It’s finally that time again — where did the summer go? Along with stuffing backpacks and curating outfits the night before the first day, comes packing hand sanitizer and tissue boxes. As students and teachers return to the classroom, the various returning pathogens are equally eager to reunite with their hosts after a summer away.  

Jerne Shapiro, MPH, a University of Florida Emerging Pathogens Institute member, discussed the diseases that surge as students from kindergarten to college flood hallways, lecture rooms and cafeterias. Shapiro, an epidemiologist within the UF College of Public Health and Health Professions, is well-versed in staying safe from infectious diseases in the classroom.

What are the most common illnesses you typically see spike when students go back to school? 

We certainly see an increase in respiratory-like illnesses such as respiratory syncytial virus, or RSV, and the common cold. We also see increases in strep throat, pink eye — that highly infectious conjunctivitis in our eyes — and head lice. 

When coming back to school, kids need to think not only about infectious diseases, but also about getting overheated and dehydrated because they’ll be playing outside and on the playground. 

When we’re hot, humid, and/or sweating, we can get fungal infections like ringworm and jock itch that can develop in warm, moist areas of the body, like the armpits and groin. We sometimes see increases in skin infections like impetigo, which is a highly contagious condition caused by staph or strep bacteria, as well as MRSA, which may appear as boils or abscesses, particularly in contact sports settings or where hygiene is poor.  

Why does back-to-school season often coincide with an increase in contagious illnesses? 

Heat is helpful for certain pathogens, like bacteria and fungi, that thrive in warm, humid conditions. However, during the colder months, lower temperatures and reduced humidity allow respiratory pathogens like influenza and RSV to persist longer in the environment and spread more easily.  

But when we really consider what facilitates disease transmission, it’s helpful to think of a triangle: The host, the environment and the pathogen itself. We’ve got to understand the host, humans in this case, and ask how susceptible they are. Then we consider the environment. What environment are we in? Is it hot or humid? Are we in a densely populated area? And finally, when thinking about the pathogen, what type of temperature, humidity and environment does it like to live in? Where does it thrive, and how easily does it spread from person to person? 

When we’re going back to school, and we start thinking through the lens of that triangle, where do those three different attributes come together for successful disease transmission? The classroom. And often, students had fewer social interactions over the summer months, so when they return, they might not have immunity to what is currently circulating — the disease de jour, if you will. Factors like hand hygiene practices, sleep and stress can weaken our immune systems, as well, making us more susceptible to different pathogens.  

What are some early signs parents should look out for with their kids? 

Some of these illnesses can share overlapping symptoms. For pink eye, bloodshot eyes and eye discharge are sure giveaways. 

If you’re looking at respiratory illnesses, it’s important to differentiate between an upper and lower respiratory tract infection. Upper respiratory is typically a runny nose, sore throat, cough, sneezing and sometimes a fever. Lower respiratory tract infections often lead to difficulty breathing, with signs such as wheezing and rapid respiration. Watch for nostril flaring during inhalation and the abdomen sinking in while breathing; these are signs of labored breathing. These are called retractions, and the skin around the ribs or abdomen may appear tighter due to the increased effort with each breath.  

If you’re concerned about your child, you should seek medical care from a pediatrician. If you’re very concerned, especially if there is trouble breathing, seek immediate care at an urgent care or the emergency department. 

RSV is a growing concern for young children. What should parents know about preventing and managing it? 

RSV is the leading cause of hospitalizations for infants in the United States. RSV is a respiratory virus, so it spreads by breathing in droplets when an infected person is normally exhaling, talking or coughing. It can also be spread by touching your eyes, nose or mouth after coming into contact with contaminated surfaces.  

Our most vulnerable age group for RSV is infants. Pregnant individuals who receive the RSV vaccine produce protective antibodies that can be transmitted through the placenta to the newborn. These maternal antibodies can help protect the baby for the first few months of life and can also come through breast milk to continue to protect the newborn. 

In addition to maternal vaccination, a vaccine is also available for infants, but it’s all about the timing. RSV is a very seasonal pathogen, so we want to make sure that we’re giving both kinds of vaccine at the right time for an infant who may be at risk for more severe complications.  

How can caregivers differentiate between the common cold and more serious infections like RSV and the flu?  

It’s important to remember that these are generalizations because every immune system differs. If the symptoms are mild, mostly nasal, then it’s likely a common cold. But not all common colds are created equal. I’ve had some, what I call baby colds, in which I moved through them in a couple of days, and I’ve had some other colds that knocked me out flat. 

If you have a fever, body aches and deep fatigue, think influenza. If you notice labored breathing and a wheeze, particularly in our infants, think RSV.  

Now, COVID-19 can range from asymptomatic to severely ill, and symptoms often resemble influenza or a cold. Secondary symptoms like loss of taste/smell or diarrhea may help identify it, but their absence doesn’t rule out COVID-19 because the symptoms are less common with the new variants. I still have COVID tests at my house, and if I’m concerned, we just do a swab.  

And that’s with all of those. If you are concerned, getting tested is the only reliable way to know. 

What advice do you have for parents and students regarding whether to stay home or return to school? 

Don’t return to work or school if you are sick. If you’ve had a fever, wait until you’ve been fever-free for at least 24 hours without taking fever-reducing medicine. You can show respect for others and protect your community by distancing yourself or wearing a well-fitting mask, like an N95 or KN95. I bring a mask in my bag in case any of my students ever need to use it or want one. It’s always available to them.  

I think it’s important to know that for illnesses like COVID and influenza, five days is the most infectious period and an excellent marker for how long you should stay away from others. You may still be infectious after this time, but can return to work or school and should consider wearing a mask for a few more days to protect those around you.  

What common illnesses should incoming college students know about as they start their fall semester? 

We often see strep, COVID, the common cold and mononucleosis, caused by Epstein-Barr virus, on college campuses. Many of these are spread by respiratory droplets when people cough, sneeze or talk in close proximity. Pathogens like SARS-CoV-2, which causes COVID-19, can also spread through aerosols that linger in the air and travel farther distances, especially in poorly ventilated or crowded indoor spaces like dorms and lecture halls. 

Sexually transmitted infections remain a serious concern on college campuses. What should students know about prevention and testing? 

In the United States, about one in five people has an STI on any given day, including both curable and lifelong infections like chlamydia, herpes, HPV and HIV. Young people aged 15 to 24 account for nearly half of all new STI cases in the U.S. This occurs for numerous reasons, but it can also be the most sexually active time in a person’s life. Students can prevent STIs by correctly and consistently using a condom, and they can get tested from their primary care provider, the campus infirmary, community clinics and even local branches of the state health department. 

We have to take the stigma out of STIs so that people don’t feel shame in accessing medical care and having genuine conversations with their partners to discuss signs, symptoms, how to get tested and their expectations from the relationships they’re in. 

What are your top three tips for keeping students and families healthy throughout the school year? 

Stay home if you’re sick, wash your hands and get vaccinated.