Influenza B
What is influenza B? Everything you need to know about its symptoms, duration, and the most effective treatments against the influenza B virus.
Symptoms and Causes
Influenza B is a seasonal infectious disease, as it manifests in outbreaks mainly during the winter. It is caused by the influenza B virus and primarily affects the respiratory system, although it can also impact overall health.
The influenza B virus infects only humans, who are its natural carriers. As a result, its effects are generally mild, and it does not usually cause pandemics—unlike influenza A, which mutates more rapidly and can originate from aquatic birds.
Although influenza B does not typically cause severe health issues and resolves on its own in approximately five days, it can become complicated in some vulnerable groups, such as:
- Infants under one year old.
- Adults over 65 years old.
- Pregnant women.
- Individuals with weakened immune systems.
- Patients recovering in a hospital or nursing home.
- People with obesity (BMI equal to or greater than 40).
- Patients with chronic illnesses.
- Individuals under 20 years old undergoing long-term aspirin therapy.
Since influenza B spreads easily, prevention is crucial to avoid public health issues and overwhelming healthcare centers.
Symptoms
The symptoms of influenza B appear suddenly and are easily recognizable by most people. The most common include:
- General discomfort.
- Muscle and joint pain.
- Fever.
- Headache.
- Cough.
- Sore throat.
- Runny nose.
- Fatigue.
Occasionally, digestive issues such as diarrhea or nausea may occur.
When fatigue persists after the illness has subsided, it is known as post-viral asthenia syndrome, characterized by a lack of energy and weakness. The exact cause of this condition remains unknown.
Causes
Influenza B is caused by the influenza B virus, which spreads through the air or via objects touched by an infected person.
Risk Factors
Influenza B can affect people of all ages, but certain factors increase the risk of contracting it, such as:
- Being in close contact with infected individuals.
- Living or working in crowded environments, especially nursing homes and hospitals.
- Having a weakened immune system.
Complications
When at-risk groups contract influenza B, they may develop the following complications:
- Pneumonia.
- Respiratory tract infections such as bronchitis or asthma.
- Ear infections.
- Reye’s syndrome, which causes inflammation of the liver or brain.
- In extremely vulnerable patients, it can be fatal.
Prevention
To prevent influenza B infection, it is advisable to follow these recommendations:
- Avoid contact with individuals infected with the influenza B virus.
- Steer clear of crowded places.
- Wear a mask when interacting with infected individuals or to prevent spreading the virus when sick.
- Cover your mouth with a tissue or elbow when sneezing—never with your hand.
- Wash hands frequently.
- Get vaccinated against the influenza B virus, especially if you are in a high-risk group.
Which doctor treats influenza B?
Specialists in infectious diseases, pediatrics, geriatrics, and family medicine are responsible for diagnosing and treating influenza B.
Diagnosis
Specialists diagnose influenza B through a clinical history review and a physical examination.
Generally, no additional tests are required. However, in some cases, a PCR (polymerase chain reaction) test may be conducted to determine whether the infection is due to influenza A or B. This involves taking a nasopharyngeal swab sample. Additionally, blood tests may be requested to assess vital organ function in high-risk patients.
Treatment
As influenza B is a viral infection, there is no cure, but treatments are available to alleviate symptoms. Standard recommendations include:
- Relative rest.
- Hydration (drinking plenty of water or natural fruit juices).
- Medication (usually acetaminophen) to reduce fever and relieve pain.
- Specific antiviral drugs for influenza. These medications are used in suspected or confirmed cases within the first three days of symptom onset if the patient meets risk criteria (severe infection requiring hospitalization, age under 5 or over 65, obesity, immunosuppression, significant chronic comorbidity, active cancer, pregnancy, individuals living with immunosuppressed patients, or children/adolescents receiving salicylate therapy).