By Hagop M. Kantarjian, M.D.
Nonresident Fellow in Health Policy, Baker Institute
and
Leonard Zwelling, M.D.
President, Zwelling Consultants
The COVID-19 outbreak has now reached pandemic proportions, threatening the health of millions worldwide and adversely affecting the international economy. Opinions in the U.S. about its severity and impact are divided along political fault lines. Understanding the status of COVID-19, its potential impact in the U.S., and the needed preventive measures could save many lives.
To begin with, COVID-19 is not similar to influenza. The influenza season of 2017-2018 infected 45 million Americans and killed 61,000, a mortality rate about 0.13%. COVID-19 can potentially cause death in 2%-3% of infected individuals, a mortality rate 20 to 30 times higher than that of the flu. But the actual death rate is unknown because we do not have the tests to measure its spread in the population (prevalence) and the number of new cases (incidence).
Other known facts about previous influenza pandemics/epidemics vary between extremes. The first alarming example is that of the 1918-1920 epic pandemic “Spanish flu.” It came in three waves over two years, infected one-third of the world population (500 million of 1.5 billion ), and caused the death of an estimated 50 million worldwide (the range is 20 million to 100 million). At that time, there were no vaccines or antibiotics, and accurate figures are not available. What is known is that areas that implemented preventive measures had lower mortality rates than those that did not. An opposite example is the swine flu in 1976. It was estimated then that a flu epidemic was occurring every 11 years, that one had not happened in 39 years, and cases of swine flu were reported at a U.S. Army base. This led to a massive vaccination campaign, but the epidemic never happened. This example has been highlighted to advocate for a conservative approach. The third example, the scenario of the swine flu of 2009, falls in between the previous examples. The virus infected 60 million Americans and caused the death of 12,469, a mortality rate of 0.02%. A vaccine was available, but because political ideology influenced vaccination rates, there was a higher mortality in red states, which had lower vaccination rates.
What can these examples teach us about COVID-19? Very little at present. We know the virus is highly infectious, that it may be present for as long as one to two weeks before symptoms occur, and that it may stick to surfaces for up to eight days. We do not know whether it will come in multiple waves or demonstrate a seasonal variation (disappear and then re-emerge). We do not have a vaccine yet, nor do we have a preventive drug (like oseltamivir [Tamiflu]). We know the mortality rate is 2%-3% among infected individuals, but because testing is not yet widely available, the real denominator is underestimated, and the mortality may be perhaps 1% or less. We also know that while the daily incidence started to decrease in China with extreme precautions and after two to three months from the start of the pandemic, the rates in Europe and the United States are following the early trend from China, with a 33% increased daily incidence in the first one to two months. Therefore, unless we adopt extreme precautions, things are going to get worse before they get better.
What might happen if we do not adopt a sound scientific approach to the COVID-19 pandemic? Based on current rates, as many as 40 million to 80 million Americans might be infected. Assuming a mortality rate of 1%, this would mean the death of 400,000 to 800,000 Americans in the next year. The all-cause mortality in the U.S. is 2.8 million a year, so COVID-19 could possibly increase the death rate in the U.S. by 15% to 30% over the next two years. This does not even account for the impact on the U.S. economy and its downstream effect on the daily lives of Americans. Until we know more about COVID-19, extreme cautionary and preventive measures are necessary in order to lessen the consequences on the U.S. health care and economy. This means frequent hand washing, avoiding crowds, maximizing social distance, and staying home if ill. This is especially important for older Americans and those with medical conditions (such as cancer). Without a doubt, we will be learning more about COVID-19 in the coming days. For now, we should prepare for the worst and hope for the best, but containment (reducing new cases) and mitigation (caring for the ill) is the right posture.