Influenza (Flu)

Influenza is a contagious viral disease caused by the influenza virus that can affect the upper respiratory tract or the lungs. This disease is an important health problem because it causes epidemics and even deaths every year, especially in the winter months.

Influenza virus

Influenza viruses are divided into types A, B and C. Influenza A and B viruses cause annual seasonal flu, while influenza C virus causes smaller-scale and milder infections. Influenza A virus is the most common cause of flu and causes influenza in both humans and animals. Influenza A virus is also divided into subtypes according to the proteins on the cell surface. The most talked-about of these are H1N1, the cause of swine flu; H5N1 and H7N9, the causes of bird flu; and H3N2, the cause of standard seasonal flu.

What is swine flu (H1N1)?

Influenza type A/H1N1 virus first emerged in North America in 2009 and caused a pandemic, that is, a large-scale intercontinental epidemic, that year. However, about 1.5 years later, the World Health Organization (WHO) announced that this pandemic had ended. Because it was the largest pandemic in the last 40 years and because of the uncertainty at the time, it caused great fear around the world. However, A/H1N1 now appears every year as a cause of annual seasonal flu.

Do we need to be afraid of swine flu?

It has largely lost its importance since the 2009 pandemic. It is no longer significant, other than being just one subtype of the flu that occurs every winter.

Symptoms of the flu

In influenza, symptoms include fever, headache, joint and muscle pain, shortness of breath, a feeling of fatigue, a runny or stuffy nose, sneezing and a sore throat.

Course and contagiousness of the flu

Symptoms of the disease begin about 1-4 days, on average 2 days, after the virus enters the body through the respiratory tract. In uncomplicated flu (without additional illness), the illness lasts 3-7 days, but cough and muscle pain may continue for up to 2 weeks.

Should we use antibiotics for colds, the common cold and the flu?

No. Because the causes of these diseases are viruses, antibiotics have no effect on their treatment. However, antibiotics are often used by patients on their own, without seeing a doctor, or because of a wrong diagnosis.

However, if a complication (sinusitis, otitis, pneumonia) develops during the flu, antibiotic treatment must be started. For this reason, if the illness worsens when you expect to recover from the flu, you must see a doctor.

Should I get a flu vaccine? Can I get the flu again?

The flu vaccine prepared every year is formulated according to the influenza subtypes circulating in the previous year. The flu vaccine in our country also provides immunity against A/H1N1, A/H3N2 and influenza B. However, it should be kept in mind that, because this virus mutates, that is, changes, rapidly, illness can still occur from these influenza subtypes. Studies around the world have shown that the vaccine lessens the course of the disease and reduces the death rate in special patient groups. A flu vaccine protects a healthy person for about one year, so it needs to be repeated every year. An egg allergy is not an obstacle to the flu vaccine; the vaccine is withheld only from people who have previously had anaphylaxis to the flu vaccine.

According to the recommendation of the World Health Organization, everyone aged 6 months and over should be vaccinated. However, priority should be given to people in risk groups. The people in risk groups are:

-People aged 50 and over,

-People of any age living in a nursing home or in a health facility providing chronic care,

-Patients with chronic lung and heart disease,

-Children aged 6 months to 18 years receiving long-term aspirin therapy,

-People with chronic kidney disease,

-People with diabetes,

-Patients with immune deficiency or immunosuppression (cancer patients, people with AIDS, organ transplant recipients, people taking steroids, people undergoing chemotherapy or radiotherapy),

-Pregnant women,

-Children aged 6 months to 5 years,

-People with a body mass index (BMI) of 40 or above,

-People with neurological disease,

-Women in the first 2 weeks after giving birth,

-Doctors, nurses and other staff working in hospitals,

-People working in nursing homes and health facilities providing chronic care,

-People living in the same household as high-risk individuals (organ transplant patients, etc.).

When is the vaccination season? If it has passed, should I still get vaccinated?

The flu vaccine is recommended every year in October. However, if you have not been vaccinated, we recommend that you get vaccinated as soon as possible. After vaccination, it begins to protect against the disease within 14 days.

Is there a treatment for the flu?

Yes, there is a treatment. Antiviral drugs are most effective in the first 48 hours; in high-risk or severely ill patients, treatment is started without waiting for the test result. For people over 65, people with chronic diseases (asthma, heart disease and diabetes) or pregnant women, treatment should be started immediately because of the high risk. If you are over 65 or have an additional illness, be sure to see your doctor for treatment.

How can I prevent the spread of the flu?

The circulation of the virus in the community can be limited with some measures. Examples include avoiding close contact with a sick person (kissing, shaking hands), covering your mouth with a tissue when coughing and sneezing, staying away from crowded places, not going to school or work when ill, washing your hands frequently with soap and water, and not touching your face with your hands.

Four precautions against the flu!

1. Get vaccinated (the most effective way of protection).
2. Develop habits that will prevent the spread of the virus.
3. See a physician if you become ill.
4. Patients in risk groups should have a respiratory test early for treatment.

 

Specialist in Infectious Diseases and Clinical Microbiology
Dr. Emre Y. Vudalı