Michelle Varela, of Roosevelt, and Margarita Sanchez, of Brentwood, discuss...

Michelle Varela, of Roosevelt, and Margarita Sanchez, of Brentwood, discuss COVID-19 versus the regular flu on Wednesday in Roberto Clemente Park in Brentwood. Credit: Corey Sipkin

Amid the mass death of the COVID-19 pandemic, experts say there may be an unintended health benefit: The same social-distancing, mask-wearing and other measures aimed at preventing transmission of the coronavirus also may be leading to fewer cases of the flu, the common cold and other contagious illnesses.

Michelle Varela of Roosevelt noticed it in her family.

“The kids before got sick a lot, because they went to school,” Varela, 34, said in Spanish. “There was always a child with a cold, or the change in weather always affected them. But now, no. They haven’t gotten a cold or anything like that.”

There are few statistics on the prevalence of the common cold in the COVID-19 era, because people typically don’t go to the doctor for a cold. But experts said flu-test data indicates COVID-19 precautions are having an effect on influenza.

In the Northern Hemisphere, flu cases typically peak in February and continue through the end of May, but this year the number of lab-confirmed flu cases fell sharply in early April, after much of the world was in some form of a COVID-19-related lockdown, according to a May 21 article in the journal Nature.

“Public-health measures such as movement restrictions, social distancing and increased personal hygiene likely had an effect on decreasing influenza and other respiratory virus transmission,” a World Health Organization statement to Nature said.

The New York State Department of Health had planned to issue weekly flu surveillance reports through May but halted them after April 11 because there were so few new test-confirmed flu cases after an unusually sharp decline in late March and early April, department spokeswoman Jill Montag said in a statement. Social distancing and people staying home were among the likely factors in the drop, she said.

In the Southern Hemisphere, where it is now winter and peak flu season, countries are reporting a huge fall in influenza cases, The Wall Street Journal reported.

Dr. David Hirschwerk, an infectious disease specialist at New Hyde Park-based Northwell Health, said part of the reason for the decline in lab-confirmed flu cases probably is that because of a shortage of swabs and the liquid that test samples are stored in, “We were prioritizing testing for COVID and not always testing for influenza.”

The same swabs and liquids are used for both coronavirus and flu tests, he said.

Dr. Susan Donelan, medical director of health care epidemiology at Stony Brook Medicine, said although it’s unclear how much of the decline was from less flu testing and how much was from fewer actual cases, “There are a whole host of different pathogens that hopefully will be transmitted less readily if people follow the precautions they need to use to avoid the coronavirus.”

A number of bacteria and viruses are “pretty much transmitted by the same face-to-face droplet spread” as the coronavirus, including the common cold, whooping cough and respiratory syncytial virus, a common infection in children under 2, she said. Measures to reduce the spread of the coronavirus, such as covering the nose and mouth, also should help prevent the transmission of other viruses and bacteria, she said.

Brentwood resident Ramon Reina visiting Roberto Clemente Park with his daughter, Elizabeth,...

Brentwood resident Ramon Reina visiting Roberto Clemente Park with his daughter, Elizabeth, on Wednesday. Credit: Corey Sipkin

Ramon Reina, 47, of Brentwood, said in Spanish that he “used to get colds a lot. But I’m not getting them now.” His wife and 11-year-old daughter also haven’t gotten sick since the pandemic began, he said.

“We’ve been inside and keeping our distance,” he said.

Margarita Sanchez, 36, of Brentwood, who has three children, ages 12 to 16, said in Spanish that “by now, someone should have gotten a cold, but no one has. I have all this cold medicine, but we haven’t used it.”

Sanchez said she has been especially vigilant this year to look for cold and flu symptoms, because some also are coronavirus symptoms.

Those similarities mean that when the flu season begins in October, more people likely will be going to their doctors or to COVID-19 test centers seeking a COVID-19 test, including people with mild flu-like symptoms who wouldn't have gone to the doctor in the past, Hirschwerk said. 

“Hopefully if there is an adequate supply of testing, then anyone who develops a respiratory illness really is going to need to think about getting tested for COVID, not just to understand their own situations for themselves individually, but for their families, and for schools and their workplaces,” he said.

That’s why it’s so important to get vaccinated against the flu this year, he said. Social distancing and face coverings, combined with flu vaccines, can reduce the prevalence of the flu and reduce the strain on the health care system from people seeking testing, and from people being hospitalized for the flu or COVID-19, he said.

Between 140,000 and 810,000 Americans have been hospitalized for influenza each year since 2010, with 12,000 to 61,000 annual deaths, according to the U.S. Centers for Disease Control and Prevention.

Experts have been warning for weeks that a second wave of coronavirus infections this fall, combined with the flu season, could overwhelm hospitals.

A flu vaccination “will save a lot of patients from having to be evaluated by their health care provider,” Hirschwerk said.

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