Shanghai Treatment Expert Group: It is not appropriate to over-interpret the fecal spread of the new coronavirus

Recently, the outbreak of Wuhan’s new coronavirus pneumonia has attracted worldwide attention, and the information bombing on social media has touched the hearts of the people of the whole country. In order to help you understand the dynamic changes in the epidemic, Fudan University affiliated Huashan Hospital infection department WeChat public number “Huashan infection” daily update of the epidemic-related data, and invited Huashan Hospital infection experts Wang Xinyu, Zhang Wenhong on the epidemic trends, hot issues and related precautions, specifically to answer questions and interpretation.

Wang Xinyu is the deputy director of the infection department of Huashan Hospital, Zhang Wenhong is the director of the infection department of Huashan Hospital, the Standing Committee and Secretary-General of the Chinese Medical Association’s Infection Credit Association, the vice chairman of the Infection Branch of the Chinese Society of Preventive Medicine, he leads the Huashan Hospital Infection Department is a national key discipline, participated in the treatment of SARS and human infection with H7N9 avian influenza, Zhang Wenhong is also the head of the expert group on the medical treatment of pneumonia with the new coronavirus infection in Shanghai. Since the outbreak in Wuhan, Wang Xinyu, Zhang Wenhong continued to track, has been in the “Huashan infection” even written several articles, their text is both professional and rigorous and easy to understand, the news authorized to forward, we hope that “Huashan infection” this group of articles to readers more rational view of the epidemic, more effectiveself in self-protection work has been beneficial.

NEWS: New coronary pneumonia patient’s feces detects positive virus nucleic acid, sparks panic

From February 1st, the center of gravity for the new coronavirus has shifted back to the route of transmission, as a series of studies have found that viral nucleic acids can be detected in the feces of new coronary patients. This can not be caused by another public panic, it is not the mask is all white, hands are also white wash? The previous safeguards were futile?

Source:

First reported in a paper published in the New England Journal of Medicine, a leading U.S. medical journal, which documented the details of the first case of new coronary pneumonia admitted to the U.S. mainland, one of the two highlights of the paper was the detection of the nucleic acid of the new coronavirus in the patient’s faeces.

Immediately after the media reported that the three hospitals in Shenzhen revealed that the institute’s liver disease research found that some of the new coronary virus infection of pneumonia confirmed patients in the feces tested positive for 2019-nCoV nucleic acid.

Expert interpretation: it is not appropriate to over-interpret the spread of the new coronavirus’s feces, careful response can be

01. Which infectious diseases are transmitted through the?

First of all, explain to everyone what is called manure mass spread. Fecal mouth transmission is a transmission route of many infectious diseases, and we talked about the spread of droplets, contact transmission and so on. The so-called feces transmission, refers to because the digestive tract contains a large number of pathogens (infectious substances), excreted through feces, because the feces directly contaminated food, or contaminated hands, and then indirectly polluted food, through the digestive tract into the body, resulting in the process of infection.

Infectious diseases that are common routes of fecal transmission include hepatitis A virus, viral hepatitis E, and infectious diseases that can cause diarrhoea, such as norovirus gastroenteritis, typhoid fever, cholera, etc.

So what are the common features of these infectious diseases? It is a symptom of the digestive tract, especially diarrhea and vomiting. In other words, fecal propagation and digestive tract symptoms are often paired and rarely accompanied by respiratory symptoms.

Let’s look at the pathogens that are known to be characterized by respiratory symptoms, such as rhinoviruses, para-flu viruses, influenza A and influenza B viruses, respiratory syncytial viruses, adenoviruses, mycoplasma pneumoniae, etc. are all spread by respiratory and contact transmission, none of which is spread by dung. Even though some pathogens have a small number of diarrhea symptoms, this is only part of the overall performance, a small proportion, generally does not become an effective route of transmission.

So what about the other coronaviruses that have been found before? Common human coronaviruses (including 229E, NL63, OC43, and HKU1) usually cause mild or moderate upper respiratory diseases, such as colds. Symptoms include runny nose, headache, cough, sore throat, fever, etc., sometimes causing pneumonia or bronchitis and other lower respiratory diseases. In the years since the virus was discovered to the present, there have never been clear cases of fecal transmission routes reported. MERS-CoV and SARS-CoV often cause more severe symptoms. Symptoms usually include fever, cough and shortness of breath, and even develop pneumonia, but there are no clear cases of fecal transmission.

02. Is it true or false: someone has said that SARS in 2003 may have feces spread?

At this time, some people will take the 2003 SARS pandemic, Hong Kong’s Taobao Garden concentrated outbreak case to say, that is not the way of dung?

Let’s start by reviewing the circumstances of the time. In late March 2003, SARS broke out in Hong Kong’s Taobao Garden. As at 15 April 2003, there were 321 SARS cases in Taobao Gardens. Infections were clearly concentrated in Block E, accounting for 41 per cent of the cumulative total. There were 107 residents of Taoda E infected with SARS, most of whom lived in vertical units of 7 and 8 of Seat E. Seating, like the rest of the buildings in Taobao Garden, is 33 storeys high and has eight units on each floor. Each building has eight upright sewage pipes to collect sewage. The sewer sits connect to the water toilets, washbasins, bathtubs and bathroom spit drains, each with a U-shaped water collector.

