What is flu?
Flu or Influenza is an acute infection of the upper respiratory tract (nose, throat, lungs) and is caused by the influenza virus that pops up every year during the winter period. Hence the name Influenza. There are three types of this virus, A, B and C. The A type is responsible for the most serious infections.
The flu virus is particularly contagious. It is often sufficient to come into contact with an infected person so that the viruses can penetrate the nasal mucosa, the windpipe and the bronchi and spread there. A flu epidemic can affect 5 to 10% of the population in a few weeks.
What is the difference between flu and a cold?
Many people confuse a common cold with flu. In both cases it is an infection of the upper respiratory tract by viruses.
You are usually more seriously ill from flu than from a cold. Fever and muscle pain usually do not occur with a cold. The symptoms of a cold generally also disappear faster and complications such as pneumonia are rare.
The most important flu symptoms are:
- fast emerging fever (> 38 ° C)
- muscle pain, headache
- tired and exhausted
- sore throat
How does the flu virus spread?
The flu virus is mainly transmitted through the air with saliva droplets released by coughing or sneezing. These droplets, which move in the air, can directly infect someone through breathing. This mainly happens in spaces where people are close to each other and where there is poor ventilation, for example in a train or bus, a school or daycare. Via the air, viruses also end up on all kinds of objects. A person can become infected if he touches an object (eg a doorknob, toy) that contains viruses and then touches his eyes, nose or mouth. The saliva can also be transmitted through the hands (shielding the mouth during coughing) through objects touched by it.
The flu virus is highly contagious. Talking to someone who has the flu can be enough to get infected. Whoever sits on a bus or train next to someone who has the flu can just get infected. Those who spend a lot of time in crowded places or in confined spaces have a good chance of being infected.
During a flu epidemic, around 10 to 20% of people get the flu. Up to 45% can fall ill with school-aged children and children staying in a daycare center. If the flu virus swirls around your family or yourself in the family, at least 30% of the other family members also get flu.
How serious is flu?
For most people, flu is a benign disease. Healthy people normally heal automatically after five to seven days. The fever diminishes after two days and disappears after five days. It can take a few weeks before you are completely old. The cough can also last for a few weeks.
However, serious complications can occur in certain risk individuals, such as pneumonia, which can even be fatal. Every year several thousand people die in our country as a result of such complications.
For whom can the flu be dangerous?
The flu can aggravate existing diseases, such as diabetes. It can also cause serious complications in some people, such as pneumonia.
The following people are considered to be at risk:
- people with chronic heart disease; these are often people who have had a heart attack, who have heart problems such as cardiac arrhythmias, or people who have had heart surgery;
- people with a chronic lung disease such as asthma, COPD, cystic fibrosis
- people with diabetes (diabetes); not only people who inject insulin, but also people who take tablets with blood sugar lowering drugs or follow a diet;
- kidney and liver patients;
- people with a weakened immune system due to illness (eg cancer, HIV …) or medical treatment, for example people who have recently undergone a bone marrow transplant, people with cancer who have undergone chemotherapy or radiation, people with chronic inflammatory diseases (such as chronic arthritis, Crohn’s disease and psoriasis) taking immunosuppressive drugs;
- people with a severe neurological disorder (eg: cerebral palsy);
- people aged 65 and over. Elderly people staying in a retirement home or care home are extremely susceptible to infection in an epidemic;
- pregnant women.
Vaccination against pneumococci
A significant part of the disease and death from a flu epidemic is the result of bacterial surinfection, often caused by pneumococci.
You can get vaccinated against pneumococci. This vaccine must be administered every 5 to 7 years.
The following people are advised to get vaccinated against pneumococci:
- patients with functional asplenia (malfunctioning spleen) or after splenectomy (removal of the spleen).
- all persons older than 65 years
- patients older than 50 years with:
– chronic heart and lung diseases
– chronic liver disease with or without cirrhosis
– HIV-infected patients
- Vaccination can be considered for all patients with:
– organ transplant
– lymphoma, chronic lymphocytic leukemia, multiple myeloma
– cerebrospinal fluid leak
– other chronic conditions such as chronic kidney disease or cardiovascular disease.
Can flu be prevented?
The only proven effective method of prevention is vaccination. Antiviral drugs can also prevent flu, but are more likely to be used in people who are already sick. They inhibit the infection and mitigate the symptoms.
You can also take the following measures:
- Hold your hand or handkerchief in front of your mouth when you sneeze or cough. Then wash your hands with soap and water (or rub them in with hand alcohol).
