Covid-19

The explosion of cases of the disease in humans caused by the corona viruses

On 30 January 2020, WHO declared Covid-19 as an international public health emergency that threatened countries with very weak health systems. The well-known corona viruses that cause disease in humans are severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003, Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, and the 2019 novel coronavirus (2019-nCoV, which was then officially formalized named SARS-CoV-2) at the end of December 2019 (Tu et al., 2020). The corona virus that causes MERS was first discovered in 2012 in Saudi Arabia (Al-Osail and Al-Wazzah, 2017, Al Hazmi, 2016). This disease can heal itself and generally appears only in Middle Eastern countries.

Corona virus transmission in all 3 cases

SARS is believed to be transmitted through aerosols produced by sufferers when coughing or sneezing. The virus will spread from the droplet to the closest people in the surrounding environment through the air through the mouth, nose and eyes. The virus can also spread by touching the infected surface and then touching the mouth, nose or eyes (Al-Hazmi, 2016, Centers for Disease Control and Prevention, 2014).

At present, there is very little research on the pathophysiological characteristics of COVID-19, and there is still much uncertainty about the mechanism of its spread. The virus that causes the respiratory disease is very contagious when the patient shows symptoms. However, there is considerable evidence that human-to-human transmission occurred during the asymptomatic Covid-19 incubation period, which is estimated to be between 2 to 10 days (Sohrabi et al, 2020).

The structure of the corona virus

Corona viruses are circular or enveloped pleomorphic particles containing single-stranded RNA associated with nucleoproteins in the form of capsid protein matrices. The viral envelope contains a protein in the form of spikes that leads outwards so that it is shaped like a crown or halo (Baron, 1996).

The corona virus genome consists of about 30,000 nucleotides which encode 4 structural proteins, nucleocapsid protein (N), membrane protein (M), spike protein (S) and protein envelope (E) and several non-structural proteins (nsp). The capsid is a protein envelope, inside the capsid, there is a core capsid or N-protein attached to a single strand of RNA that makes the virus able to enter human cells and turn it into a virus factory. Protein-N envelops the viral RNA genome which plays an important role in its replication and transcription (Boopathi, 2020). Corona virus is an RNA virus with spikes containing protein and fat-containing envelope. These parts are very fragile against heat, UV, and some chemicals.

Virus prevention and control

Many reported preventative measures against COVID-19 SARS virus infection, including increasing body immunity by using Chinese herbal plants (Hui et al, 2020), using a combination of herbal plants and vitamin C (Chen et al, 2020), using eucalyptus oil or eucalyptus oil (Usachev et al., 2013), using ginger (Chang et al., 2013). While the spread and prevention control is done by diligently washing hands and wearing masks and environmental disinfection. One way to disinfect the environment is to reduce the amount of virus in the air, especially in confined spaces where air circulation is limited. This method can be disinfected using UV light, with ozone, and with heat.

Disinfection with heat

Disinfection with heat is recommended by the USDA (US Department of Agriculture) for animal pens that are affected by avian influenza. The technique is to heat the room for 2-7 days at 100-1200F or 37.8-48.90C (USDA, 2016; USDA, 2018). For Covid-19 therapy, Biovox (2020) even created a device to heat the patient in a controlled heating device that worked at 41.50C for 3 hours in the patient's state of anaesthesia. It is hoped that the virus will be destroyed and produce pieces of antigen that can trigger the operation of the immune system in the patient's body. Kampf et al. (2020) reported that in test tubes, the SARS Cov-2 virus strain in various parts of the world could be inactivated varied for 1 minute at 800C to 80 minutes at 310C. The averages are 600C for 30 minutes, 650C for 15 minutes, and 800C for 1 minute, with a reduction of 104. Even for the SARS CoV virus, denaturation of nucleocapsid proteins in the membrane occurs perfectly at 550C for 10 minutes (Lee et al., 2005 in Kampf et al., 2020).

Disinfection with UV light

UV-A, UV-B and UV-C rays are effective against MRSA and Gram-negative bacteria (Sheldon et al., 2005). The use of a room disinfection system with UV-C using an automated triple-emitter has successfully activated mouse hepatitis virus, A59 strain (MHV-A59) and MERS-CoV virus on the surface of objects with a reduction greater than 105 (Bedell et al, 2016). It was also found that aerosols from the corona virus were 7-10 times more susceptible to UV-C compared to MS2 aerosols and adenovirus aerosols. Unlike bacterial aerosols, moisture does not affect the susceptibility of the corona virus. Also, the level of disinfection by UV-C is very different for corona virus aerosols compared to corona virus solutions (Walker and Ko, 2007).