Emerging Infectious Diseases (COVID-19)

Emerging infectious diseases are defined by the Centers for Disease Control and Prevention (CDC, 2018) as those infectious diseases whose incidence in humans has increased in the past two decades or threatens to increase in the near future. They are outbreaks of previously unknown diseases that have newly appeared or have existed but are rapidly increasing in incidence or geographic scope (National Institutes of Health [NIH], 2018). They persist in an uncontrolled manner and respect no national boundaries. They threaten the health and safety of all people because prevention and control recommendations may not be immediately available when the disease appears (CDC, 2018). Recent outbreaks of emerging infectious diseases include H1N1 influenza virus (swine flu, 2009), avian influenza (2013), chikungunya virus (2013), Ebola virus (2013), Zika virus (2015), and the novel coronavirus disease 2019 (COVID-19), the primary focus of this entry.

An outbreak of novel coronavirus infections was first reported to the World Health Organization (WHO) on December 31, 2019. The virus was termed “severe acute respiratory syndrome coronavirus-2” (SARS-CoV-2), more commonly known as COVID-19, and WHO declared a global pandemic on March 11, 2020 (Majumder & Minko, 2021). By early February 2020, a vaccine candidate had been designed and manufactured, and by March 2020, the first clinical trials were beginning. Authorization for emergency use was granted by the U.S. Food and Drug Administration in December 2020 for two vaccines (NIH, 2021). As of March 2, 2022, the WHO reported 437,333,859 confirmed cases of COVID-19; 5,960,972 deaths; and 10,585,766,316 vaccine doses administered (https://covid19.who.int).

COVID-19 is a respiratory disease spread through droplets produced when an infected person coughs, sneezes, or talks. Symptoms appear 2 to 14 days after exposure. Complicating the risk for transmission, approximately 10% to 30% of people with COVID-19 remain asymptomatic (Marian, 2021). Although most patients have mild or moderate disease, up to 10% have severe and even life-threatening symptoms, and mortality is approximately 1% to 2%. Lung changes in people with serious disease include formation of hyaline membranes (fibrous layers that settle in the alveoli and prevent oxygen absorption), interstitial and alveolar edema, hemorrhage, microthrombi, and inflammatory activation.

Because COVID-19 is a novel coronavirus, humans had no prior exposure and no prior immune response, making the world's entire population susceptible until either a vaccine was developed or herd immunity was achieved. Complications include acute respiratory distress syndrome, cardiac arrhythmias, acute cardiac injury, heart failure, stroke, Guillain-Barré syndrome, and acute kidney injury. Long-term complications, sometimes called long COVID, occur when health issues continue for more than 4 weeks after diagnosis. Symptoms of long COVID include fatigue, rapid heart rate, chest pain, fever, shortness of breath, oxygen dependence, cough, joint pain, muscle pain, memory or concentration problems, anxiety, depression, headache, sleep difficulty, loss of smell and taste, and dizziness (Desai et al., 2022).

Causes ⬆ ⬇

Infection with SARS-CoV-2 causes COVID-19. The reproduction number, or R, is defined as the average number of people whom someone with the virus will infect. The R value for the seasonal flu is approximately 1.3, and the R value for COVID-19 has been estimated at 3. Transmission also likely depends on the viral load, or the quantity of the virus in a given volume of fluid or droplets, after an infected person coughs or sneezes, or even exhales. The virus enters the uninfected person through the mouth or nose and latches onto the ACE2 (angiotensin-converting enzyme) receptor, which is a protein that breaks down angiotensin. It then merges with the cell membrane and releases its genetic material into the healthy cell of the respiratory tract in the uninfected person, who thereby becomes infected.

Variants of a virus occur as viruses mutate, and different variants emerge over time. A variant of concern is generally considered to be more infectious, more likely to cause reinfections, and more likely to lead to breakthrough infections in people who are vaccinated. With the emergence of alpha and beta variants, new waves of infections occurred around the world in 2020 (Karim & Karim, 2022). In 2021 the delta variant rapidly became dominant and appeared to be more transmissible than other variants (CDC, 2021). On November 25, 2021, omicron was reported as a new variant of concern when vaccine immunity from COVID-19 was more common around the world (Karim & Karim, 2022). Making COVID-19 disease even more complicated, variants such as omicron may have subvariants (BA.1 virus, BA.2 virus) that may have different transmission rates, degrees of severity rates, or responses to treatment (Chen & Wei, 2022). While scientists continue to investigate the omicron variant, experts suggest that not only may it be even more transmissible than previous variants, but also other variants are likely to emerge in the next months and years. The CDC lists the following characteristics and medical conditions that place people at risk for severe illness from COVID-19: older age; smoking; having cancer, diabetes mellitus, chronic liver disease, HIV disease, chronic heart disease, chronic lung disease, chronic kidney disease, dementia, Down syndrome, or tuberculosis; being overweight or obese, immunocompromised, or pregnant; and having a history of organ transplant, stroke, or substance use disorder. Being uninsured or underinsured is also a risk factor for COVID-19.

Genetic Considerations ⬆ ⬇

The clinical manifestations of the disease caused by the SARS-CoV-2 virus can vary widely in severity; some patients have no or mild symptoms, while others develop rapid respiratory failure. Studies have identified two genomic regions that are associated with the development of more severe disease progression. These include a six gene region on chromosome 3. Five of the six genes (LZTFL1, CCR9, CXCR6, XCR1, and FYCO1) are involved in T-cell and dendritic-cell function, while the sixth gene (SLC6A20) is regulated by ACE2 (the SARS-CoV-2 receptor). Another study demonstrated an association with the ABO blood group locus on chromosome 9. Patients with blood group A had an increased risk of severe COVID-19, and those with blood group O had a decreased risk. However, future studies will need to be conducted to further elucidate the mechanism of this genetic risk.

Sex and Life Span Considerations ⬆ ⬇

The severity and mortality of COVID-19 are higher in males than females, possibly because viral clearance is slower in males, and females have a stronger response to pathogens (Pradhan & Olsson, 2020). In a study of 16 countries with a total population of 2.4 billion, mortality rates were 77% higher in men than women. In addition, mortality was eight times higher in people 55 to 64 years old as compared to those 54 years old and younger. People 65 years old and older had mortality rates 62 times higher than those 54 years old and younger (Yanez et al., 2020). Thus, being male and being 65 years old or older are risk factors for severe illness and death from COVID-19. There is some evidence suggesting that pregnant women with COVID-19 are more likely to deliver before week 37 of gestation and more at risk for pregnancy loss. Pregnant or postpartum individuals with COVID-19 also have a higher risk of mortality or serious morbidity from obstetric complications as compared to individuals without the infection (Metz et al., 2022). Although COVID-19–associated hospitalizations and deaths occur more frequently in adults than children, who usually experience milder illness than adults, it can cause severe illness in children and adolescents. The highly transmissible delta variant caused increased COVID-19 hospitalizations for children across the United States during 2021 (CDC, 2021).

Health Disparities and Sexual/Gender Minority Health ⬆ ⬇

The role of race and ethnicity with respect to hospitalization and mortality rates is complicated. The U.S. Commission on Civil Rights (2021) reported that COVID-19 has had a disproportionate toll on Native American communities. They note that the Navajo Nation experiences one of the highest infection rates in the United States. With respect to other groups, in a study of 7,868 patients age 18 years and older with COVID-19 across 88 hospitals in the United States, the authors found a disproportionate number of the patients were Hispanic and Black (33% Hispanic, 26% Black, 6% Asian, and 35% White). More than half of the deaths occurred in Hispanic and Black patients. When considering the racial/ethnic breakdown of the U.S. population in 2020 (White 58%, Hispanic 19%, Black 12%), Hispanic and Black patients bore a disproportionate representation with respect to mortality and morbidity from COVID-19 (Rodriguez et al., 2021). The reasons for this discrepancy may include inequities in COVID-19 testing and the fact that Hispanic and Black persons are overrepresented in the essential workforce leading to higher risk for exposure. Additionally, discrimination in healthcare and living in urban areas may increase risk for exposure. There is some evidence that Hispanic and Black pregnant women may be at higher risk for severe disease than White pregnant women. Because sexual and gender minority persons have been historically affected disproportionately by lack of health insurance, poverty, discrimination, mental health disorders, and substance use disorders as compared to nongender and sexual minorities, COVID-19 presents additional burdens for them.

