COVID-19, the disease caused by SARS-nCoV-2, the novel coronavirus first reported in China on Dec. 31, 2019, has quickly become a global concern, grabbing headlines, necessitating quarantines, and disrupting travel and commerce. Here’s what emergency physicians need to know about the epidemic.

The first cases of COVID-19 clustered around a “wet market” in Wuhan, Hubei province. Since then, more than 110,000 cases have been reported in more than 80 countries, though the majority of them are in China.¹

The first reported U.S. COVID-19 cases have largely followed the early distribution models based on air traffic from Hubei province, clustering in major transport hubs like Los Angeles, New York, and Chicago.^1,2 What we know of the epidemiology, pathophysiology, and best approaches to management of COVID-19 relies heavily on what we’ve learned from past outbreaks. As public health and infectious disease specialists scramble to understand a novel viral disease with international implications, emergency and other frontline health care workers need accurate information to prepare their departments for the possibility of encountering patients infected with the virus.

Background and Public Health

If all of this seems reminiscent of the 2003 SARS coronavirus outbreak, that’s because it is. Both outbreaks started with small outbreaks of a severe respiratory disease within fairly isolated Chinese populations, which then escalated rapidly to involve large numbers of patients throughout the region, eventually spreading to far-flung nations along busy commerce and tourism aviation routes.³

The initial Chinese government response to SARS was characterized by efforts to minimize its severity and to avoid public scrutiny. This strategy resulted in a delayed international response and further spread of the disease.³ Despite controversy surrounding potential suppression of early reports of a novel coronavirus in late December 2019, the Chinese public health response to COVID-19 stands in stark contrast with the SARS outbreak.⁴ Rather than months of suppression, the decision to report the virus to World Health Organization authorities within days enabled an early, robust international response and facilitated genetic sequencing of the virus, potentially fast-tracking efforts to discover effective antiviral therapies and vaccines.⁵

Specific efforts to contain the disease and decrease its spread implemented during both the SARS outbreak and the current COVID-19 outbreak include instituting quarantines, closing borders, restricting air and sea travel, and closing local markets thought to contribute to animal-human disease transmission.^6,7

Vaccine development in the setting of an outbreak of a highly infectious viral pathogen can be a valuable step in minimizing spread of the disease. In the SARS outbreak, no viable vaccine was available, and although an S-protein-based vaccine to SARS coronavirus has shown efficacy in animal models, no coronavirus vaccine has been released for human use.⁸ Challenges in the development of attenuated coronavirus vaccines include the use of highly concentrated native coronavirus by laboratory workers, which potentially can lead to inadvertent transmission of disease to those working on vaccine development.⁹ Similar difficulties in developing a vaccine to the current coronavirus can be anticipated, although clinical trials are already under way.

Clinical Management

Among the most daunting tasks for the ED worker evaluating possible COVID-19 patients is triage. Current Centers for Disease Control and Prevention (CDC) guidelines for determining whether a patient should appropriately be considered a “person under investigation” (PUI) are listed in Table 1.

Table 1: CDC Guidelines for Identifying Persons Under Investigation¹⁹

* Close contact defined as being within six feet of a confirmed case for prolonged period or having direct contact with infectious secretions of a COVID-19 case. ** Observed or subjective. *** CDC cites cough and shortness of breath as examples.

Note that these are guidelines designed as a national public health response to an outbreak. They do not always translate smoothly into a busy ED triage system. At our institution, the rule-out COVID-19 triage process is based on recommendations by Koenig during the MERS coronavirus outbreak, summarized as “Identify, Isolate, and Inform.”¹⁰

Identification should ideally occur prior to or during triage. At our institution, the electronic medical record requires the triage nurse to ask every patient about recent international travel. A positive screen prompts further automated questions regarding travel to China or other areas with many cases and whether the patient has had cough, shortness of breath, or fever. Of note, during previous outbreaks of MERS coronavirus and Ebola virus, we determined that broader regional terms like “the Arabian Peninsula” or “West Africa” were not familiar to all staff and sometimes led to both over- and under-triage. We now limit the triage form to specific countries relevant to a current outbreak.

If the patient screens positive for both travel to an affected area and any of the aforementioned symptoms, they need some kind of isolation. A surgical mask is applied, and a provider is notified. In most cases, the provider notifies the infectious disease team, who can help determine whether the patient meets CDC PUI inclusion criteria and can inform the local department of public health and the CDC.

