Prevention, we know, is always better than cure. This age-old adage has stood the test of time and has become all the more relevant now in the current pandemic of coronavirus disease 2019 (COVID‑19), caused by the SARS-CoV-2 virus. It has high transmissibility and has spread rapidly to more than 200 countries.  Since December 2019 when it first emerged, around 28 million people worldwide have been infected with the virus.

The world is eagerly awaiting a safe and effective vaccine to control the pandemic. However, a vaccine is not likely to be available for public use at least till the next year. The World Health Organization (WHO) is hopeful that the pandemic will last for less than 2 years. How will this virus evolve? We do not know.

Prevention therefore is the only answer to Covid-19. And to prevent infection, it is important to know how the virus spreads.

SARS-CoV-2 mainly spreads from person to person through respiratory droplets produced during coughing, sneezing or talking. Anybody who is in close contact i.e. within a distance of 1 m is at risk of acquiring the infection. Transmission may also occur through fomites i.e. via contact with contaminated surfaces.

Protocols for prevention focus on the routes of spread to break the chain of transmission. These preventive measures need to be followed by both the healthcare facilities as well as the general public.  It is important that we comply with them to stay healthy.

Maintain physical distancing

Physical distancing is keeping a distance of at least 1 m (3 feet), ideally 2 m (6 feet or 2 arms’ length) from other people when outside your home or in public places to prevent spread of infection. The droplets may be directly inhaled if you are in close proximity with somebody who has the infection through coughing, sneezing or even talking loudly.

Physical distancing is a better and preferred term of use instead of social distancing as social distancing implies social isolation.

• Avoid gatherings; stay at home as much as you can and step out only when it’s essential.
• Avoid shaking hands or hugging.
• If you have symptoms suggestive of Covid-19 or have been exposed to the virus, it is important to stay home i.e. “self-quarantine or self-isolate”.

 Practice meticulous hand hygiene

Hand hygiene is the simplest, effective and least expensive intervention to prevent infections including Covid-19. Hand hygiene includes either hand washing with soap and water or the use of alcohol-based hand rubs (sanitizers), which contain at least 70% alcohol or antiseptic hand wash.

Avoid touching one’s mouth, nose and eyes with dirty hands. Wash hands frequently and thoroughly, for at least 40-60 seconds); include fingers and all surfaces of the hands.  Alcohol based sanitizers should be used for at least 20 seconds.

Follow respiratory hygiene

Respiratory droplets spread the virus. Hence, the WHO recommends covering the nose and mouth with a tissue when coughing or sneezing.¹

• Cough into sleeves, not hands, if tissue is not available.
• Dispose of the used tissue promptly in the dustbin.
• Wash hands immediately with soap and water or use a hand sanitizer or antiseptic handwash after contact with respiratory secretions.

A person who is suspected to have Covid-19 should wear a medical mask.

Regularly clean and disinfect frequently touched surfaces

All frequently touched surfaces such as tables, door knobs, light switches, handles, desks, phones, keyboards, toilets, taps, etc. should be regularly cleaned and disinfected.

Use detergent or soap and water to clean surfaces if they are dirty followed by disinfection with any household disinfectant. The WHO recommends use of either 0.1% (1000ppm) sodium hypochlorite or 70-90% ethanol for Covid-19. ¹

Keep the area well-ventilated and wear gloves when using a disinfectant. Avoid using disinfectant sprays. Instead, use a cloth soaked in the disinfectant to wipe surfaces. ²

Wear a mask

Always cover your nose and mouth with a non-medical (cloth) mask when outside your home, or in public places, especially when the recommended physical distancing cannot be adhered to. The government has advised against use of masks with valves as they do not stop the virus from exhaling out.

The WHO advises: ³

• The mask should completely cover the mouth and nose and securely tied so there is no gap between the face and the mask
• Change your mask if it has become dirty or is wet.
• Do not touch the front of the mask when removing the mask. Remove by holding it from the elastic loops or ribbons.
• Wash hands immediately after removing the mask. Do not touch eyes or mouth.
• Do not share masks.

A person who has mild symptoms suggestive of Covid-19 should use a medical mask. Care givers should also wear a medical mask for their protection.

Oral hygiene

Oral hygiene forms an integral part of personal hygiene. It has been identified as a risk factor for complications associated with COVID-19 infection, especially in persons who have comorbid conditions.

The portal of entry of the SARS-CoV-2 virus is through the nose and mouth. The virus replicates in the throat, which becomes a source for the shed virus. Therefore, along with hand washing and use of masks, oral hygiene is essential to reduce the risk of infection by reducing the bacterial load in the mouth and curb spread of the virus in the community.⁴

Gargling is a commonly performed oral health-care practice. It has been hypothesized to remove the oral or pharyngeal protease, which promotes replication of the virus. ⁴

An antiseptic mouthwash which has rapid onset of action and wide spectrum of antimicrobial action is desirable. Povidone-iodine (PVP-I) fits the bill. It has universal spectrum of antimicrobial action. In addition to its antibacterial and antifungal activity, PVP-I has demonstrated virucidal activity against a range of viruses, including SARS-CoV and MERS-CoV.  It has also shown virucidal activity against the SARS-CoV-2 virus. It has been a widely used antiseptic for several decades.

In an in vitro study, all the PVP-I oral antiseptic preparations (0.5%, 1% and 1.5%) rapidly inactivated SARS-CoV-2 virus. The viricidal activity could be demonstrated at the lowest contact time of 15 seconds and at the lowest concentration of 0.5 % PVP-I. ⁵ Gargling does not eliminate the virus from the throat of the infected patient, but it may decrease the viral load and reduce droplet and air-borne transmission. Given its rapid and effective virucidal activity, PVP-I gargles can be a part of protocols for infection control for Covid-19 and “augment health and hygiene measures to reduce the spread of COVID-19 in the community”.  ⁶

PVP-I is listed in the 21st WHO Model List of Essential Medicines published in 2019. PVP-I mouthwash is also included in the WHO R&D blueprint for experimental therapies against COVID-19.

References

1. WHO Infection prevention and control during health care when coronavirus disease (COVID-19) is suspected or confirmed Interim guidance 29 June 2020
2. Q&A: Considerations for the cleaning and disinfection of environmental surfaces in the context of COVID-19 in non-health care settings, WHO. May 16, 2020. Available at: https://www.who.int/news-room/q-a-detail/q-a-considerations-for-the-cleaning-and-disinfection-of-environmental-surfaces-in-the-context-of-covid-19-in-non-health-care-settings
3. WHO Advice on the use of masks in the context of COVID-19 Interim guidance, 5 June 2020. https://www.who.int/publications/i/item/advice-on-the-use-of-masks-in-the-community-during-home-care-and-in-healthcare-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak 
4. Maren Eggers, Torsten Koburger-Janssen, Markus Eickmann, et al. In vitro bactericidal and virucidal efficacy of povidone-iodine gargle/mouthwash against respiratory and oral tract pathogens. Infect Dis Ther. 2018 Jun;7(2):249-259.
5. Avinash S Bidra, Jesse S Pelletier, Jonna B Westover, et al. Rapid in-vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using povidone-iodine oral antiseptic rinse. J Prosthodont. 2020 Jul;29(6):529-533.
6. Anderson DE, Sivalingam V, Kang AEZ. Povidone-iodine demonstrates rapid in vitro virucidal activity against SARS-CoV-2, the virus causing COVID-19 disease. Infect Dis Ther. 2020:1–7.

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA