By Hagop Kantarjian, M.D.
Nonresident Fellow in Health Policy, Baker Institute
Leonard Zwelling, M.D.
President, Zwelling Consultants
On March 12, 2020 we posted the first Baker Institute blog on COVID-19. Information on COVID-19 is very fluid and accumulating rapidly. Therefore, periodic updates will improve strategies at the individual and societal levels to minimize the spread and consequences of the disease.
COVID-19 in now a world pandemic that poses an immediate short-term threat to the health of millions worldwide, to our societal fabric, and to the international economy. Opinions in the U.S. about its severity and impact were divided until recently. There is now a consensus that COVID-19 must be viewed as a serious pandemic threat.
As of today (March 19, 2020, 8:00 a.m), more than 230,000 people are infected worldwide and 9,500+ have died (mortality rate 4.1% worldwide). In the United States, 9,500+ Americans are infected and 160+ have died (mortality rate 1.6%). The differences in mortality rates in different countries (higher in China, Italy, Spain; lower in the United States, South Korea, Switzerland, Austria and Norway) are attributed to different factors (over/underreporting; frequency and criteria for COVID-19 testing; socio-economic factors and habits). What is less discussed is the potential effect of existing lung damage on COVID-19 associated mortality. COVID-19 kills through damaging the lungs — hence its other name, Severe Acute Respiratory Syndrome (SARS)-associated coronavirus (CoV), or SARS-CoV-2. Smoking in China (over 65% of adult men; much less among women), and in some European countries like Italy and Spain, is still quite common; smoking is much less common in the U.S. (14% of adults). Smoking may predispose to the disease or its more dire consequences.
The first cases were reported in China on November 17, 2019. With intense screening and restrictive measures, the spread in China subsided by early March 2020, three to four months later. The first case in the United States was reported on January 16, 2020. The U.S. was late in COVID-19 testing due to issues in developing the test by the U.S. Centers for Disease Control and Prevention (CDC). This is now up and running. Serious preventive measures (discussed later in this post) started being applied in larger cities in early March 2020 (and in Houston starting March 16, 2020). The infection rates in the U.S. are following the early trends in China, with an increased prevalence of 33% daily. So by the time you read this article in the coming week, the number of infected cases in the U.S. will have tripled or more, certainly to over 400,000+ cases. Based on the trend in China, it is anticipated that the first wave of COVID-19 in the U.S. will subside by May 2020 (also perhaps helped by warmer weather).
First, the known facts about COVID-19: This is not a regular influenza virus. The influenza season of 2017-2018 infected 45 million Americans and killed 61,000, a mortality rate of about 0.13%. COVID-19 can potentially cause death in 1-4% of infected individuals, a mortality rate 20-40 times higher than that of the flu.
COVID-19 is a highly contagious airborne virus. It can survive in air droplets for up to three hours, and on inert surfaces for several hours (copper, four hours; cardboard, 24 hours; plastic and stainless steel, two to three days). A person infected with COVID-19 can have no symptoms for three to seven days, and many individuals have no or mild symptoms. The clinical disease and infectivity last another week. This explains why it can spread broadly, and why restrictive measures in cities for two weeks are effective. We still do not know if it will recur in several waves (like the 1918 Spanish influenza), or if it will have seasonal variations (subsiding in warmer weather and recurring in the cold season). About 85% of the deaths have been people 60 years of age or older.
Can previous viral epidemics inform us about COVID-19? The 1918-1920 “Spanish flu” pandemic developed in three waves over two years, infected a third of the world population (500 million of 1.5 billion) and caused the death of 50 million (range 20 million to 100 million; estimated mortality rate 10% over the three waves). Most of the deaths were in the second wave. But there were no vaccines or antibiotics then. COVID-19 may or may not recur. If it does, based on current progress, effective and safe vaccines and new drugs to treat the virus will hopefully be available within a year. So the COVID-19 pandemic will be much less severe than the 1918 Spanish flu (discussed later). The swine flu in 1976, based on predictions of an anticipated massive epidemic, led to a vaccination campaign of 45 million Americans, but the epidemic never happened. The swine flu of 2009 infected 60 million Americans and caused the death of 12,469 (mortality rate of 0.02%). A vaccine was available, and different vaccination rates in different geographies demonstrated its benefits in reducing mortality. We do not believe that the COVID-19 pandemic will follow the roadmap of previous epidemics. Here is why.
The CDC produced different models to predict the effects of COVID-19. But these models are only as good as the assumptions used to develop them. They estimate infection rates as low as 20% and as high as 60%, and mortality rates as low as 0.5% or as high as 4%. Depending on the models, and assuming no “modifying interventions,” with a U.S. population of 330 million, COVID-19 might infect as few as 60 million or up to 170 million Americans. The number of deaths would range from 300,000 to several million. There is one interesting example that experts have paid little attention to: the Diamond Princess Boat cruise COVID-19 closed box experience. Of some 3,300 crew members and passengers, 712 were infected (21%) and seven died (1%). These figures could represent the best infection and mortality rate estimates for the U.S. in general, with the caveat that they occurred under optimal conditions of isolation, comprehensive testing and optimal medical management. Based on these estimates, the first COVID-19 wave may infect 69 million and cause the death of 690,000 in the U.S. This could overwhelm available hospital infrastructures (hospital beds, ICU beds, respirators), particularly in epicenters of COVID-19 spread (New York, Seattle, San Francisco), and increase mortality. In such COVID-19 epicenters, more aggressive measures to build medical infrastructures are needed to keep mortality rates low.
These figures need to be seriously considered as Americans deliberate the value of restrictions on individual freedoms (proper hygiene and social distancing, avoiding large gatherings, closing theaters and restaurants temporarily, staying home if ill) versus societal obligations (minimizing the COVID-19 effects on the most vulnerable Americans). The experiences of Hong Kong, Taiwan, Singapore and South Korea, compared with Europe, are of interest. For example, by February 1, 2020, Taiwan, an island of 23 million but an international hub close to China, implemented travel restrictions from China and other internal isolation and containment measures. As of March 16, 2020, only 67 cases of COVID-19 (only one death) were reported. South Korea (population 51 million) implemented early and broad COVID-19 testing (10,000 tests daily) in addition to restrictive isolation; so far 8,565 are infected (infection rate less than 1%) and 91 have died (mortality rate 1%). Despite a slow start in the U.S., we could still mimic the South Korean experience. As of early March, many large cities have implemented optimal social distancing measures, canceling large events; shutting down schools, restaurants and theaters; and curtailing businesses where close personal contacts occur. The U.S. has also initiated broader COVID-19 testing, about 3,000 daily as of this week (the number will ramp up to 15,000 daily soon).
Importantly, the figures cited above can be further improved by multiple modifying interventions: 1) Earlier and broader testing of COVID-19. 2) Strict preventive hygienic and societal measures. 3) A safe and effective vaccine (human testing has started, and we hope it will be available before a potential second COVID-19 wave). 4) Effective therapies to treat the virus (at least 50 antiviral drugs are now being tested). In essence, we hope for a relatively optimistic outlook for the COVID-19 pandemic in the United States, if all “modifiers” are realized quickly. In addition, the U.S. government and the states are addressing measures to lessen the consequences of COVID-19. On March 13, a national emergency was declared. Massive federal funding has been proposed to address the epidemic. States are expanding Medicaid to include people needing testing for COVID-19. Cities are expanding the number of hospital and intensive care unit beds. A $1+ trillion economic stimulus package is under discussion.
A note on COVID-19 testing. The current CDC testing criteria (cough and shortness of breath, fever, suspected exposure to a COVID-19 infected person) are too restrictive. About 7% of infected people have no symptoms, and it is unclear whether they can infect others. However, another 7-18% have mild symptoms and can definitely infect others, but are not tested today under the CDC criteria. Based on the experience in China, it is believed that these are the COVID-19 infected patients who continue to spread the virus because they are not being tested and isolated. Also, Houston is home to one of the largest medical centers in the world (including the No. 1 cancer center). These hospitals care for patients with conditions rendering them vulnerable to COVID-19 (diabetes; heart, kidney and lung diseases; cancer). Perhaps, once testing is widely available, health care workers in contact with patients should be tested under different criteria (e.g., for minor symptoms and/or periodically).
Our view is in contrast to the generally pessimistic outlook prevalent today, but is shared by a few others. The next two to four weeks will clarify better the COVID-19 picture. For now, we prepare for the worst and hope our cautious optimism is realized, and that by May 2020, things will have turned around for our nation.
About the authors
Hagop Kantarjian, M.D., is a medical oncologist and a nonresident fellow in health policy at the Baker Institute. His opinions do not reflect those of his institution affiliation.
Leonard Zwelling, M.D., M.B.A., is the president of Zwelling Consultants and a graduate of the Robert Wood Johnson Foundation Health Policy Fellowship.