COVID-19: Lessons Learned during the Pandemic

Elise M. Martin, MD, MS
Assistant Professor of Medicine, Associate Medical Director of Infection Prevention and
Hospital Epidemiology, University of Pittsburgh Medical Center, Pittsburgh, PA

  • Key clinical takeaways

This audio lecture is part of a high-yield learning activity from AudioDigest’s Internal Medicine Library. To get CME for this activity go here to create a trial account.

Educational Objectives ⟶

The goal of this program is to improve the prevention and management of COVID-19 in the general population. After hearing and assimilating this program, the clinician will be better able to:
1. Counsel patients about activities that place them at highest risk for contracting COVID-19
2. Identify patients who are at risk for severe outcomes of COVID-19 based on comorbid conditions.
3. Recommend appropriate isolation periods for asymptomatic and symptomatic patients with positive COVID-19 test results.

Summary⟶

Symptoms of COVID-19: include cough, fever, myalgia, headache, dyspnea, sore throat, various gastrointestinal (GI) symptoms, and loss of smell or taste (in a minority of cases); a recent update shows 43% of the individuals experience fever; 50% have cough; the severity of symptoms varies widely

Prevalence of asymptomatic disease: Annals of Internal Medicine article — reported wide variability in infections rates among various populations and in the proportions of positive cases that are asymptomatic; study in Iceland — testing of ≈13,000 people found low rates of COVID-19; among those who tested positive, 43% were asymptomatic; findings were similar among other low-risk populations (eg, residents of Italy and San Francisco had low rates of infection, with half of these individuals being asymptomatic); higher risk populations — eg, homeless shelters, inmates in Arkansas, North Carolina, Ohio, and Virginia; among 4700 tested individuals, 70% were positive for SARS-CoV-2; of these, 96% were asymptomatic; the US Centers for Disease Control and Prevention (CDC) currently estimates that asymptomatic persons accounts for ≈40% of SARS-CoV-2 infection

Course of asymptomatic infection: New England Journal of Medicine article — found 23 positive tests among 76 residents of a skilled nursing facility; of these 23 people, 12 were asymptomatic; follow-up of these individuals revealed that 11 of 12 eventually developed symptoms (ie, virus had been detected during the presymptomatic phase); on retesting of 49 initially negative residents, ≈50% of tests were positive; among those who tested positive, 15 were asymptomatic, 13 of whom later developed symptoms

Risk factors: crowded places; close physical contact with individuals from outside one’s household; being in enclosed spaces with poor ventilation; long duration of exposure to an infected person; failure to wear a mask, practice social distancing, or adhere to appropriate hand hygiene and disinfection; ethnicity — compared with Whites, rates of cases of COVID-19 and associated rates of hospitalization and death are higher among Blacks; Latinos also have higher rates of cases and hospitalization, but death rates are only slightly higher; rates of cases, hospitalization, and death are also comparatively higher among American Indians and Alaska Natives; targeted measures are needed to address these groups; reasons for disparities are unclear but may relate to socioeconomic status, access to health care, and high-risk employment

Infection without obvious exposure: MMWR report — restaurants and bars in restaurants have been identified as sources of serious risk (ie, places in which people are unmasked and in close contact with other unmasked people, especially when eating a meal); no significant increase in risk was found for other activities, such as shopping, going to the office or a salon, or small gatherings

Infection among health care workers: MMWR report — found 6% seroprevalence of antibodies to SARS-CoV-2 among 3200 health care personnel, which was similar to the prevalence in their communities; however, health care workers at Beth Israel Deaconess Medical Center or The Johns Hopkins Hospital have low rates of positivity despite relatively high rates in their communities (ie, health workers are acquiring infection at a lower rate than other individuals); 29% of those who tested positive did not have symptoms in the preceding months; 69% had not received a formal diagnosis of COVID-19; consistent mask-wearing was associated with lower rates of seropositivity

Risk factors for severe disease: data show higher risk for poor outcomes among those with advanced age, cancer, chronic kidney disease, chronic obstructive pulmonary disease, immunocompromised state related to organ transplantation, obesity, heart disease, sickle cell disease, and type 2 diabetes; possibly associated with increased risk — other lung diseases, other immunocompromising conditions, pregnancy, and type 1 diabetes

Complications: most commonly, acute respiratory distress syndrome and other respiratory complications requiring mechanical ventilation; others — cardiac abnormalities, including arrhythmias; thromboembolic events; inflammatory conditions, such as Guillain-Barré syndrome or a newly identified process known as multisystem inflammatory syndrome (seen in children; similar to Kawasaki disease); secondary infection (bacterial or fungal, including Aspergillus); possible viral co-infection (eg, influenza)

