COVID, norovirus, whooping cough, bird flu, dengue fever -- there is no shortage of viruses making headlines in the U.S. right now.

But why does it seem like so many are getting sick lately?

We spoke to "virus hunter" Mary Rodgers, an associate research fellow at Abbott, about what's circulating right now and why.

Rodgers monitors viruses around the world to track any changes or mutations that could become concerning.

"They're constantly moving and changing and mutating, and we know that they can do this at any moment so we can never let our guard down," Rodgers said. "We have to be faster and we have to work together with partners around the world to keep an eye on them."

According to Rodgers, it's a particularly virus-heavy time -- and it could soon worsen.

"We can't necessarily rank which one is the scariest per se, but we need to really be prepared for everything that's circulating, especially the respiratory pathogens, because we're in the sort of respiratory season where things like RSV, flu, COVID and even strep throat are spreading in some places more than others," she said. "And as we have holiday travel coming up, that could change. Hot spots can then become the entire country potentially that are seeing spikes in all of these different respiratory pathogens."

Recently, health officials have warned about spikes in whooping cough, particularly in young children, with levels reaching numbers not seen in 20 years in Illinois.

Just this month, Chicago has seen "several small outbreaks" of suspected norovirus cases, according to a spokesperson for the Chicago Department of Public Health.

In addition to the many respiratory viruses circulating, one of the current viruses being tracked by virus hunters like Rodgers is bird flu.

"We certainly have been keeping an eye on H5N1, which is avian influenza, in particular in the U.S. because we're seeing more and more human cases lately," Rodgers said. "These are primarily in people who are at risk because they're interacting with livestock ,and livestock are currently the reservoir or the place that you're most likely to find avian influenza, as you'd expect, because it's a virus that primarily affects animals and birds. But that could always change. And so that's why we have to keep an eye on it as people get cases. They've been mild, which is good news, but that could always change."

The Centers for Disease Control and Prevention confirmed the first severe illness in a person with bird flu on Wednesday. A patient was hospitalized in Louisiana, marking the "first instance of severe illness linked to the virus in the United States."

Since April 2024, there have been 61 human cases of bird flu reported in the U.S., according to the CDC.

"We've learned one thing through COVID and that is that we can't assume anything," Rodgers said. "So it's really important to have an active view and proactively be looking at how these viruses are changing so that we can respond. We know that every outbreak is different and it's really important that we're all staying as healthy as possible so that we can be prepared for whatever's coming next."

When it comes to COVID-19, Rodgers said the XEC variant remains the dominant variant in the U.S.

"We've continued to see COVID evolving, and that's to be expected, actually," Rodgers said. "As people's immune responses develop to one strain, the virus is motivated to change so it can escape from those immune responses. And that's what we're seeing today. We're certainly keeping an eye on those changes so that we can make sure that tests are working and the sequences are out there to update the vaccines to be able to keep pace with those changes that happen in the virus. But from what we're seeing circulating today and the growing predominant strain for COVID is XEC, which is something we're keeping an eye on. But we also know that what the WHO analysis has shown is that this is a low risk to the public. It's not particularly more dangerous than other COVID strains, but it is changing. So we need to keep an eye on it."

While the symptoms for COVID remain unchanged so far, they can mimic the early signs of a myriad of other viruses.

"The symptoms to keep an eye out for, particularly if you're concerned you may have been exposed to COVID, would be the usual symptoms that were seen in past waves. So something like a fever or a cough or a very sore throat, those are the early warning signs that someone should get a test or check to see if they have COVID," Rodgers said. "But the thing is, a lot of these other pathogens have the same initial symptoms, so it's really hard to tell if someone might have COVID versus flu just based on symptoms alone. So you kind of have to check in with your health care provider to see what they would recommend. But obviously, testing is going to give you the definitive answer so that you'll know whether or not your family has COVID or flu, which all kind of start with the same fever, sore throat, runny nose and a test is really key in those kinds of situations."