In Prevention Part 1, I will discuss the public health policies designed to control the spread of SARS-CoV-2 infections. This book entitled, Decameron, was written in the city of Florence Italy in 1350 during the Black Death pandemic. The author describes behavior very similar to what is happening today. Many chose to ignore the mandates to shelter in place, and those who went to bars and congregate with others died, while those who fled to the countryside and isolated themselves survived. When we ignore history, we are doomed to relive it, and that is exactly what is happening in many parts of the United States. I hope other countries will learn from our mistakes. Infection control has been termed non pharmacologic intervention. As outlined in the Imperial College, COVID 19 response team report of March 16th 2020, there are five tools designed to control the spread of infection in the absence of any available vaccine. To simplify their recommendations, I have eliminated one tool, social distancing of those over 70 years of age because this approach has proven to be ineffective. Please see the SARS-CoV-2 vaccination part one video that subscribes Sweden's failed effort to encourage natural hard immunity. The four tools are, one, all infected individuals avoid contact with others and wear masks and maintain distances of at least six feet. Two, voluntary quarantine, individuals who had come in contact with the infected patients agreed to avoid contact with others for 14 days. Three, social distancing of the entire population, avoiding large gatherings. Four, closing of schools, universities, and non essential businesses. These tools can be used to implement one of two basic strategies. Suppression, all four tools are applied to reduce person to person contact to a level that drops the R subzero to below one. So the number of new cases progressively decreases and the epidemic is suppressed but not eliminated. Mitigation, applies tactics one through three, isolation, quarantine, and social distancing of the entire population. To reduce there are some not, but the value stays above one. In this approach, the epidemic continues to grow but at a slower rate. In this graph, the black line shows what happens if nothing is done. The peak exceeds the ICU bed capacity redline by over 30 fold upper graph, and the number of people estimated to die in Great Britain would be 510,000, or in the United States 2.2 million. If mitigations applied the orange line, the number of ICU beds required to manage patients would exceed capacity by 35%, best seen in the magnified lower panel. At the beginning of the pandemic, the Imperial College team recommended suppression, employing isolation of infected individuals, social distancing for everyone, and school, university, and non essential businesses closing. In countries where this approach was faithfully implemented, infecting patients never exceeded the bed capacity, and deaths were minimized. The duration of suppression strategy was recommended to be three months, and then upon discontinuation, watching closely and triggering if a specific number of ICU beds again filled with COVID 19 patients. This simulation shows what happens if the trigger is set at 100 ICU beds to reinitiate suppression. Discontinuation was allowed when the ICU bed occupancy dropped below 50. Over time the area under the epidemic curve would become smaller and smaller. With the rapid development of vaccines suppression was no longer required. As discussed in the epidemiologic section, the Chinese government insisted on continued suppression, causing unnecessary financial, and psychological harm to their population. Other approaches for monitoring are also possible, for example an internet connected electronic thermometer sends body temperatures to a smartphone through a company called Kinsa, and then to an Internet site allowing real time regional monitoring of fever. A publication on the clinical infectious diseases in 2018 documented a very close correlation condition 0.95 between the number of doctor visits for influenza like illness and the number of individuals with fever. This simple smartphone application would allow close monitoring of COVID 19. This system can also be used to quickly identify new cases as we open up our businesses and schools. When this video was first created, I asked the key question, will the US health system rise to the occasion? The answer is a resounding No. Initially our federal government failed to anticipate the need for COVID 19 rapid testing and the CDC was unable to coordinate national efforts and there is now a call to redesign this organization. At the state level, shelter in place was never implemented in many less populated states. States with Republican Governors refused to encourage social distancing, opposed the use of masks, and several of even questioned the effectiveness and safety of our vaccines. As discussed in the epidemiology section, consequently the US leads the world in the number of COVID-19 infections and deaths. In summary, four key actions can be taken to control infection spread in the absence of a vaccine. One, isolate all infected individuals, two, quarantine contacts, three, have everyone's socially distance, and four, close schools and non essential businesses. In a democracy Implementation of non pharmacological interventions is very challenging. Applications of the mitigation tools 1 to 3, versus suppression tools 1 to 4, depends on the level of disease spread. With a high percentage of vaccination in most countries, suppression is no longer required. The US failed at both the national and state level, to follow appropriate infection control measures, explaining why we continue to lead the world in the number of SARS-CoV-2 infections and death
