Virus Season Persists Despite Spring

Though it’s spring, the season for viruses is still ongoing.

The flu and COVID-19, including a new variant identified as BA.3.2—nicknamed “cicada”—are continuing to spread. There are also several respiratory illnesses and a troublesome stomach virus causing discomfort for many Americans.

The symptoms of these viruses are quite alike: sniffles, cough, body aches, and fever. Doctors suggest that testing is the only reliable way to determine which virus you may have.

Last year, influenza A was particularly severe in the United States, primarily due to the H3N2 subclade K variant. According to Marlene Wolfe, an assistant professor at Emory University, as cases spiked in January, “we began to see a rise in other viruses as well.” She noted that while we often think of respiratory illness season as confined to fall and winter, various viruses actually emerge at different points in this timeframe.

Regions such as Arkansas, North Dakota, Vermont, and Wyoming are still grappling with moderate respiratory illness levels, while the rest of the country shows lower infection rates, as reported by the CDC.

Some states, including Michigan, Nebraska, Nevada, South Dakota, Tennessee, West Virginia, and Vermont, are still seeing high levels of RSV, or respiratory syncytial virus.

How to Identify Your Illness

Dr. Greeta Sood, an epidemiologist at Johns Hopkins Bayview Medical Center, has noted that distinguishing between these respiratory illnesses is challenging. Symptoms of COVID-19 no longer prominently feature loss of taste or smell, which were once critical indicators early in the pandemic.

“It’s hard to predict whether someone has COVID, influenza, or prolonged RSV based solely on what’s circulating,” Sood explained.

Currently, local wastewater data may provide insights into the most prevalent viruses in your community. Jennifer Nuzzo of Brown University stated, “Although it’s quieter for these diseases compared to past years, your location can influence which is more likely to affect you.”

Wolfe emphasized the importance of being aware of the viruses in your area, as there can be significant differences from state to state. “Different viruses have varying dynamics regarding when and where cases arise, making it essential to stay informed,” she said.

Is It COVID-19?

With masks mostly absent, not many people received the new COVID shots this winter, largely due to confusion about eligibility.

The CDC revealed that the BA.3.2 variant is detected in wastewater and nasal samples in 25 states. Experts worry that its mutations could help it bypass immunity from previous infections or booster doses.

Sood remarked that “this variant is quite distinct immunologically from prior ones,” meaning there is some risk due to potentially lower immunity, which could lead to a rise in cases.

As of mid-March, only 0.55% of sampled COVID viruses in the U.S. were the BA.3.2 variant. The CDC indicated that Europe didn’t see a spike in cases following its initial detection last April. Presently, while COVID-19 cases remain low, there is a slight uptick in Florida and Massachusetts, while declining elsewhere.

“Overall, COVID cases don’t seem to be dramatically rising,” Sood commented, noting that predicting the impact of BA.3.2 is difficult. Several past variants have appeared distinct without causing significant waves.

The CDC data shows mixed levels of COVID across the U.S., with some areas experiencing high or moderate case counts while others remain low. Recent data from WastewaterSCAN indicates a little increase in cases.

Nuzzo highlighted that COVID hasn’t settled into a predictable pattern. Any increases in certain states shouldn’t be a cause for alarm at this time, as there are no alarming trends reported.

However, those at high risk should think about receiving boosters roughly every six months. Nuzzo suggested timing boosters with travel or local case trends, indicating that personal circumstances should drive these decisions.

Flu Update

An earlier wave of flu cases this season was mainly driven by a mutated influenza A strain known as H3N2, subclade K. There was a notable spike from Thanksgiving to early January, raising fears of a repeat of the previous year’s severe flu season.

“Fortunately, it hasn’t turned out to be as severe as last year’s,” Nuzzo commented, adding that last year was the worst on record for child flu deaths.

According to the CDC, 115 pediatric flu deaths have been reported this season, following two consecutive years of record highs. Despite efforts, there have still been fatalities, including a teenager in California earlier this month.

Influenza A cases began decreasing in January but continue affecting many. In contrast, influenza B cases are rising in some states, like Washington and North Dakota. However, the overall national trend is downwards.

Wolfe shared that influenza B is still prevalent in wastewater, and it’s vital to note that there’s still time to get vaccinated, especially for those who received their last shot in the fall. “It’s not too late if traveling, but we’re nearing the end of the season,” she remarked.

Respiratory Syncytial Virus (RSV)

RSV can show symptoms similar to a cold but poses a greater risk to children and infants. This season, RSV has plateaued, yet remains significant in wastewater data.

CDC data indicates that RSV levels vary across the country, consistently high or very high in states such as Hawaii, Iowa, and Michigan, with rising cases in North Dakota.

Sood noted that while RSV typically peaks early in the season, it hasn’t declined as expected this year. Some states are recommending antibody treatments for newborns.

Human Metapneumovirus (HMPV)

HMPV, a virus akin to RSV, is also circulating at elevated levels nationwide, which is normal for this time of year, according to Wolfe. “It typically peaks in mid-April,” she said.

Norovirus – The ‘Two-Bucket Disease’

You will know if you have norovirus. Sometimes referred to as stomach flu, it’s actually a gastrointestinal virus. This highly contagious illness has been prevalent and continues to emerge. Recently, a notable outbreak on a cruise ship affected over 150 individuals.

Symptoms include sudden vomiting and diarrhea lasting several days, earning it its infamous nickname.

According to WastewaterSCAN, norovirus levels remain high but aren’t on the rise. Compared to last year, the CDC has recorded fewer cases this season.

“Currently, the trend mirrors what we used to see prior to last year, with a peak around late February,” Wolfe concluded, noting that it’s a relief that it’s not as severe as the previous year.