Influenza A and B

What is it?
Influenza is a viral infection that causes a flu-like illness of varying severity. It is caused by exposure to the Influenza A or B virus and results in a cough, sore throat, fever and feeling tired. . Most cases of influenza occur in the winter months but can occur as early as the end of summer and as late as the end of winter. Viral strains can change, making the flu season worse in some years than others.

In the U.S., according to the Center for Disease Control, about 10-20% of the population will get Influenza A or B every year, requiring 200,000 hospital admissions. If a case of influenza is especially severe, complications such as sinus infections, ear infections, bronchitis or pneumonia can occur. About 20,000 deaths occur annually.People who are older, in poor health or have problems with their immune systems are more likely to develop influenza and have complications from a case of influenza.

Respiratory secretions such as mucous or droplets from a sneeze transmit the influenza virus. The incubation period, or the time between exposure and feeling sick, is between 18 hours and three days. You can transmit the virus before you are feeling sick, and viral shedding continues for a few days after you are feeling better.

Symptoms of influenza include sore throat, runny nose, aches and pains, headache, eye discomfort, cough, chest pain and labored breathing. Most people notice a sudden onset of these symptoms. People usually report a fever which can sometime be very high, and may be accompanied by chills. Feeling very tired or run down is common. Because they share many of the same symptoms, influenza is often confused with the common cold. Although several viruses other than influenza also cause colds, they are not as severe.

How is Influenza diagnosed?
Most doctors evaluate the clinical symptoms of their patients to determine if the have influenza. After asking you about how and when your illness started and what kind of symptoms you’re having, you’ll be examined. In most cases, the history and physical exam findings will allow your doctor to eliminate other possible causes of your illness and make a diagnosis.

If it’s not clear, a viral culture can be taken, or a rapid test can be done to see if there are Influenza A or B viruses present. Your doctor will use a swab to take a sample of the material in your nose for these tests. Viral cultures take 3-7 days for results, so this test is not used very often. Rapid tests, which take about 30 minutes, are about 70-80% accurate. If your doctor needs more information, blood tests or a chest X-ray might be needed.

How is Influenza treated?
For most people supportive care is all that’s needed. That means bed rest, lots of fluids and over-the-counter medications to take care of aches and pains, high fevers, sore throats and runny noses. Within five to seven days, the majority of people are feeling better.

Medications can reduce the severity and duration of symptoms of influenza. Amatidine and rimantidine are effective against influenza A. Oseltamvir and zanamvir are effective against both influenza A and B. These drugs are most effective when taken within a few hours of noticing symptoms, but must be taken within 24-40 hours or they will not have a significant effect. Because they are very costly, most doctors prescribe them for people with other medical conditions that make it harder to fight the illness.

If you are experiencing problems like dehydration, coughing up blood, difficulty breathing, duration of longer than a week, or notice a return of symptoms after a few days, go back to see your doctor.

How can Influenza be prevented?
Because influenza is transmitted through respiratory secretions, frequent hand washing can be very helpful in reducing your exposure to influenza viruses. People who have influenza should always use tissues when sneezing or wiping runny noses, and also wash their hands before touching communal items.

A vaccine for Influenza A and B is available. You’ll need to get a new vaccination each year because the strains of Influenza virus can change slightly from year to year. It takes two weeks or so for the vaccine to become effective, and studies show that it can reduce the development of influenza by 90%. Check with your docter on the best time to take this vaccine.

Recently an inhaled vaccine has become available. It’s equally as effectiveness as the injectable vaccine and approved for people between 5 and 54 years old. People occasionally report having a mid runny nose, sore throat or headache after the inhaled version of the vaccine. Kids may also have some vomiting.

For people who did not get a flu shot, taking the oral flu medications (amatidine, rimantidine, oseltamvir or zanamvir), used to treat influenza has been shown to prevent the illness. The recommended preventative dosage is half of the usual dose.

Are there side effects?
The most common side effect from influenza shots is soreness and redness at the vaccination site. Some people experience aches or fever that may last a day or two.

Who should be vaccinated, and when?
According to the CDC, there are several groups of people who should get a flu shot every year. (Please contact your doctor for information whether you need to take the vaccine.)

• People who are at an increased risk of complications, such as
  • Children
  • Elderly people (>65)
  • People who live in nursing homes
  • People with poor immune systems or chronic illnesses
  • Pregnant women
  • People with compromised respiratory function
• Adults between 54 and 65
  • More commonly have multiple medical conditions
• Healthcare workers
  • In contact with people who are vulnerable to flu complications.

This article is provided as a source of information, if you have any health concerns , whatsoever , please consult your doctor.