Coronavirus: How do health care workers become infected and why do they become severely ill?

Infection statistics in various countries show that medical professionals can account for up to one-third of the total number of people infected. In the fight against Covid-19, medical personnel worldwide are paying a very high price. Thousands of health workers have been infected with the virus, and the number of doctors who have died continues to rise. Doctors, nurses, medical orderlies and other hospital staff are the most susceptible group to infection, despite wearing protective suits and masks. They are also the most severely affected by the disease.

Why is this happening? According to experts, this is mainly due to the concentration of the virus around them. Once inside the body, the virus infects cells and begins to replicate, making its own copies. These copies accumulate in the human body over the next few days, worsening the patient’s condition. The higher the concentration of the virus, the more severe the associated disease and the more contagious the patient.

Healthcare workers are exposed to a higher concentration of viral infections on a daily basis, making them not only more susceptible to infection than others, but also making the disease more severe for them. “The more virus I have, the more likely I am to pass it on to others,” says Professor Wendy Barklay of the Institute of Infectious Diseases at Imperial College London. Doctors are in close proximity to the infected and are at risk not only of becoming infected but also of receiving large doses of the virus. According to WHO, one of the patients in the Chinese city of Wuhan, who underwent scheduled surgery, infected 14 health care workers, even though he had no symptoms of coronavirus at the time. “The immune system of even a very healthy person is struggling to fight all these viruses. The more viruses that enter the body, the stronger the battle between them and the immune system,” says Professor Barkley. “If you do an experiment on animals by infecting them with different doses of the virus, the most severe condition will be found in those who received the highest amount of the virus.”

In a person with Covid-19, the virus may reside in the upper respiratory tract and be spread by breathing or coughing. “Every time we breathe or talk, droplets from our nasopharynx enter the air,” explains Wendy Barclay in an interview with BBC Newsnight. Some of these droplets settle on surfaces, which is why so much attention is paid to distance and hand washing requirements. It is not known how many infected droplets a person must inhale or touch to become ill. “In the case of the influenza virus, which is very well studied, it only takes three particles to enter the body to start an infection. For Sars CoV-2 (Covid-19), not enough is known at the moment, but it is possible that the situation is the same,” he explains. At present, it is impossible to accurately measure the risks to medical personnel who are constantly in a viral environment. There is limited data from the World Health Organization (WHO) from which to draw conclusions. For example, during the SARS outbreak in 2002-2003, 21% of all confirmed cases worldwide were among healthcare workers. Now, similar statistics can be observed. In Italy, for example, there are more than 6200 infected medical workers. The total number of infected people in the country exceeds 120 thousand. In Spain, there are currently over 6500 healthcare workers with Covid-19, representing 12% of the total number of infected individuals.

In Spain, the number of infected medical workers is currently 12% of the total. In early March, China reported approximately 3,300 infected doctors and hospital staff. This represents 4-12% of all confirmed cases. One of the UK’s health officials told the BBC that in some of the country’s hospitals, up to 50% of the staff had taken sick leave or gone into self-isolation. If measures to control the spread of infection fail, hospitals themselves can become hotbeds of infection. Doctors have already told the BBC how they tried to send patients who did not have the coronavirus home early to protect them from possible infection.

Health workers in Zimbabwe have gone on strike, and a three-week strict quarantine has been declared in the country. It is this potential risk of infection that angers healthcare workers in several countries who lack personal protective equipment (PPE). In France, doctors have filed a lawsuit against the government for allegedly failing to take action to increase the production of medical masks, endangering the lives of healthcare workers.

Doctors and nurses in Zimbabwe have gone on strike to protest a lack of personal protective equipment at a time when the country is implementing a strict three-week quarantine. In the United Kingdom, Neil Dixon, general secretary of the Healthcare Workers Federation, said a lack of personal protective equipment was undermining doctors’ and nurses’ confidence in the system. Although the country’s authorities have enlisted the help of the army to distribute medical masks to health workers, “it will take some time to rebuild lost confidence,” Dixon says. “Another problem is that the production of these goods is concentrated in Asian countries, including China,” he points out. “And in the long run, it will be very difficult for China to ensure supplies in the required volumes.”