• Seasonal influenza is an infectious respiratory disease caused
by two types of influenza viruses A and B.
• It circulates every winter in the North Hemisphere affecting 5-15% of the population every year.
• Influenza viruses can cause from mild to severe illness and occasionally lead to premature death.
• By understanding how you can prevent influenza, you can contribute to reducing the number of cases, hospitalizations and premature deaths.
• Influenza is preventable.
Seasonal influenza spreads from person to person:
by direct contact through droplets from an infected person coughing or sneezing.
by indirect contact through fomites, i.e. when droplets or secretions from nose or throat settle on surface areas such as hands or objects (like keyboards or door handles). The virus can survive in certain areas for a few hours depending on the conditions and can infect others through the transfer from the hands to mucous membranes.
fever | sore throat | rhinorrhea | dry cough | fatigue | headache | myalgias
Usually influenza symptoms have acute onset and are more severe than similar symptoms of common colds. Fever is usually high (>38.5°C). However, as mild or asymptomatic infections can occur (up to 30%), you might inadvertently infect your patients or your colleagues.
• Vaccination annually against seasonal influenza is the most
effective way of prevention and is the most tangible and measurable
means to control the transmission of influenza viruses
between staff and patients, especially those at higher risk of
developing influenza related complications.
• Risk groups comprise elderly people and those with chronic medical conditions including:
- asthma and other respiratory diseases
- diabetes and other endocrine diseases
- cardiovascular diseases
- kidney diseases
- liver diseases
- metabolic diseases
- neurological diseases, especially if they affect respiration physiology
• Complications can occur in anyone but are far more common for
patients in risk groups.
• Common influenza complications include pneumonia, otitis media, sinusitis, dehydration and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. In elderly people, influenza can cause and/or worsen cardiovascular and cerebrovascular conditions (heart attacks and strokes).
• Complications may lead to hospitalization (about 5%) and premature death, especially in elderly people and individuals with underlying medical conditions1.
Immunization against seasonal influenza is recommended for all health and social care staff directly involved in patient care working in:
- medical practices
- health centres
- nursing homes for the elderly
- medical staff
- ambulance and pre-hospital personnel
- other care staff
- other health professionals
- administrative staff with patient contact
• Compared to adults working in non-health care settings, healthcare workers
are at signicantly higher risk of influenza.3
• About 30% of cases are asymptomatic, however still able to transmit the virus. Infected healthy adults are known to be contagious one day before and up to 5-7 days after symptom onset. Children and immune compromised patients can transmit the influenza virus for much longer.
• Higher vaccination coverage against influenza among healthcare
professionals can reduce influenza-related illness, and even deaths in
a healthcare facility.
• This is particularly relevant in settings such as nursing homes where patients are at higher risk for influenza-related complications and are known to have a lower immune response to vaccines.3
• The reduction is equivalent to preventing five deaths, two admissions to hospital with influenza-like illness, seven general practitioner consultations for influenza-like illness and nine cases of influenza-like illness per 100 residents.4
WHEN SHOULD I GET VACCINATED?
• Influenza seasons are unpredictable and can begin as early as October and
last until May.
• Vaccination should ideally be done in mid-autumn each year.
• About two weeks are needed for antibody production.
• One dose of influenza vaccine is needed intramuscularly.
WHY IS AN INFLUENZA VACCINE REQUIRED EVERY YEAR?
Influenza viruses change each year (antigenic drift) which is is why a new
influenza vaccine has to be given. The influenza vaccine is formulated to
keep up with the influenza virus subtypes as they change.
Annual influenza vaccination amongst healthcare professionals is important to protect yourself, your colleagues and especially your at-risk patients. Influenza may be particularly serious for patients at higher risk of developing influenza-related complications.
· Fever, sore throat, runny nose, dry
cough, fatigue, headache, and muscle ache
· Croup and bronchiolitis common in children
• Otitis media
• Worsening of chronic medical condition present before inuenza illness (e.g. congestive heart failure)
Common adverse events (<1 in 100 doses)
• Soreness/pain, redness and/or swelling
around the injection site
• Short-term fever (1–2 days), may be high (>39.0 °C) in children
• Short-term fatigue (1–2 days)
• Myalgia (1–2 days)
• Adverse reactions are more common in children not previously exposed to the vaccine or virus than in adults
Rare and Very rare adverse events (<1 in a 10,000 doses)
• Guillain-Barré syndrome <1 in 1,000,000 doses diosed)
1. Comparison of clinical features and outcomes of medically attended
influenza A and inuenza B in a defined population over four seasons:
2004-2005 through 2007-2008. Irving et al., Influenza and Other Respiratory
Viruses. 2012 Jan;6(1):37-43. doi: 10.1111/j.1750-2659.2011.00263.x. Epub
2011 May 25.
2. H1N1 hemagglutinin-inhibition seroprevalence in Emergency Department Health Care workers after the first wave of the 2009 influenza pandemic. Pediatr Emerg Care 2011 Sep;27(9):804-7. doi: 10.1097/PEC.0b013e31822c125e.
3. Incidence of Influenza in healthy adults and healthcare workers: a systematic review and meta-analysis - PLoS One 2011; 6 (10):e26239
4. Effectiveness of an influenza vaccine programme for care home staff to prevent death, morbidity and health service use among residents: cluster randomised controlled trial - BMJ 2006; 333:1241
Note: Text in this fact sheet is derived and adapted from the ECDC Communication Toolkit for Healthcare workers and People in high risk groups.