Management of Influenza

Antiviral Treatment

The American Thorax Society recommends initiating treatment as early as possible within the 48-hour window for patients with acute influenza-like illness, fever >38°C, and symptom duration ≤2 days 2, 3
The Journal of Infection guidelines suggest that all three criteria must be present for standard antiviral treatment: (1) acute influenza-like illness, (2) fever >38°C, and (3) symptom duration ≤2 days 2, 3
Immunocompromised or very elderly patients may receive antivirals despite lack of documented fever, as they may not mount adequate febrile responses 2, 3, 1
Severely ill hospitalized patients, particularly if immunocompromised, may benefit from oseltamivir even when started >48 hours after symptom onset, though evidence for this is limited 2, 3, 1

The Thorax society recommends not routinely prescribing antibiotics for previously healthy adults with acute bronchitis complicating influenza in the absence of pneumonia 2, 3, 4
Consider antibiotics only if worsening symptoms develop (recrudescent fever or increasing dyspnea) 2, 3
High-risk patients should receive antibiotics if lower respiratory features are present 2, 3
Preferred oral antibiotics: co-amoxiclav or tetracycline 2, 3

Patients with ≥2 of the following unstable clinical factors should remain hospitalized: temperature >37.8°C, heart rate >100/min, respiratory rate >24/min, systolic blood pressure <90 mmHg, oxygen saturation <90%, inability to maintain oral intake, or abnormal mental status 2, 3
Arrange follow-up for all patients with significant complications or worsening of underlying disease with their general practitioner or hospital clinic 2, 3, 4

Avoid unnecessary antibiotics in uncomplicated influenza—bacterial co-infection typically develops 4-5 days after initial symptoms, not at presentation 4
Be vigilant for Staphylococcus aureus pneumonia, which is more common during influenza outbreaks than typical community-acquired pneumonia 4