“Long-term coexistence” with the virus Are we ready?

“There’s no need to over-render, and there’s no need to panic. Zhang Wenhong, director of the infection department at Huashan Hospital, said in a recent article discussing new coronary pneumonia. We are entering a new phase of resistance after experiencing an outbreak that was raging in the early stages of the new coronavirus outbreak. Although today we cannot say that we are familiar with this new virus, many of its general characteristics are already in our grasp.

Some of the most important features include its high concealment, its infectiousness over SARS, and its lethality below SARS.

Stealth stems from the infectious nature of the incubation period of the new coronavirus, as well as the presence of asymptomatic infections.

China’s National Health and Reform Commission pointed out that from the observation, the new coronavirus in the incubation period is also contagious.

Many patients with new coronary pneumonia in the early stages of the disease show the characteristics of “not serious illness”, only fatigue, dry cough, poor appetite and other mild symptoms, and normal body temperature is difficult to distinguish. These patients with light diseases, without self-knowledge, already have the ability to transmit. The study found that the median incubation period for new coronary pneumonia was 3 days, up to 14 days, and that these “walking sources of infection” made prevention and control difficult to increase dramatically.

Moreover, asymptomatic infections occur everywhere.

Simply put, “asymptomatic infection” refers to the patient without any symptoms, but the nucleic acid test results are positive, and can spread the virus to others. For example, a confirmed case in Anyang, Henan Province, returned to Anyang from Wuhan on January 10, so far there have been no symptoms of infection with the new coronavirus, but its father, mother, aunt, aunt milk a total of 5 people have cluster edgy disease, and confirmed the new coronary pneumonia. None of the five family members had a history of living or travel in Wuhan, but had contact with the patient.

Yuan Guoyong, a member of the National Health and Health Commission’s high-level expert group and a professor in the Department of Microbiology at the University of Hong Kong, documented another case of asymptomatic infection in the incidence of family aggregation.

After the family returned to Shenzhen from Wuhan, a total of 5 people (4 adults, 1 child) were diagnosed with a new coronavirus infection. Among them, the infected child 10 years old, although there are no fever, cough, weakness, diarrhea and other typical symptoms, but at his parents’ insistence, the doctor performed a ct scan of the lungs, the results showed that the lungs have a glass-like lesions, and then the virus tested positive, confirmed as asymptomatic infection.

At the same time, there have been more reports of patients with “three yin” tests for pharynx nucleic acid testing.

In the regular process, the suspected patients with new coronary pneumonia twice pharynx swab nucleic acid test, if two negative, can basically rule out the possibility of infection. In one case reported by the Sino-Japanese Friendship Hospital in Beijing, the patient had three pharynx swabs tested, all of which were negative, and finally passed the ophthalmic irrigation test to obtain a lower respiratory sample before the diagnosis of new coronary pneumonia.

In this case, the lesions occur in the lower respiratory tract, making it difficult to detect pathogens in the lower respiratory tract, and with limited medical resources, it is difficult to sample samples of the lower respiratory tract in each case of a negative suspected patient. The emergence of “three yin” cases may make it more difficult to diagnose.

Due to the long incubation period of the new coronavirus, mild symptoms (not even symptoms), and the difficulty of diagnosis, some cases of transmission of new coronary pneumonia appear to be “out of thin air”, the transmission chain is more fuzzy, difficult to trace the pathogen.

In general, epidemiology measures the infection of the virus using the basic infection number R0, and it now appears that the basic infection of new coronary pneumonia has surpassed SARS.

On February 11th, a new study published by several universities and several research institutions in China and the United States on the paper’s pre-printing platform, medRxiv, cited one of the most detailed data to date and concluded that the new coronavirus R0 value (basic infection) was 3.77.

Only when the infection rate drops below 1 will the number of new cases gradually decrease and calm the outbreak. Under the current circumstances, a great deal of investment can be made to achieve this goal.

Experts from different backgrounds have warned that we need to plan for the long-term coexistence of the new coronavirus in response to its high lysoprene and covertness.

