Even though it's spring, multiple respiratory viruses are still spreading across the U.S., and their symptoms are nearly identical, making it impossible to know which one you have without a test. Flu and COVID, including a new variant called BA.3.2 nicknamed "cicada," continue circulating alongside respiratory syncytial virus (RSV), human metapneumovirus (HMPV), and other respiratory illnesses that are leaving many Americans feeling sick .

Why Can't Doctors Tell These Viruses Apart Just by Symptoms?

The challenge facing patients and healthcare providers is straightforward: the symptoms for flu, COVID, RSV, and other spring respiratory viruses are virtually indistinguishable. Sniffles, cough, muscle aches, and fever appear across all of them, making clinical diagnosis impossible without laboratory confirmation .

COVID symptoms have changed significantly since the early pandemic years. Loss of taste and smell, once a hallmark COVID symptom, is no longer reliable for diagnosis.

"We also can't really predict, like before, what someone has based on what is circulating. It could be COVID, it could be influenza, and now we have added the prolonged RSV to the mix," explained Dr. Geeta Sood.

Dr. Geeta Sood, Epidemiologist at Johns Hopkins Bayview Medical Center

The geographic distribution of these viruses also varies widely. Arkansas, North Dakota, Vermont, and Wyoming are still experiencing moderate amounts of respiratory illnesses, while infections are low elsewhere. RSV cases remain high in Michigan, Nebraska, Nevada, South Dakota, Tennessee, West Virginia, and Vermont .

Which Virus Is Most Likely in Your Area Right Now?

One practical tool for understanding which virus you might have is checking your local wastewater data. Public health initiatives like WastewaterSCAN collect surveillance data that shows which viruses are circulating in your community, and this information can hint at what you may have contracted .

"It's relatively quiet for these diseases compared to other years, but where you live may put one or another as more likely," said Jennifer Nuzzo.

Jennifer Nuzzo, Director of the Pandemic Center at Brown University School of Public Health

Marlene Wolfe, an assistant professor of environmental health at Emory University and program director of WastewaterSCAN, emphasized that understanding which viruses are circulating in your specific community is important because the dynamics of when and where cases appear differs significantly from virus to virus .

Here's what's happening with each major virus right now:

• COVID-19 (BA.3.2 variant): The heavily mutated BA.3.2 variant, nicknamed "cicada," has been detected in wastewater and nasal swabs in 25 states. As of mid-March, only about 0.55% of COVID viruses sampled in the U.S. were this variant. Cases are rising in Florida and Massachusetts but declining across the rest of the country .
• Influenza A: Cases peaked between Thanksgiving and early January, driven by a mutated strain called "subclade K." The 2025-26 flu season has recorded 115 pediatric influenza deaths so far, compared to 199 deaths during the 2023-24 season, the previous record-breaking year. Cases continue to drop nationwide, though the virus is still causing infections .
• Respiratory Syncytial Virus (RSV): RSV has plateaued but remains circulating at moderate levels across the country and high levels in several states. Unusually, RSV is not declining as much as expected for this time of year, with some states still recommending antibodies for newborns .

How to Protect Yourself and Know When to Get Vaccinated

• Get tested if symptomatic: Since symptoms are indistinguishable, testing is the only reliable way to know which virus you have. This information helps guide treatment decisions and informs whether you should isolate .
• Consider flu vaccination if you haven't: It's not too late to get the flu vaccine, especially if you received your last one in early fall. Dr. Geeta Sood emphasized that there is still time for people planning to travel or wanting protection, though the season is winding down .
• Time COVID boosters strategically: People at high risk for complications should consider getting a COVID booster every six months or so. Jennifer Nuzzo suggested timing boosters with travel, when you really don't want to get COVID, or when local case numbers are climbing .
• Check local wastewater data: Monitor your community's wastewater surveillance data to understand which viruses are circulating. This can help you make informed decisions about vaccination timing and precautions .

The BA.3.2 COVID variant is drawing particular attention because its spike proteins carry mutations that experts worry could allow it to evade immunity from prior infections or booster shots.

"This variant is very immunologically distinct compared to previous variants, and whenever that happens, there always is a risk that due to the fact that we have less immunity to this organism, so it could cause a spike in cases," said Dr. Geeta Sood.

Dr. Geeta Sood, Epidemiologist at Johns Hopkins Bayview Medical Center

However, there's some reassuring context: COVID cases did not spike in Europe following the first detected case of BA.3.2 last April, and CDC data shows that COVID cases overall don't look like they are increasing dramatically in the U.S. right now. Dr. Sood noted that there have been a number of variants that similarly have been very immunologically distinct, and we haven't seen a wave .

The bottom line is that spring respiratory illness season is far from over. While masks have largely disappeared and fewer people got new COVID shots this winter, partly due to confusion over eligibility, the viruses continue circulating. Staying informed about what's spreading in your community, getting tested when symptomatic, and making vaccination decisions based on your personal risk factors and local trends are your best tools for navigating this extended season .