The Ongoing COVID-19 Epidemic in the United States

In May, the United States began relaxing restrictions that were put into place to prevent the transmission of SARS-CoV-2. Although federal guidelines for the reopening process were published, states have created and implemented individual plans for reopening. The result has been an unmitigated disaster. While certain states, including former hotspots such as New Jersey, New York, and Illinois have managed to “flatten the curve,” the majority of other states, including Florida, Texas, California, Arizona, and others, have seen record numbers of new cases of COVID-19 [1]. The United States, as a whole, is experiencing in excess of 40,000 new cases per day and still leads global incident case counts [2].  More troubling, the United States has seen massive day over day increases in the number of confirmed incident COVID-19 cases. All signs point to one clear conclusion—the US COVID-19 epidemic is quickly spiraling out of control.

How did we get here?

COVID-19 is spread via respiratory droplets and, we now believe, aerosols. Research suggests that the SARS-CoV-2 virus has an unprecedented ability to stay suspended in the air for long periods of time, enabling particularly explosive spread of the SARS-CoV-2 virus (3). When dealing with a respiratory pathogen for which there is no vaccine, it is essential that we have the ability to quickly and accurately identify and isolate cases and subsequently identify, notify, and quarantine their close contacts. 

In order to accomplish this feat, we need to have the necessary infrastructure. This includes having sufficient numbers of tests, testing facilities, laboratories with the capabilities to process tests, and trained testing and laboratory personnel. Additionally, teams of contact tracers must be hired, trained, and put to work. Most importantly, there needs to be central leadership that handles logistics and provides strict standards for how individuals protect themselves and state governments protect their populations.

The United States has failed to provide every level of this infrastructure. A recent New York Times article paints a grim and accurate picture of testing in the United States [4]. In New Orleans, lines stretch for city blocks, but tests run out within five minutes of facilities opening. In Phoenix, people are waiting in line for eight hours in 100 degree heat to get drive through testing. In Texas, testing is in such high demand that new restrictions on who can receive a test have been put in place. Throughout the United States, tests aren’t available when and where they are needed and laboratories don’t have the capacity or expertise to analyze the results.

Contact tracing is a process where potentially exposed persons are notified and asked to self-quarantine. Self-quarantine can help prevent asymptomatic and pre-symptomatic transmission and encourage early testing and treatment. The process, however, requires a large amount of manpower to be effective. Most states have fallen short of establishing the necessary work force to effectively implement contact tracing procedures, yet have begun the reopening process regardless [5].

These issues are exacerbated by the lack of leadership, logistical and financial support, and scientific guidance at the federal level. The COVID-19 response has largely been left in the hands of each individual state. As a result, there is no centralized process for testing, no national contact tracing workforce, and no uniform guidelines for relaxing restrictions and reopening society. This has led to an inconsistent, often politicized, response to the COVID-19 epidemic in the US.

The United States required specific infrastructure to prevent and control the spread of the SARS-CoV-2 virus. This infrastructure, however, was not built out prior to relaxing restrictions in most states, which has led to climbing case counts in nearly 40 states [4].

Case counts are rising while mortality rates are falling. Why?

There is a counterintuitive trend occurring within the United States. COVID-19 case counts are increasing while deaths are simultaneously decreasing [6, 7]. This phenomenon has been touted by the Trump administration as an indication of success in the fight against COVID-19 [8]. The truth is more complicated.

In some ways, these numbers can be a positive indication of progress in the COVID-19 epidemic. For one, we have a better understanding of the disease. We have new and more effective treatments. Prone positioning, blood thinners, dexamethasone, and remdesivir have emerged as lines of defense against COVID-19 by speeding recovery and preventing death [6, 7]. We have also increased awareness of the virus. Those who are most susceptible can take precautions against infection and seek care if they present with symptoms. Although testing lags far behind what is necessary, capacity has been increased. Earlier testing leads to earlier treatment, which can also improve health outcomes.

It is, however, much too early to declare victory in the fight against COVID-19. The United States benefited from decreased infection rates and resulting hospitalizations from April through May. Case counts are on the rise again and hospitals are quickly reaching capacity. When hospitals do reach capacity, they will no longer have the resources to effectively treat all patients, which will result in an increase in the rate of mortality.

There is also a statistical problem with aligning incident case counts with mortality data. Death lags significantly behind infection. Reporting of death occurs even later than that. The result is an offset of a number of weeks between documentation of infection and death. We are currently observing deaths that resulted from the lower number of infections in May. We are still a few weeks from being able to track deaths from infections occurring in June and July. 

