How Does Common Cold Spreads in Schools & Other Crowded Places? The common cold is an acute viral infection of the upper respiratory tract. The upper respiratory tract includes the nose, sinuses, throat (pharynx), and larynx. Schools are high-risk environments for the transmission of the common cold and other viruses due to close student interactions, shared materials, and variable hygiene practices. Close student’ interactions include those in the classrooms, group work, as well as at recess, in lunchrooms etc. What variable hygiene practice means is that young children are still learning good hygiene habits. As a result, that makes them more likely to spread germs.
Transmission routes:
The common cold spreads in schools primarily through 3 main transmission routes: 1. Airborne Transmission (Droplets & Aerosols); 2. Direct Contact Transmission; 3. Surface (Fomite) Transmission. Handwashing is one of the most effective ways to prevent the spread of the common cold.
Understanding the key transmission pathways can help educators and parents implement effective prevention strategies.
Of course, you may ask: what viruses can cause common cold and other infections of the upper respiratory tract?
For example: rhinovirus is one of the viruses that can cause the common cold. However, there are many other viruses that cause common cold or other upper respiratory infections. Furthermore, you may ask: how long does it take from the moment one gets in touch with the virus to first signs and symptoms of being sick? That period is called: incubation period. The incubation period varies with the virus type. For rhinovirus, the incubation period is just under about 2 days i.e. about 1.9 days. These are incubation periods for some of other viruses: influenza B: 0.6 days, influenza A 1.4 days, parainfluzenza 2.6 days, human coronavirus 3,2 days, adenovirus 5.6 days, measles 12,5 days.
Let’s explore these 3 modes of transmission further:
1. Airborne Transmission (Droplets & Aerosols)
When an infected student coughs, sneezes, or talks, they release virus-laden droplets and aerosolized particles into the air.
Droplet Transmission: Larger droplets (>5 microns) travel short distances (3-6 feet) before settling on surfaces or being inhaled by nearby individuals.
Aerosol Transmission: Smaller particles (<5 microns) can linger in the air for extended periods, increasing the risk of inhalation, especially in poorly ventilated classrooms.
In order to prevent airborne transmission, it is important that we encourage respiratory hygiene and handwashing, improve ventilation, and consider using masks during peak cold season and in very crowded classrooms.
2. Direct Contact Transmission
Students frequently engage in handshakes, high-fives, and other physical interactions. All those direct physical interactions can contribute to the spreading of the common cold virus in the classrooms and other crowded areas. If an infected student, for example, has mucus on their hands and touches another child’s hands or face, germs can transfer instantly.
In order to prevent direct contact transmission, it is important to encourage frequent handwashing. Handwashing needs to be done with soap and clean running water, especially after sneezing, coughing, or blowing noses. While some public health agencies recommend washing your hands for at least 20 seconds, the Indelible Learning approach to proper handwashing is to emphasize proper technique, not necessarily duration i.e. 20 seconds. If soap and clean running water are not available, students and educators can use alcohol-based hand sanitizers. Schools and Districts should purchase hand sanitizers that contain at least 60% alcohol to be effective against viruses.
Another important strategy is to teach students (and educators) to avoid touching their eyes, nose, and mouth. Touching one’s face is a major route for germs to enter the body. We call this prevention strategy: promoting face awareness.
3. Surface (Fomite) Transmission
Cold viruses can survive on surfaces like desks, doorknobs, and school supplies (like pencils and books) for hours to days. When students touch these contaminated surfaces and then rub their eyes, nose, or mouth, the virus can enter into their body.
In order to prevent surface (fomite) transmission, we recommend these prevention strategies:
3a. Regular disinfection of high-touch surfaces in classrooms.
3b. Encourage students to use their own school supplies rather than sharing.
3c. Promote proper hand hygiene before and after touching shared objects.
The Critical Role of Hand Hygiene in Preventing Common Cold
Handwashing is one of the most effective ways to prevent the spread of the common cold. Studies show that children who wash their hands regularly at school have significantly fewer colds and other infections. Schools that implement structured hand hygiene programs see reduced absenteeism due to illness.
Final Takeaway
Teaching students proper hand hygiene, respiratory etiquette, and cleaning habits can dramatically reduce the spread of colds in schools. By emphasizing clean hands, clean air, and clean surfaces, educators and parents can help create a healthier learning environment. Implementing these evidence-based strategies will not only reduce illness-related absences but also enhance overall school health and wellness.
References:
- New considerations in the treatment and prevention of rhinovirus infections. Pediatr Ann. 2005 Jan;34(1):53-7. doi: 10.3928/0090-4481-20050101-12
- G. Michael Allan and Bruce Arroll Prevention and treatment of the common cold: making sense of the evidence. CMAJ February 18, 2014 186 (3) 190-199; DOI: https://doi.org/10.1503/cmaj.121442
- Justin Lessler, Nicholas G Reich, Ron Brookmeyer, Trish M Perl, Kenrad E Nelson, Derek A T Cummings. Incubation periods of acute respiratory viral infections: a systematic review. Lancet Infect Dis 2009 May; 9(5):291-300. doi: 10.1016/S1473-3099(09)70069-6
- Sarah L McGuinness, S Fiona Barker, Joanne O’Toole, Allen C Cheng, Andrew B Forbes, Martha Sinclair, Karin Leder. Effect of hygiene interventions on acute respiratory infections in childcare, school and domestic settings in low- and middle-income countries: a systematic review Trop Med Int Health . 2018 Aug;23(8):816-833. doi: 10.1111/tmi.13080.
Dr. Jasminka Vukanovic-Criley MD, FACP, FHM is a multiple award-winning physician, internist, hospitalist, healthcare & education innovator & Associate Clinical Professor of Medicine at UCLA. She is a career mentor & advisor to numerous undergraduate, graduate & postgraduate students & faculty. As a researcher, Dr. Criley received awards from the National Institutes of Health & the U.S. Department of Education Her work focuses on creating research-driven #edtech games & digital media to improve health, civics, science education & promote healthy habits. Dr Criley is also a founding Board member of Physician’s Weekly. She can be reached on X at @criley_md and at www.linkedin.com/in/jasminka-criley-md