Long-term sequelae: many people recover from the infection but have persistent symptoms, such as fatigue, dyspnea, joint pain, and/or chest pain; researchers are attempting to identify risk factors for long-term sequelae and how these symptoms (which are not believed to represent persistent infection) should be treated

Diagnostic testing: the most common test for identifying active infection is reverse transcription polymerase chain reaction (RT-PCR) using a respiratory specimen (most commonly, nasopharyngeal swab, but also performed with nasal swabs; use of self-collected nasal swabs is being explored); sensitivity and specificity are considered high; false-positive results are believed to be uncommon

Significance of persistent positive tests: frequently, tests remain positive for weeks to months after an initial positive result; however, research has shown that viral infectiousness does not persist beyond ≈8 days

Other diagnostic tests: serologic testing — not widely used because it detects prior rather than active infection; antigen tests — can be used for active infection; specificity and sensitivity are likely inferior to those of RT-PCR; not widely used

Outcomes of serial testing: University of Pittsburgh Medical Center (UPMC) study — of 30,000 tests, 485 were repeated; among those repeated, the initial retest was positive in 74; subsequent retests were approximately equally likely to be positive or negative; among the tests that were initially negative, only 15 were positive on subsequent testing (ie, 96% of repeat tests were negative

Management: remdesivir can be used in patients who are on supplemental oxygen or mechanical ventilation; the REMAP trial at UPMC provides data on the use corticosteroids; other drugs that have been studied include hydroxychloroquine with or without azithromycin, tocilizumab, and lopinavir-ritonavir, none of which are currently recommended; at UPMC, vitamin C and therapeutic anticoagulation are being explored; an Emergency Use Authorization has been given for convalescent plasma

Prevention: the virus spreads directly from person to person, largely through droplets, and possibly via airborne transmission; preventing spread depends on identifying infected individuals (including those who are asymptomatic), isolating them, and quarantining their close contacts; other measures include social distancing of ≥6 ft, hand hygiene, cleaning and disinfection (although contact with surfaces is not believed to be the primary source of transmission), and use of face coverings or personal protective equipment

Universal masking in the health care environment: data from an adult hospital and a children’s hospital in Paris, and from Massachusetts General Hospital, suggest significant reduction in the rate of acquisition of COVID-19 among health care workers after the institution of this practice; data from Duke University — prior to universal masking, infection rates in health care workers were similar to those in the community; following the institution of universal masking, rates of transmission linked to health care exposures was minimal

Masking in the community: data from Germany reveal a significant reduction in cases of COVID-19 with universal masking; data from China show that risk for infection is reduced by 79% if individuals mask when in contact with infected members of their households; US data show no transmission from infected, symptomatic hair stylists to their clients when all parties wore masks

Precautions for care of patients with known or suspected infection: N95 mask or powered air purifying respirator, eye protection, gowns, and gloves; similar precautions are recommended for procedures with high risk of aerosolizing the virus (eg, intubation, extubation, manual ventilation, noninvasive ventilation, bronchoscopy, tracheostomy)

Duration of infectiousness: now being evaluated based on symptoms rather than testing; mild to moderate illness — consider infectious for ≤10 days; keep in isolation for 10 days after the first symptoms appear and until there has been no occurrence of fever for 24 hr (while not taking antipyretic medication); if symptoms have not improved, do not remove precautions; severe or critical illness — the CDC recommends precautions for 10 to 20 days (discontinue only if improved and follow the same criteria for absence of fever); for COVID-19, most patients requiring supplemental oxygen are considered in the severe category; asymptomatic with positive testing — infectious for 10 days after the test

Reinfection: data from Hong Kong, Reno, NV, and Qatar suggest possible cases of reinfection; distinction from persistent test positivity — determine whether there have been new exposures and/or new symptoms; perform whole-genome sequencing to determine whether the strain of virus differs between the first and second instances

Test Your Knowledge ⟶

1. Data show that in populations at high risk of contracting COVID-19 (eg, residents of homeless shelters, prison inmates), there is a _______ rate of asymptomatic disease among those who test positive; among residents of a skilled nursing facility, a _______ percentage of asymptomatic cases of COVID-19 eventually became symptomatic.

(A) High; high

(B) High; low

(C) Low; high

(D) Low; low

The correct answer is A. Among 4700 tested individuals from prisons and homeless shelters, 70% were positive for SARS-CoV-2; of these, 96% were asymptomatic. Per an article in the New England Journal of Medicine, 23 of 76 residents of a skilled nursing facility tested positive for COVID-19, and of these 23 people, 12 were asymptomatic. Follow-up of these individuals revealed that 11 of 12 eventually developed symptoms (ie, virus had been detected during the presymptomatic phase). Arons MM et al: Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility. N Engl J Med. 2020;382(22):2081-2090. Rogers JH et al: Characteristics of COVID-19 in homeless shelters: a community-based surveillance study [published online ahead of print, 2020 Sep 15]. Ann Intern Med. 2020;M20-3799. doi:10.7326/M20-3799

  

2. According to an MMWR report, which of the following activities was(were) found to significantly increase risk for COVID-19 infection?

