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
...evention...
...Influenza Vaccines — United States, 2020–21...
...Contraindications and Precautions...
...e 3. Dose Volumes for Inactivated Influen...
...nza Vaccine Dosing Algorithm for Children Aged...
Preventi...
...prophylaxis...
...drugs should NOT be used for routin...
...can consider antiviral chemoproph...
...n consider antiviral chemoprophylaxis fo...
...ans can consider short-term antivi...
...Clinicians can consider short-term antivi...
...n consider educating patients and...
...icians should use an NAI (oral oseltamivir or in...
...cians should administer pre-exposure antiviral...
...cians should test for influenza and...
...ns can consider post-exposure antiviral chemoprop...
...cians can consider post-exposure antivi...
Clinicians can consider educating patients and...
...ophylaxis is given, clinicians should administer...
...linicians should not administer once-da...
...icians should administer post-exposure antiviral c...
...ns should test for influenza and switch to an...
...cians should administer an NAI (inhaled zanam...
Treatment
...reatme...
...ntiviral Dos...
...rsons of any age who are hospitalized with...
...ents of any age with severe or progr...
...tients who are at high risk of com...
...Children younger than 2 years and adults...
...nant women and those within 2 weeks postp...
...ith illness onset ≤2 days before presentatio...
...Symptomatic outpatients who are househ...
...Symptomatic healthcare providers wh...
...tiviral Treatment for Suspected or Confirmed Infl...
...Clinicians should start antiviral...
...inicians should NOT routinely use higher d...
...inicians should treat uncomplicated inf...
...icians can consider longer duratio...
...terial Coinfection...
...should investigate and empirically treat bacteria...
...s should investigate and empirically trea...
...can consider investigating bacterial coinfecti...
...tiviral Failu...
...should investigate other causes besides influenza...
...viral-resistant Infection Testing...
...Patients who develop laboratory-con...
...ith an immunocompromising condition an...
...laboratory-confirmed influenza who inadvertently...
...s with severe influenza who do not impr...
...Clinicians should remain informed on cur...
...ctive Therapy...
...icians should NOT administer corticostero...
...icians should NOT routinely adminis...
...4. Antiviral Agents and Dosing Recommen...
Institutional Outbreak Control
...ional Outbreak Control
...stitutional Out...
...ve surveillance for additional cases should be imp...
...control measures should be implemented as...
...Implementation of outbreak control measure...
When an influenza outbreak has been ide...
...viral treatment should be administe...
...emoprophylaxis should be administered as s...
Antiviral chemoprophylaxis should be admin...
...Clinicians can consider antiviral chem...
...icians can consider antiviral chem...
...an consider antiviral chemoprophylaxis for staff...
...Clinicians should administer antiviral ch...
...Control Measures for Managing Institutional Influ...
Diagnosis
...iagnos...
...esting
...(including emergency department patients)...
...s should test for influenza in high-risk pati...
...ians should test for influenza in...
...inicians can consider influenza testing for pa...
...ring low influenza activity without any li...
...talized Patient...
...s should test for influenza on admissio...
...nicians should test for influenza on admi...
...d test for influenza on admission in all patien...
...nicians should test for influenza in all pat...
...cians should test for influenza on admission in al...
...can consider testing for influenza in p...
...and Symptoms of Uncomplicated Influenz...
Table 7. Clinical Manifestations and Complica...
...Persons Who Are at High Risk of Com...
...roups in Whom to Consider a Diagnosis o...
...0. Influenza Diagnostic Tests for R...
...ultiplex Assays Authorized for Simultaneous...
...Interpretation of Influenza Testing Res...
.... List of Differential Diagnoses to Cons...
...Guide for Considering Influenza Te...
...ecimens...
...ians should collect upper respiratory...
...should collect nasopharyngeal (optimall...
...should collect endotracheal aspirate or bro...
...Clinicians should NOT collect or routinely te...
...cians should NOT collect serum specimens, i...
...iagnostic Tests...
...nicians should use rapid molecular assays (i.e.,...
...ould use reverse-transcription polymerase chain...
...Clinicians should use multiplex RT-PCR assays...
...ns can consider using multiplex RT-PC...
...should NOT use immunofluorescence assays fo...
...-up testing with RT-PCR or other mole...
...inicians should NOT use RIDTs in hospitalized pati...
...follow-up testing with RT-PCR or other molecular...
...ns should NOT use viral culture for i...
but viral culture can be considered...
...Clinicians should NOT use serologic tes...