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
Preventio...
...fluenza Vaccines — United States,...
...le 2. Contraindications and Precautions t...
...Volumes for Inactivated Influenza Vaccines Li...
...uenza Vaccine Dosing Algorithm for C...
...eventio...
...hemoprophyl...
...gs should NOT be used for routine o...
...ians can consider antiviral chemopr...
...cians can consider antiviral chemoprophylaxis...
...Clinicians can consider short-term an...
...ans can consider short-term antivira...
...can consider educating patients and parents of p...
...ns should use an NAI (oral oseltamivir o...
...ns should administer pre-exposure antiviral c...
...cians should test for influenza and sw...
...cians can consider post-exposure antiviral...
...Clinicians can consider post-exposure antiviral c...
...ns can consider educating patients and a...
...chemoprophylaxis is given, clinicians shoul...
...nicians should not administer once-da...
...cians should administer post-exposure antivir...
...icians should test for influenza and s...
...cians should administer an NAI (inhale...
Treatment
...atment...
...iral Dosing...
...s of any age who are hospitalized with i...
...f any age with severe or progressive il...
...ents who are at high risk of complicat...
...Children younger than 2 years and adults ≥65...
...men and those within 2 weeks postpartum...
...ients with illness onset ≤2 days befo...
...ymptomatic outpatients who are household contacts...
...atic healthcare providers who care f...
...Treatment for Suspected or Confirmed...
...inicians should start antiviral treatment...
...nicians should NOT routinely use high...
...inicians should treat uncomplicated influe...
...can consider longer duration of an...
...rial Coinfection
...should investigate and empirically t...
...ians should investigate and empirically treat b...
...s can consider investigating bacterial...
Antiviral Fail...
...cians should investigate other causes besides...
...tiviral-resistant Infection T...
...develop laboratory-confirmed influen...
...ents with an immunocompromising condition and evi...
...ts with laboratory-confirmed influenza who i...
Patients with severe influenza who do not...
...should remain informed on current CDC an...
Adjunctive Therap...
...inicians should NOT administer cort...
...nicians should NOT routinely admin...
...able 4. Antiviral Agents and Dosing Recom...
Institutional Outbreak Control
...utional Outbreak Control...
...tutional Outbre...
...ive surveillance for additional cases...
...k control measures should be implemented a...
...Implementation of outbreak control measure...
...en an influenza outbreak has been identif...
...Empiric antiviral treatment should b...
...moprophylaxis should be administered as soon...
...ral chemoprophylaxis should be admi...
...Clinicians can consider antiviral ch...
...ians can consider antiviral chemoprophylaxis...
...Clinicians can consider antiviral che...
...ans should administer antiviral chem...
...ol Measures for Managing Institutional...
Diagnosis
Diagnosi...
Testing
...ents (including emergency departme...
...hould test for influenza in high-risk pat...
...should test for influenza in patients who prese...
...linicians can consider influenza test...
...fluenza activity without any link to...
Hospitalized Patien...
...ould test for influenza on admission in all p...
...ians should test for influenza on ad...
...ld test for influenza on admission in all pa...
...cians should test for influenza in...
...Clinicians should test for influenza on admissio...
...ans can consider testing for influenza in patient...
...Signs and Symptoms of Uncomplicated Influenza...
...nical Manifestations and Complications Associated...
...e 8. Persons Who Are at High Risk of Complications...
...in Whom to Consider a Diagnosis of Influenz...
Table 10. Influenza Diagnostic Tests fo...
...iplex Assays Authorized for Simultaneous Det...
...terpretation of Influenza Testing Results on R...
...st of Differential Diagnoses to Consi...
...for Considering Influenza Testing...
Specimen...
...cians should collect upper respiratory tract speci...
...ans should collect nasopharyngeal (optimally, as...
...ould collect endotracheal aspirate or bronchoalveo...
...Clinicians should NOT collect or routinely te...
...ians should NOT collect serum specimens, includi...
...iagnostic Test...
...Clinicians should use rapid molecular assays (i.e...
Clinicians should use reverse-tran...
...ians should use multiplex RT-PCR assays targetin...
...s can consider using multiplex RT-PCR assays...
...linicians should NOT use immunofluorescence...
...low-up testing with RT-PCR or other m...
...ns should NOT use RIDTs in hospitalized patients...
...up testing with RT-PCR or other molecular assay...
...ould NOT use viral culture for initial...
...ture can be considered to confirm negative te...
...s should NOT use serologic testing fo...