This dangerous vomiting and diarrhea virus is surging across the US

A highly contagious illness that can cause severe and even deadly vomiting and diarrhea is spreading at an alarmingly high rate across the United States, health experts warned.

Rotavirus, known for causing severe vomiting and diarrhea, is an illness that usually sees an increase in cases during the typical cold and flu season. The recent surge, which is continuing on an upward trajectory, has been enough to grab the attention of the Centers for Disease Control and Prevention (CDC).

"The increase in rotavirus infections that we have seen over the past 4-6 months is unusual, compared to previous seasons over the past 2 decades when rotavirus vaccines have been available," Dr. Andi L. Shane, chief of the division of pediatric infectious disease at Children’s Healthcare of Atlanta and professor of pediatrics at Emory University School of Medicine, told USA TODAY. "The trend in the increasing rates of rotavirus infections is concerning, as well as the corresponding decrease in rotavirus immunization rates."

WasteWaterSCAN, a Stanford University-led tool for tracking the spread of disease by testing wastewater samples, categorized rotavirus activity as "high" as of April 12, noting a 40% increase in concentrations since February.

Data from the CDC's National Respiratory and Enteric Virus Surveillance System (NREVSS) shows a steep incline in rotavirus cases beginning in January, with the latest data from April 4 representing the highest rate of infection since August 2025.

Of the 2,329 tests administered the week ending April 4, 7.30% were positive. At a low point in January, only 1.66% of 2,950 tests returned positive.

"There has been nationwide observation and discussion regarding increases in the numbers of children with rotavirus infections seeking medical attention for vomiting, diarrhea, and dehydration," said Shane. "Families ... have been asking questions about which vaccines are needed, and because rotavirus immunization has been so successful over the past two decades in reducing rotavirus disease, many parents are not aware of rotavirus and the dehydration that it can cause."

Here's what to know about rotavirus and how to protect yourself against it.

What is rotavirus? How does it spread?

Rotavirus is a contagious virus that causes vomiting, watery diarrhea, fever, and could lead to dehydration, according to the CDC. People infected with rotavirus pass the virus in their stool, which is how it gets into the environment and can infect others.

The disease can become serious for some people, resulting in severe dehydration, hospitalization and sometimes death, Dr. Rochelle Walensky, Advisor for Medical Affairs at the Vaccine Integrity Project and former Director of the CDC, told USA TODAY.

Rotavirus is spread when virus particles enter the mouth. Usually, this means touching a contaminated surface or stool directly and putting unwashed hands into or near the mouth, or eating contaminated food.

Anyone can get rotavirus, but infections are more common and more likely to become serious in infants and young children, older adults and people with weakened immune systems.

"(Children) are more likely to experience dehydration, as they have higher fluid needs relative to their body weight, limited fluid reserves, and are unable to tolerate rapid fluid losses from the vomiting and diarrhea that result from rotavirus infection," Shane said.

Because of its fecal-oral transmission, rotavirus commonly spreads among families and in hospitals and childcare centers, according to the CDC. Children are most likely to get rotavirus from January through June.

There is no treatment for rotavirus beyond supportive care, which includes staying hydrated.

Rotavirus symptoms

People infected by rotavirus typically start showing symptoms two days after exposure, according to the CDC. The most common symptoms include: 

• Severe watery diarrhea
• Vomiting
• Fever
• Stomach pain

Vomiting and watery diarrhea can last three to eight days.

Since the virus causes excessive diarrhea and vomiting, dehydration is also a common concern, especially in infants and young children. Symptoms to look out for include:

• Decreased urination
• Dry mouth and throat
• Feeling dizzy when standing up
• Crying with few or no tears
• Unusual sleepiness or fussiness

Rotavirus prevention and vaccines

Vaccination is the most effective form of protection against rotavirus, according to Shane, Walensky and the CDC.

It is given by mouth as liquid drops to infants in either a two- or three-dose series between two and six months of age, said Shane. It is highly effective, preventing severe rotavirus infections in 9 out of 10 immunizations and preventing any infection at all in 7 out of 10.

Before the vaccine, rotavirus annually sent more than 400,000 children to doctors' offices and 200,000 to emergency rooms. About 70,000 children were hospitalized, and 20 to 60 deaths occurred each year, according to the National Foundation of Infectious Diseases.

Widespread vaccination has prevented about 60,000 hospitalizations from rotavirus each year, said Walensky.

"It's important to remember that our baseline expectation for the number of cases has decreased significantly since the introduction of the rotavirus vaccine," she said. "So even high activity now is less in terms of duration and magnitude than we used to see."

Walensky also noted that the current rate of infection isn't entirely unusual for what we see during a seasonal surge. And, she said we don't currently have evidence to link the spike directly to decreased vaccine uptake.

"That said, federal vaccine policy chaos and the unfounded doubt that federal leaders have sown in vaccine safety and effectiveness cannot be good for uptake," she said.

Shane, on the other hand, said she has seen more cases than usual.

"While there is likely not a single contributing factor, decreasing uptake of rotavirus immunization is likely one contributing factor to the increase in rotavirus infections that we are seeing," said Shane.

Besides immunization, the best ways to prevent the spread include handwashing, good hygiene, and isolating sick people. It's important to remember that alcohol-based hand hygiene, such as hand sanitizer, is not good at preventing rotavirus disease, said Walensky, and that hand-washing with soap is necessary.

Latest status on rotavirus vaccinations

The vaccination protecting against rotavirus is one of four that were removed from the CDC's childhood schedule by Health and Human Services Secretary Robert F. Kennedy Jr., with President Donald Trump's backing. Kennedy said cutting the number of vaccinations aligns the United States with other developed nations.

These changes, among others, drew the ire of medical institutions like the American Academy of Pediatrics, which went as far as to release its own schedule in August 2025, saying the federal process was no longer credible.

In a response posted to social media, Kennedy hit back at the pediatrics academy's criticism, implying the organization's views were influenced by corporate pharmaceutical funders.

Some of the modifications to federal recommendations were paused in March when a federal judge sided with the APA and its allies, deeming HHS's overhaul unlawful. HHS vowed to appeal the decisions.

As of April 21, a notice atop the CDC vaccine schedule webpage for children 18 and under noted that the stay implemented by the ruling means recommendations have reverted to those from July 2, 2025, which includes rotavirus vaccination at two, three and six months.