By Gary Evans, Medical Writer

In what is considered an underestimate, the Centers for Disease Control and Prevention (CDC) recently reported that more than 9,000 healthcare workers in the United States have been infected with novel coronavirus and 27 have died.

Despite the severity of a spectrum of cases, 90% of the healthcare workers recovered without hospitalization. In addition to overcoming fear to treat patients, the healthcare workforce is proving resilient in the face of the COVID-19 pandemic.

“We always knew that healthcare workers would be essential to combatting pandemics, but I think you can see with this one, it is more true than many of us had anticipated,” Robert Redfield, MD, director of the CDC, said at recent meeting. “This virus is clearly one of the most infectious respiratory viruses that we have ever had to deal with.”

In CDC surveillance data from Feb. 12 to April 9, healthcare personnel (HCP) accounted for 9,282 of 49,370 COVID-19 case reports with occupational information.1 The information was gathered from CDC surveillance forms. The numbers and percentages vary depending on the detail provided in individual reports.

“This [report] is likely an underestimation because HCP status was available for only 16% of reported cases nationwide,” the CDC stated. “HCP with mild or asymptomatic infections might also have been less likely to be tested, thus less likely to be reported. The total number of COVID-19 cases among HCP is expected to rise as more U.S. communities experience widespread transmission.”

Although only 6% of the infected workers were at least age 65 years, 37% of deaths occurred in this older age group. In addition, 38% of those infected had underlying risk factors including asthma, chronic obstructive pulmonary disease, diabetes, cardiovascular disease, and an immune-compromised condition.

“Older HCP or those with underlying health conditions should consider consulting with their healthcare provider and employee health program to better understand and manage their risks regarding COVID-19,” the CDC recommended. “The increased prevalence of severe outcomes in older HCP should be considered when mobilizing retired HCP to increase surge capacity, especially in the face of limited PPE [personal protective equipment] availability.”

One approach is to assign these workers to lower-risk duties like administrative tasks, the CDC noted.

Almost Half Exposed in Community

Breaking down the cases reveals 55% of medical workers reported healthcare exposures, with the remainder citing household (27%), community (13%), or exposures in multiple settings (5%). The data reflect the “potential for exposure in multiple settings, especially as community transmission increases. Further, transmission might come from unrecognized sources, including presymptomatic or asymptomatic persons,” the CDC reported.

The numbers overall are fairly consistent with what is reported in other countries, says Torree McGowan, MD, FACEP, an emergency physician at St. Charles Medical Center in Bend, OR.

“Unfortunately, the more you are exposed and the higher the levels of exposures, the higher the risks of infection,” she says. “Healthcare workers are around very sick people who are shedding a lot of virus on a regular basis. But only about half the healthcare workers in the study had their [exposure] at work. We have to be careful outside the hospital, not just within it.”

As the boundaries blur, it will be more challenging to make the distinction between community and occupational transmission to healthcare staff. More benign strains of coronavirus cause colds of unknown origin, but the severity of this infection raises issues of occupational health and workers’ compensation.

“When we have healthcare workers who get sick with a cold, we are not always sure if they picked it up from work or from the community,” McGowan says. “As this virus spreads more in communities, [the source of transmission] probably won’t matter as much once we have ways to treat this — especially when we get a vaccine in place. There is a whole other question of workers’ compensation and workplace injuries that is completely different. From a medical standpoint, it probably doesn’t matter, but from a financial and liability standpoint, that is a different conversation.”

Among those who reported contact with a confirmed COVID-19 patient in a healthcare setting, details of the exposure and whether the worker was wearing PPE could not be determined. Among HCP patients with data available, the median age was 42 years. Among HCP patients with data available on age and health outcomes, 6,760 were not hospitalized. However, 723 were hospitalized, and 184 were admitted to an intensive care unit (ICU).

Although 92% of the healthcare workers reported at least one symptom among fever, cough, or shortness of breath, the remaining 8% did not report any of these symptoms. Preventing asymptomatic transmission was one of the justifications for the recent CDC recommendation for all healthcare workers to wear surgical masks while on duty. (See related story in this issue.)

“Assuring source control among all HCP, patients, and visitors in healthcare settings is a promising strategy for further reducing transmission,” the CDC stated. “Even if everyone in a healthcare setting is covering their nose and mouth to contain their respiratory secretions, it is still critical that, when caring for patients, HCP continue to wear recommended PPE.”

Given the shift to community spread, contact tracing after occupational exposures is likely to be fruitless.

“Additional measures that will likely reduce the risk for infected HCP transmitting the virus to colleagues and patients include screening all HCP for fever and respiratory symptoms at the beginning of their shifts, prioritizing HCP for testing, and ensuring options to discourage working while ill such as flexible and nonpunitive medical leave policies,” the CDC concluded.

Redfield said COVID-19 is peaking in the United States, but will likely increase again in the colder days ahead and coincide with seasonal flu.

“It is very probable that by late fall 2020, winter 2021, that we will be back in the throes of fighting a substantial outbreak against this virus,” he said. “Hopefully, this time we will be able to stay in the mode of high containment because of astute early diagnosis, contact tracing, isolation, things that [HCP] will be a critical component of.”

