The coronavirus disease 2019 (COVID-19) outbreak in North, Central, and South America has become the epicenter of the current pandemic. We have suggested previously that the infection rate of this virus might be lower in people living at high altitude (over 2,500 m) compared to that in the lowlands. Based on data from official sources, we performed a new epidemiological analysis of the development of the pandemic in 23 countries on the American continent as of May 23, 2020. Our results confirm our previous finding, further showing that the incidence of COVID-19 on the American continent decreases significantly starting at 1,000 m above sea level (masl). Moreover, epidemiological modeling indicates that the virus transmission rate is lower in the highlands (>1,000 masl) than in the lowlands (<1,000 masl). Finally, evaluating the differences in the recovery percentage of patients, the death-to-case ratio, and the theoretical fraction of undiagnosed cases, we found that the severity of COVID-19 is also decreased above 1,000 m. We conclude that the impact of the COVID-19 decreases significantly with altitude.

COVID-19 can evolve to a severe lung compromise with life-threatening hypoxemia. The mechanisms involved are not fully understood. Their understanding is crucial to improve the outcomes. Initially, past-experience lead to the implementation of standardized protocols assuming this disease would be the same as SARS-CoV. Impulsive use of ventilators in extreme cases ended up in up to 88% fatality. We compare medical and physiological high altitude acute and chronic hypoxia experience with COVID-19 hypoxemia. A pathophysiological analysis is performed based on literature review and histopathological findings. Application of the Tolerance to Hypoxia formula = Hemoglobin/PaCO₂ + 3.01 to COVID-19, enlightens its critical hypoxemia. Pneumolysis is defined as progressive alveolar-capillary destruction resulting from the CoV-2 attack to pneumocytes. The adequate interpretation of the histopathological lung biopsy photomicrographs reveals these alterations. The three theoretical pathophysiological stages of progressive hypoxemia (silent hypoxemia, gasping, and death zone) are described. At high altitude, normal low oxygen saturation (SpO₂) levels (with intact lung tissue and adequate acid–base status) could be considered silent hypoxemia. At sea level, in COVID-19, the silent hypoxemia starting at SpO₂ ≤ 90% (comparable to a normal SPO₂ {88–92%} at 3500 m) suddenly evolves to critical hypoxemia. This, as a consequence of progressive pneumolysis + inflammation + overexpressed immunity + HAPE-type edema resulting in pulmonary shunting. The proposed treatment is based on the improvement of the Tolerance to Hypoxia (Hemoglobin factor), oxygen therapy, inflammation reduction, antibiotics, antitussives, rehydration & anticoagulation if required. Understanding the pathophysiology of COVID-19 may assist in this disease's management.

Acute high-altitude illnesses are of great concern for physicians and people traveling to high altitude. Our recent article “Acute Mountain Sickness, High-Altitude Pulmonary Edema and High-Altitude Cerebral Edema, a View from the High Andes” was questioned by some sea-level high-altitude experts. As a result of this, we answer some observations and further explain our opinion on these diseases. High-Altitude Pulmonary Edema (HAPE) can be better understood through the Oxygen Transport Triad, which involves the pneumo-dynamic pump (ventilation), the hemo-dynamic pump (heart and circulation), and hemoglobin. The two pumps are the first physiologic response upon initial exposure to hypobaric hypoxia. Hemoglobin is the balancing energy-saving time-evolving equilibrating factor. The acid-base balance must be adequately interpreted using the high-altitude Van Slyke correction factors. Pulse-oximetry measurements during breath-holding at high altitude allow for the evaluation of high altitude diseases. The Tolerance to Hypoxia Formula shows that, paradoxically, the higher the altitude, the more tolerance to hypoxia. In order to survive, all organisms adapt physiologically and optimally to the high-altitude environment, and there cannot be any “loss of adaptation”. A favorable evolution in HAPE and pulmonary hypertension can result from the oxygen treatment along with other measures.

The coronavirus disease 2019 (COVID-19) outbreak in North, Central, and South America has become the epicenter of the current pandemic. We have suggested previously that the infection rate of this virus might be lower in people living at high altitude (over 2,500 m) compared to that in the lowlands. Based on data from official sources, we performed a new epidemiological analysis of the development of the pandemic in 23 countries on the American continent as of May 23, 2020. Our results confirm our previous finding, further showing that the incidence of COVID-19 on the American continent decreases significantly starting at 1,000 m above sea level (masl). Moreover, epidemiological modeling indicates that the virus transmission rate capacity is lower in the highlands (>1,000 masl) than in the lowlands (<1,000 masl). Finally, evaluating the differences in the recovery percentage of patients, the death-to-case ratio, and the theoretical fraction of undiagnosed cases, we found that the severity of COVID-19 is also decreased above 1,000 m. We conclude that the impact of the COVID-19 decreases significantly with altitude. Highlights: There is a negative correlation between altitude and COVID-19 incidence on the American Continent starting from 1,000 m above sea level. The transmission rate of SARS-CoV-2 is lower in the highlands than in the lowlands. The severity of COVID-19 decreases significantly with increased altitude.

Background: Travelling to high altitude for entertainment or work is sometimes associated with acute high altitude pathologies. In the past, scientific literature from the lowlander point of view was mostly based on mountain climbing. All guides were developed by sea-level scientists but it was not applicable to high altitude cities. Nowadays, altitude descent and evacuation are not mandatory in populated highland cities. Methods: We present how to diagnose and treat acute high altitude pathologies based on 50 years of high altitude physiology and medical practice in hypobaric hypoxic diseases in La Paz, Bolivia (3,600m; 11,811ft), at the High Altitude Pulmonary and Pathology Institute (HAPPI – IPPA) altitudeclinic.com.Results: Acute Mountain Sickness, High Altitude Pulmonary Edema, and High Altitude Cerebral Edema are all medical conditions faced by some travelers. These can occasionally present after flights to high altitude cities, both in lowlanders or high-altitude residents during re-entry, particularly after spending more than 20 days at sea level.Conclusions: Acute high altitude ascent diseases can be adequately diagnosed and treated without descent. Traveling to high altitude should not be feared as it has many benefits;

Near the end of 2021, the COVID-19 Pandemic continues to create havoc worldwide, with predominance in the northern hemisphere by Nov 21, 2021. Popular belief stated that living under chronic hypobaric hypoxia would be correlated with higher COVID-19 severity. Despite the controversy, one of our forthcoming multinational publications gives significant scientific proof of a lower case fatality rate (CFR) at high altitude cities > 2,500 m as compared to the lowlands (< 1,000 m) in Bolivia, Peru, Colombia, Ecuador, and Mexico. It is crucial to determine what factors could be affecting this outcome, as they can provide the starting point for future research in COVID-19 and other possible viral pandemias’ management. We hereby provide possible explanations that could play a role in COVID-19 high-altitude protective behavior and we divide them into two branches. 1) The physiological (higher hemoglobin levels, higher erythropoietin levels, higher nitric oxide, lower arterial carbon dioxide levels, lower incidence of asthma and other comorbidities, lower number of ACE2 receptors, higher capillarity, cardio-vascular high altitude adaptation, lower incidence of asthma and other co-morbidities, increased mitochondrial effectivity, greater immunity, and lower coagulation pathologies in high-altitude inhabitants; and 2) the environmental (higher Ultra-Violet radiation, lower molecular density in the atmosphere, the absence of mosquitoes, and lower humidity). Further studies in all these areas are required to help face the Pandemic more efficiently.