Global Health Considerations ⬆ ⬇

COVID-19 is a worldwide epidemic. As of March 2, 2022, the WHO reports approximately 450,000,000 confirmed cases of COVID-19 and approximately 6 million deaths. The United States has the highest number of confirmed cases, followed in order by India, Brazil, France, the United Kingdom, the Russian Federation, and Germany.

Assessment ⬆ ⬇

ASSESSMENT

History

Determine if the patient has a history of travel to areas of high contagion and has been in close contact (within 6 feet) of a known COVID-19–positive person or someone who has been exposed to the illness. Determine the length of time since the exposure. Ask about the nature of the patient's employment, with particular attention to high-risk positions such as healthcare workers or workers in emergency or essential services such as transportation, food service, or sales. Solicit a history of the patient's symptoms, with particular attention to a history of fever, fatigue, and nonproductive cough. The patient may also report body aches, shortness of breath, and diarrhea. If the patient is stable enough to take a history, determine any comorbid conditions, such as diabetes mellitus and obesity, and whether the patient has taken preventive measures such as masking and social distancing. Ask if the patient has received a vaccine against COVID-19, the type of vaccine, the date received, and any booster doses. Ask if the patient has self-medicated to manage the symptoms of COVID-19 or to try to prevent the infection.

Physical Examination

Examination should occur with staff wearing personal protective equipment (PPE) and, if possible, in a private room with negative pressure to prevent viral transmission. Fever is the most common symptom of COVID-19, followed by cough, dyspnea, fatigue, and diarrhea. New onset of dysgusia (loss of taste) and anosmia (loss of smell) may occur. The patient may have tachycardia and tachypnea, and early assessment with pulse oximetry is important to identify hypoxemia, a sign of pending respiratory failure. Further respiratory symptoms include increased work of breathing, use of accessory muscles to breathe, and mild expiratory wheezes. Patients also may have circumoral cyanosis and confusion as their oxygen levels decrease. Repeat examinations are necessary as the disease progresses to a more serious or critical stage. Consider a COVID-19 diagnosis for people presenting with conditions such as septic shock, acute kidney injury, diabetic ketoacidosis, or acute cardiac disease.

Psychosocial

COVID-19 is a life-threatening illness whose prevention and treatment have been surrounded by healthcare-related and social controversies. The family's response depends on their view of the disease and treatment and may range from extreme anxiety to concern to guilt to a more confrontational approach. The potential for other family members to contract the disease makes interactions more complex. Ultimately, the family may be faced with the death of a loved one and personal COVID-19 diagnosis. Continuously assess the coping mechanisms and anxiety levels in both patients and families.

Diagnostic Highlights

Test	Normal Result	Abnormality With Condition	Explanation
SARS-CoV-2 reverse-transcription polymerase chain reaction assay	Negative	Positive for SARS-CoV-2 genetic material (RNA)	Test of secretions from a nasal swab can identify small amounts of viral RNA
Chest x-ray, computed tomography of chest	Clear lung fields	Ground glass opacity (hazy opacification) due to air displacement by fluid; bilateral infiltrates without cardiomegaly or pulmonary vascular redistribution; peribronchial thickening	Findings reflect noncardiogenic pulmonary edema, viral infection, and inflammation
Arterial blood gases (ABGs)	Pao₂ 80–95 mm Hg; Paco₂ 35–45 mm Hg; SaO₂> 95%	Pao₂< 80 mm Hg; Paco₂ varies; SaO₂< 95%	Poor gas exchange leads to hypoxemia and, as respiratory failure progresses, to hypercapnea. When the Paco₂ is divided by the Fio₂, the result is 200 or less. Patients with COVID-19 may have “silent hypoxemia,” low levels of oxygenation without difficulty breathing (Tobin et al., 2020).

