With all the anxiety and press coverage surrounding COVID-19 (one of the Coronaviruses), I thought it would be useful to put epidemics and pandemics into perspective relative to history and our natural environment–both shaped by humanity. Epidemics and pandemics are nothing new. The five worst in history, according to the Robert Wood Foundation, were the: Black Death (1347 to 1351), Spanish Flu (1918), HIV/AIDS (1959 to current), Plague of Justinian (541), and Antonine Plague (165 to 180). Cholera outbreaks receive an “honorable mention” with its many smaller outbreaks over the centuries.
Infectious disease often has its origins as a result of the mutations of microbes and/or our contact with animals. For example, the harvesting of migrating fruit bats was thought to be the source of an Ebola outbreak in the Democratic Republic of Congo in 2007.
As early as 1854 the importance of the role of sanitation in fostering public health became clear with the discovery of sewage in John Snow’s well (the Broad Street pump). By plotting where recent cases of cholera were occurring on a map Snow found the epicenter to be a town well, where he found traces of sewage. After shutting down the well, new cases of cholera stopped. Although the discovery of microbes wouldn’t be made until the 1880s, people reluctantly and gradually accepted the importance of sanitation for drinking water and food in relation to public health.
Today, we have a much more detailed understanding of how to protect ourselves from infectious disease, but its implementation is often hindered by cultural, social, political, and economic factors. Take for example the resistance to distributing condoms, and the needle exchange programs to stem the AIDS epidemic.
So too with the COVID-19 pandemic. The original outbreak in Wuhan, China was initially denied by the government; in fact, the alarm cited by Dr. Li Wenliang had him reprimanded by the Chinese government for disrupting the social order (he died of the disease). However, once the outbreaks began to explode, much to its credit, the Chinese government did take effective measures by constructing makeshift hospitals and implementing quarantines.
In some ways, we are not much different from England in the 1850s; on the world stage we are not prepared for the greater threats of pandemics. This is due to people increasingly living, hunting, or farming in wooded or jungle areas, putting themselves in greater proximity to wildlife. Factory farms require the use of antibiotics to fatten cattle and protect farm animals from infectious disease due to breeding them in crowded conditions. This widespread use of antibiotics is the major reason for the mutation of multiple drug resistant bacteria, resulting in the growing ineffectiveness of many of our antibiotics. Other factors such as greater international travel, an aging population in the West, war, and growing inequality and poverty all create ideal settings for the spread of infectious disease. These threats are particularly acute in refugee camps (including those near the Mexican border) and homeless populations.
Given this dangerous mix, well-funded global and national disease surveillance systems are necessary to both track and quickly intervene at the first signs of outbreaks. However, as Garrett discussed in terms of the global surveillance system, and Wilson regarding the 2013 Ebola outbreak, organizations such as the World Health Organization (WHO) and the Centers for Disease Control (CDC) are ill-prepared for these tasks. This is because public health organizations tend to be underfunded when there appears to be less immediate threats. When outbreaks do occur, governments then rush in with monies to fix the problem (at a time when the surveillance and first responder infrastructures, and other resources have to be rebuilt). The public health cutbacks over the past three years by the Trump Administration is a good example. As reported in the Guardian, “There is no one in the White House tasked specifically to oversee a coordinated government-wide response in the event of a pandemic, since the post of senior director for global health security and biothreats on the national security council (NSC) was eliminated last May.”
Surveillance is complicated and expesnsive since our biosphere is ever changing; we see a range of emerging infections. Some are bacterial, some are viral. This is a natural process related to mutations and changes in the world’s flora and fauna. As Peter Simmonds concludes in Microbiology Today, “RNA viruses (such as COVID-19) are characterized by a remarkable capacity to adapt to new environments, new selection pressures and new hosts when opportunity arises.” This means that whatever we do to combat them, they can adapt quickly, which is why it is so difficult to produce the annual influenza vaccine with near 100% effectiveness.
As we know, humans play a major role in all this, our impact on climate change being a major driver. The following diagram shows how climate affects the incidence of various diseases by following the chart from the center outwards (click to enlarge).
The best way to minimize the impacts of epidemics and pandemics is to maintain a high degree of sanitation, surveillance, and a centralized rapid response strategy to react at the first signs of an outbreak. This requires a consistent, intergovernmental political will and finances, even when there have been no bio-threats over an extended period of time. The development of and wide access to vaccines are also critical.
Although we know there will be a high death count from COVID-19 we don’t know how severe or prolonged this will be. We do know, however, that increased global travel, population density, and climate change will increase the likelihood of epidemics and pandemics.