SOLVING the Problem through Knowledge
In the current coronavirus environment much public health and epidemiology discussion has occurred. One of the basic principles of determining how infectious a virus is or any pathogen is called the basic reproduction number. This is also referred to as R0 pronounced “R” “naught” or “R” zero. The number is a objective value of infectivity and used to determine how infectious any given agent is.
Some viruses are highly infectious like measles having a basic reproductive number of over 12. Other viruses are less infectious like rubella around five. Coronavirus is of unclear R0 value somewhere between 2 to 3. As we social distance and have less contact this value decreases since the virus does not have the opportunity to spread effectively
Understanding herd humanity is also important in public health and frequently discussed by experts. The concept of herd immunity is that if enough people have immunity to any given disease it can no longer be spread because there are not enough people available to develop the infection. An example makes the concept easy to understand. No matter how infectious a disease, in a room of 100 people , if 98 have natural immunity or immunity from a vaccine and one person has active disease, then the one uninfected person is highly unlikely to contract it. For diseases with high basic reproductive numbers like measles over 90% of the population needs immunity to protect the remaining 10%. For a disease that is much less transmissible like coronavirus if the R0 value is 2.4 then if 60% of the population has immunity, herd immunity is created and spread is highly unlikely That’s why understanding the underlying basic reproductive number is crucial to determine good public health policy. Getting the information about coronavirus will be critical moving forward. The mechanism of spread whether it be airborne, very small particles or by droplet, larger particles or body fluids (ebola) which are much more difficult to spread is critical to determine R0.
We need much more research and testing to understand all these various factors with regard to coronavirus. Every model that is described by public health experts, governors and the president are based on these underlying principles which as we all know appear to be changing on a regular basis. In addition if a virus mutates its basic reproductive number can change upward or downward. Understanding the nature and extent of asymptomatic spread of coronavirus is also very important to plan public health policy.
Our greatest tools still remain
social distancing
remaining at home in, a shelter in place mode
washing hands
Wearing face protection covering the mouth and nose and not touching the face
To date no true effective treatment has been established in spite of many statements by politicians to the contrary. The likelihood of the vaccine being available widely within a two-year framework is virtually nil.
Continue to follow basic public health principles described above. Help those less fortunate in need. Together we will overcome this challenge
Reference
https://jamanetwork.com/journals/jama/fullarticle/2765665
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copyright Nicolas Argy 2020