- Wash your hands regularly with soap and water: rub well while counting to 30. Then rinse well and dry. Cleaning wipes with alcohol are also effective;
- Touch your mouth, nose or eyes as little as possible;
- Always use paper handkerchiefs or tissues for coughing, sneezing or snouts and use them once. Then throw them in the trash can (preferably sealed) and then wash hands;
- Clean regularly. Clean hard surfaces and objects (such as the kitchen sink, kitchen utensils, taps, door handles, handrails and telephones) regularly. Do this with a normal detergent.
- Avoid as many (closed) places as possible where many people come together (such as train, tram, cinema …). Regularly ventilate the room where several people are together.
- Avoid contact with sick people as much as possible.
- Ensure good physical condition and avoid physical stress (due to insufficient sleep, strong cooling, for example). Prefer not to smoke.
- It has never been conclusively demonstrated that Echinacea or other plant supplements, or high doses of vitamin C flu (or colds) can occur.
Who needs to be vaccinated against seasonal flu?
In Belgium, the High Health Council recommends that the following people should be vaccinated as a priority against seasonal flu:
Group 1: persons at risk for complications, ie:
- all persons older than 65 years
- all persons admitted to an institution
- all patients from the age of 6 months who suffer from a chronic disorder, whether or not stabilized, of the lungs, heart, liver, kidneys, metabolic disorders (such as diabetes), or immune disorders (natural or as a result of medical treatment)
- children between 6 months and 18 years who undergo long-term aspirin therapy.
Group 2: all persons working in the health sector and in direct contact with persons in group 1.
Group 3: Pregnant women who are in the second or third trimester of their pregnancy at the time of vaccination
Group 4: all persons between 50 and 64 years of age, even if they do not suffer from a risk disorder, because there is one chance in three that they have at least one complication risk, especially people who smoke, drink excessively and are obese
For all these risk groups, the flu vaccine is partially reimbursed by health insurance.
What are the benefits of influenza vaccination?
The flu shot protects you against serious consequences of the most common flu viruses. If you have had the annual flu shot, the chance that you will get the flu is much smaller. If you do get the flu, the disease is usually less severe. In addition, the flu shot reduces the risk of complications such as pneumonia and worsening of existing diseases, such as diabetes disruption
I am not one of the target groups, can I still get vaccinated?
Yes, this is possible for the seasonal flu vaccine. You are then much less likely to fall ill and, for example, have to take time off work, and you also have less chance of complications. You do have to pay the costs yourself, unless your employer pays for the vaccine.
Can pregnant women be vaccinated?
Pregnant women in the second or third trimester are a risk group and are eligible for vaccination. Pregnant women are advised against being vaccinated in the first trimester of their pregnancy.
Why do you have to get vaccinated again every year?
The flu virus regularly undergoes mutations, changes. The antibodies that are produced one year against the flu virus do not systematically recognize the virus the following year. So we are in fact poorly armed against the flu, and can get infected several times, each time with the slightly modified virus.
To be protected against possible complications, risk persons must therefore be vaccinated annually with the new vaccine based on the characteristics of the virus from the previous year.
This can also explain why people who have had themselves vaccinated can still get the flu. This is because they can be infected by a new flu virus against which the vaccine does not yet offer protection, or against a relatively rare virus that is no longer included in the vaccine. But usually the vaccine still offers some protection and the disease is less severe and there are also fewer complications compared to people who have not been vaccinated.
Can you still get the flu if you are vaccinated?
The flu vaccine has an overall efficiency of 70%; the effectiveness varies according to age: the effect decreases in older people.
So vaccinated people can still get the flu, but usually it is a less severe form. The effectiveness is mainly reflected in a reduction in complications: thanks to the vaccine, the number of hospitalizations is reduced by 70% and the death rate by 80%.
Of course, the flu vaccine only offers protection against the flu viruses and not against other winter ailments caused by totally different viruses. For example, despite the flu shot you may still have a cold, a sore throat or a ‘stomach flu’. This does not mean that the flu vaccine has failed, but simply that you are unlucky and have fallen victim to another virus.
What are the side effects of the flu vaccine?
Side effects are rare and usually not serious. It is possible that the place where the puncture was given (the upper arm) is somewhat swollen and reddered for a few days. It can be itchy or a bit painful. You don’t have to worry about this, it will disappear spontaneously after a few days.
Sometimes a little tiredness, a slight increase in temperature, headache, joint pain or muscle pain may occur. You can sweat a little or be shivery, like with a starting flu. This too usually disappears by itself.
If other symptoms occur in the days following vaccination (such as skin rash, pain, nausea, etc.) then you should consult your doctor.
Persons who are allergic to eggs (anaphylactic shock, breathing difficulties …) or who have previously reacted poorly to certain vaccines must inform their doctor. You may then not receive a vaccine.
The fear that people could get the flu from the flu vaccine is totally unfounded. The vaccine contains only killed virus particles and therefore cannot cause flu.