About Influenza (Flu)

Overview

Influenza, also known as the flu, is a contagious respiratory illness caused by influenza viruses. It primarily affects the nose, throat, and sometimes the lungs. The flu can range from mild to severe and can even lead to death in some cases. It is characterized by symptoms such as fever, cough, sore throat, body aches, fatigue, and congestion. The flu is highly contagious and can easily spread from person to person through respiratory droplets when an infected individual coughs or sneezes. It is important to note that the flu is different from the common cold, although they share similar symptoms. Getting an annual flu vaccine is the best way to prevent the flu and reduce its impact on individuals and communities.

Causes and Risk Factors

The pathophysiologic causes of influenza involve lung inflammation due to direct viral infection of the respiratory epithelium. This inflammation can spread and lead to multiple organ failure, although these consequences are typically a result of severe respiratory distress. Additionally, there is an association between Influenza virus infection and cardiac complications, but the specific mechanisms are not fully understood.

The non-modifiable risk factors for influenza cannot be changed or controlled. These include:

• Being over the age of 65
• Pregnancy
• Having a chronic disease or a weakened immune system

The modifiable risk factors for influenza can be influenced or changed. These include:

• Smoking
• Poor lung function
• Obesity or high body mass index (BMI)

It's important to note that these risk factors can be modified through lifestyle changes. However, it's always advisable to consult with a healthcare professional for personalized advice.

Symptoms

The most common early symptoms of influenza include:

• Fever or feeling feverish/chills
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headaches
• Fatigue (tiredness)

As influenza progresses or becomes more severe, additional symptoms may occur, such as:

• Difficulty breathing or shortness of breath
• Increased severity of respiratory symptoms
• Worsening of asthma symptoms (if you have asthma)
• Pneumonia, bronchitis, or respiratory failure
• Kidney failure, heart inflammation, sepsis
• Stomach symptoms like diarrhea or abdominal pain

It's important to note that not everyone with influenza will experience all of these symptoms. If you have concerns about your symptoms or their severity, it's best to consult with your healthcare professional for appropriate evaluation and guidance.

Diagnosis

To diagnose influenza, the following examinations, tests, and procedures are commonly performed:

• Clinical assessment: Evaluating symptoms such as fever, headache, sore throat, cough, or myalgia.
• Viral culture: This test involves collecting a respiratory specimen and growing the influenza virus in a laboratory to confirm its presence.
• Rapid antigen testing: This test provides quick results by detecting viral antigens in respiratory specimens. However, it may have lower sensitivity compared to other tests.
• Reverse transcription polymerase chain reaction (RT-PCR): This molecular test detects influenza-specific RNA and is highly sensitive and specific.

To determine the severity of influenza, additional examinations, tests, and procedures may include:

• Radiographic imaging: Chest X-rays or computed tomography (CT) scans can help assess lung involvement in severe cases.
• Other blood tests: Complete blood count (CBC) and inflammatory markers may be measured to evaluate the body's response to infection.

It's important to note that the choice of tests may vary depending on the laboratory, timing of specimen collection, and availability of resources. Consult with your healthcare professional for accurate diagnosis and assessment.

Treatment Options

The goals of treatment for influenza are to reduce the severity of symptoms, prevent complications, and shorten the duration of the illness. Here are the different types of treatments and how they work to achieve these goals:

• Antiviral Medications: Prescription antiviral drugs can be used to treat influenza. These medications work by interrupting the function of enzymes on the virus surface, preventing the release of viral particles from infected cells. Taking antiviral drugs within 48 hours of symptom onset is crucial for their effectiveness.
• Combination Therapy: Combination drug therapy is an alternative treatment option for influenza. It involves using two or more drugs to target multiple pathways of the virus and host, resulting in enhanced therapeutic efficacy. Combination therapy can also reduce drug toxicity and increase patient tolerance.
• Self-care and Health Behavior Changes:
  • Making certain changes in your daily routine can help manage influenza symptoms and prevent its spread. These include:
    • Practicing good hand hygiene
    • Covering your mouth and nose when coughing or sneezing
    • Staying home when sick
    • Avoiding close contact with others who are ill.
  • Supportive care measures can help alleviate discomfort during influenza infection. These measures include:
    • Staying hydrated
    • Getting plenty of rest
    • Using over-the-counter medications to relieve symptoms such as fever, cough, and congestion. People with other medical conditions including high blood pressure or taking other medications should check with their healthcare provider before starting a new OTC medication.

It's important to consult with a healthcare professional for personalized advice on which treatment options are suitable for your individual situation.

Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.