HOCl against Coronavirus Covid-19

Abstract:
The surgeon needs to have an inexpensive, available, nontoxic, and practical disinfectant that is effective in sanitizing against the COVID-19 (Coronavirus Disease 2019) virus. The purpose of this article was to review the evidence for using hypochlorous acid in the office setting on a daily basis. The method used to assemble recommendations was a review of the literature including evidence for this solution when used in different locations and industries other than the oral-maxillofacial clinic facility. The results indicate that this material can be used with a high predictability for disinfecting against the COVID-19 (Coronavirus Disease 2019) virus.

COVID-19 (Coronavirus Disease 2019) Virus Structure and Mechanism of Infection

Coronavirus Disease 2019 (COVID-19) is a novel virus. It causes severe acute respiratory syndrome. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent responsible for a surface-to-surface communicable disease that had infected approximately 4.7 million persons as of May 17, 2020. Health care providers need options to limit and control the spread of the virus between themselves and patients.

COVID-19 is an enveloped, positive-sense, single-stranded RNA virus approximately 60 to 140 nm in diameter. The virus's Spike glycoprotein S1 firmly binds to the angiotensin converting enzyme 2 (ACE2) receptor, which allows entry into the host cell. COVID-19 infection creates a cytokine storm, severe pneumonia, multiple-organ failure, and acute cardiac injury.

Transmission occurs through touch or aerosol spreading of the virus. A common pathway of spreading this virus is through respiratory aerosols from an infected person. During speech, humans emit thousands of oral fluid droplets per second that can remain airborne for 8 to 14 minutes. COVID-19 is detectable for up to 3 hours in surface aerosols, for up to 4 hours on copper, for up to 24 hours on cardboard, and for up to 2 to 3 days on plastic and stainless steel. There is a need to disinfect surfaces potentially exposed to COVID-19 to prevent transmission.

Discussion

The coronavirus pandemic has caused both a massive health care and economic disruption across the world. The current unavailability of an effective antiviral drug or approved vaccine means that the implementation of effective preventive measures is necessary to counteract COVID-19. Oral-maxillofacial surgeons are high-risk providers providing needed care to patients. As more OMS and surgical offices open during reopening in the United States and elsewhere in the world, the need to reduce the risk of transmission of COVID-19 between patients and providers is necessary. It is widely believed that with proper screening and discretion, along with adequate personal protective equipment, there is a low probability of becoming infected. The goal of this article is to provide information regarding disinfection in the clinical office setting using HOCl, a relatively inexpensive, nontoxic, noncorrosive, and well-studied compound.

HOCl has uses in many industries from farming and restaurants, regarding food, to health care applications, including chronic wound care and disinfection. In addition to the use of HOCl as a liquid-based disinfectant, fogging with hypochlorous vapor has shown virucidal activity against numerous types of viruses and bacteria. This is of potential benefit to disinfect large spaces such as medical and dental offices where aerosols can be airborne for extended periods. In terms of particle size, oral-maxillofacial surgeons may be at a slightly lower risk than their dental counterparts because ultrasonic scaling and high-speed handpieces create smaller particles that remain airborne longer. However, aerosols are still created with surgical handpieces. Additionally, the COVID-19 virus can be present on some surfaces for days, and the disinfection of all surfaces of an operatory is important to reduce transmission.

Many properties of HOCl contribute to why it may be the disinfectant of choice in the OMS setting. Although the shelf life of HOCl is relatively short, it is effective for up to 2 weeks under ideal conditions. It can be made on-site inexpensively. A gallon of HOCl can be purchased from manufacturers but it is far more economical for an oral-maxillofacial surgeon to produce the solution on-site in the office. A variety of HOCl systems costing less than $275 are available on the market. By combining non-iodinated salt, water, and electricity, 1 L of HOCl can be made in 8 minutes and the process can be repeated many times throughout the day. By comparison, a pack of common disinfecting wipes containing quaternary ammonium compounds costs between $4 and $15 for a pack containing 80 sheets. These wipes may only last a day or two depending the size of the office and area to clean. Shortages of these products can occur, making sourcing them difficult as well.

In addition to using HOCl in the form of wipes for disinfecting, using HOCl vapors through a fogging machine is an economical way to disinfect a large operating room or suite in which aerosols were produced during surgery. Foggers or misting machines are handheld machines and can be purchased for a reasonable cost. The aerosol mist ideally should be less than 20 μm in size to maximally disinfect an area. It is important to note that the fogging process can alter the physical and chemical properties of the disinfectant, making it more dilute and basic. As mentioned before, the AFC concentration can be reduced by approximately 70% and the pH can increase by about 1.3. To make a vapor as effective as a solution containing 100 ppm of HOCl, the solution would need to be concentrated. The fine mist can be left in the empty surgical room without thought regarding harmful chemical effects; the surfaces are then wiped clean and dry after a few minutes and, for a more dilute solution, after 10 minutes.

HOCl is one disinfectant that, when combined with adequate personal protective equipment, screening and social-distancing techniques, hand washing, and high-volume evacuation suction, may help reduce the transmission of COVID-19 in the outpatient OMS setting. It comprises many of the desired effects of the ideal disinfectant: It is easy to use, is inexpensive, has a good safety profile, and can be used to disinfect large areas quickly and with a broad range of bactericidal and virucidal effects.