodies of small animals. As described in the “Echoes of Ebola” article by Leslie Roberts in 2017, treatment methods that have been found effective in Madagascar include oral antibiotics, disinfection, and rat/flea control. According to the article, the primary concern of doctors is that the plague will spread beyond Madagascar to the rest of the world, and their focus in the future is combating the disease effectively in an urban setting.

HR: References as listed in text, class discussion, Microsoft Word for spelling/grammar check

The significance of emerging and re-emerging diseases in the modern world is their unexpected appearance and resistance to existing medical practices. For example, the most recent global scare, the 2014 Ebola outbreak, was identified as early as 1976 but not considered a threat. The 2014 strain spread at an astonishing speed without being contained, and according to the movie “Spillover”, nearly jumped to a global pandemic when it reached the populous city of Lagos. The nurse who refused to release an infected ambassador planning an international trip is now hailed as a national hero, and only recently has a vaccine for the disease been developed and administered.

Aside from spreading astonishingly fast between humans via physical contact or bodily fluids, Ebola is a zoonotic disease. That means it was originally found in animals and continues to be harbored and spread by certain animal species. In the case of Ebola, its animal reservoir is a bat, and human contact with bats and/or bat droppings, along with possibly infected bushmeat, creates a risk of infection. One of the main dangers of zoonotic diseases is that animals cannot be educated or contained (as people can be) to prevent disease spread. Therefore, aside from analyzing and monitoring animal diseases around the world, zoonotic diseases cannot be prevented or controlled until their transmission to humans.

Modern human habits and cultural practices also contribute to the occurrence of major outbreaks. Not only is modern development encroaching more and more on wild lands, creating more human contact with potential zoonotic diseases (as detailed in the film “Spillover” and class discussion), but modern cities provide closer human interaction than ever before in history. As described in the “Influenza 1918” film, large cities in the US such as Philadelphia, Detroit, and New York served as fuel for the 1918 Spanish Flu outbreak. Furthermore, a November 2018 Washington Post article by Erin Blakemore describes the modern “outbreak culture” as being one of “denial, blame, and mistrust”. In other words, people are often slow to recognize that an outbreak is occurring and trust each other enough to work together to stop it. An example of this “outbreak culture” is provided in a May 2019 National Geographic article entitled “Life amid an Ebola outbreak: Combating mistrust—and saving lives” by Rachel Jones. She describes the struggles of foreign doctors in Africa to gain the trust and cooperation of locals in treatment and prevention of Ebola. Some simply refuse treatment, while others attack medical centers and try to prevent collection of samples for medical research.

Eliminating such mistrust and fear is one way for humans to become prepared for the next pandemic. Particularly in isolated areas where zoonotic diseases are more likely to occur and spread without notice, people need to be aware of the dangers and means of preventing disease. One example of current efforts in this area is the work of Ebola survivor Mulyanza Vithya Huguette (as described in the aforementioned National Geographic article), who travels to share and educate African women about the Ebola virus. Picture of this (photo 6/18) found at: https://www.nationalgeographic.com/culture/2019/05/ebola-democratic-republic-congo/ . Additionally, advancements in research and technology, such as the recently developed Ebola vaccines, will be necessary to fight future outbreaks.

HR: References as mentioned in text, class discussion, Microsoft Word for spelling/grammar check

As we discussed in class, the appearance of plagues occurred as a result of the transition between hunter-gatherer and sedentary lifestyles. With help from the text and articles provided in Canvas, I separated the changes made by this transition into three distinct factors: closer proximity to other humans, closer proximity to animals, and more opportunities for interaction with disease carrying pests. Historical and contemporary examples of each of these factors provides insight into how plagues appeared in history, as well as how modern human impact continues to shape the development of infectious diseases.

When hunter-gatherers became sedentary, they formed communities that created close interpersonal interaction. People spent more time in close quarters with others daily, and it became easier for diseases to be passed from one infected individual to an entire group in a short period of time. One example of this was the 1918 “Spanish Flu” influenza outbreak, where newly prosperous cities like Philadelphia were hit hardest by the disease due to the densely packed areas of people. The influenza film we watched in class emphasized that large gatherings like rallies and drives for the war effort brought people in close quarters, allowing for much more physical contact and facilitated spread just as clan gatherings or rituals would in ancient societies. Furthermore, settlements formed by the new sedentary lifestyle were not efficient with waste disposal. Even in modern times, as mentioned in the article “American Epidemic” (by Melinda Moyer, published in Scientific American in 2018) large cities like Hong Kong can have trouble maintaining public sanitation and hygiene. A small U-shaped bend in the bathroom ventilation pipes of the building harbored the SARS virus and facilitated its spread, leading to a SARS outbreak based in the city in 2003.

The second factor introduced by a transition from hunter-gatherer to sedentary life was increased interaction with animals. Domesticated animals became reservoirs for human disease. One example from the PowerPoints in class is cows, who served as a reservoir for smallpox in the from of the cattle disease rinderpest. Even house pets like domesticated dogs can carry and transmit rabies to humans, fortunately a lot less common in modern times due to vaccines developed during the 20^th century, as described in the CDC article “Control of Infected Diseases- Achievements in Public Health 1900-1999” provided in class. Another example of animal-human interaction causing disease is the spread of Nipah from bats to humans, as described in the film “Spillover”. Collection methods for date palm juice by humans allowed for bats to drink or even urinate in the collected juice, leading to human infection which spread by saliva to the rest of the community and causing a 2004 epidemic in India.

The final factor in causing human disease with a sedentary lifestyle is increased interaction with pests. Some pests are carried by domesticated animals (like fleas on cats or dogs), while others simply established a home for themselves amongst the newly established sedentary cities. One historical example is schistosomiasis or “pharaoh’s plague”, as it is described in the text (The Power of Plagues by Irwin Sherman, published 2017) as originally affecting ancient Egyptian settlements due to their construction of irrigation ditches. The parasite reservoir was a small snail living in the ditches, and people were infected by skin contact of the parasite entering the body, breeding inside, and ejecting their progeny back into the water source via human feces. Modern human impact includes the increased geographic range of such diseases, both by rising global temperatures (expanding the area in which the schistosomiasis worm can survive) and increased global travel by humans (allowing for infected individuals to transmit a disease to people farther away from patent zero). Another example of this increased geographic range is described in the article “Catching Fever” (by Lois Parshley, published in Scientific American in 2018). Rift Valley fever is transmitted by mosquitos and was originally identified in 1931 as being restricted to southern and eastern Africa. In 1977, however, the disease was found to have migrated north to Egypt, and then on to Saudi Arabia and Yemen, where it continues to be a potential threat today.

Modern concerns about facilitated disease spread due to increased globalization and global warming bear striking similarities to historical examples of facilitated disease spread due to hunter-gatherer’s transition to a sedentary lifestyle. The potential for a global epidemic, as was narrowly avoided in Lagos with Ebola in the film “Spillover”, means that human technology will need to adapt to protect its citizens in the future, just as it did to develop modern sanitary and medical practices to combat the plagues of the past.

HR: References as listed in the text, class discussion, spelling/grammar check by Microsoft Word