Winter Plan for Respiratory Infections - Recommendations in more detail

Winter Plan for Respiratory Infections

The recommendations in more detail:

1. Hand hygiene 
Hand hygiene is the most effective measure for preventing the spread of infections. It is recommended to wash hands thoroughly with soap and water, scrubbing for one minute on both the tops and bottoms of the hands and between the fingers. Be sure to rinse off all soap residue and dry hands thoroughly with a personal or disposable towel. You should do this every time your hands are visibly soiled, after using the toilet, after contact with rubbish, after coughing, sneezing or blowing your nose, before preparing a meal and before the meal itself, when coming home from outside or after touching surfaces that are touched by many people (such as door handles, switches in public places, shopping trolleys, support poles in public transport, etc.), after contact with animals, and after taking care of someone who is ill.

When using hand sanitiser, such as in healthcare settings, it is best to rub it thoroughly over all surfaces of your hands for about 40 seconds or until they feel dry.

2. Ventilation
Ventilation is highly effective in minimising the transmission of respiratory infections among individuals in indoor environments. In various settings such as homes, workplaces, classrooms, public transport, shops, catering establishments, and public indoor events, several measures can be implemented to enhance safety:

Open windows and doors: Regularly open windows and doors to ensure a steady flow of fresh air, ideally from opposite sides of the room (cross-ventilation), to promote effective airflow.

Ventilate regularly: Ventilate the room multiple times a day, particularly in high-traffic areas like living rooms, offices, and classrooms. Ideally, ventilate the space every hour for at least a few minutes.

Monitor air quality: If necessary, use a CO₂ meter to measure air quality. Elevated CO₂ levels may indicate poor ventilation, which can heighten the risk of infections. Check the guidelines for the proper use and interpretation of the CO₂ meter [38]. Recommendations in Belgium vary depending on the sector and context, such as homes, schools, offices, or industrial sectors. Generally, a CO₂ concentration of up to 900 ppm (parts per million) is recommended for maintaining indoor air quality in residential environments and offices. At CO₂ levels between 900 and 1,200 ppm, air quality remains acceptable; however, enhanced ventilation is strongly recommended. When the concentration exceeds 1,200 ppm, increased ventilation becomes essential. Learn more at https://www.health.belgium.be/en/node/41521.
 
Use mechanical ventilation systems correctly: If you have a mechanical ventilation system, such as an exhaust system or balanced ventilation, ensure it is functioning properly, regularly maintained, and adjusted. Increase the setting if there are several people in the room.

Air purification: In rooms where natural ventilation is challenging, or to enhance an efficient ventilation system, you can use air purifiers with HEPA filters to improve air quality by removing particles and pathogens from the air. Learn more at https://www.health.belgium.be/en/air-purification-devices.

Avoid recirculating air: Avoid ventilation systems that recirculate air without filtration, as these can spread germs. Detailed information can be found at https://www.health.belgium.be/en/importance-indoor-air-quality.

3. Acute illness / acute respiratory infection (ARI)
ARI (Acute Respiratory Infection) refers to the acute phase of a respiratory infection: "being acutely ill". The duration of this phase varies for each individual, depending on the specific respiratory pathogen, the patient’s condition, and the severity of the infection. Signs of an acute respiratory infection include (non-exhaustive list):
- General malaise
- Fever (typically in the case of flu and severe infections, more common in children)
- Shivers
- Sore throat
- Blocked nose or runny nose
- Coughing (dry or productive/with mucus)
- Shortness of breath or difficulty breathing
- Fatigue
- Muscle pain and/or joint pain
- Sweating/night sweats
- Headache
- Hoarseness
- Loss of appetite
- Loss of taste and smell (may occur in the case of some viruses such as COVID-19)
- Conjunctivitis (redness or irritation of the eyes)
- Chest pain (especially in the case of a severe cough)
- Swelling of lymph nodes in the neck
- Earache (especially in children, due to secondary ear infections)
- Nausea or vomiting (sometimes in the case of flu, especially in children)
- Vomiting (more common in children, usually in fits of coughing with phlegm)
- Diarrhoea (rare, but can occur with some viruses such as flu)

You are ‘acutely ill’ if you really don't feel well, are unable to work or go to school, or function normally. If you experience fever, chills, shortness of breath, or are unable to function normally, you are classified as 'acutely ill.' Those who are acutely ill should remain at home to recover and prevent the spread of infection to others. During the days when you are acutely ill, your infectiousness is at its highest, and you should avoid all contact with others.

Those who are no longer acutely ill and can leave home, go back to work or school, should take appropriate precautions. When you feel better and no longer have acute symptoms such as fever, sneezing, watery eyes, or sore throat—though mild residual symptoms like dry cough, hoarseness, fatigue, and swollen glands may persist for more than a week—you can consider returning to school or work. However, remember that respiratory infections can remain contagious for several days after symptoms begin, sometimes lasting over a week, even if you have been vaccinated.

Therefore, as long as you have mild symptoms, continue to wear a mask when in contact with others, maintain sufficient distance if possible, and avoid contact with vulnerable individuals until all symptoms have disappeared. When in doubt, it is best to consult with your doctor or pharmacist.

4. Contagiousness
Contagiousness refers to the extent to which respiratory pathogens, such as the influenza virus, RSV, pneumococci, and coronaviruses (including SARS-CoV-2 and other cold viruses), are transmitted from person to person. These pathogens spread (shedding) primarily through droplet infection (coughing, sneezing) and direct contact (transmission via hands). Contagiousness is influenced by factors such as population density, seasonal weather conditions, room ventilation, and personal hygiene. During the winter months in Belgium, infections increase due to more indoor activities and close contact between people.

