During the height of the pandemic, transmission of other respiratory viruses, including the flu, declined due to face masks, increased social distancing and better hand washing hygiene. 

The 2020 flu season hit historical lows, and between March 1 and May 16, 2020, flu activity decreased 98%, according to a report from the U.S. Department of Health and Human Services and Centers for Disease Control and Prevention. 

However, as more people became vaccinated for COVID-19 and social distancing and masking measures loosened, there has been a surge of respiratory illnesses around the world. An Israeli study published in JAMA Network Open found an increase in rates of various infections among children up to 3 years old and in respiratory infections among all age groups during the three months after the easing of COVID-19-related social restrictions.

Moffitt Cancer Center is also seeing a rise in bone marrow transplant patients diagnosed with respiratory viruses. Between April and June 2020, there were five reported cases of rhinovirus and enterovirus, two common respiratory viruses. During the same three months in 2021 there were 17 cases, and in 2022 there were 45. 

While the number of respiratory virus cases is historically higher in the winter months, hospitals are starting to see more and more cases diagnosed into the summer.

"These respiratory viruses were not able to emerge until the use of masks and social distancing was relaxed. The non-COVID viruses can be very dangerous or even deadly for our patients, especially our bone marrow transplant patients."

- Dr. John Greene, Infectious Diseases Program

“These respiratory viruses were not able to emerge until the use of masks and social distancing was relaxed,” said Dr. John Greene, chair of the Infectious Diseases Program at Moffitt. “The non-COVID viruses can be very dangerous or even deadly for our patients, especially our bone marrow transplant patients.”

Prior studies have shown that hematology patients have a greater risk of having prolonged viral shedding, or releasing a copy of the virus from the body, and therefore test positive for the virus for a longer period of time. On average, hematology patients shed a virus for two to four weeks, with some reported to shed as long as 12 weeks.

“Our patients need to remain vigilant,” said Greene. “They should be wearing masks around crowds and avoiding poorly ventilated indoor places. They need to maintain their flu and COVID vaccination as recommended and stay away from friends and family members who are sick.”