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Rigorous adherence to infection control measures is critical as a novel coronavirus (2019-nCoV) continues to emerge globally, threatening to transmit in the community and hospitals in the absence of an effective treatment or a vaccine, the Centers for Disease Control and Prevention (CDC) emphasizes.
As this report was filed, the CDC reported the second case of person-to-person transmission in the United States and issued new infection control measures and travel restrictions. In addition, an American who was already in quarantine in Texas after returning from Wuhan, China, became the 15th case in the United States as of Feb. 13, 2020. China reeled under thousands of cases increasing daily as the virus spread out to some 28 countries globally. The World Health Organization (WHO) designated a new name for the virus, changing it from 2019-nCoV to COVID-19. The CDC was in the process of updating its guidelines as this issue went to print.
Although there is more unknown than known at this stage, a theory emerging among some infectious disease experts is that the 2019-nCoV coronavirus seems to be more of a threat to spread in communities than be amplified in hospital outbreaks like its predecessors, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
However, a recently published report of 138 hospitalized patients in Wuhan, China, may dash that hope, while underscoring the importance of hospital infection control.
“Of the 138 patients, 57 (41.3%) were presumed to have been infected in [the] hospital,” the authors report.1 In addition, 40 healthcare workers caring for patients were infected, including 10 who contracted the coronavirus from a single patient. That appeared to be a case of the “super spreader” phenomenon seen with SARS and MERS, meaning a highly infectious patient who may also be unsuspected and thus cared for without full precautions. Thus, hospitals face the continuous threat of incoming community cases that must be identified and isolated to protect patients and healthcare workers.
“We are using an aggressive and cautious approach to [infection] control practices,” says Ryan Fagan, MD, MPH, healthcare infection control team lead for the CDC response. “These [guidelines]2 are aimed at protecting both patients and healthcare personnel. These recommendations are formed in part by our experience with healthcare-associated transmission of SARS and MERS. It’s important to point out though, that it is too soon to conclude the degree to which 2019-nCoV transmission [will be like] either of those viruses in healthcare settings.”
In addition to the new hospital infection control practices, federal health officials have implemented an aggressive travel protocol and screening for the coronavirus.
That includes ordering the evacuation of some U.S. citizens from China and placing those who had been in Hubei province — the epicenter of the outbreak — in 14 days’ quarantine upon return.
Asked at a Feb. 3, 2020, press conference about concerns expressed by China that the U.S. response may cause panic, Nancy Messonnier, MD, director of the CDC National Center for Respiratory Diseases, gave a forceful response.
“This is an unprecedented situation and we have taken aggressive measures,” she said. “A couple of weeks ago there were 41 cases in China. This morning the numbers are 17,000 — 17,000 cases with a novel coronavirus that the population doesn’t have immunity to, and for which, because things have been moving so quickly, we don’t have the information base that we want. [It is a] largely expanding outbreak, with person-to-person and community transmission in China.”
In statistics that underscore Messionnier’s point, China updated the count on Feb. 10, 2020, reporting 42,638 cases, including 7,333 in serious condition and 1,016 deaths.3 At least 333 cases, including the 15 in the United States, have been reported in other nations worldwide, some of which also have reported person-to-person spread. In addition, the first two deaths outside of mainland China have occurred in the Philippines and Hong Kong.
“[There also are] concerning data suggesting that people who are asymptomatic or mildly symptomatic may be transmitting the disease,” she said. Given these disturbing developments, the CDC took aggressive steps to stop the 2019-nCoV from gaining a foothold in the United States, Messonnier said.
“Action now has the biggest potential to slow this thing down,” she said.
In a move that was widely anticipated, WHO declared the 2019 coronavirus outbreak in China a Public Health Emergency of International Concern4 on Jan. 30, 2020. (See “WHO International Emergency: A Great Wall Around China?”)
Amid this growing sense of urgency, the CDC rolled out updated infection control recommendations and updated other aspects of its response at a training session for clinicians.
“Based on the early reports, we are seeing an incubation period of approximately five days — ranging all the way from two to 14 days,” says Aron Hall, DVM, MSPH, epidemiology task force deputy lead for the CDC response. “We are also seeing a basic reproductive number of about two, indicating that there are two additional cases resulting from each confirmed case [of 2019-nCoV].”
