ABSTRACT
Influenza causes severe respiratory illnesses, which often require admission to hospital and critical care. Diagnosis of influenza is predominately clinically; however, tracheal secretions can be sent for laboratory testing. Rapid influenza diagnostic tests are available but have a lower sensitivity than other methods and reliability is determined by the conditions in which they are used. The World Health Organization identifies three types of influenza: seasonal, pandemic, and zoonotic or variant. Potential differential diagnosis to influenza includes community acquired pneumonia, hospital acquired pneumonia, severe acute respiratory infection, exacerbation of chronic lung disease, for example asthma or chronic obstructive pulmonary disease, sepsis, encephalopathy, encephalitis, transverse myelitis, meningitis, Guillain-Barre syndrome, myocarditis and rhabdomyolysis. Patients with suspected or confirmed influenza could transmit the pathogen to healthcare workers. Influenza can be a common reason for admission to critical care in seasonal epidemics. Influenza is a respiratory illness with a wide range of signs and symptoms.