It is generally believed that the majority of infected individuals are highly contagious and spread many pathogens within the first 5 to 7 days after the onset of symptoms. A smaller proportion of infected individuals continue to spread pathogens for many days beyond this period.

Not every infected person will display symptoms, meaning some individuals can spread pathogens without being aware of it. Vaccination does help against severe infection and complications, but does not prevent the vaccinated person from spreading pathogens anyway.

5. Face masks are effective in avoiding transmission of respiratory infections. Wearing face masks when necessary is not only sensible but also a fundamental courtesy and a sign of consideration for yourself and those around you. Face masks do need to be worn correctly to be effective: use surgical face masks available in pharmacies and most larger shops, and change the mask regularly (at least once every four hours of wear, but more often if you are sick or it gets dirty or damp). Wear the face mask snugly over your nose and mouth, with the lower edge under your chin. Secure the bendable strip around the bridge of your nose, and place the loops behind your ears for a snug fit. To remove the face mask, use the ear straps or bands, and dispose of it immediately in a sealed bin. Wash your hands both before applying and after removing the face mask.

Vulnerable individuals in crowded places are advised to wear FFP2 masks, which are available at pharmacies.

6. Social distancing
The effectiveness of 'social distancing' in preventing the transmission of respiratory pathogens remains a topic of debate. However, epidemiological and modelling studies have found that social distancing measures—maintaining physical distance and avoiding crowded places—are effective strategies and important non-pharmaceutical interventions for reducing the spread of seasonal respiratory infections. Research consistently demonstrates that this approach significantly lowers transmission rates of respiratory infections and helps flatten the epidemiological curve. Its success relies on community compliance and adherence to recommended guidelines. While effective, these measures unfortunately also have socioeconomic consequences and can lead to psychological effects from isolation. Social distancing is especially effective when combined with other measures, such as proper ventilation and hand hygiene.

Social distancing is particularly effective in limiting droplet transmission, where pathogens are spread via larger droplets (greater than 5 micrometres) during coughing, sneezing, or talking. Studies confirm that droplets typically settle within a distance of 1.5 metres, supporting the idea that social distancing helps limit the spread of respiratory pathogens, particularly in poorly ventilated spaces where aerosols (smaller droplets) can linger longer in the air.

The belief that social distancing provides sufficient protection in all cases is incorrect. In poorly ventilated rooms or during activities like singing or shouting, aerosols can travel further than 1.5 metres. This means that merely practising social distancing without proper ventilation may be insufficient.

Outdoors, where aerosols are more quickly dispersed and diluted by air currents, social distancing has a lesser impact on pathogen transmission. In this context, ventilation plays a more crucial role.

7. Get vaccinated: Discuss with your doctor, pharmacist, home health nurse, or midwife whether you are eligible for vaccination against typical winter respiratory infections, including seasonal influenza, COVID-19, pneumococcus, and RSV. This is especially important if you belong to a 'vulnerable group'—for instance, if you are over 65 years old, have a chronic condition affecting the lungs, heart, blood vessels, liver, or kidneys, have a weakened immune system (such as after transplantation or chemotherapy), or if you are pregnant, planning to become pregnant, or have recently given birth etc.). You may also be eligible for priority vaccination if you live with or care for someone who is vulnerable.

8. Vulnerable people: You may consider yourself vulnerable if you are over 65 years old; have a chronic condition affecting the lungs, heart, liver, or kidneys; have a metabolic disorder (including diabetes) or a neuromuscular disorder; have an immune disorder; or are pregnant. Newborns and infants are also vulnerable.

9. Children and adolescents: For children, only the first four basic recommendations apply, which do not include wearing face masks. However, we still ask children and their parents to be mindful of infection risks in crowded places, particularly when in contact with vulnerable individuals.

10. Limiting the number of people present in an indoor space:
Limiting the number of people present in indoor spaces is a recommendation linked to the ‘social distancing’ recommendation and is also related to the risk of aerogenic transmission, whereby infectious aerosols (small droplets containing respiratory pathogens) can remain suspended in the air for long periods of time, especially in poorly ventilated spaces. Recent scientific findings highlight that good ventilation is essential for reducing the accumulation of aerosols and, consequently, the risk of pathogen transmission. When the number of people in an indoor space is reduced, the total amount of aerosols produced also decreases, further lowering the risk of contamination. This is particularly crucial in spaces where people gather for extended periods or engage in activities that generate more aerosols, such as singing or exercising.

Additionally, alongside ventilation, reducing group size proves more effective in environments with high aerosol production, such as nightclubs or concert halls. Ventilation alone cannot completely eliminate the risk, but when combined with other measures, such as limiting the number of attendees, it can greatly decrease the likelihood of contamination. This underscores the importance of recommendations that prioritise both ventilation and minimising group size in indoor spaces, particularly during peak seasons for respiratory infections.

11. Protection by means of protective screens

The effectiveness of protective screens, such as Plexiglas barriers (e.g., between employees and customers at counters), for reducing the transmission of respiratory pathogens remains a topic of ongoing research and debate. They do appear to provide some protection against direct transmission via larger respiratory droplets released during coughing or talking, but are of limited effectiveness in preventing the spread of smaller aerosol droplets, which can remain suspended in the air and travel over longer distances, especially in poorly ventilated areas.

Reducing airborne transmission of pathogens is more effective with a combined approach: enhanced ventilation and filtration systems like HEPA filters, wearing masks, and maintaining physical distance are generally more impactful than relying solely on physical barriers such as screens.