As CoVID-2019 spreads rapidly across the planet, scientists around the world are trying to find a "zero patient" – the first person to become infected with a coronavirus. Advances in genetic analysis make it possible to track the genealogy of a virus by those who have infected it. Combined with epidemiological studies, scientists can identify the people who may have been the first to spread the disease, causing an outbreak. The definition of a “zero patient” can help solve critical questions of how, when and why the outbreak occurred. This can help prevent infection of a large number of people now and in the future.
What is known about the source of the coronavirus?
The Chinese authorities initially reported that the first case of coronavirus was reported on December 31, 2019. All subsequent infections were immediately associated with the fish market in Wuhan, Hubei Province, the epicenter of the CoVID 2019 outbreak. Almost 82% of the more than 78,000 cases reported in China and worldwide are in Hubei. Such data is cited by Johns Hopkins University. Read more about finding a coronavirus drug in our special material.
See also: How can you distinguish coronavirus from colds and flu?
However, a paper by Chinese experts published in Lancet magazine claims that the first case of CoVID 2019 infection was reported on December 1, 2019, and that person "did not contact" the Wuhan fish market. According to the BBC News, the patient was found to be an elderly man with Alzheimer's. The man lived in four or five bus stops from the fish market, and since he was sick, he didn't leave his house. In the following days, three more people developed symptoms of the disease – two of them did not visit the fish market. It is not specified who is particularly ill and whether he has contacted an older man.
The researchers also found that 27 people (from a sample of 41 patients) hospitalized at the start of the epidemic visited the fish market. We remind that the World Health Organization (WHO) takes into account the most likely hypothesis about the occurrence of coronavirus in the Wuhan fish market. Experts suspect that one of the wild animals on the market could infect humans. It was only after a while that the virus started to spread from person to person.
Can a "zero patient" cause an epidemic?
Can a person provoke an epidemic or even a pandemic? The Ebola outbreak in West Africa from 2014 to 2016 was the largest since the virus was first detected in 1976. According to the WHO, it claimed the lives of over 11,000 people and infected at least 28,000 people. The outbreak lasted more than two years and cases were reported in 10 countries. As a result, the scientists concluded that the outbreak of a new Ebola tribe began with one person – a two-year-old boy from Guinea – who was probably infected by playing in the tree cavity where a bat colony lived.
But the most famous “null patient” is Mary Mallon, nicknamed Typhoid Mary. So the woman was called because of the outbreak of typhoid in New York in 1906. Mallon is originally from Ireland and emigrated to the United States, where she worked as a cook for wealthy families. After several cases of typhoid fever, the doctors attributed the outbreak to Mallon. All families for which the woman was preparing suffered from typhus without exception. Then the doctors found that typhoid Mary was a healthy carrier – such people are infected, but the symptoms of the disease are either mild or absent. In addition, one person is contagious to others. There is growing evidence that some people spread viruses more efficiently than others. Such a "super distributor" of coronavirus is probably a Chinese woman who did not become sick herself, but immediately infected five people.
Do you think scientists can find a zero patient and who can he be? Share your opinion in the comments and with the participants in our telegram chat
With regard to the spread of the coronavirus, WHO experts do not rule out that it can develop into a real pandemic. At the time of this writing, the number of people infected in Italy had exceeded 300. This makes the country a potential outbreak of CoVID-20 in Europe. However, do not forget that the number of people who have recovered significantly exceeds the number of deaths, even if the worst expectations of the WHO experts are met.