Primary Nursing Diagnosis ⬆ ⬇

Diagnosis

DiagnosisImpaired gas exchange related to increased alveolar-capillary permeability, interstitial edema, and decreased lung compliance as evidenced by abnormal ABGs, dyspnea, abnormal breathing pattern, confusion, hypoxemia, and/or irritability

Outcomes

OutcomesRespiratory status: Gas exchange; Respiratory status: Ventilation; Respiratory status: Airway patency; Mechanical ventilation response: Adult; Fluid balance; Comfort status: Physical; Vital signs; Anxiety level

Interventions

InterventionsAirway insertion and stabilization; Airway management; Respiratory monitoring; Oxygen therapy; Mechanical ventilation management; Vital signs monitoring; Anxiety reduction; Fluid management

Planning and Implementation ⬆ ⬇

PLANNING AND IMPLEMENTATION

Collaborative

Key management principles include early diagnosis, immediate patient isolation, and supportive care with fluids, nutrition, respiratory support, and oxygenation (Majumder & Minko, 2021). To date, there is no effective treatment for COVID-19 although multiple drugs are currently undergoing randomized controlled trials. A series of antiviral therapies have been developed and tested. The corticosteroid dexamethasone has become a mainstay of treatment by reducing deaths by one-third in patients with COVID-19 on mechanical ventilation (https://www.recoverytrial.net). Baricitinib and tocilizumab, drugs used to manage inflammation due to rheumatoid arthritis, may help control the exaggerated inflammatory response resulting from COVID-19. Recent findings indicate that they may reduce deaths of hospitalized patients (https://www.recoverytrial.net). A monoclonal antibody combination has been found to reduce deaths for patients who are hospitalized with COVID-19 who have not mounted an immune response (https://www.recoverytrial.net).

Critically ill patients may develop cardiopulmonary failure, which is treated with oxygen therapy and noninvasive or invasive mechanical ventilation, vasoactive medications, and if needed, extracorporeal membrane oxygenation. Other modalities of mechanical cardiopulmonary support such as left ventricular assist device may be warranted. Prone positioning is considered standard of care for patients with both acute respiratory distress syndrome (ARDS) and severe hypoxemic respiratory failure with COVID-19 (Rajagopal et al., 2020). Just as in ARDS, severity of respiratory failure due to COVID-19 is determined by the ratio of Pao₂ to inspired oxygen concentration (Fio₂) when the patient is on at least 5 cm H₂O of positive end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP). Three categories of ARDS severity are mild (ratio = 200–300), moderate (ratio = 100–200), and severe (ratio of ≥100). As of early 2022, the care of people with severe COVID-19 remains challenging and an area of intensive investigation to determine an effective treatment.

Rehabilitation after an acute infection with COVID-19 focuses on patients who have experienced physical, mental, and cognitive impairments that threaten the return to their previous circumstances. Plans for rehabilitation need to occur early in the recovery phase with consultation from a multidisciplinary team collaborating with the acute care team. Occupational and physical therapy for positioning and splinting followed by passive range of motion and using communication devices can occur early in the disease course when the patient is no longer unstable. When the patient's sedation level allows for it, active range of motion, bed mobility, sitting on the edge of the bed, and cognitive stimulation continue rehabilitation care until the patient is transferred to a less-intensive care environment.

Pharmacologic Highlights

Medication or Drug Class	Dosage	Description	Rationale
Antivirals (remdesivir, ritonavir-boosted nirmatrelvir, sotrovimab, molnupiravir)	Varies by drug	Anti-SARS-CoV-2 therapies	Inhibit viral replication (Singh & de Wit, 2020)
Dexamethasone	6 mg daily PO or IV	Synthetic corticosteroid	Anti-inflammatory that reduces mortality in mechanically ventilated patients and those requiring oxygen (Marian, 2021)
COVID-19 mRNA vaccine	Varies by drug	mRNA vaccine	Induces cells to make a protein that then stimulates the immune system to develop antibodies to COVID-19; only effective prophylactically; not administered during an acute viral infection
Anti-SARS-CoV-2 monoclonal antibodies (combination of casirivimab and imdevimab)	Varies by drug	Monoclonal antibodies are proteins genetically engineered from a single clone and consisting of identical antibody molecules; used for patients with mild to moderate infection hospitalized for a reason other than COVID-19	Should be started as soon as patient has positive SARS-CoV-2 reverse-transcription polymerase chain reaction assay and within 10 days of symptom onset (https://www.recoverytrial.net)
Immunomodulators (baricitinib, tocilizumab)	Varies by drug	May control the inflammatory response to COVID-19	Reduces deaths in patients hospitalized with COVID-19 (https://www.recoverytrial.net)

Other Drugs: Anticoagulation, inhaled pulmonary vasodilators, neuromuscular blocking agents. Research continues to determine the role of antiviral medications, convalescent plasma, immunotherapy (Majumder & Minko, 2021).