Infection Prevention

After a potential PUI is identified and a surgical mask has been placed on the patient, the CDC states that they be moved to an airborne infection isolation room (AIIR).^11,12 In facilities that have limited availability of an appropriate bed, any private room with a closed door may be temporized until an AIIR is available. Patients undergoing observation by state departments of health may contact emergency departments prior to their arrival so that an AIIR might be available sooner. However, advance warning is not always possible. Facilities without AIIRs should transfer PUIs to facilities that do.

Protecting health care worker is a top priority. Attention to guideline-based patient isolation and infection prevention are the primary ways that frontline providers can protect themselves. The first case series of 138 patients infected with coronavirus noted that 29 percent of patients were medical staff, suggesting a high rate of nosocomial infections.¹³ Recent reports suggest that this is inhibiting the ability of some Chinese hospitals to maintain staffing and care for patients.¹⁴

Personal protective equipment (PPE) should be worn at all times when caring for a PUI. PPE guidelines for COVID-19 are based on recommendations for previous MERS and SARS coronavirus outbreaks (these differ from Ebola virus recommendations). The components are listed in Table 2.

Table 2. Personal Protective Equipment for COVID-19²⁰

*American National Standards Institute/Association for the Advancement of Medical Instrumentation recognizes four levels of liquid protection. Yellow contact gowns are level 1 and not intended for protection against long, fluid-intense procedures or body fluids at pressure.

Entry into patient rooms should be limited as much as possible. Procedures producing aerosolized patient secretions (open suctioning, induction of sputum) should be avoided. Health care workers at highest risk are those who are improperly trained in infection control, inconsistently use PPE, or perform high-risk procedures (eg, endotracheal intubation).¹²

Diagnosis and Clinical Features

In the first case series of infected patients with COVID-19, nearly all (98 to 100 percent) had fever, and leukopenia was associated with ICU admission, acute respiratory distress syndrome (ARDS), and death.¹³ A retrospective review of chest CT performed in confirmed cases showed a high incidence of multilobar ground glass opacities (86 percent) with or without consolidation.¹⁴ This is comparable with radiographic findings in MERS coronavirus and SARS coronavirus infections.

Current data suggest a case fatality rate of about 2 to 4 percent, although that number is likely to drop as milder cases will be more likely to be diagnosed as testing becomes more common. So far, 26 percent of infected patients have required critical care.¹³ While this may seem relatively benign, especially when compared to a 60 percent case fatality rate with Ebola virus, it is worth noting that the 1918 influenza pandemic had a similar case fatality rate (5 percent). The primary difference at this stage between the two is the dispersion globally of the disease.¹⁶

COVID-19 cases are definitively diagnosed by a positive real-time polymerase chain reaction (rt-PCR) isolation of viral RNA from respiratory secretions. This is theoretically possible from any upper or lower respiratory samples (nasopharyngeal swabs, sputum, bronchoalveolar lavage, nasopharyngeal wash, or aspirate), and it should be performed in any person meeting criteria for a PUI.¹⁷ Samples should be collected, handled, and shipped under the guidance of state or regional public health departments to appropriate reference laboratories capable of performing the specific SARS-nCoV-2 rt-PCR.

Management

The foundation of COVID-19 management is supportive care and minimizing transmission. At this time, there is no evidence-based pathogen-specific treatment available. Neuraminidase inhibitors (oseltamivir, peramivir, zanamivir), ganciclovir, acyclovir, and ribavirin are considered ineffective against coronavirus and likely have no role in management.¹⁸ Drugs considered possibly effective and currently being offered under “compassionate use” standards in multiple countries include remdesivir, lopinavir/ritonavir, interferon beta, convalescent plasma, and monoclonal antibodies.¹⁸ Extracorporeal membrane oxygenation (ECMO) has been used in multiple cases in China, although candidacy guidelines do not exist.¹⁸ Use of any of these approaches should be in communication with CDC personnel and infectious disease specialists. While antibacterial therapy is unlikely to benefit most patients with COVID-19, most patients in Chinese case series with acute respiratory distress syndrome (ARDS) or septic shock received empiric broad-spectrum antibacterial therapy. The rate of bacterial superinfection is unknown. Additionally, about 40 percent of patients with ARDS received steroid therapy, reflecting the ongoing controversy of steroid use in ARDS.¹³

Conclusion

As China reels from the COVID-19 outbreak, the world prepares to limit its spread. Emergency physicians are on the front line of any infectious outbreak and should maintain a working knowledge of the features of infection, recommendations for isolation and health care worker protection, and the local and national public health infrastructure for reporting PUIs.

Dr. Green is assistant professor of emergency medicine and global health at the University of Alabama at Birmingham. Dr. Pigott is professor and vice chair for academic development in the department of emergency medicine at the University of Alabama at Birmingham.

References

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