The Actual Situation of Covid-19 Infection at High Altitudes in Perú
Extraordinary Expert Professor, Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Perú
Academic Editors: Gustavo Zubieta-Calleja and Natalia Zubieta-DeUrioste
Special Issue: Oxygen Transport Physiology and COVID at High Altitude
Received: August 03, 2022 | Accepted: November 13, 2022 | Published: December 12, 2022
OBM Genetics 2022, Volume 6, Issue 4, doi:10.21926/obm.genet.2204173
Recommended citation: Garmendia-Lorena F. The Actual Situation of Covid-19 Infection at High Altitudes in Perú. OBM Genetics 2022; 6(4): 173; doi:10.21926/obm.genet.2204173.
© 2022 by the authors. This is an open access article distributed under the conditions of the Creative Commons by Attribution License, which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is correctly cited.
According to the last census in 2017, 34,08% of Peruvians live above 2000 meters above sea level (masl) , an environment characterized by low air and oxygen partial pressures, hypoxia, lower environmental temperatures and humidity, high solar irradiation, high rainfall. Based on previous in-depth studies and our own experience, it is now known that normal high-altitude dwellers have adapted to high altitude through physiological changes and thus developed other characteristics associated with sea-level dwellers [2,3].
Regarding the effects of high-altitude hypoxia on humans, three different situations need to be distinguished: first, the acute exposition to the high altitude of people who climb from sea level to high altitude ; second, the acclimatization of high-altitude dwellers born or live at high altitude for a long time without any limitations , and finally, the process of adaptation through genetic changes in people who have lived at high altitude for a long time, depending on the time lived at high altitude [2,6].
The most essential biological phenomenon related to human acclimatization to high altitude is the decrease in the partial pressure of inhaled oxygen due to the decrease in barometric pressure, which is inversely proportional to the increase in altitude, while the amount of oxygen remains constant at 20,93% .
Geographically, Perú is divided into 3 main regions: the coastal, the highland, and the jungle, and administratively into 24 departments or states, 196 provinces, and 1896 districts. Coastal departments extend from Tumbes to Tacna and are considered the coast departments by their boundaries with the Pacific Ocean. The high-altitude departments are located in the Andes, and the Jungle departments are in the Peruvian Jungle on the oriental side of the Andes . The COVID-19 outbreak began in Wuhan, China in December 2019 . The first case in Perú was reported on March 6, 2020 , and the first death occurred in March and has since expanded throughout the country, with Ucayali being the last department to report an infection in March 2020. On 15th March, it was declared a curfew.
This is an observational, descriptive, retrospective, and longitudinal study based on the information obtained from the Peruvian Ministry of Health, COVID-19 Situational Room, warnings from the National Epidemiology Center, Prevention and Disease Control, and the Panamerican Health Organization (PAHO), compiled and analyzed the COVID-19 pandemic in Perú from its inception to July 6, 2022 .
The evolution of the pandemic is summarized in Figure 1.
Figure 1 Evolution of the COVID-19 pandemic in Perú. Source: National Center of Epidemiology, Prevention, and Control of Diseases, Ministry of Health, Perú, 2020 .
The evolution of COVID-19 from the beginning to the present has particular characteristics that are worthy of analysis. The data in Table 1 showed that Perú is now the country with the highest mortality per million population rate in South America, and the second in lethality percentage. Table 2 describes the information for the coastal departments, which have the highest morbidity rates in Perú. Table 3 describes information for high-altitude departments, where the prevalence was lower than in other regions. Table 4 describes the data for the Jungle departments. Table 5 shows the comparison of the three regions.
Table 1 Morbidity and mortality in South American countries during COVID-19 pandemic, ranked by Mortality/Million. (Venezuela data seems questionable). Source: Datosmacro.expasion.com .
Table 2 described the incidence and mortality of COVID-19 in the coastal departments of Perú, and the data showed that the prevalence in coastal areas was the highest in Perú.
COVID-19 morbidity and mortality in high-altitude departments were shown in Table 3, where the results indicated a lower incidence than in other regions in Perú.
Morbidity and mortality of COVID-19 in the Peruvian jungle areas were presented in Table 4.
A comparison of the incidence and lethality of COVID-19 in the above three regions was shown in Table 5.
The data in this paper demonstrated that the number of COVID-19 infections and deaths in Perú was not only high but also has the highest mortality rate in the South American countries [9,10,11]. An outstanding fact is that the prevalence varies across the main territory regions, with high-altitude departments having lower rates than coastal and jungle areas .