Q&A

The CDC sent the following responses to Hospital Employee Health via email from report authors Sherry Burrer, MD, and Matthew Stuckey, PhD, MPH. Both serve on the CDC’s COVID-19 Response Health Systems Worker Safety Task Force.

HEH: Based on this report, would you recommend that hospital employee health departments identify older workers and others with underlying risks of COVID-19 complications and consider removing them from care of these patients?

CDC: We stress that older HCP or those with underlying health conditions should consult their healthcare provider and employee health program to better understand and manage their risks regarding COVID-19. Healthcare facilities can consider limiting exposure of HCP at high risk of severe illness to patients with confirmed or suspected COVID-19. Another consideration is preferential assignment of older HCP or those with underlying health conditions to lower-risk settings such as telemedicine, administrative assignments, or clinics for non-COVID-19 patients. During severe PPE supply limitations, one method may be to exclude HCP at higher risk for severe illness from COVID-19 from caring for patients with confirmed or suspected COVID-19 infection.

HEH: Did you see any signs of increased infection severity or outcomes in African American HCP?

CDC: Because of missing data, all analyses are descriptive, and no statistical comparisons were performed. While we were able to present data on health outcomes (hospitalizations, ICU admissions, and deaths) by age, additional work is needed to confirm findings about the impact of other potentially important factors, such as disparities in race and ethnicity or underlying health conditions.

HEH: The report does not include information on what PPE was used. Would the HCP have been expected to wear PPE for suspected coronavirus cases during this surveillance period?

CDC: During this period, HCP were recommended to follow the guidance in place by CDC regarding PPE and caring for confirmed and suspected COVID-19 patients: gloves, isolation gown, eye protection, and an N95 respirator or higher-level respirator — or a facemask, if respirators are not available.

HEH: How does the growing presence of COVID-19 complicate identification of occupational infections? Can you comment on whether there will be a point where it will be less meaningful to make this distinction, or is it always important to try to determine if occupational infections are occurring?

CDC: It is important to determine if occupational infections are occurring so we can better understand which specific HCP groups are most affected and how the exposures are happening. This information would inform interventions and guidance. However, done alone, contact tracing after recognized occupational exposures likely will fail to identify many HCP at risk for developing COVID-19. This is a consequence of asymptomatic transmission and the fact that determining work-relatedness becomes more challenging as community transmission increases. Our analysis indicated that HCP reported exposures at work, at home, and/or in the community, highlighting the potential for exposure in multiple settings.

HEH: Does the CDC recommend that healthcare workers be assessed for fever when they report to work?

CDC: Additional measures in healthcare settings may reduce the risk for infected HCP transmitting the virus to colleagues and patients regardless of the source of HCP infection. These include screening all HCP for fever and respiratory symptoms at the beginning of their shifts, prioritizing HCP for testing, and ensuring options to discourage working while ill (e.g., flexible and nonpunitive medical leave policies).

HEH: How can healthcare facilities address asymptomatic workers?

CDC: Given the evidence for presymptomatic and asymptomatic transmission, assuring source control and covering the nose and mouth [with masks] among all HCP, patients, and visitors in healthcare settings is a promising strategy for further reducing transmission.

‘More Questions Than Answers’

The thought of asymptomatic healthcare workers spreading coronavirus to patients and co-workers is one of the more daunting aspects of responding to the pandemic.

“After reading this, I feel I have more questions than answers,” says Hamad Husainy, DO, FACEP, an emergency physician at Helen Keller Hospital in Sheffield, AL. “How many of us have it [asymptomatically] and are walking around spreading it to other people?”

Ultimately, better testing capabilities are needed to understand transmission to healthcare workers in the hospital and community.

“It is something from an epidemiological standpoint that we don’t have a really great handle on yet,” Husainy says. “With the lack of real-time testing and the lack of overtly sensitive testing, we really can’t accurately represent real time what the situation looks like. We will get there.”

That said, historical respiratory virus testing has had questionable accuracy, with a rapid test for flu typically yielding an accuracy rate of 58%.

“That is a little bit better than a coin flip,” Husainy says. “We have an ELISA [enzyme-linked immunosorbent assay] test with a 3.5-hour turnaround that has a much better sensitivity, but we are talking about something that has been around a long time. Most places aren’t even using that test, because nobody wants to wait in urgent care or a hospital or get a call back with results. For flu, really the recommendations in emergency medicine are if you suspect flu and it’s flu season, they have the flu. We rarely test for it.”

In an important difference, antiviral treatment for flu is available and may be administered empirically. A similar situation may result with the first treatments for novel coronavirus.

“You can imagine if a drug company gets FDA [Food and Drug Administration] approval for a treatment or reduction of symptoms of coronavirus, people are just going to give it for the mere suspicion [of infection],” he says. “In the short term, that does have some utility, as long as there are appropriate studies on the drug to make sure it is not harmful.”

In the interim, assume everyone is infected — including yourself, McGowan recommends.

“That’s how everyone is operating because it is the people without symptoms who are really spreading this,” she says. “People are being fairly careful now if they start to get sick. The best research we have right now is that you are contagious about two or three days before you start to have symptoms. Once we get better testing, we could try to limit these exposures.”

REFERENCE

  1. Centers for Disease Control and Prevention. Characteristics of health care personnel with COVID-19 — United States, February 12-April 9, 2020. MMWR Morb Mortal Wkly Rep 2020;69:477-481.