(A) Dining in a restaurant

(B) Working in an office

(C) Receiving services in a salon

(D) All the above

The correct answer is A.In an MMWR report, restaurants and bars in restaurants were identified as sources of serious risk (ie, places in which people are unmasked and in close contact with other unmasked people, especially when eating a meal). No significant increase in risk was found for other activities, such as shopping, going to the office or a salon, or small gatherings. Fisher KA et al. Community and close contact exposures associated with COVID-19 among symptomatic adults ≥18 years in 11 outpatient health care facilities - United States, July 2020. MMWR Morb Mortal Wkly Rep. 2020;69(36):1258-1264. Published 2020 Sep 11. doi:10.15585/mmwr.mm6936a5

 

3. Of the following conditions, which has been most definitively associated with risk for severe outcomes of COVID-19 infection?

(A) AIDS

(B) Heart disease

(C) Cystic fibrosis

(D) Type 1 diabetes

The correct answer is B. Data show higher risk for poor outcomes among those with advanced age, cancer, chronic kidney disease, chronic obstructive pulmonary disease, immunocompromised state related to organ transplantation, obesity, heart disease, sickle cell disease, and type 2 diabetes. More data are needed on risk associated with other lung diseases, other immunocompromising conditions, pregnancy, and type 1 diabetes. Ssentongo P et al: Association of cardiovascular disease and 10 other pre-existing comorbidities with COVID-19 mortality: A systematic review and meta-analysis. PLoS One. 2020;15(8):e0238215. Published 2020 Aug 26. doi:10.1371/journal.pone.0238215

 

4. Which of the following types of tests detect(s) active COVID-19 infection?

1. Transcription polymerase chain reaction (RT-PCR)
2. Serologic testing
3. Antigen tests

(A) 1

(B) 1,2

(C) 1,3

(D) 2,3

The correct answer is C.  The most common test for identifying active infection is reverse transcription polymerase chain reaction (RT-PCR) using a respiratory specimen. Serologic testing is not widely used because it detects prior rather than active infection. Antigen tests can be used for active infection, but specificity and sensitivity are likely inferior to those of RT-PCR; therefore, it is not widely used. Kubina R, Dziedzic A. Molecular and serological tests for COVID-19: a comparative review of SARS-CoV-2 coronavirus laboratory and point-of-care diagnostics. Diagnostics (Basel). 2020;10(6):434. Published 2020 Jun 26. doi:10.3390/diagnostics10060434

 

5. An Emergency Use Authorization has been issued by the US Food and Drug Administration for treatment of COVID-19 with which of the following agents?

(A) Enoxaparin

(B) Tocilizumab

(C) Lopinavir-ritonavir

(D) Convalescent plasma

The correct answer is D. Drugs that have been studied for treating COVID-19 include hydroxychloroquine with or without azithromycin, tocilizumab, and lopinavir-ritonavir, none of which are currently recommended. Use of therapeutic anticoagulation is being explored. An Emergency Use Authorization has been given for use of convalescent plasma. Pau AK et al. Convalescent plasma for the treatment of COVID-19: perspectives of the National Institutes of Health COVID-19 Treatment Guidelines Panel [published online ahead of print, 2020 Sep 25]. Ann Intern Med. 2020;M20-6448. doi:10.7326/M20-6448

 

6. According to the Centers for Disease Control and Prevention, precautions can be lifted for patients who have mild to moderate symptoms of COVID-19:

(A) After 10 days, regardless of whether there are persistent symptoms

(B) After 10 days, only if there has been no recurrence of fever while not taking antipyretic medication

(C) After 20 days, regardless of whether there are persistent symptoms

The correct answer is B.  In cases of mild to moderate illness, the patient should be kept in isolation for 10 days after their first symptoms appear. Precautions should not be removed if symptoms are not improved; patients must be free of fever for 24 hr without use of fever-reducing medication. Walsh KA et al. The duration of infectiousness of individuals infected with SARS-CoV-2. J Infect. 2020;81(6):847-856. doi:10.1016/j.jinf.2020.10.009

 

For more Coronavirus Resources & Tools from Wolters Kluwer including UpToDate and Ovid



ADDITIONAL RESOURCES:

Other relevant information on COVID from NEJM Journal Watch and NEJM Group is freely available at the NEJM Covid-19 resource page.

Visit ACCME’s database of activities supporting the safe rollout of COVID-19 vaccines.





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