COVID-19: How the pandemic reached one of the poles

Animals could be transmitters of the virus

The COVID-19 pandemic originating in Wuhan, China has spread throughout the planet in recent months. Until the end of December the Antarctic continent was the only territory to which the coronavirus causing the disease had not reached, but it is no longer immune. The subject of analysis in an investigation published in The Conversation focuses on understanding how the admission process was.

For the moment the only outbreak has been located in the Chilean base General Bernardo O’Higgins, located in the north of the Antarctic peninsula, where 36 people tested positive for the presence of COVID-19 and were quickly evacuated to the Chilean city of Punta Arenas.

There are several reasons that explain the late arrival of the virus in Antarctica. First its isolation from the rest of the continental masses with a minimum of about 1 000 kilometers between South America and the Antarctic peninsula, and a maximum of 3 950 kilometers between South Africa and the nearest Antarctic region.

Secondly, the fact that in an area of ​​14 million square kilometers (about 28 times the surface of Spain) apart from the existence of scientific bases, there are no human settlements and the maximum human presence is only about 5,000 people in these bases and about 55,000 tourists during the austral summer, which which makes it difficult for there to be a massive spread of the virus throughout the continent from a single outbreak.

The scientific bases in general have limited logistical capacities and have only very basic medical attention (EMCO Press) 

The spread of the virus globally at the end of February 2020 has also contributed to this late arrival. Since on those dates the summer campaign for research and tourist cruises in the region ends, which entails a drastic reduction in the movements of people and therefore the risk of introduction of the virus on the continent. However, At the beginning of March, an outbreak was detected on a tourist cruise ship already in Antarctic latitudes which, without landing, returned to South America immediately.

Preventing the arrival of the virus in Antarctica has been and continues to be the primary concern of national Antarctic research programs for several reasons. On the one hand, the protection of the health of the people who participate in scientific expeditions and, on the other, the effects that may have on the Antarctic fauna.

Scientific bases in general have limited logistical capabilities and have only very basic medical care, so that the appearance of a COVID-19 outbreak that results in severe symptoms could seriously compromise the lives of those affected. Added to this are the difficulties posed by an evacuation due to the distance, the weather conditions and the existing infrastructure.

Spotless continent, barely

Preventing the arrival of the virus in Antarctica has been and continues to be the main concern of national Antarctic research programs for several reasons 

The risk of spreading the virus in Antarctica is really plausible since its climatic conditions seem to allow its viability. Besides, andhe way of life in Antarctica in closed and not very spacious places such as bases and research or tourist vessels can favor a rapid contagion of all the people who live in these conditions.

Reducing the risk of introduction of the virus in Antarctica involves the application of strict quarantine rules for two weeks and the performance of diagnostic tests to detect the virus, as PCRs, so that participants in Antarctic campaigns are free from infection.

On the other hand, during this campaign, contacts between bases and ships from different countries have been limited, generating bubbles in each of them to eliminate the risk of spreading the virus in the event of an outbreak.

With current information, COVID-19 is considered a zoonosis, that is, a disease that has passed from an animal species to humans. Therefore, it cannot be ruled out that the opposite situation could arise in which the virus could pass from humans to other animal species again. So far there have been several infections from pets, dogs or cats, zoo animals and farm minks.to. Therefore, one of the concerns with the arrival of the virus in Antarctica is how it could affect native species such as penguins, seals or whales. Information on the susceptibility of these species to the virus is currently non-existent, so any risk assessment has to be based on indirect studies.

Reducing the risk of introduction of the virus in Antarctica involves the application of strict quarantine rules for two weeks and the performance of diagnostic tests to detect the virus 

Some studies Through experimental infections, they indicate that some birds such as poultry or ducks and mammals such as pigs show a very poor development of the disease. Other studies have estimated the risk of infection in different species of vertebrates based on the structure of the ACE2 receptor, which is the gateway of the virus to cells and therefore the route of infection and spread of the virus. Only two species of Antarctic birds are represented in this study, the Adélie penguin and the Emperor penguin, showing a very low risk of affinity to the virus. From the results, it can be estimated that both penguins and other species of seabirds present in Antarctica show a low risk of being infected by COVID-19. In the same way, the seal species present in the study related to the species present in Antarctica also show a low risk.

However, there are other species that show a high level of affinity to the virus and therefore a greater risk of infection, as are the cetaceans, including Antarctic species such as the minke whale, the killer whale or the sperm whale.

However, the results of this study also indicate a low probability of infection in species such as bats, which, as has been seen, could be the origin of the virus, therefore, while there are no more direct results, it is necessary to maintain the precautionary principle and consider that there is a certain risk of infection in the fauna of Antarctic vertebrates.

Polar transmitters

No other group of people can be less than 5 meters away from the Antarctic fauna, so the risk of transmission in that case would be very low 

Who are the groups of people most at risk of transmitting the disease? In the first place, researchers who work directly with animals would be the group most at risk, given the close contact with them.

Following the rules established by the Antarctic Treaty Environmental Protection Committee, the international agreement that governs activity in Antarctica, no other group of people can be less than 5 meters away from the Antarctic fauna, so the risk of transmission in that case would be very low, although accidental encounters with animals should be avoided.

There is a third group of people present in Antarctica, tourists, who also cannot get close to the fauna and, therefore, present a low risk of transmitting the virus as long as the regulations are followed.

In any case, and to avoid as much as possible the possibility of contagion to fauna, Behavior guidelines have been given, such as reducing the handling of animals to the minimum necessary, and of equipment, such as the use of gloves, masks, maintaining a strict disinfection of the materials used in field work. On the other hand, it is also recommended not to leave personal equipment in the vicinity of the animal groups to prevent them from approaching and eventually coming into contact with the material.