In the United States, enterovirus infections increase in September and October as children return to school and spend significant time together in crowded places. According to the U.S. Centers for Disease Control and Prevention (CDC), 10-15 million infections from different types of enteroviruses occur in the United States each year. Enteroviruses are spread through the fecal-oral route and some enteroviruses can spread when an infected person sneezes or coughs droplets into the air or onto surfaces. This is why environmental surveillance of both air and wastewater can offer useful, complementary views of enterovirus circulation.
Enterovirus refers to a group of non-enveloped RNA viruses that can cause a wide variety of illnesses. Poliovirus is itself a type of enterovirus, so in scientific literature, the term “non-polio enterovirus” is used to refer to all other enteroviruses circulating today. The Cleveland Clinic explains that enteroviruses are usually named starting with “EV,” followed by letters and numbers that note the type (like EV-D68, EV-A6 or EV-A71).
Through our air sampling in schools, clinics, and other congregate settings, the Lungfish research consortium tests for non-polio enterovirus along with other pathogens. As Dr. Shelby O’Connor noted during a webinar last May, we use air samplers, namely the InBio Apollo and the Thermo Scientific AerosolSense sampler, to capture pathogen genetic material from the air and then test that material at the O’Connor Laboratory at UW-Madison.
Schools are especially important for environmental surveillance for enterovirus and other pathogens because children are in close contact for hours at a time in a shared indoor space. During a webinar held in July 2026, our team members described how we place these air samplers in cafeterias, gyms, and libraries where they run continuously, drawing in air and collecting it in a cartridge. The team then collects the cartridges on a weekly basis and processes them at UW-Madison. Because the samplers run passively in the background, they do not disrupt the school day and do not require action from teachers or students.
This air sampling work has led to important findings. As Dr. O’Connor explained, our team has been able to confirm that the presence of pathogens in the air corresponds to the presence of sick individuals in these spaces. We have also detected circulating viruses before people seek medical care for symptoms.
In addition to our efforts to detect different types of enterovirus through the air, our team has also created the Rhinovirus Serotypes in Wastewater dashboard. Human rhinovirus is part of the Enterovirus genus in the Picornaviridae family. There are more than 100 different rhinovirus types which are further subdivided into three distinct species (Rhinovirus A, B, and C). Unlike other classical enteroviruses that tend to concentrate in the digestive system, rhinovirus usually affects the nose, throat and upper airways. As a result, rhinovirus is typically spread by coughing, sneezing and touching contaminated surfaces. According to the CDC, rhinovirus circulates all year but infection rates increase in the early fall and spring. The Rhinovirus Serotypes in Wastewater dashboard shows exactly when and where each type is circulating. One of the team’s most interesting findings is that rhinovirus types occur in nationwide waves. In other words, the most prevalent serotype in California will likely be the same as in Boston. Lungfish’s environmental surveillance of air and wastewater can provide public health professionals, educators, community members, clinicians, and parents with helpful information as children return to school.