Viral illnesses surge in the new year

As the new year begins, several viral illnesses are spreading rapidly across the country.

COVID-19

As of the week ending Dec. 28, 2024, CDC data shows that wastewater activity of SARS-CoV-2 is either "high" or "very high" in 28 states. Although wastewater levels of COVID-19 are lower than they were at the same time last year, they have grown significantly over the last few weeks, and health experts say the number of new cases will likely continue to rise. 

"Nationally, COVID-19 levels in wastewater have been increasing through the month of December, following a period of low levels in October and November," said Jonathan Yoder, deputy director of CDC's Division of Infectious Disease Readiness.

"There's a good chance that a lot of people are going to get sick in the next couple of weeks and be unaware of it," said Michael Hoerger, an associate professor at Tulane University School of Medicine. "Most people are not tracking CDC data, and so their only way of knowing whether we're in a wave is if they've gotten sick."

Flu  

For the week ending Dec. 28, 23 states and the District of Columbia reported "very high" levels of influenza-like illness (ILI), and 17 states reported "high" levels of ILI activity. 

Overall, there were 26,088 flu-related hospitalizations for the week ending Dec. 28, an increase from the 14,755 hospitalizations reported the week before. The weekly hospitalization rate was 4.3 per 100,000 people.

So far, CDC estimates that there have been at least 5.3 million cases, 63,000 hospitalizations, and 2,700 deaths this flu season. There were also two pediatric flu deaths reported the week ending Dec. 28, 2024, bringing the total number of pediatric deaths to 11 for the 2024-2025 season.

RSV

Based on CDC's wastewater monitoring, eight states reported "very high" levels of RSV, and 14 states reported "high" levels of RSV. An additional 10 states reported "moderate" levels of RSV.  

Although some cases of RSV are mild, certain groups, including premature babies, infants, older adults, and those with weak immune systems, have a greater risk of developing severe infections. According to CDC, RSV leads to around 58,000 to 80,000 hospitalizations among children under the age of 5, and 100,000 to 150,000 hospitalizations among adults ages 60 and older every year.

Between Oct. 1 and Dec. 7, 2024, CDC estimates between 22,000 and 45,000 people were hospitalized with RSV. There were also between 980 and 2,300 deaths from RSV during the same period.

Norovirus

Norovirus is the leading cause of foodborne illness in the United States, with outbreaks being most common between November and April. It is extremely contagious and can quickly lead to gastrointestinal symptoms like diarrhea, vomiting, nausea, and stomach pain.

According to data from state health departments, there were 91 outbreaks of norovirus during the week of Dec. 5, 2024, up from 69 outbreaks during the last week of November. In comparison, the highest number of outbreaks for the same period over the last several years was 65.

Currently, there is no vaccine or antiviral treatment for norovirus. In general, doctors recommend staying home from work or school and drinking plenty of fluids as the infection clears up.

To avoid getting sick with norovirus, health experts recommend practicing good hand hygiene, including washing thoroughly with soap and water. Hand sanitizer alone is not enough to protect against norovirus.

Aside from good hand hygiene, CDC recommends cooking oysters and other shellfish until they reach 145 degrees. People should also thoroughly wash their fruits and vegetables, as well as any food preparation surfaces. 

Although vaccination rates remain low, health experts continue to recommend that people get COVID-19 and flu shots to protect themselves against severe disease.

"The best protection is to get vaccinated," Yoder said. "Although vaccinated people sometimes get infected with the virus that causes COVID-19, staying up to date on COVID-19 vaccines significantly lowers the risk of getting very sick, being hospitalized, or dying from COVID-19." 

Other ways to reduce the risk of infection and prevent the spread of respiratory viruses include:

• Testing if you have symptoms or have been exposed to someone who is sick
• Staying home when you're sick
• Seeking treatment if you're at high risk of severe illness
• Wearing a mask
• Practicing social distancing