Influenza

Influenza, also known as the flu, is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness and can lead to complications such as pneumonia, bronchitis, and sinus and ear infections.

Types of Influenza

• Influenza A: This type of flu virus is found in many animals, including ducks, chickens, pigs, and horses, as well as humans. Influenza A viruses are constantly changing, which means that people can get infected with the same strain multiple times.
• Influenza B: This type of flu virus is found only in humans. Influenza B viruses also change over time, but the changes tend to be smaller than those seen in influenza A viruses.
• Influenza C: This type of flu virus is relatively rare and typically causes mild illness. Influenza C viruses are not thought to cause human flu epidemics.

Symptoms of Influenza

The symptoms of influenza can vary from person to person, but common symptoms include:

• Fever and chills
• Cough and sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headaches
• Fatigue
• Diarrhea and vomiting (more common in children than adults)

Transmission of Influenza

Influenza viruses are spread from person to person through:

• Respiratory droplets produced when an infected person talks, coughs, or sneezes
• Contact with contaminated surfaces or objects and then touching one's mouth, nose, or eyes

Complications of Influenza

Certain people are at higher risk for complications from influenza, including:

• Older adults (65 years and older)
• Young children (under the age of 5)
• Pregnant women
• People with certain chronic health conditions, such as heart disease, lung disease, or diabetes
• People with weakened immune systems, such as those with HIV/AIDS or undergoing chemotherapy

Treatment and Prevention of Influenza

Treatment for influenza typically involves:

• Rest and hydration to help manage symptoms
• Over-the-counter medications, such as pain relievers and decongestants, to relieve symptoms
• Antiviral medications, such as oseltamivir (Tamiflu) or zanamivir (Relenza), which can help shorten the duration and severity of illness if started within 48 hours of symptom onset

Prevention measures include:

• Getting vaccinated against influenza each year
• Practicing good hygiene, such as washing hands frequently and avoiding close contact with people who are sick
• Avoiding touching one's eyes, nose, and mouth
• Cleaning and disinfecting surfaces and objects that may be contaminated with influenza viruses