Influenza A vs. Influenza B: What Minnesota Families Need to Know This Flu Season
No doubt, someone you know or even you yourself has contracted influenza A over the holidays or into the New Year. Patients coming into the four Urgency Room locations in the Twin Cities have told our board-certified ER physicians that they feel completely fine one moment and incapacitated the next. We’ve also heard the phrase “hit by a train” from patients describing body aches, fever, chills, and the onset of severe physical symptoms of influenza A, the dominant strain here in Minnesota, particularly in December.
What is Influenza A?
It is a highly contagious respiratory virus that causes seasonal “flu” epidemics and even global pandemics. It is currently the dominant strain nationwide, accounting for 94% of all flu cases. Our labs at The Urgency Room reported a 50% positivity rate for influenza A in December, which is incredibly contagious. Influenza is spread through respiratory droplets that are inhaled or spread by touching a contaminated surface. because of its ability to mutate rapidly.
Symptoms of influenza A
- Sudden Onset Fever- at ranges above 100.4°F to 104°Finfluenza is known to cause especially high and long-lasting fevers. High fevers such as 104°F. Often, fevers include chills and shaking. Patients report “not being able to get warm.”
- Extreme fatigue, which may persist up to two weeks, is common and recovery to normal energy levels can be slow.
- Severe body aches, described as feeling “hit by a truck,” with deep muscle pain.
- Persistent dry cough, sore throat, and nasal congestion
- Gastrointestinal Symptoms- In addition to respiratory symptoms, some patients also have GI symptoms, including nausea, vomiting, and diarrhea. Any patient can have GI symptoms, but GI symptoms are more common in children.
What is Influenza B?
This strain typically appears later in the winter and peaks in the spring, and does not cause pandemics. It also tends to follow an influenza A spike. Similar to influenza A, Influenza B is a respiratory virus that causes fever, cough, congestion, fatigue, and body aches. Influenza B is often associated with more gastrointestinal issues, such as nausea, vomiting, and diarrhea. While generally considered “milder” than the dominant influenza A for most adults, influenza B is notorious for causing complications in children under 5 and school-aged teens.
Symptoms of Influenza B are the same as those of influenza A, but may include more GI symptoms.
- Abrupt Onset of Fever of above 100°F and can exceed 103°F in children.
- Respiratory concerns include a persistent cough (dry or wet), sore throat, and nasal congestion.
- Intense Body Pain, including severe muscle and body aches (myalgia) and sharp headaches that make movement difficult.
- Extreme Fatigue
Red Flags You Need to Be Seen?
Generally, influenza A and influenza B symptoms can be managed at home with fever control, rest , and hydration. Some patients are at higher risk for complications, such as adults over 65, children under 5, pregnant women, and people with chronic conditions like asthma, heart disease, diabetes, or weakened immune systems, who benefit from assessment for antiviral treatment to prevent complications. Antiviral treatment given early in the illness, ideally within 48 hours of the onset of symptoms, can sometimes shorten the illness slightly but, more importantly, prevent more serious complications from influenza. These groups should see a doctor as soon as symptoms begin for antiviral treatment, which may prevent complications if started within 48 hours.
For all patients, the following symptoms, especially in children, require immediate medical attention.
- Breathing problems like shortness of breath or working hard to breathe, increased effort to breathe, or “retractions” when the ribs pull in deeply with each breath, trouble talking, wheezing or noisy breathing.
- Color Changes of bluish or gray lips, face, or nail beds.
- Severe Dehydration: symptoms include poor fluid intake, not urinating for several hours, dry mouth, or severe weakness/unsteadiness. In children, signs include a significant decrease in the number of wet diapers, going more than 6 hours without urinating (shorter time in young children or infants), or more hours or no tears when crying.
- Feeling very weak or fainting
- Behavioral Warnings- of extreme irritability (child does not want to be held), lethargy, or not interacting when awake.
- Pain & Fever causing an adult or child to refuse to get up or walk, or a fever above 104°F that does not respond to medication. Persistent Fever- fever that is not improving as the illness progresses may be a sign of a secondary bacterial infection, such as pneumonia.
Prevention
You can protect yourself and your family from influenza by getting vaccinated, wearing a mask if in close contact with someone infected, and maintaining excellent handwashing habits at home, school, and work.
Dr. Kristi Trussell, ER Physician and Assistant Medical Director of The Urgency Room