Is SARS-CoV-2 airborne?

A group of 239 scientists from 32 countries are preparing to publish a commentary outlining the evidence for airborne spread of SARS-CoV-2 [9]. These scientists are appealing to the medical community and national and international bodies to recognize the airborne spread of SARS-CoV-2. Unfortunately, there is going to be a lot of fear resulting from this commentary. A quick Google search will net you dozens of articles already written on the subject. Let’s analyze the evidence and talk about the implications.

The authors begin by citing several studies that have shown that viruses are released during exhalation, talking, and coughing in microdroplets that can spread beyond distances of 3-6 feet (the current social distancing guideline). They also cite evidence that SARS-CoV-1 (the first SARS virus) was spread through airborne transmission. Furthermore, retrospective studies have indicated airborne spread of SARS-CoV-2. In particular, one study of a Chinese restaurant cluster (a large number of cases resulting from a single exposure) analyzed video footage of the interactions between persons within the restaurant. They found that individuals who later became infected with the virus had no direct or indirect contact with the index (first) case. This would implicate airborne transmission as the route of infection.

It appears that the majority of new COVID-19 infections result from “superspeader” events, where a single individual infects a large number of other individuals. In Boston, a few individuals unknowingly infected with COVID-19 passed the virus to at least 99 other people. In Washington, a single infected person infected 52 others at a 2.5-hour choir practice. In Arkansas, an infected pastor and his wife spread the virus to 30 church congregants. In Georgia, a funeral was attended by more than 100 people. The resulting secondary cases sparked one of the worst outbreaks in the country [10]. These are just a few examples.

As you can imagine, these circumstances, where individuals are interacting with one another in close proximity, are the perfect conditions for the virus to spread. There is evidence that now suggests that as few as 10% of infected people cause 80% of new cases, indicating that these superspreader events are crucial to the sustained transmission of SARS-CoV-2 in the population [10, 11]. The explosiveness of these events indicates that airborne transmission is possible. Even in the event of droplet spread, we would not expect to observe so many secondary cases arising from a single infection.

This evidence is by no means conclusive. The authors of the commentary say as much. However, they, and I, believe that the evidence is significant enough to begin taking precautions against airborne spread. The authors offer three simple measures that can be implemented to protect against airborne spread: provide sufficient and effective ventilation, supplement general ventilation with airborne infection controls, and avoid overcrowding, particularly in public transport and public buildings.

You cannot control the first two points in your day to day life, but you can certainly adhere to the third. Avoiding these so-called “superspreader” locations drastically reduces your risk of infection. Taking additional precautions, such as wearing a mask while indoors with others, can also reduce your risk.

Where do we go from here?

The United States has made many unforced errors in response to the COVID-19 pandemic, contributing to the highest overall case counts and number of deaths in the world. It is imperative that the United States not make the error of continuing the reopening process in the states experiencing massive influxes of new cases day over day. Instead, we should reverse course, implementing stricter restrictions until such a time as sufficient levels of testing and contact tracing can be achieved.

References

[1] Johns Hopkins University. America Is Reopening. But have we flattened the curve? 2020 [cited 2020 July 7th].

[2] Johns Hopkins University. New Cases of COVID-19 In World Countries. 2020 [cited 2020 July 7th].

[3] Jayaweera M, Perera H, Gunawardana B, Manatunge J. Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy. Environ Res. 2020; 188:109819-.

[4] Mervosh S, Fernandez M. Months Into Virus Crisis, U.S. Cities Still Lack Testing Capacity. The New York Times. 2020.

[5] Firozi P. The Health 202: U.S. isn't ready for the contact tracing it needs to stem the coronavirus. The Washingotn Post. 2020.

[6] Bernstein L, Weiner R, Achenbach J. Coronavirus deaths lag behind surging infections but may catch up soon. The Washington Post. 2020.

[7] Wu KJ. U.S. Coronavirus Cases Are Rising Sharply, but Deaths Are Still Down. The New York Times. 2020.

[8] Cohen M. White House defiant as Covid-19 deaths approach 130,000. Politico. 2020.

[9] Morawska L, Milton DK. It is Time to Address Airborne Transmission of COVID-19. Clinical Infectious Diseases. 2020.

[10] Aschwanden C. How ‘Superspreading’ Events Drive Most COVID-19 Spread. Scientific American. 2020.

[11] Honderich H. Coronavirus: What makes a gathering a ‘superspreader’ event? BBC News. 2020.