12 June 2020
A multinational team of researchers has found that Covid-19 is less severe in population living at altitude 3,000 metres and above.
SARS-CoV-2, which has frightened the most powerful governments, may be fearful of heights. Yes, the deadly coronavirus may be acrophobic.
The scientists have done a comparative study of novel coronavirus infections securing data from Covid-19 cases in the world’s highest plateau region of Tibet, mountains of Bolivia and Ecuador, and pitting them against the figures of lowland areas.
They hypothesised that that high-altitude inhabitants (particularly those living at 2,500 metres above sea level or higher) are less susceptible to develop severe adverse effects in an acute SARS-CoV-2 virus infection.
They found that Tibet, with a population of 90 lakh and heavy tourist and commercial exchange with Wuhan – the Chinese epicentre of coronavirus outbreak, had remarkably low levels of Covid-19 positive cases.
Tibet plateau region (Tibet, Qinghai and part of Sichuan) reported only 134 Covid-19 patients, the researchers say, of which they studied 67 cases from Sinchua, the most-affected of the three administrative units. Tibet itself had just one case of Covid-19.
They found 54 per cent patients being asymptomatic while 10 per cent developed severe complications. But all recovered well.
What surprised the researchers was that 29 per cent of all Covid-19 patients examined in this study had co-morbid medical condition. All of them beat the pandemic. This is unlike anywhere in the world and much against China’s own record in the lowland.
The scientists found similar corroboration from the high mountainous regions of Bolivia and Ecuador in South America. In Bolivia, the highland Andes population had a Covid-19 infectivity rate that was one-third of the lowland areas of the country. In Ecuador, it was one-fourth.
The researchers ran the test for 120 towns and cities worldwide that are located 3,000 metres above sea level. They found a definite decrease in Covid-19 cases with increasing altitude.
The researchers have attributed these findings to certain factors. Covid-19 is essentially a hypoxia-causing ailment.
Patients start starving of oxygen in case of severe viral-load of novel coronavirus at higher altitude. However, people living at higher altitudes already deal with such a hypoxia. Ever noticed their faces being more reddish than others? That is a result of more haemoglobin in their blood so that they can carry more oxygen inside their body.
Dryness of air, windy nature of weather, and greater prevalence of ultraviolet rays than in lowland areas are among the environmental factors that the researchers have hypothesised to be helping the resident population of highland areas fight off coronavirus infection more effectively.
Ultraviolet rays and the direct sunlight have been particularly found to be effective in reducing the number of SARS-CoV-2 – by up to half over an exposure of two minutes. Open air ventilation is another recommended method to reduce prevalence of novel coronavirus. High altitude areas have them naturally in abundance.
In India, Sikkim, Arunachal Pradesh, Nagaland, Meghalaya and Mizoram are among the states with low Covid-19 cases. In fact, these states have seen a spike on the return of migrants. Hilly districts of Uttarakhand, Himachal Pradesh and Union Territory of Ladakh too have seen a surge in coronavirus cases with the return of migrants. Local spread has been limited in the hilly regions.