Those living at higher altitudes may be less vulnerable to COVID-19
Populations at high altitudes may be less susceptible to developing severe symptoms of the novel coronavirus (COVID-19), according to a new study published in the journal Respiratory Physiology & Neurobiology.
For the study, researchers analyzed the epidemiological data in the Tibetan region of China, in which the peak of the epidemic is over; Bolivia, one of the last countries affected by the pandemic, which has a third of its territory extended at high-altitude; and Ecuador, a country deeply affected by the pandemic, in which half of the population lives at high-altitude areas.
The first analysis took place in Lhasa, the capital of Tibet, located at an elevation of 3,500 meters above sea level (MASL). A representative cohort of 67 patients who were diagnosed with COVID-19 in Sichuan reveals that 54 percent were completely asymptomatic and less than 10 percent of the patients presented fever. Nevertheless, 10 percent of the SARS-CoV-2 positive cohort developed severe medical condition, however, all the patients fully recovered after treatment, resulting in no mortality. Moreover, 29 percent of all the patients were potential high-risk due to predisposition with chronic respiratory or cardiovascular disease at the time of COVID-19 diagnosis, the researchers said.
The second analysis was performed for the central South American country Bolivia. La Paz, the administrative capital of Bolivia is situated in a range of 2,400 to 4,000 MASL, with a greater part of its metropolitan population located in the region of El Alto, at 4,150 MASL. There are a total of 54 cases in Bolivian provinces located at high-altitudes, according to the study.
Worldwide, there are about 120 towns and cities are located over 3,000 MASL. The researchers also analyzed the real-time geographic data of the COVID-19 pandemic and combined the data with a digital elevation model to illustrate the distribution of global positive COVID-19 cases in relation to altitude.
According to the researchers, the results clearly indicate a decrease of prevalence and impact of SARS-CoV-2 infection in populations living at altitude of above 3,000 MASL. The reason for decreased severity of the global COVID-19 outbreak at high altitude could relate to both environmental and physiological factors.