Controlling the transmission of COVID 19 – a concern for all

We all are in the middle of a pandemic and the whole world is fighting agitatedly to recover. It started in December 2019 in Wuhan, China and silently transmitted to humans, eventually gained momentum for human-to-human transmission.  

With the increase in world population, industrialization, globalization and urbanization, it is now much easier for a contagious disease to spread worldwide within a short period of time, unless necessary measures are taken. 

Scientists claim that if this virus could be controlled from the beginning with due seriousness, such a catastrophic situation would not have arisen. 

Generally, a nation is supposed to report any unusual cases or diseases immediately to the WHO so that necessary steps can be taken. Unfortunately, Covid-19 was asymptomatic in the beginning, which made it difficult to take necessary steps to limit its transmission. 

It is imperative for us to learn about the modes of transmission of this deadly virus so that we may play our part in breaking its transmission cycle.

Human-to-human transmission

A healthy person can get infected through droplets (>5 µm) while talking, coughing and sneezing. As the droplets can remain air-borne for some time, it may be transmitted through air while staying in close proximity or being within 6 feet or 2 meters (14 feet in some reports) of the infected person, contact with fomites (any objects where the droplets have landed) and feces (some coronaviruses cause diarrhea). In such cases, frequent hand-washing, maintaining social distance and using appropriate personal protective equipment (PPE) should be considered.
Transmission through the environment
The coronavirus can survive in droplets for up to 3 hours, on surfaces for 7-8 hours, on cloths and tissues for 8-12 hours, on flat smooth surfaces (glass, ceramics) for 24-48 hours, in a drink for up to 4 days and a refrigerator for 1 month. Suggested disinfectants are, any detergent (for household use e.g. hand wash), 70% ethyl alcohol for small areas, and 0.5% sodium hypochlorite (bleach) for large areas. Food items can be cooked at a temperature of above 79C to destroy such pathogenic viruses.  

What to do if someone gets infected?

In spite of taking all the aforementioned precautions, if someone gets infected, what are we supposed to do? A suspected carrier who shows symptoms of COVID-19, needs to be tested for confirmation and an isolated for 14 days.  People who came in contact with a positive case should be home quarantined for at least 14 days for any symptoms to appear. If   similar symptoms appear they should be tested and isolated for 14 days. Once patients completely recover, they develop immunity   against the infecting virus. Such recovered patients do not pose a threat to the community. It is observed with concern that many people do not understand the concept of isolation and quarantine necessary for limiting transmission of COVID-19 and try to flee and hide in. Such activities are seriously detrimental and can cause further   spread in mass population.

Options for treatment and prevention

As this virus is new to all scientists, they are trying to find if existing antiviral or other drugs can be used for a quick fix. Unfortunately, none of the drugs showed promising results. A number of scientists in different countries have been trying relentlessly to develop a vaccine for COVID-19 based on their previous knowledge on related viruses. However, a systematic trial and vaccine development process might take 18 more months before it is available in the market. A suitable drug or vaccine could be very useful to break this transmission cycle in this crisis period. 

COVID-19 pandemic wave has now covered 212 countries and territories around the world. There is a total of 3,821,452 confirmed cases and a death toll of 265,113 (as of 7 May 2020). It is high time to act seriously    to stop the transmission of this ominous virus. We need to create awareness among the public and make them understand the catastrophic nature of this disease. It is the responsibility of each and every individual to actively participate in this battle against COVID 19. 
 
The writer is a Professor at the Department of Microbiology, Stamford University, Bangladesh