Influenza Update for the 2020 - 2021 Flu Season
Key Points
Key Points
- Seasonal influenza A and B virus epidemics are associated with significant morbidity and mortality each year in the United States and worldwide. During 2010-2019, annual seasonal influenza epidemics of variable severity were associated with an estimated 9.3 million to 45 million illnesses, 140,000 to 810,000 hospitalizations, and 12,000 to 61,000 deaths in the U.S. Source: [ cdc.gov/flu/about/burden/index.html ]
- Most people recover from uncomplicated influenza, but influenza can cause complications that result in severe illness and death, particularly among very young children, older adults, pregnant and postpartum women within 2 weeks of delivery, people with neurologic disorders, and people with certain chronic medical conditions including chronic pulmonary, cardiac, and metabolic disease, and those who are immunocompromised.
- Early treatment with antivirals reduces the duration of symptoms and risk of some complications (bronchitis, otitis media, and pneumonia) and hospitalization, and may decrease mortality among high-risk populations.
- Annual vaccination is the best method for preventing or mitigating the impact of influenza, but in certain situations chemoprophylaxis with antiviral medications can be used for pre-exposure or post-exposure prevention and can help control outbreaks in certain populations.
- Because prevention and control of influenza is a dynamic field, clinicians should consult the website of the Centers for Disease Control and Prevention (CDC) [ cdc.gov/flu/index.htm ] for the latest information about influenza vaccines, influenza tests, and approved antiviral medications.
Testing and Treatment of Influenza When SARS-CoV-2 and Influenza Viruses are Co-circulating
- Consolidated Clinical Algorithm for Outpatient Clinic or Emergency Department Patients with Acute Respiratory Illness Symptoms (With or Without Fever): cdc.gov/flu/professionals/diagnosis/testing-guidance-for-clinicians.htm
- Clinical Algorithm for Outpatient Clinic or Emergency Department Patients with Acute Respiratory Illness Symptoms (With or Without Fever) Not Requiring Hospital Admission: cdc.gov/flu/professionals/diagnosis/testing-guidance-for-outpatient.htm
- Clinical Algorithm for Patients with Acute Respiratory Illness Symptoms Requiring Hospital Admission (With or Without Fever): cdc.gov/flu/professionals/diagnosis/testing-guidance-for-clinicians-hospitaized.htm
- Testing and Management Considerations for Nursing Home Residents: cdc.gov/flu/professionals/diagnosis/testing-management-considerations-nursinghomes.htm
- NIH COVID-19 Treatment Guidelines on Influenza and COVID-19: covid19treatmentguidelines.nih.gov/special-populations/influenza/
Prevention
...Prevention...
...za Vaccines — United States, 2020–21 Influe...
...raindications and Precautions to the Use...
...3. Dose Volumes for Inactivated Influen...
...Influenza Vaccine Dosing Algorithm for Ch...
...Prevention...
...Chemoprophy...
...drugs should NOT be used for routine or wid...
...s can consider antiviral chemoproph...
...s can consider antiviral chemoprophylaxis for the...
...icians can consider short-term antiviral chemo...
...n consider short-term antiviral chemoprop...
...can consider educating patients and parents of pa...
...nicians should use an NAI (oral oseltamiv...
...nicians should administer pre-expo...
...inicians should test for influenza and swit...
...ns can consider post-exposure antiviral chem...
Clinicians can consider post-expo...
...nicians can consider educating patien...
...emoprophylaxis is given, clinicians should admi...
...s should not administer once-daily post-exposu...
...icians should administer post-expo...
...should test for influenza and switch to ant...
...hould administer an NAI (inhaled zana...
Treatment
...Treat...
...Persons of any age who are hospitalized...
...utpatients of any age with severe or progre...
...patients who are at high risk of complications fr...
...unger than 2 years and adults ≥65...
...nant women and those within 2 weeks postpart...
...tpatients with illness onset ≤2 days before pres...
...omatic outpatients who are househo...
...Symptomatic healthcare providers who care for pati...
...Anti...
...ians should start antiviral treatment as soon as p...
Clinicians should NOT routinely use highe...
...s should treat uncomplicated influenza in otherw...
Clinicians can consider longer duration...
...Bacterial Coinfect...
...cians should investigate and empiricall...
Clinicians should investigate an...
...linicians can consider investigating bacterial...
...Antiviral Fail...
...nicians should investigate other causes b...
...Antivira...
...Patients who develop laboratory-confirmed i...
...s with an immunocompromising condition a...
...tients with laboratory-confirmed influ...
...atients with severe influenza who do not improv...
...Clinicians should remain informed...
...ould NOT administer corticosteroid...
...linicians should NOT routinely administer immuno...
...iviral Agents and Dosing Recommendations f...
Institutional Outbreak Control
...Institutional...
...Institutional O...
...ve surveillance for additional cases should be im...
...eak control measures should be implemented a...
Implementation of outbreak control mea...
...influenza outbreak has been identified in a...
...ntiviral treatment should be administered as soo...
...emoprophylaxis should be administe...
...l chemoprophylaxis should be administered t...
...can consider antiviral chemoprophy...
...cians can consider antiviral chemop...
...n consider antiviral chemoprophylaxis for staff...
...ans should administer antiviral chem...
...5. Control Measures for Managing Institutional I...
Diagnosis
...Diagnosis...
...Testing...
Outpatie...
...ans should test for influenza in high-risk...
...ians should test for influenza in patie...
...an consider influenza testing for patie...
...During low influenza activity without any link t...
...Hospitalized Patients...
...icians should test for influenza on admissi...
...ld test for influenza on admission in al...
...nicians should test for influenza o...
...ns should test for influenza in all patients w...
...nicians should test for influenza on admission...
...ns can consider testing for influenza...
...Signs and Symptoms of Uncomplicated Influenzaa...
...7. Clinical Manifestations and Complications...
...ns Who Are at High Risk of Complications F...
...ups in Whom to Consider a Diagnosis o...
.... Influenza Diagnostic Tests for Respirato...
...11. Multiplex Assays Authorized for Simultaneous...
...pretation of Influenza Testing Results on Respir...
...13. List of Differential Diagnoses to Consider...
...igure 2. Guide for Considering Influenz...
...Specim...
...linicians should collect upper respirat...
...icians should collect nasopharyngeal (optimally, a...
...should collect endotracheal aspirat...
...Clinicians should NOT collect or routin...
...ns should NOT collect serum specimens, i...
...Diagnostic T...
...nicians should use rapid molecular assays (i.e...
...ould use reverse-transcription polymera...
...cians should use multiplex RT-PCR assays...
...ns can consider using multiplex RT-PCR assays...
...s should NOT use immunofluorescence...
...llow-up testing with RT-PCR or other mole...
...uld NOT use RIDTs in hospitalized...
...follow-up testing with RT-PCR or ot...
...linicians should NOT use viral culture f...
...ral culture can be considered to confirm negat...
...Clinicians should NOT use serologic testing for...