Independent

Providing acute and critical care to patients with COVID-19 is challenging because it involves the maintenance of airway, breathing, and circulation simultaneously with protecting caregivers with PPE. Patients may develop rapidly developing respiratory failure, septic shock, metabolic acidosis, coagulation disorders, and multiple organ failure (Yuan et al., 2020), and the protocol for donning and removing several levels of protective equipment is a time-consuming and necessary addition to acute and critical care management. In addition to oxygen therapy and either noninvasive ventilation (CPAP or bilevel positive airway pressure [BiPAP]) or invasive mechanical ventilation, current expert opinion is to place the patient in the prone position for up to 16 of 24 hours with repositioning every 2 hours (Makic, 2020; Rajagopal et al., 2020). Patients have better outcomes if prone position is used in the initial hours of severe hypoxia. However, prone position presents challenges such as inadvertent dislodgement of IV lines and endotracheal tubes, concerns about aggravating hemodynamic instability, skin injury, gastroesophageal reflux, and the physical difficulties of rotating patients (three to five persons are needed). Prior to proning, protective dressings of the feet, knees, hips, shoulders, and face should be placed along with eye lubrication and taping to protect the corneas. Correct patient selection for prone position and timely initiation when warranted are important. Contraindications include extreme obesity, pregnancy, unstable spine, seizures, elevated intracranial pressure, facial surgery, and hemodynamic instability (Makic, 2020).

To augment gas exchange, the patient needs periodical endotracheal suctioning. Prior to suctioning, hyperventilate and hyperoxygenate the patient to prevent the ill effects of suctioning, such as cardiac dysrhythmias or hypotension. As the patient improves, get them out of bed for brief periods, even if they are intubated and on a ventilator. Provide passive range-of-motion exercises every 8 hours to prevent contractures. Communication with family is challenging because of infection control protocols. Arrange communication mechanisms that protect patients, families, and staff from COVID-19 exposure. Explain the critical care environment and technology, but emphasize the importance of the patient's humanness over and above the technology. Maintain open communication among all involved. Answer all questions, and provide methods for patients and families to communicate. Patients and families are likely to be fearful and anxious. Families are well-aware that with a COVID-19 diagnosis, intubation indicates a worsening condition and may indicate that the patient has a terminal illness. Acknowledge their fear without providing false reassurance.

Evidence-Based Practice and Health Policy

Coppo, A., Bellani, G., Winterton, D., Di Pierro, M., Soria, A., Faverio, P., Cairo, M., Mori, S., Messinesi, G., Contro, E., Bonfanti, P., Benini, A., Valsecchi, M., Antolini, L., & Foti, G. (2020). Feasibility and physiological effects of prone positioning in non-intubated patients with acute respiratory failure due to COVID-19 (PRON-COVID): A prospective cohort study. Lancet Respiratory Medicine, 8(8), 765–774.

The authors initiated a study of patients 18 to 75 years of age (N = 56) hospitalized with a confirmed diagnosis of COVID-19–related pneumonia receiving supplemental oxygen or noninvasive CPAP. Patients were helped into the prone position, which was maintained for a minimum of 3 hours. Clinical data were collected at baseline, after 10 minutes of prone positioning, and 1 hour after returning to supine position.
Oxygenation substantially improved from supine to prone position. After resuming the supine position, improved oxygenation occurred in 50% of the patients. Patients with improved oxygenation had shorter time between admission and prone positioning. The authors encouraged further investigation of the prone position in COVID-19 patients.

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DRG Information ⬇

Introduction ⬆ ⬇