As cases of norovirus spread across the United States, Allegheny County officials are reporting that several outbreaks of the stomach bug have hit long-term care facilities in recent weeks. Hospital data also shows an uptick in local emergency room visits with complaints of vomiting.
And while norovirus makes its rounds, cases of influenza, RSV and COVID-19 are also increasing. Allegheny County Health Department Officials advise people to take precautions to stay healthy and to stay home if symptoms arise, but also note that an uptick in these illnesses is expected in the aftermath of holiday gatherings.
“This is pretty typical,” said Dr. Barbara Nightingale, the health department’s deputy director for clinical services. “Somewhere around December, January or February we tend to see increased rates [of illness].”
COVID-19 cases began slowly climbing up over the past few weeks, though they remain less than half the rate of cases during the same time last year, according to county data. But cases of RSV and influenza have skyrocketed, according to Nightingale. Reported influenza infections — largely influenza type A — doubled between the weeks of December 15 and December 22. Cases of RSV, or respiratory syncytial virus, rose by 25% during the same period.
Hospital visits related to the flu also doubled and those related to RSV increased by 48%, according to county data. Nightingale urged residents to get a COVID-19 and flu shot if they haven’t already and for those who qualify for an RSV vaccine to get inoculated as soon as possible.
“The people that are the most impacted … tend to be children under five-years-old and then older people,” Nightingale said, adding that “it’s really important for people to get [vaccinated] because we have vaccines for COVID-19, influenza, and RSV [that] are very safe and effective.”
Though the county monitors outbreaks of norovirus, the health department was unable to provide an exact number of cases. Officials said the uptick is similar to previous years.
Nationwide, a rising number of cases of the flu, RSV, COVID-19 and stomach bug has been described by health experts as a winter “quad-demic.”
There were 91 suspected or confirmed norovirus outbreaks in the first week of December in the U.S., according to the most recent data available from the Centers for Disease Control and Prevention. (That number reflects the number of clusters of confirmed cases in a particular area.) The spike comes earlier in the cold and flu season than in recent years. During the same week in 2020, just two clusters of norovirus cases were reported. In the years since the pandemic, the largest norovirus outbreak this early in winter was 56 clusters of cases.
Norovirus symptoms typically appear within 40 hours and can last up to three days. Primary symptoms include severe diarrhea, nausea, vomiting and stomach cramps.
It’s not yet clear what’s driving the surge in cases. Norovirus most commonly spreads in healthcare facilities including long-term care facilities, with these locations accounting for more than half of all outbreaks in the U.S., according to the CDC. Outbreaks at hospitals and similar facilities can last for months and become deadly compared to outbreaks among healthier people. The virus can spread in other congregate spaces like college dorms, jails and cruise ships.
Restaurants and large gatherings are another risky environment: norovirus is the leading cause of outbreaks from contaminated food in the U.S. Common foods involved in outbreaks include oysters, fruits and leafy greens. The FDA has issued several recalls for oysters contaminated with norovirus in recent weeks.
Anyone can contract the virus, but young children, the elderly and those with weakened immune systems are at greater risk of complications. There are no antiviral medications or vaccines for norovirus infections.
Norovirus is resilient and can survive freezing temperatures, heat and dryness, which means it can linger on surfaces for days. Experts suggest cleaning surfaces with bleach or hydrogen peroxide cleaners. Nightingale stressed hand washing as a key defense, noting that alcohol-based hand sanitizers are ineffective at killing the virus.
“Washing hands is really the most effective way to kill,” the norovirus, Nightingale said. “[And] it’s really important when cooking food to make sure that you cook it thoroughly because it can actually survive if you just steam something for a brief while.”
If symptoms do arise, Nightingale suggests resting and drinking plenty of water to avoid dehydration. She advises those unable to keep fluids down to seek medical care.
As for the major respiratory viruses, she notes that symptoms can overlap, making it hard to distinguish between influenza, RSV and COVID-19. Nightingale suggests speaking with a medical provider or taking an at-home test if you present with symptoms like a runny nose, cough, muscle aches or fever.
“If you have a risk for severe disease, it’s important to be able to know what the diagnosis is so that [doctors] can provide the correct antiviral to prevent longer-term consequences,” she said.
