Several transmission routes of COVID-19

Time: 2020-03-30 11:58:10 This Article is Composed by www.lightfromchina.org

How does the COVID-19 spread?

Here are some of the most common routes of transmission. (source: National Healthy Commission: COVID-19 transmission and prevention guidelines )

THE MAIN WAYS OF TRANSMISSION:

1. Droplet transmission

Sneezing, coughing, talking and breathing can produce droplets. And having a close contact with patients infected with novel coronavirus could also cause coronavirus transmission, especially when they are speaking or coughing without wearing a mask.

Droplet transmission  
Droplet transmission

2. Contact transmission

As droplets from coronavirus patients have contaminated object surfaces through contact with them by chance, people will be infected with the disease when they touch their mouths, nasal mucosa and other tunica mucosa after touching the contaminated object surfaces.

Contact transmission
Contact transmission

SPECIAL WAYS OF TRANSMISSION:

1. Aerosol transmission

It means that the droplet nucleus composed of protein and pathogens, which is formed by droplets from coronavirus patients that lose their fluids in the air suspension process, could float afar through the mode of aerosol, bringing a long-distance transmission.

Aerosol transmission
Aerosol transmission

2. Feces-mouth transmission

3. It means that if food and water are contaminated by coronavirus patients’ feces, people will be infected with the disease when food and water enter into the human digestive tract.

Feces-mouth transmission
Feces-mouth transmission

4. Other routes of transmission 

In addition, the coronavirus could also be spread when people have close contact with animals  or eat undercooked meat carrying the coronavirus.

LOW PROBABILITY WAYS OF TRANSMISSION

1. Is it possible to spread the coronavirus by skin contact? ---No. 

The fourth edition of the COVID-19 Treatment Program issued by the National Health Commission mentions the “contact transmission” of the coronavirus. The “contact” here means the contact with the tunica mucosa such as mouth, nose, and eyes. Unless skin cuts exist, people through skin contact will be infected with the disease.

2. Is it possible for feces or sewer to spread the coronavirus? ---Maybe

According to the official Weibo news of the Shenzhen Municipal Health Commission, on February 1, the Third Shenzhen People’s Hospital revealed that the research conducted by the Institute of Liver Disease found that the feces of confirmed patients with the novel coronaviruse were tested positive for COVID-19. This may indicate the presence of live virus in the feces. This finding illustrates the risk of feces-mouth transmission. (Source: Liu Yanxia, Department of Laboratory Medicine, Zhujiang Hospital of Southern Medical University) However, according to the National Health Commission, the ability and conditions for such transmission need further research and confirmation.

3. Are takeaways and express delivery likely to spread the virus? --It’s not a high probability, but it’s worth your attention.

In terms of takeaway or express delivery transmission, Zhan Qingyuan, the national novel coronavirus clinical supervisor expert and the director of the fourth and fifth respiratory departments of China-Japan Friendship Hospital, said: “The infection risk is extremely low.” In addition, he pointed out that the rate of contact with takeaways is also relatively low, and the main contact relies on the packaging bag. While experts note that the likelihood of the coronavirus spreading via takeaways or express delivery is minimal, that doesn’t mean it’s impossible. Therefore, during this special period, in addition to the purchase of essential daily necessities, we should try to reduce the chances of takeaways and express delivery, in order to reduce the probability of infection. (Source: CCTV news)

4.  Is it possible for the coronavirus to be transmitted directly from mother to child? --It’s not clear for the moment

Although COVID-19 has previously been identified in two newborns, it is not clear how the two babies were infected with the disease. But there are precedents that a confirmed pregnant woman gave birth to a healthy baby. Therefore, judging from the present situation, even though the pregnant mother is infected with the coronavirus, the baby could also grow healthily in her womb.

5.   Is aerosol transmission possible in daily life? --Less likely

Aerosol transmission requires three conditions simultaneously, namely confined space, long time and high concentration of coronavirus, therefore aerosol transmission is possible under such extreme conditions. Ordinary people, in daily life environment with good ventilation conditions, have a very low probability of transmission, so to speak, there is almost no infection risk of aerosol transmission.

Our advice for you

1.   Advise your family to reduce unnecessary outdoor activities

Your family seems healthy, but he may be an asymptomatic carrier! The Asymptomatic carrier refers to an infected person who has no clinical diagnosis such as fever, cough, and eye pupils but a positive antibody test. According to paper issued in the Volume 41, 2020, of Chinese Journal of Epidemiology, the infection rate of close contacts with asymptomatic carriers is 4.11%. Asymptomatic infections have been found mainly in people with close contacts with patients, such as among families. If you have no travel recording to the epidemic areas and their surroundings over the past 14 days, no family-onset disease breaks out around you, and you have no close contact with confirmed or suspected patients, you do not need to worry too much. 

2.  Take protective measures when you need to go out

You should strengthen awareness of protection. Going out for walks, gathering with friends and walking your dog are all undesirable behaviors during the epidemic outbreak. In special times, you should develop the habit of wearing a mask, and you’d better not to go out. Your decline of a friend’s warm-hearted invitation is a commitment to the life of both him and his families.

Proofreader: Wang Qianqian  Zhang Nana
Translator:He YipuDing JiahuaWu ChanyuLu QianqianLi Sirui
Compiler of Chinese materials:Chang GengyuanZhang Xiaomin

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