Seasonal Influenza in adults ✅

▪️Clinical symptom:

Influenza characteristically begins with the abrupt onset of fever (usually ranges from 37.8 to 40.0°C), nonproductive cough, and myalgia when Influenza virus is circulating,

Other common symptoms include including malaise, sore throat, nausea, nasal congestion, and headache.
Among adults ≥ 65 years and immunocompromised patients, influenza should also be
suspected during an influenza outbreak in the setting of atypical systemic symptoms, with
or without fever

▫️Laboratory findings - Laboratory findings are generally not helpful .
*WBC >15,000 suggest bacterial superinfection.

▫️Radiographic findings – Chest radiography is normal in patients with uncomplicated influenza.

▪️Incubation period

one to four days (average two days).
*household contacts (known as the serial interval) is three to four days

▪️Clinical course:

Adults with uncomplicated Influenza typically have fever and respiratory
symptoms for about three days, after which time most show signs of improvement; complete
recovery may take 10 to 14 days.

▪️High risk:

*Children <5 years, but especially <2 years
*Adults ≥65 years of age
*People who are pregnant or up to 2 weeks postpartum
*Residents of nursing homes and long-term care facilities
*People with medical conditions

▪️Additional evaluation :

-Signs and symptoms suggestive of pneumonia (cough with dyspnea, tachypnea, hypoxia, and fever)
-Abnormalities on lung auscultation
-Persistent fever for >3 to 5 days
-Development of fever after initial defervescence
-Worsening symptoms.

In such patients, we obtain chest radiography, COVID-19 testing, sputum Gram stain and culture, blood cultures, nasal methicillin-resistant Staphylococcus aureus PCR, Streptococcus pneumonia urine antigen, and Legionella testing.

▪️dosage:

Oseltamivir 75mg orally twice daily for 5 days(treatment dose)

Oseltamivir 75mg orally once daily for 7 days(prophylaxis dose)

▪️Site of care -

Hospitalization is warranted for patients with significant dehydration and for severely ill patients, especially those with respiratory distress, hypoxemia, impaired
cardiopulmonary function, or altered mental status.

▪️Treatment:

Hydration should be maintained. Acetaminophen or nonsteroidal anti-inflammatory drugs may be
used for management. of fever, headache, and myalgia

.

▪️Hospitalized patients management:

▫️ Antiviral treatment

▫️Concomitant infection − For patients in the following circumstances, we suggest administration of empiric antibacterial treatment for pneumonia (in addition to antiviral treatment for influenza, if:

-Patients with respiratory failure and/or hemodynamic instability
-Patients who fail to improve after three to five days of antiviral therapy and supportive care
-Patients who develop fever after defervescence.

▫️Patients should be treated with an agent active against Streptococcus pneumoniae and Streptococcus pyogenes (such as ceftriaxone, levofloxacin, or moxifloxacin). In addition, for patients with severe or necrotizing pneumonia, empiric treatment for MRSA infection (with vancomycin or linezolid) should be administered.

▫️Pneumonia is the most common complication of Influenza.
Bacterial pneumonia typically occurs within a few days of influenza onset.

▪️Outpatients treatment

▫️Outpatients at risk for complications or severe illness:
Start antiviral therapy

▫️ Outpatients who may transmit infection to high-risk contacts - such as household contacts
and health care workers, we suggest antiviral treatment

▫️Outpatients who are not at high risk for complications or transmission(if onset of symptom <48h)