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...
...Influenza Vaccines — United States, 2020–2...
...2. Contraindications and Precautions to the Use o...
...se Volumes for Inactivated Influenza...
.... Influenza Vaccine Dosing Algorithm for Children...
Prevention
...Chemoprop...
Antiviral drugs should NOT be used for routine...
...s can consider antiviral chemoprophylaxis fo...
...ns can consider antiviral chemoprophylaxis for...
...an consider short-term antiviral chem...
...inicians can consider short-term ant...
...icians can consider educating patients and p...
Clinicians should use an NAI (oral o...
Clinicians should administer pr...
...should test for influenza and switch to a...
...inicians can consider post-exposure antivir...
...cians can consider post-exposure an...
...icians can consider educating patients a...
...If chemoprophylaxis is given, clinic...
...ans should not administer once-daily post...
...hould administer post-exposure antivi...
...ould test for influenza and switch to anti...
...Clinicians should administer an NAI (inhaled zanam...
Treatment
...Treatment...
...Antiviral Dosing...
...Persons of any age who are hospitalized with in...
...of any age with severe or progressiv...
...tients who are at high risk of complica...
...ldren younger than 2 years and adults ≥...
...nant women and those within 2 weeks postpar...
...tpatients with illness onset ≤2 days before pres...
...outpatients who are household contacts of...
...ealthcare providers who care for pat...
...Antiviral Treatm...
...icians should start antiviral treatment as soo...
...should NOT routinely use higher doses...
...inicians should treat uncomplicate...
...icians can consider longer duration of antiviral...
...Bacteria...
...cians should investigate and empirically tre...
...hould investigate and empirically...
...icians can consider investigating bacterial coinfe...
...Antivira...
...ns should investigate other causes be...
...Antivira...
...nts who develop laboratory-confirmed...
...atients with an immunocompromising condition...
...atients with laboratory-confirmed influenz...
...tients with severe influenza who do not impr...
...inicians should remain informed on cu...
...Adjunctive Ther...
...ns should NOT administer corticoster...
...icians should NOT routinely administer...
...viral Agents and Dosing Recommendati...
Institutional Outbreak Control
...Instituti...
...Ins...
...Active surveillance for additional...
...eak control measures should be implemented as s...
...Implementation of outbreak control measures...
...n influenza outbreak has been ident...
...ric antiviral treatment should be administe...
Antiviral chemoprophylaxis should be admini...
...ral chemoprophylaxis should be administ...
...inicians can consider antiviral che...
...can consider antiviral chemoprophylaxis for st...
...can consider antiviral chemoprophylaxis f...
...ians should administer antiviral chemoprophyla...
...ontrol Measures for Managing Instit...
Diagnosis
...Diagnosis...
...Testing...
...Outpatients...
...hould test for influenza in high-r...
...hould test for influenza in patients who p...
...ns can consider influenza testing for patients...
...ng low influenza activity without any lin...
...Hospitalized Pati...
...icians should test for influenza on admission in...
...icians should test for influenza on a...
...should test for influenza on admission in all pati...
...ld test for influenza in all patients who...
...ans should test for influenza on admission in al...
...nicians can consider testing for influenza...
...and Symptoms of Uncomplicated InfluenzaaHav...
...nical Manifestations and Complications A...
...Who Are at High Risk of Complications From In...
...roups in Whom to Consider a Diagnosis of...
...10. Influenza Diagnostic Tests for Respirator...
...able 11. Multiplex Assays Authorized fo...
Table 12. Interpretation of Influenza Testing...
.... List of Differential Diagnoses to Con...
...e 2. Guide for Considering Influenza...
...Specimen...
...should collect upper respiratory tract spec...
...s should collect nasopharyngeal (optimally,...
...ans should collect endotracheal asp...
...should NOT collect or routinely test specimens fo...
Clinicians should NOT collect serum specimens...
...Clinicians should use rapid molecular assa...
...should use reverse-transcription poly...
Clinicians should use multiplex R...
...Clinicians can consider using multiplex RT-PCR...
...s should NOT use immunofluorescence assa...
...w-up testing with RT-PCR or other m...
...ians should NOT use RIDTs in hospitalized...
...ow-up testing with RT-PCR or other m...
...uld NOT use viral culture for initial or primar...
but viral culture can be considered to confirm...
...s should NOT use serologic testing for dia...