News Flash

SUMMARY 

See this health alert for:

• Approach to Influenza Season in the COVID-19 Era
• COVID-19 Quarantine and Negative SARS-CoV-2 Test Results

Approach to Influenza Season in the COVID-19 Era

Requested Actions

• Always test for SARS-CoV-2 in patients presenting with acute respiratory illness.
• Continue to provide or recommend influenza vaccination throughout the course of the winter respiratory virus season (e.g., now through March).
• Track surveillance information sources to maintain awareness of the level and trajectory of influenza and COVID-19 activity in the region.
• Follow prevailing guidelines for influenza testing and treatment based upon local and regional surveillance data, patient clinical status, and care setting. See below for more details.
• Follow prevailing guidelines and your institution’s policies for isolation and infection control precautions. See below for more details on general features of such guidelines.

Influenza Surveillance (through October 24)

• Washington State: no influenza detection or isolates obtained yet from 300+ specimens submitted weekly to commercial and public health laboratories in the state
• National: minimal-to-nil activity
• Global: Inter-seasonal influenza activity in the northern hemisphere has been below historical norms and influenza activity in temperate and tropical regions of the southern hemisphere have been minimal-to-nil during their recently ending winter respiratory virus season.

Note: These trends are likely driven by COVID-19 prevention measures and reduced travel locally and abroad. To a lesser extent, diversion of health care system attention and disease surveillance by the COVID-19 pandemic may be a source of under-detection and/or under-reporting of influenza infections. Only time will tell the extent to which global and regional influenza activity will remain suppressed by ongoing COVID-19 prevention measures.  

COVID-19 Surveillance

• Snohomish Health District
• Washington State Department of Health
• Centers for Disease Control and Prevention
• World Health Organization

Influenza & SARS-CoV-2 Testing

• Although influenza is typically more abrupt in onset with characteristic fever-and-cough while COVID-19 has a more subacute evolution with protean manifestations, only testing can definitively distinguish between SARS-CoV-2 and influenza virus infections. Dual testing is also necessary to identify rare coinfections that may occur.
• Until further notice, all individuals presenting with an acute respiratory illness or other compatible clinical syndrome should continue to be tested for SARS-CoV-2 infection.
• Prior to demonstration of influenza circulation in the region, clinicians evaluating patients with acute respiratory illness may elect to test for influenza either sporadically based on clinical judgment or systematically as a surveillance tool.
• Once SARS-CoV-2 and influenza viruses are co-circulating in the region:

1. Patients hospitalized with acute respiratory illness should also be tested for influenza.
2. Outpatients with acute respiratory illness should be tested for influenza if the results will change clinical or infection control management of the patient (e.g., decision making regarding use of anti-viral therapy, placement in congregate settings).
3. Testing for other pathogens should be considered depending on clinical circumstances, especially in patients with influenza in whom bacterial superinfection is a well-recognized complication.

Antiviral Treatment of Influenza when Influenza Viruses and SARS-CoV-2 are Co-circulating

• The treatment of influenza is the same in all patients regardless of SARS-CoV-2 coinfection.
• Among hospitalized patients with influenza-like illness, immediate empiric treatment for influenza with oseltamivir is recommended without waiting for influenza testing results.
• Antiviral treatment of influenza can be stopped when influenza has been ruled out by nucleic acid detection assay in upper respiratory tract specimens for non-intubated patients and in both upper and lower respiratory tract specimens for intubated patients.

Isolation

• Influenza cases: 
  1. Droplet precautions in health care settings
  2. Consider airborne precautions for aerosol-generating procedures
  3. Continue until 7 days after onset AND afebrile for at least 24 hours without use of anti-pyretics.
• COVID-19 cases:
  1. Droplet precautions
  2. Add airborne precautions as available with a prioritization for patients likely to be generating aerosols.
  3. Continue until at least 10 days after onset (or 10 days after testing if asymptomatic) AND afebrile for at least 24 hours without use of anti-pyretics AND other symptoms improving.
  4. Extend to 20 days for severely ill or immunosuppressed patients.

Additional Resources

• Centers for Disease Control and Prevention (CDC). Information for Clinicians on Influenza Virus Testing. https://www.cdc.gov/flu/professionals/diagnosis/index.htm
• CDC. Influenza Anti-viral Medications. https://www.cdc.gov/flu/professionals/antivirals/index.htm 
• CDC. Influenza Infection Control.  https://www.cdc.gov/flu/professionals/infectioncontrol/index.htm 
• CDC. Interim Infection Prevention and Control (COVID-19). https://www.cdc.gov/coronavirus/2019-ncov/hcp/infection-control-recommendations.html 
• National Institutes of Health.  Influenza and COVID-19. https://www.covid19treatmentguidelines.nih.gov/special-populations/influenza/ 
• Infectious Diseases Society of America.  Clinical Practice Guidelines [Influenza]. https://www.idsociety.org/practice-guideline/influenza/

COVID-19 Quarantine and Negative SARS-CoV-2 Test Results

Requested Actions

• When notifying a patient of positive SARS-CoV-2 results, advise them to tell their household and other close contacts to remain at home and wait for follow-up contact from the Health District.   
• Counsel patients who have been exposed to COVID-19 to quarantine at home for 14 days after the last exposure occurred.
• Immediately test all symptomatic COVID-19 contacts for SARS-CoV-2 if they present to you.
• Time testing among asymptomatic COVID-19 contacts to approximately 4-7 days after last exposure to optimize yield and impact on disease intervention efforts.
• Advise contacts with negative SARS-CoV-2 results to remain in quarantine for the full 14-day period after last exposure, regardless of negative test results.

Overview

The Health District’s case investigation and contact notification staff have discovered occasional misinformation coming to patients from clinicians about duration of quarantine for COVID-19 exposure. Specifically, we offer the following clarifications to aid clinicians in counseling patients:

• A negative SARS-CoV-2 result does not permit a contact of a case to be released from quarantine prior to termination of the full 14-day period since last exposure.
• For contacts living in a setting with one or more cases, day 1-of-14 is counted from the day after the last case in the setting has been released from isolation. For example, a household has two serial cases, A and B, plus your patient, C. C goes into quarantine as soon as the first case, A, is diagnosed on November 1. On November 5, case B is diagnosed with COVID. C remains well and pursues testing at that time. The results are negative. On November 15, case B is released from isolation. Contact C’s quarantine will continue for another 14 days from that date, through November 29. 
• Cases and contacts who cannot safely isolate or quarantine at home may be referred for voluntary admission to the Snohomish County’s Isolation & Quarantine Facility at the Evergreen Fairgrounds in Monroe.  To make a referral, call the site supervisor at 425-238-3439.

Chris Spitters, MD, MPH
Health Officer
Snohomish Health District