The COVID-19 epidemic began in Wuhan, China in December 2019 and quickly expanded globally . The first case in Perú was registered in March 2020 , since then until March 7, 2022, 3,640,061 people were infected, 213,551 people died, for a lethality rate of 5.87%, and the mortality rate was 36.55 per million persons .
There is a controversy as to whether COVID-19 is less prevalent at high altitudes than at sea level. Woolcott and Bergman sustained that there is no better situation at high altitudes [13,14] but was refuted by Zubieta-Calleja , nevertheless, Woolcott and Berman still insisted . Millet et al. also suggested that altitude/hypoxia may be associated with elevated risk for patients with COVID-19 .In comparing the results from the Rocky Mounts and New York, more extensive studies have demonstrated that COVID-19 prevalence was lower at high altitudes than at lower altitudes in the Americas including the USA [17,18].
In addition, many other studies have indicated that the COVID-19 pandemic is less prevalent at high altitudes than at lower altitudes [8,19,20,21,22]. However, it is difficult to explain these divergences, which may be related to the number of cases, different social attitudes in front of the pandemic, health facilities, geographic differences, etc. [23,24,25,26].
At high altitudes in the Andes, like Perú [8,20,21,22,23,24,25,26], Colombia , Ecuador [28,29], Bolivia [30,31], and Brazil , the prevalence of the COVID-19 pandemic is lower compared to lower altitudes . There are also some very distant countries , such as Tibetan , China plateaus , India , and Saudi Arabia , which show the same situation.
There is now a wealth of information demonstrating that high altitude limits the prevalence of the COVID-19 pandemic, but the mechanisms underlying this phenomenon have not yet been elucidated.
It has been suggested that low barometric and partial oxygen pressures would cause a decrease in the average half-lifetime of the virus and/or a decrease in the regulation of the angiotensin-converting enzyme 2 (ACE2), the main SARS-CoV-2 virus receptor in human epithelial cells [38,39]. but normal residents who have adapted to high altitudes, whose pathophysiological features have changed, can live unrestricted at high altitudes, has he developed resistance to the SARS-CoV-2 virus? Under some responses, the normal high-altitude dwellers experience increased erythrocytosis, higher hemoglobin, greater oxygen transport, and higher concentrations of erythropoietin in the blood . Among critically ill patients treated in UCI, high-altitude residents have better outcomes than those at sea level [41,42].
In addition, meteorological and geographic conditions , and low serum erythropoietin concentrations  are negative factors for contagiousness and lethality. High levels of social informality have had an important effect on the high prevalence of pandemics, not only in the absence of continuous hygiene advice, such as the use of masks, social distancing, and crowd avoidance but also implies the absence of protection and services provided by the state . This has been evident in the most contagious places such as markets, informal employment, and transportation, as well as other forms of informality.
One important issue to consider is the situation of persons who need to return to high altitudes after COVID-19 healing due to work, travel, sports, and other reasons and develop acute disease, which might lead to confusion between the acute mountain sickness or Hurtado´s diseases [47,48] and COVID-19 pulmonary inflammation. Therefore, it is also necessary to evaluate the pulmonary function afterward to detect the possibility of a functional restriction, which would be a risk for climbing to high altitudes .
The COVID-19 pandemic in Perú has brought serious consequences to health, society, and the economy. The prevalence was so high that it caused the collapse of the health system, making it necessary to improvise increase the number of hospitalization and ICU beds, and the utilization of new strategies to bring recovery patients back to high altitudes .
As shown in Figure 1, the evolution of the pandemic had 3 waves, and now it is very worrying that this could be the beginning of another wave. One explanation is the emergence of new virus variants that are insensitive to the actual vaccines [24,51,52,53,54,55,56]. And Zubieta-Calleja and Zubieta-DeUrioste hypothesized 16 possible reasons that could explain the lower incidence of SARS-CoV-2 .
The limitations of this work are that the statistical indicators are relative and only referential, depending on the number of rapid and molecular tests performed and the presence of asymptomatic patients or those who do not go to health facilities without being diagnosed.
In conclusion, COVID-19 had a very high pandemic in Perú and has its own epidemiological characteristics due to its territorial diversity and social determinants, with data showing a lower prevalence, lethality, and mortality in the departments of the mountains than those in the jungle and coastal departments.
FG-L has participated in the data recollection, manuscript drafting, critical review of manuscript, final aproval of manuscript, asume the responsability respect other aspects of manuscript.
The autor declare that he dose’t have any conflict of interest.
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