Health officials say influenza, COVID-19, including the emerging Cicada Variant BA.3.2, RSV, and norovirus continue circulating across the United States this spring, with overlapping symptoms making testing essential for diagnosis.
Respiratory Viruses Continue Circulating Nationwide
Doctors say Americans experiencing cough, fever, fatigue, or congestion may struggle to identify whether they have COVID-19, influenza, or another respiratory illness without laboratory testing.
“The symptoms are extremely similar across these infections,” said Dr. Geeta Sood, an epidemiologist at Johns Hopkins Bayview Medical Center in Baltimore. “There is not really a distinct trait between these respiratory illnesses.”
Public health experts report that influenza, respiratory syncytial virus, human metapneumovirus, and COVID-19 are all circulating simultaneously, a pattern typical of respiratory illness season extending through early spring.
Marlene Wolfe, an assistant professor of environmental health at Emory University, said multiple viruses often overlap during colder months. “Different viruses pop up throughout the season,” Wolfe said.
According to the Centers for Disease Control and Prevention, respiratory illness levels remain moderate in Arkansas, North Dakota, Vermont, and Wyoming, while infections are low across most other states, even as the Cicada Variant BA.3.2 continues to be monitored.
Wastewater monitoring, which tracks virus levels in communities, can help residents understand which illnesses are more prevalent locally, experts say.
Jennifer Nuzzo, director of the Pandemic Center at Brown University School of Public Health, said activity overall appears calmer than in recent years. “It’s relatively quiet compared to other seasons,” she said, adding that trends vary widely by region.
New COVID Variant Detected but No Major Surge Yet
Health officials are monitoring BA.3.2, a heavily mutated COVID-19 variant nicknamed “cicada,” detected in wastewater and clinical samples across 25 states.
Experts say the variant contains mutations that may allow it to partially evade immunity from prior infections or booster shots, though current data does not indicate a major surge.
“This variant is very immunologically distinct,” Sood said. “Whenever that happens, there is always a risk of increased cases.”
As of mid-March, Cicada Variant BA.3.2 accounted for about 0.55% of sampled COVID-19 cases nationwide, according to CDC data. Overall, COVID-19 levels remain low, though modest increases are reported in Florida and Massachusetts.
Nuzzo said small regional rises are not cause for alarm. “We don’t see any concerning trends for COVID right now,” she said.
Officials note vaccination rates declined this winter, partly because of confusion about eligibility for updated boosters. Experts recommend high-risk individuals consider booster shots approximately every six months, especially before travel or during local case increases.
Flu, RSV, and Norovirus Continue to Affect Communities
An early flu surge driven by an influenza A H3N2 strain peaked between Thanksgiving and January and has since declined nationwide, health officials say. The CDC reports 115 pediatric flu deaths so far this season, following two record-breaking years.
“It didn’t turn out as severe as last year,” Nuzzo said, though influenza remains a leading respiratory infection.
RSV continues circulating at moderate levels, with elevated activity in several states. Sood said the virus is lingering longer than expected this season, prompting some areas to continue recommending preventive antibody treatments for newborns.
Human metapneumovirus, a respiratory virus related to RSV, is also spreading at expected seasonal levels and typically peaks in mid-April, Wolfe said.
Meanwhile, norovirus, sometimes called the “two-bucket disease” because of intense vomiting and diarrhea, remains widespread but stable. More than 150 passengers and crew aboard a cruise ship recently became ill during a norovirus outbreak reported by the CDC.
Unlike respiratory viruses, norovirus causes sudden gastrointestinal symptoms lasting several days. Wastewater surveillance shows cases remain high but are no longer increasing.
Health experts emphasize that symptoms alone rarely reveal which virus is responsible, whether it is norovirus or respiratory infections like the Cicada Variant BA.3.2. Testing, vaccination, and monitoring local health data remain key tools for prevention.
