Effect of Ay Tsao fumigation disinfection in fence system on prevention of COVID-19

A new type of coronavirus SARS-CoV-2 has erupted around the world, and China has now effectively controlled the epidemic in its territory, and providing strong support to the global fight against COVID-19. One of china's effective control measures is that the using of Ay Tsao fumigation disinfection to curb the spread of the virus. In response, we looked through government documents issued throughout China requesting the use of Ay Tsao fumigation disinfection, then we investigated the effectiveness of the elimination of all levels of medical institutions which use Ay Tsao fumigation disinfection and the results showed these institutions achieved the desired results: so many medical units which used Ay Tsao fumigation disinfection has completely controlled the spread of the virus in their closed public space, and there was no infection in his inner space. Furthermore, based on the chemical structure of the synaptation of the volatile components of Ay Tsao and the SARS-CoV-2, we speculate the mechanism of the effective substances in Ay Tsao to against the SARS-CoV-2.


Introduction
According to Worldometers global real-time statistics, as of 07:30 Beijing time on April 10,2020, the number of confirmed cases of COVID-19 in the world has exceeded 1.6 million, reaching 1600185, of which 95559 have died. In the war between human and SARS-CoV-2, many countries need to recognize and recognize what has happened.

The Chinese Government promotes the use of Ay Tsao fumigation disinfection in public places
China's government decisively adopted closed isolation measures, and immediately to apply a combination of health management fence system [1] (Figure 1), which effectively curb the spread of the SARS-CoV-2 in China. China's efforts to fight the COVID-19 have earned time and experience for other countries. The palisade system has shown extremely high feasibility in preventing epidemic, hazardous, and infectious diseases over time, such as middle east respiratory syndrome (MERS) [2], severe acute respiratory syndrome (SARS) [3].
The system is mainly composed of 5 fences :1. Clean environment 2. Indoor air disinfection 3. Wear masks, wash hands, separate meals 4. Improve immunity diet 5. Physical exercise. The indoor air fumigation and disinfection in the fence system is required by Chinese government departments at all levels medical units. The fence principle of preventive measures: each fence is not as high as the highest infectious activity of the virus, but each fence can reduce the vitality of the virus to a certain extent (the percentage in the picture, obtained by statistics), and ultimately prevent the virus. So long as the virus does not erupt in the body, we can resist it through our own immunity; so long as the speed of transmission of the epidemic can be controlled, the epidemic will not crush medical system.
The second fence in the system is indoor disinfection, in which Ay Tsao fumigation ( Figure 2) in a public closed space is an epidemic prevention measure with obvious characteristics of traditional Chinese medicine [4]. It is one of the most important methods of epidemic prevention in the documents issued by governments all over China. The smoke and volatiles produced by Ay Tsao can effectively block the transmission of the virus through aerosol ( Figure 3). Therefore, the use of Ay Tsao fumigation disinfection in hospitals and wards can significantly prevent the occurrence of cross-infection [5]. The data shown that the average sterilization rate of indoor can reach 91% [6], which conforms to 96% and 100% of class II and III environmental hygiene standards, and has completely reached the hygienic standard  of the total number of bacterial colonies in the ambient air of hospitals and wards. Moreover, Ay Tsao is cheap and easy to obtain in China. The use of Ay Tsao for fumigation is not only suitable for hospital air disinfection, but also for office, bus vehicles, home disinfection, which is very effective for a closed environment.

The Conception of the Anti-Virus Principle of Ay Tsao
According to the structure of the SARS-CoV-2 and the molecular characteristics of the "spike glycoprotein" (Figure 4), we speculated that the components of β-Caryophyllene ( Figure 5) in the volatile material of Ay Tsao interacted with the virus particles, thus reducing the viral infection efficacy. β-Caryophyllene contains two double bonds, which can penetrate into the virus through the viral membrane and resonate with the two bonds in the ring structure of the atgc in the viral RNA, disrupting the environment of the RNA replication procedure, which may be a way to fumigate the virus. Wang analysied the clinical characteristics of 138 2019-nCoV inpatients in Wuhan, the results showed that 41.3% of the patients may have occurred through nosocomial infection [7]. And the Ay Tsao fumigation may be able to accelerate particle settling velocity through condensation and polymerization between small particles, thus blocking the SARS-CoV-2 propagation through aerosol ( Figure 6).
On the other hand, modern medical pharmacology has proved that Ay Tsao is an antibacterial and antiviral drug, which has the effect of inhibiting and killing germs, and also has the effect of preventing and treating respiratory diseases. There have been studies showing that the effective substances in Ay Tsao can stimulate the human immune system and guide human immune cells to phagocytosis of virus particles (Figure 7). existing in vitro experiments have shown that essential oils and other active components in Ay Tsao (Figure 8) have broad-spectrum antibacterial, antifungal, and viral inhibitory abilities. Modern studies have also proved that moxibustion therapy can catalyze, activate the body's immune system, improve the level of immune response, adjust the imbalance of norepinephrine (NE), serotonin (5-hydroxytryptamine), etc. In neurotransmitters, Ay Tsao can promote the stability of the environment within the collective so as to play a role in preventing and treating diseases [8].
From the study of different viruses in vitro, it was found that the essential oil of Ay Tsao which extracted by steam distillation, had the activity of anti-acne-herpes zoster virus (varicella-zoster virus, VZV), and the higher the dose, the more lasting the inhibition effect [9]. The      The epidemic prevention measures adopted in China by Ai fumigation disinfection benefit from China's abundant Ay Tsao resources, and various forms of Ay Tsao processing methods also make an important contribution to the large-scale use of Ay Tsao fumigation disinfection in China. where the graphene strip fumigant production line is shown in (Figure 9). The product has the advantages of high strength (up to metal material strength), waterproof, longterm fumigation (2h/cm), no environmental pollution (PM2.5) and so on.

Results from the use of fumigation
Ay Tsao fumigation disinfection is included in the epidemic prevention program of governments around China (Figure 10), which will be used for a long time according to the current situation of the world epidemic. we counted the medical units that use emaciation to achieve 100% containment of virus infection (Table 1) and showed the effect of epidemic prevention and control in the area where the medical unit is located (Figure 11).  . Effect map of epidemic prevention and control in the area using Ay Tsao fumigation disinfection (A) Regional map of the peak epidemic in China (B) Regional map of the controlled epidemic in China

Conclusion
The COVID-19 was first outbreak occurred in China, we did not get any warning, nor any experience from other countries to learn from, our country's public health infrastructure is not as good as developed