To prevent such transmission, the CDC issued guidance on identifying, testing, and isolating persons under investigation (PUI). (See Figure 1.)
The definitions to identify PUIs include clinical features combined with epidemiologic risk in the following definitions:
• Fever or signs/symptoms of lower respiratory illness (e.g., cough or shortness of breath) and any person, including healthcare workers, who has had close contact with a laboratory-confirmed 2019-nCoV patient within 14 days of symptom onset;
• Fever and signs/symptoms of a lower respiratory illness (e.g., cough or shortness of breath) and a history of travel from Hubei Province, China, within 14 days of symptom onset;
• Fever and signs/symptoms of a lower respiratory illness (e.g., cough or shortness of breath) requiring hospitalization and a history of travel from mainland China within 14 days of symptom onset.
Note that given the reports of the virus spreading in China beyond the Hubei province, the CDC added the aforementioned new PUI definition for those hospitalized with fever and respiratory illness who have traveled anywhere in China in the last 14 days.
Thus, the CDC is trying to balance the severity of illness and the epidemiologic data to identify PUIs without undercount or overkill.
Those who meet any of the described case definitions should be considered a PUI and referred to state and local public health officials for 2019-nCoV testing. The testing has been done by the CDC, but as this report was filed, the CDC was distributing test kits to state health departments to speed up the process. (See “Two U.S. Cases of Person-to-Person Transmission, More Expected.”)
“Infection control begins when [the patient] arrives at the facility and maybe even before arrival in terms of initial triage practices,” Fagan says. “Putting face masks on patients with respiratory illness is a standard precaution that we should all be prepared to do, including for influenza and other respiratory viruses.”
The recommendations apply to emergency medical services (EMS) and first responders transporting a suspected case of the new coronavirus.
“The specific situations will vary in that unique setting,” Fagan says. “We are in the process of developing some tools based on the guidance. That includes [adhering to] contact precautions, wearing a respirator, and covering their eyes for EMS workers who are riding in the compartment with a person under investigation for coronavirus.”
After donning a surgical mask, people under investigation for coronavirus infection should be evaluated in a private room with the door closed, ideally an airborne infection isolation room, the CDC recommends. “Healthcare personnel entering the room should use standard precautions, contact precautions, airborne precautions, and use eye protection (e.g., goggles or a face shield),” the CDC states.
The framework boils down to “identify, isolate, and inform,” Fagan says. Immediately inform your infection control team and local public health department of these cases, he added.
“In our recommendations for healthcare personnel, we are specifically recommending the use of respirators,” he says. “Some respirators like N95s are filtering face piece respirators, so they cover the nose and the mouth. There are a variety of options that provide that and additional higher levels of protections. Any of these N95 respirators are effective in filtering out coronaviruses.”
That said, the CDC believes the primary routes of exposure for coronavirus are likely to be close proximity to a patient, droplet contamination, or direct contact.
“The respirators, we think, are important for the concern about inhalational risk, but we also want to [stress] that it is part of an ensemble where you are also protecting your eyes, which have vulnerable mucous membranes. Cover the eyes and the mucous membranes of the face from direct droplet spread. Part of the reason for this is to avoid accidental self-contamination from touching gloved hands to your eyes and face in patient care settings.”
Given the many documented instances and studies of healthcare workers contaminating themselves while doffing PPE, it may be helpful to have someone observe workers removing gear after treating a patient, says Connie Steed, MSN, RN, CIC, FAPIC, president of the Association for Professionals in Infection Control and Epidemiology.
“If they have a confirmed or suspect case, make sure there are observers that are watching as they don and doff PPE going in and out of the room to ensure the healthcare workers’ safety,” she told Hospital Infection Control & Prevention. “I have talked with our infection prevention team about doing just-in-time-reminder competencies for frontline healthcare workers on how to put on and take off respirators. That seems to be the biggest issue as the hands [touch] the face.”
Emergency departments will bear the brunt of this if suspect cases descend on hospitals.
“Previous outbreaks have forced us to be more forward-thinking,” says Shannon Sovndal, MD, of Boulder (CO) Emergency Physicians. “New processes, such as updated triage questions and isolation techniques, have better prepared the ER [emergency room] to face new threats. We have a foundation in place which should aid us in addressing threats such as coronavirus from China, but vigilance, aggressive intervention, and constant modification will be needed.”