According to a joint survey conducted by several official agencies in hong Kong SAR, China, u-shaped water concentrators connected to toilets, bathtubs, etc. are often used, and can act as an isolation is available most of the time. However, since most households are accustomed to using mops rather than water when cleaning the bathroom floor, the U-shaped water concentrator that connects the drains of the platform may not be able to act as an isolation is due to drying up. According to the relevant investigation, when the bathroom fan is activated, the air will flow back into the bathroom from the sewage pipe through the drain on the platform. It is speculated that these air currents may have emitted viral fluid stored in sewage pipes to the indoor and adjacent units of the patio, which eventually entered adjacent homes through a window.

Therefore, the relatively complete chain of infection in Taobao Garden is that the source of the patient may first pass through the sewage discharge system in Si- E, human-to-human contact, and the building’s public facilities (elevators and stairs), so that a group of residents in the unit building infected with the virus, and then infected with other households in the same seat. It may then spread the virus to residents inside and outside Block E through human-to-human contact and contaminated environmental facilities. After investigation, the authorities believed that the spread of the disease was mainly related to the design of the structure of the house, and that the virus could be transmitted through excreta or waste water.

Shanghai Treatment Expert Group: It is not appropriate to over-interpret the fecal spread of the new coronavirus

03.WHO later denied the possibility that SARS could spread in 2003

Why can’t the relatively complete chain of evidence be confirmed by the WHO? First of all, the chain of evidence is only a seemingly reasonable reasoning, no further research to confirm. That is to say, there is no way to prove that in one drain poured into a certain number of viruses, can be detected in the same unit on other floors of the house, and secondly, even if the feces spread, that feces is discharged into the dung pipe, and the ground leakage of the U-shaped tube is not connected, if used to explain the vomit, it is also far-fetched. Because even the highly contagious norovirus is known to be known today, it has never been proven to cause other floors by leaking vomit into the ground. One step further, even if it is really ground leakage caused the production of aerosols, that ultimately lead to infection is the respiratory tract, rather than the digestive tract, is not really “fecal transmission.”

So, Taobao Garden only presents a spreading hypothesis, but this hypothesis has not been proved. And even if the Taoda Garden hypothesis is confirmed, it can only explain the outbreak of Thebig Garden itself, not the thousands of confirmed CASEs of SARS that have occurred around the world before and after.

Finally, the successful control of global SARS in 2003, which did not do much control over manure control, has shown it all.

04. Say back to this new corona virus, if still worried about what to do?

If the virus nucleic acid in the feces spreads, there is also a possibility that the patient after defecate in the toilet, the solution produced by the pumping may cause infection.

This problem actually follows the last one, and our hypothesis is that the feces does contain a lot of viruses. As long as the premise of a large number of viruses is established, the aerosol contains the virus, the risk of transmission is still possible. However, if the toilet is used at home, the risk of close contact and direct respiratory transmission must be greater than the risk of aerosol inhalation from the flush toilet.

Shanghai Treatment Expert Group: It is not appropriate to over-interpret the fecal spread of the new coronavirus

How to reduce the risk of the toilet producing aerosols?

Cautious approach is that the home isolation of suspected patients in fact as long as the use of toilet flush, remember to cover the toilet lid and then flush it, this action can greatly reduce the concentration of aerosols in the air. Conditional patients can also be discharged after fecal nucleic acid transfer, but not necessary conditions.

Summary

The detection of viral nucleic acid in the feces of patients with new coronavirus pneumonia does not mean that the feces is contagious, and the transmission of feces is not theoretically very likely.

But whether it’s nursing patients with new coronary pneumonia or daily life, developing good hygiene habits, such as washing hands frequently, using the toilet lid behind the toilet and flushing it, can better protect you from reducing your risk of contracting a variety of infectious diseases, including the new coronavirus.

Of all the known viruses, none is an all-powerful warrior, either through the respiratory tract, through the digestive tract, and through body fluids. From a strategic point of view, the high fatality rate of a virus is bound to be not far away, a virus is relatively infectious and inevitable toxicity is relatively weak, which is the law of virus survival. Just for the 2019-new coronavirus, which has only been discovered by humans for more than a month, there are still many unknowns waiting for humans to discover.

The Internet era is an era of distorted expression, can quickly produce a network of celebrities, can also exaggerate any phenomenon. It is recommended that you pay special attention to statements that are highly consistent with your own ideas, be especially alert to any simple and crude statements, and learn to properly evaluate arguments and reasoning patterns.

Only by treating viruses and outbreaks scientifically can we control the outbreak better and faster, and victory will surely belong to us.

(This article was originally entitled “Zhang Wenhong: should not over-interpret the spread of the new coronavirus, prudent response can be”, author Zhang Wenhong for the Shanghai medical treatment expert group leader, Huashan Hospital infection director, WeChat first in the public number “Huashan infection”, copyright to Fudan University affiliated Huashan Hospital infection department, the news is authorized to forward.) )