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COVID-19 Mortality Data in High Altitudes

As the COVID-19 pandemic continues and new strains are being discovered every day, there is a rush in the world of science and medicine to uncover how to best prevent and treat those who have been affected. This is a worldwide problem, not solely isolated in one location. However, because the world is not uniform and environments and terrains people live in differ, are there those who live in certain areas better adapted to fighting off COVID compared to others if they were exposed? There have been rumors that those living in high altitudes (2,500m+) have some risk reduction factors associated with less infection and lower COVID-19-related mortality. One example is that people living in high altitudes have physiological traits such as increased erythropoietin production seen within their tissues that decreases the effects of COVID-19 on the human body.

A study was conducted in Ecuador between March 2020 and March 2021 to find a relationship between altitude and COVID-19 mortality rates. This study compared 221 cantons in Ecuador ranging from sea level to above 4,300 meters. Each canton was categorized as either low, moderate, high, or very high altitudes based on their location. During the one year of study, trends based on all-caused deaths and deaths relating to COVID-19 were collected and recorded. At the end of the study, it was shown that there was a 24% higher mortality rate in cantons located below 2,500m of altitude compared to cantons located above 2,500m of altitude. 1 However, when this was broken down into narrower categories, it was found that cantons located at “high altitudes” reported the second highest mortality rates due to COVID-19 compared to cantons located at “moderate and very high altitude” which reported the lowest mortality rates due to COVID-19. These results were confusing and showed conflicting information. In addition, two studies done in America and Peru showed that altitude had no protective factors against COVID-19 mortality rates, while another study in Peru demonstrated that there were “strong protective effects of altitude” against COVID-19. 2,3,4

Mixed results and debates have occurred regarding altitude and COVID-19 mortality rates since studies in this area have been limited. Multiple factors that were not accounted for in different studies could be the reason why. Overestimation, underestimation, unreported, and undiagnosed cases can greatly affect the statistics. Not accounting for underlying illnesses such as diabetes or cancer in relation to COVID-19 deaths is another factor that can contribute to the discrepancies in the research. Not to mention, there were some obvious reasons that may contribute to low mortality rates due to COVID-19, too. Two being that there may be a lower population density in higher altitudes compared to cities/countries near sea level resulting in reduced spread of the virus and that there may be less chronic conditions with people living in higher altitudes that are not exacerbated when they are exposed to COVID-19.

Ultimately, few studies have been conducted relating COVID-19 mortality rates to people living in high altitudes. A variety of theories were proposed as to the reason why people living in higher altitudes have a lower mortality rate when exposed to COVID-19, but the sample size and methods used to conduct the research led to gaps in the study. These gaps were refuted resulting in starting at square one again. Until there is more research done, and more data is collected, we cannot conclusively say that those living in higher altitudes have a lower mortality rate when exposed to COVID-19 compared to those who live at altitudes below 2,500m. The corona virus continues to evolve every day and is still affecting the lives of millions. If the virus continues at this rate, more research could be done to see if people living in high altitudes have protective factors against the virus. However, the main goal is to find a cure against this virus. This area of study can change how people live, and high altitude environments may be the next location people will want to move to.

References

  1. Ortiz-Prado E, Fernandez Naranjo RP, Vasconez E, et al. Analysis of Excess Mortality Data at Different Altitudes During the COVID-19 Outbreak in Ecuador. High Alt Med Biol. 2021;22(4):406-416. doi:10.1089/ham.2021.0070

2. Cardenas L, Valverde-Bruffau V, Gonzales GF. Altitude does not protect against SARS-CoV-2 infections and mortality due to COVID-19. Physiol Rep. 2021;9(11):e14922.             doi:10.14814/phy2.14922

3. Woolcott OO, Bergman RN. Mortality Attributed to COVID-19 in High-Altitude          Populations. High Alt Med Biol. 2020;21(4):409-416. doi:10.1089/ham.2020.0098

4. Thomson TM, Casas F, Guerrero HA, Figueroa-Mujíca R, Villafuerte FC, Machicado C.             Potential Protective Effect from COVID-19 Conferred by Altitude: A Longitudinal Analysis      in Peru During Full Lockdown. High Alt Med Biol. 2021;22(2):209-224.     doi:10.1089/ham.2020.0202

 Alex Fan was born and raised in Southern California. It was his grandmother who led him on the path towards medicine. In his free time, he enjoys going to the beach, trying new food locations, playing volleyball, and catching up with friends and family. He is currently a Drexel PA Student hoping to work with the underserved community in the near future. 

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