Masking symptomatic patients and getting a travel history can protect workers and guide triage. Infection control and PPE are critical because there is no antiviral treatment nor a vaccine for 2019-nCoV, says Daniel Lucey, MD MPH, FIDSA, FACP, an infectious diseases physician at Georgetown University Medical Center.
“Infection prevention is the best thing we have,” he said. “And that worked after a while with SARS.”
Patients with 2019-nCoV are presenting with a wide clinical spectrum from asymptomatic infection to life-threating pneumonia, says Timothy Uyeki, MD, MPH, MPP, the clinical team lead for the CDC response to the outbreak.
“In those who are symptomatic, the initial clinical course consists of mild, nonspecific respiratory signs and symptoms that overlap with those caused by many respiratory pathogens during the winter in the United States,” he says. “[The] most common onset of clinical illness in the China cases studied were fever and cough. The fever course with patients with this virus is not fully understood. Fever is not always present at illness onset. It may be intermittent, and it may be prolonged.”
The data that have been reported from China mainly are from hospitalized patients diagnosed with pneumonia and show a median time of about seven days from onset of illness to hospital admission.
“Complications that have been reported in hospitalized pneumonia patients include acute respiratory distress syndrome in about 17% to 29% of [cases],” Uyeki says. “Secondary infection has been reported in about 10%.”
About one-third of patients hospitalized with pneumonia have required intensive care for respiratory support, including invasive mechanical ventilation, he says.
“The case fatality rate in those hospitalized with pneumonia has been about 11% to 15%,” Uyeki says. “Understand that this estimate is only for hospitalized pneumonia patients. It is likely biased upward because it did not include mildly ill patients who were not hospitalized.”
The case fatality rate with SARS in 2003 was about 9% to 10%, he says.
“With MERS, [most] cases are hospitalized with severe disease — so the [mortality rate] is certainly biased upward. It’s approaching 35% to 40%.”
What patients are at greatest risk of developing severe disease with 2019-nCoV?
“At this time, we don’t really know all the risk factors,” he says. “Some early signals indicate older patients and those with chronic medical conditions seem to be at highest risk for severe outcomes. About one-third to one-half of reported patients with pneumonia had underlying medical comorbidities, including diabetes and cardiovascular diseases.”
Several reports suggest the potential for clinical deterioration during the second week of illness, even in mild cases, Uyeki says. The implications of this milder spectrum of disease are complex, as patients do not need hospitalization for supportive care, but should be monitored at home for signs of worsening illness.
Likewise, hospitalized patients could be discharged to home isolation, Fagan says, citing new CDC guidelines in this area.5 (See “CDC Guidelines for Home Isolation for Coronavirus.”)
“I wouldn’t equate discharge from the hospital with discontinuation of isolation,” he says. “What we recommend right now for patients who are confirmed cases, who are getting better and ready for discharge — or PUIs awaiting labs results — is that on a case-by-case basis, determine if they [should] be placed in home isolation.”
Again, the CDC wants to balance medical care with viral containment. “If they are a PUI and we think they can potentially become infective, we are going to continue to recommend infection control precautions, whether it is in the hospital or at home,” he says.
There are still open questions about when patients are most contagious, as well as how long they remain infectious.
“We don’t have a good under-standing of the duration of viral shedding, but it could be several weeks or longer, which has been observed with MERS and SARS,” Uyeki says.
There has been prolonged detection of viral RNA of 2019-nCoV in both the upper and lower respiratory tract. Detection of viral RNA does not necessarily mean detection of infectious virus, but it certainly may suggest that, Uyeki adds.
“This highlights the need to adhere to infection control recommendations very closely,” he says. “It’s possible, that — like SARS and MERS patients — those patients that have more severe disease may have prolonged viral replication, particularly in the lower respiratory tract. But I think we are still in the very early days of learning about both the levels and duration of viral shedding — both in the respiratory tract and, potentially, outside of it.”
Financial Disclosure: Peer Reviewer Patrick Joseph, MD, reports that he is a consultant for Genomic Health, Siemens, and CareDx. Senior Writer Gary Evans, Editor Jason Schneider, Editor Journey Roberts, Nurse Planner Patti Grant, RN, BSN, MS, CIC, and Editorial Group Manager Leslie Coplin report no consultant, stockholder, speaker’s bureau, research, or other financial relationships with companies having ties to this field of study.