Wealth Inequality & The Epidemiologic Transition

“History will judge us on how we responded to the poorest communities in their darkest hour.” Dr. Tedros Adhanom Ghebreyesus, Director-General, World Health Organization

I’m not an active twitter user, but I do have friends that are. Yesterday someone shared the following:






In the post written on 28-Mar-20,  I mentioned the following: “I think in modern, wealthy nations we often forget that our life expectancy and quality of life have increased due to advances in hygiene (such as having our trash collected and transported to a landfill) as well as medical science and technology (such as vaccines and antibiotics). If we indeed would allow “nature to take its course” without mass use of advances to healthcare in the past 200 years, most of us would not have lived as long as we have; our family lines wouldn’t have made it this far. Society has come a long way from the days of the father of epidemiology, John Snow (read about his story:  here and here).” These sentences were referencing something called the “epidemiologic transition”.

In 1996, the World Health Organization published a paper called The epidemiological transitionIn this paper the WHO defined this transition as the following: “It used to be thought that the epidemiological transition – the shift from infectious and deficiency disease to chronic noncommunicable diseases – was a unidirectional process, beginning when infectious diseases were predominant and ending when noncommunicable diseases dominated the causes of death. It has, however become apparent that this transition is more complex and dynamic: the health and disease patterns of a society evolve in diverse ways as a result of demographic, socioeconomic, technological, cultural, environmental, and biological changes. It is rather a continuous transformation process, with some diseases disappearing or re-emerging. This also indicates that such a process is not unidirectional. In fact, a reversal of the trend sometimes occurs.”

To illustrate this “epidemiological transition” , I’ll be sharing some data on an infectious disease called Tuberculosis (TB). While COVID-19 is an infectious, communicable disease, I can’t use it for the purposes of this example as data is continuously changing as it’s a novel (new) situation – there’s no established data set.


First, let’s share some background info about TB from the CDC (Source):Screen Shot 2020-03-28 at 6.47.54 PM

Now here’s some TB data from the World Health Organization (Source):

Screen Shot 2020-03-28 at 6.25.26 PM

Screen Shot 2020-03-28 at 6.25.41 PM

If you observe the map, the percentage of cases in Australia, Canada, the United States, and Western Europe is lower than in other regions of the world. Now TB is still a threat in the United States (TB in US at all-time low, but global decline small), but in the past decade, our rates of TB have been lower in comparison to what we call “developing” countries. This minor observation, was an attempt at illustrating the epidemiological transition as well as trying to these concepts back to the screenshots of Dr. Gupta’s twitter screenshots I shared at the beginning of this post. As an inhabitant of a wealthy nation, although the structure of our healthcare system is not exemplary, we still have a lot more widespread access to good hygiene practices and clean living conditions.

Works Cited & Additional Resources:

  1. Reshma Gupta, MD
  2. World Health Organization – The epidemiological transition
  3. World Health Organization, Global Health Observatory (GHO) data: How many TB cases and deaths are there? 
  4. CIDRAP, TB in US at all-time low, but global decline small
  5. CDC, TB in the United States- A Snapshot
  6. CDC – Basic TB Facts
  7. ISGlobal, Barcelona Institute for Global Health: The Epidemiological Transition (or What We Died, Die and Will Die From)
  8. International Journal of Epidemiology, Infectious diseases – Past, present, and future
  9. Nature: Global trends in emerging infectious diseases
  10. World Health Organization, Ethics and infectious disease