In an interview with Intellectuals, Professor Jin Dongxuan, Professor of Biochemistry at the University of Hong Kong, said: “If it is really very powerful and very sustained, we can’t do a lot of things that can’t be reversed, it will become routine management, we won’t seal the city because of a seasonal flu, ” said Jin Dongxuan, a professor in the Department of Biochemistry at the University of Hong Kong. The worst outcome of the future is this. “

Overseas epidemiologists have made similar statements. Alison McGeer, a professor of pathology at the University of Toronto who has worked on SARS and MERS prevention and control, concludes: “The more we know, the more we feel it is impossible to control the epidemic through public health. Humans are co-existing with a whole new virus. “

Therefore, the more likely outcome before us may not be to isolate all suspected patients, stop all production activities, families do not interact, the ban period will be extended indefinitely in order to completely block the spread of the virus, but to speed up the development of vaccines and special drugs, with the virus co-existing, each other, and the virus evolution.

And this coexistence is not in fact the “worst outcome”, and many of the viruses that have appeared in human history have finally come to this end.

Historically, human coronaviruses (HCoVs) have long been considered unimportant pathogens. There are four common human coronaviruses: 229E, OC43, NL63, and HKU1, which are already common in the population and can only cause the “common cold” in otherwise healthy people.

These today’s “harmless” common coronaviruses, similar to new coronaviruses and SARS, are also carried by bats or rats, spread across species through intermediate hosts such as birds and wild animals, and experience “mutual screening” of humans and viruses, and eventually become part of human society.

One of the results of mutual screening is that the virus is becoming less and less toxic. As the spread of the virus increases intergenerational, the historical “toxicity” of the coronavirus has been reduced. After the first transspecies spread, the new virus mutates very quickly, in which too strong the mutation causes the host to die together with the virus, interrupting transmission, and ultimately leaving low-death, highly contagious mutations to coexist to the maximum possible time with humans.

At the end of January, in an interview with First Financial, Zhang Wenhong, head of the Shanghai Medical Treatment Expert Group and director of the infection department of Huashan Hospital, concluded: “The stronger the virus (transmission) is, the weaker its toxicity may be … Because if the poison is very strong, the patient becomes seriously ill as soon as he gets sick, you are prevented, it has no chance to pass on to other people in society, so it is possible that the virus will remain. “

At present, although the clinical characteristics of the new coronavirus are similar to SARS, the fatality rate is much lower than the 9.56% sars. Data show that the current fatality rate of new coronary pneumonia is 1.4%, in some provinces have taken effective preventive measures, the fatality rate has dropped to 0.88%, the fatality rate is equivalent to some of the more serious influenza.

In addition, because of the large cognitive bias in the statistics, many virologists believe that the actual fatality rate of new coronary pneumonia may be lower.

At present, because of the new coronary pneumonia is difficult to diagnose, the statistics ignore a large number of patients with light disease and self-isolation and self-healing patients. They didn’t get treatment, they didn’t even know they were infected with the new coronavirus, and for them the process of getting sick and recovering was just a common cold.

新型冠状病毒与其他病毒平均致死率和传播数比较,图源:纽约时报

The science article, published on February 5th, also highlighted the possibility of a “co-existing outcome”. “After widespread spread, the virus may become a endemic epidemic in the population, just as the other four coronaviruses cause the common cold and occasionally new outbreaks,” the article said. “

When we accept the possibility of co-existence, the infectious disease outbreak son set by the new coronavirus looks more like a “flu Plus” than a weakened version of SARS.

Many people do not realize this possibility, in fact, because we have forgotten the history of influenza, forget that it also brought the same “horror” in the early days of its emergence, forget that it has so far taken the lives of a large number of infected people, forget that the history of mankind is more “domesticated” virus, and with the history of symbiosis, rather than the history of eradicating the virus and eliminating it.

The 1918 Spanish flu outbreak infected 500 million people, killed 50 million to 100 million, and even helped bring the first world war to an early end because countries did not have additional troops to continue fighting.

1918 年西班牙流感肆虐时的隔离病房

Today, the virus flu is a seasonal global outbreak every year, resulting in between 3 million and 5 million critical infections. The flu virus remains deadly, still causing between 250,000 and 500,000 deaths each year.

But instead of being stuck in production stagnation and imposing martial law because of a flu, we will vaccinate vulnerable people in advance and use drugs such as Tamiflu and Zanamivir to minimize losses.

Similarly, as we learn more and more about the new coronavirus, the current measures of strong isolation, represented by the city of Hubei, will eventually end, we will not come to a major blockade every winter, the key to the future will become a new coronavirus vaccine and special drugs research and development.

Our lives will get back on track, and perhaps we’ll have a new virus that’s been a weaning blow, but we don’t have to pay such a terrible life, economic cost for it. By then, we’ve learned to render too much, and we’ve long since eliminated the need for panic.

Author/Yu Fan