Influenza A
What Is Influenza A?
Influenza A is one of three influenza viruses that cause seasonal epidemics of the flu each year. It is highly contagious and can cause respiratory distress and serious illness, some of which can even lead to death.
Influenza A viruses, which are classified into different subtypes, are divided into two categories: human and animal. Human viruses are classified into two distinct species, A and B, which are further divided into subtypes based on two particular cell surface proteins. The most common human influenza A subtypes are labeled H1N1, H2N2, and H3N2. All of these are monitored by the Centers for Disease Control and Prevention for their potential pandemic threat.
Signs and Symptoms
Common signs and symptoms of Influenza A infections include:
- Fever
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body ache
- Headache
- Fatigue
- Vomiting
- Diarrhea (less common)
In some cases, more serious complications may arise, such as bacterial pneumonia, ear and sinus infections, dehydration, and pain and swelling in the joints. These complications can become particularly serious in elderly people, young children and people with weakened immune systems.
Transmission
Influenza A is usually spread via flu droplets when an infected person coughs, sneezes or talks. These droplets can travel through the air and enter another person's body by way of their eyes, nose or mouth. Contact with contaminated surfaces, such as doorknobs, can also spread Influenza A.
Treatments
Most cases of Influenza A are often mild and do not require medical care. Symptomatic treatment is typically the best approach, and this includes drinking plenty of fluids, getting plenty of rest, and taking over-the-counter medication to ease fever and muscle aches. More serious cases, however, may require anti-viral medication.