Influenza

Infectious Disease

Overview

Definition

Acute respiratory illness caused by influenza A or B viruses.

Epidemiology

Causes annual seasonal epidemics.

Etiology & Risk Factors

  • Influenza viruses (respiratory droplet transmission)

Clinical Symptoms

  • Abrupt onset high fever
  • Myalgias
  • Headache
  • Cough
  • Sore throat

Clinical Approach

Diagnosis

  • Rapid Influenza Diagnostic Test (RIDT)
  • Viral PCR

Management

  • Oseltamivir (Tamiflu) if within 48 hours
  • Supportive care
  • Annual vaccination

Complications

  • Secondary bacterial pneumonia (S. aureus)
  • Myocarditis
  • Death in vulnerable populations