The COVID-19 Pandemic Curve

by Dr. Leon Levine

In the U.S. we are only in the early stages of dealing with the pandemic and to flatten the pandemic curve, we need to allow the public health experts to do their job. In an interview this morning, Dr. Jeffrey Sachs from Columbia University, urged a public health approach to addressing the pandemic, including widespread testing, contact tracing, social distancing and isolation and protecting front line workers with appropriate personal protective equipment (PPE).   These measures need to be implemented consistently throughout the country, not only in states with higher confirmed positive cases.  People are still travelling throughout the country; flights leave daily from New York to other states.  Asymptomatic individuals could be carriers and spread the disease to other areas.

In a recent issue of the Journal of the American Medical Association, a case study described the transmission of coronavirus from an asymptomatic 20 year old woman to five family members; who developed symptoms and were admitted to the hospital.  The asymptomatic woman had traveled from Wuhan to Anyang to be with her family and was presumably infected in Wuhan.  All five family members experienced a fever and respiratory symptoms.

The U.S. CDC data showing positive cases by state are biased and need to be interpreted carefully.  We need to consider the testing capacity by state and be aware that there is unequal testing capability and unequal access to testing.  Due to this unequal access and testing, the data has significant limitations. 

The shortage of COVID 19 tests has led to several problems and continues to hamper the public health response.  First, due to an absence in federal leadership, states have had to plan and ramp up testing capacity on their own resulting in uneven testing capabilities by state. Some states like New York have quickly negotiated with private testing companies to rapidly ramp up testing and have offered more tests thus resulting in the identification of more positive cases.  Also, individuals continue to be turned away as tests are rationed and prioritized to health care workers and the sickest patients.  Any of the individuals who are infected but not tested will not be captured and reflected in the data.  The current positive cases likely represent the most severe infections whereas it has been documented that there are many asymptomatic individuals.  Also, knowing that it is difficult to get tested will discourage many people from seeking a test, resulting in an under reporting of cases. Compounding the problem is inconsistent guidance on who should receive the test. Individuals seeking a test are being tested for the flu and other sicknesses prior to being tested for COVID 19. If someone tests positive for the flu they may not be tested for COVID 19; but is it possible to have multiple sicknesses at once. This would result in an under reporting of cases.  Due to rationing of the tests many individuals who would likely test positive are not being captured and are not reflected in the data.

It is intuitive to conclude that in a densely populated city such as New York, the virus could spread rapidly resulting in the most number of cases in the U.S.  However, New York state has also tested more than 100,000 individuals approximately 3 times Washington and California, according to data obtained from COVID 19 tracking project.   Greater testing will lead to higher positive cases.  The CDC needs to report the number of tests being conducted at the state and county level since testing availability is uneven and is associated with the number of confirmed cases.  The CDC should also provide information on the general location and demographic characteristics of the cases.  We need to better identify trends and the most susceptible individuals.  For example, it is known that many of the first cases in China were also smokers.  This is understandable since the virus attacks the respiratory system.  How much does smoking increase the risk of contracting COVID 19 or suffering more severe health consequences?  Is vaping a risk factor as well?

As testing ramps up in all states, reported cases of COVID will also likely increase because we are capturing more positive cases.  After sufficient widespread and continuous testing and having more granular data we may be able to assess whether interventions such as social distancing are effective.  Dr. Sachs also emphasized learning from other countries such as Japan, South Korea and China who have flattened the curve in approximately a couple of months by implementing nationwide public health measures such as widespread testing, contact tracing, social distancing and isolation and providing sufficient amounts of PPE to front line workers.  

To flatten the pandemic curve we need a national public health approach, not a patchwork of varying measures and guidelines from states.  Until such a national public health response is implemented by the President, flattening the curve will be a very drawn out process with many lives lost.

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