Influenza-like illness

Overview of influenza-like illness

 This article is about the medical condition.
   For the virus, see Influenza virus.

Overview

Diagram illustrating the global spread of influenza-like illnesses.

Influenza-like illness (ILI) is a medical diagnosis of possible influenza or another illness causing a set of common symptoms. These symptoms include fever, cough, sore throat, muscle pain, headache, and fatigue. ILI is a clinical diagnosis and is often used in public health surveillance to monitor the spread of influenza and other respiratory viruses.

Symptoms

The symptoms of influenza-like illness are similar to those of influenza and can include:

• Fever
• Cough
• Sore throat
• Runny nose
• Muscle pain
• Headache
• Fatigue

These symptoms can vary in severity and duration, and not all individuals will experience all symptoms.

Causes

Influenza-like illness can be caused by a variety of viruses, including:

• Influenza virus
• Rhinovirus
• Coronavirus
• Adenovirus
• Respiratory syncytial virus (RSV)

These viruses are spread through respiratory droplets when an infected person coughs or sneezes.

Diagnosis

Diagnosis of influenza-like illness is primarily clinical, based on the presence of symptoms. Laboratory tests, such as polymerase chain reaction (PCR) tests, can be used to confirm the presence of specific viruses, such as the influenza virus.

Treatment

Treatment for influenza-like illness is generally supportive and may include:

• Rest
• Hydration
• Over-the-counter medications for symptom relief, such as acetaminophen or ibuprofen

In some cases, antiviral medications may be prescribed, particularly if influenza is confirmed and the patient is at high risk for complications.

Prevention

Preventive measures for influenza-like illness include:

• Vaccination against influenza
• Frequent hand washing
• Avoiding close contact with sick individuals
• Covering coughs and sneezes

Public Health Surveillance

Influenza-like illness is monitored by public health agencies to track the spread of influenza and other respiratory viruses. Surveillance data helps inform public health responses and vaccination strategies.

Related pages

• Influenza
• Common cold
• Viral infection
• Public health