Written by Prof Robert Bragg working at the Department of Microbiology and Biochemistry at the University of the Free State, Bloemfontein, South Africa
Covid-19 and the disinfectants “Fungisolve”
The recent rapid outbreak of what appears to be a completely novel strain of coronavirus in Covid19 in China is causing much concern around the world. This virus has tentatively been called Covid19 coronavirus, and this terminology will be used in this document. The world just needs to be reminded of the outbreak of Severe Acute Respiratory Syndrome (SARS) virus and the devastating consequences that virus caused. The Covid-19 virus, like SARS, are both coronaviruses. Both viruses started off in China. SARS had a human mortality rate of around 15% and increasing to 50% in people older than 60 years of age. What eventually brought the SARS outbreak under control was the fact that infected persons were not infectious until they were showing clinical signs of infection. It was thus possible to control the spread of the disease by isolating people showing clinical signs. This is not the case with Covid-19 coronavirus, as it has been established that a person in infectious without showing clinical signs. This is a similar way in which Influenza virus spreads. This makes the control of this virus very difficult. The world is on the verge of a major and serious pandemic.
The family of viruses known as coronavirus have been known for a long time. Characteristics of this virus, and the main characteristic which gives this group of family it name, is the crown-like structures which are found on the surface of the virus, known as the spike protein. The genome of this virus is made up of RNA. This means that the virus is highly likely to evolve and change. In many of the known coronaviruses, there are hypervariable regions in the spike protein which can result in the virus changing serologically. This can make vaccine development difficulty.
Coronaviruses are enveloped viruses. The enveloped viruses are generally much more susceptible to the action of disinfectants that the highly resistant naked viruses. If the viral envelope can be disrupted, the virus can no longer infect the host cell and the virus is effectively neutralized.
One of the major diseases in poultry, called infectious bronchitis is caused by a coronavirus called Infectious bronchitis virus.
The disinfectant “Fungisolve”
It will be very difficult to get any tests done on any disinfectant against the new Covid-19 coronavirus. All indications are that this is a novel virus and any tests on the efficacy of a disinfectant can only be performed once it has been established if this virus can be grown in a culture system such as a cell line or in embryonated chicken eggs. Because of the human health risks, working with this virus would need to be done in at least a Biological Safety level 3 (BSL-3) laboratory but preferably a BSL 4 laboratory. There are a limited number of BSL 4 laboratories in the world. Any work which will be currently undertaken in such high-security laboratories would be focused on understanding the virus. The procedures to test a disinfectant against a virus is straight forward. Option 1 is to perform titrations of the virus with and without exposure to the disinfectant under test. Because most disinfectant are toxic to the culture system in which the virus is grown, a 4 log reduction in virus titer is regarded as sufficient to pass a product. The other option is to mix the virus with the recommended dilution of product under test and then test for survival of virus. This is only possible if the disinfectant under test proven to be non-toxic to the culture system used for the virus. Full protocols can be supplied if a laboratory can be found where this virus can be tested.
So the likelihood of getting test data on the efficacy of any disinfectant against the Covid-19 coronavirus is very small. Thus, when deciding what disinfectant to use to combat the virus, authorities will have no option but to look at efficacy data on other coronaviruses.
Fungisolve has been extensively tested against the avian coronavirus (Infectious bronchitis virus). Test results obtained against IB Virus have been included.
The “go-to” disinfectant in the case of a serious disease outbreak is often Virkon S. The efficacy of Fungisolve has been compared to that of Virkon S in various tests. The efficacy of the two products are very similar against all pathogens tested. Pathogens tested include the very difficult to kill naked viruses, enveloped viruses, bacterial endospores, Gram negative bacteria, Gram positive bacteria, yeast species and fungal species.
Fungisolve has two main advantages over Virkon S.Fungisolve is highly stable when diluted. Tests were performed up to nine months. Virkon S is not stable when diluted.Fungisolve is non-corrosive, where Virkon S is highly corrosive.
- Fungisolve has been shown to be highly effective against coronaviruses.
- Fungisolve has also been shown to be highly effective against the significantly more difficult to inactivate naked viruses.
- Fungisolve is the least toxic, highly effective disinfectant currently available.
- Fungisolve is non-corrosive and highly stable when diluted.
- Fungisolve is not pH dependent and is not temperature sensitive.
- Fungisolve would be the best disinfectant to use for the disinfection of all surfaces for the control of this virus.
*Fungisolve contains the same active ingredient as Sporekill (see link above)