A wave of viral activity — not all of it influenza — is sweeping across the region, posing early winter threats to just about everyone, and particularly those with weakened immunity.
“We’re seeing some of everything: rhinovirus, adenovirus, parainfluenza virus, influenza A and B — a whole pool of respiratory viruses,” said Dr. Gary Leonardi, a virologist at Nassau University Medical Center in East Meadow.
Respiratory syncytial virus, or RSV, began appearing on Long Island around the first week of November, Leonardi said, and there is evidence it already has reached epidemic proportions in New York City.
That virus commonly spreads among children during winter months and can be a menace in nursing homes.
Winter is when respiratory viruses flourish, Leonardi noted, although some — such as rhinoviruses and adenoviruses, causes of the common cold — can trigger infections year-round. They become more prevalent when temperatures dip, he said.
“Right now, we’re seeing respiratory viruses circulating with increasing intensity, and when it comes to rhinoviruses there are 30 or 40 strains,” Leonardi said. “So when people get sick, it’s not always the flu.”
Parainfluenza virus — despite its name — isn’t the flu, either.
It has four distinct viral strains and generally begins its activity in autumn. One strain tends to produce more cases in odd-numbered years, according to the Centers for Disease Control and Prevention. The infection causes a loud, barking cough, often referred to as croup.
Viruses are infectious agents that are neither living nor dead and propagate themselves by hijacking their host’s DNA. Among those in circulation now, influenza viruses are the ones with reputations for outbreaks in schools and workplaces. They also are noteworthy causes of hospitalizations, usually for pneumonia.
During the 2015-16 flu season, the most recent for complete statistical data, an estimated 310,000 people were admitted to hospitals nationwide because of the infection, according to data from the CDC.
Leonardi’s lab both examines NUMC patient samples for viruses that cause respiratory symptoms, and uses those samples to identify seasonal viruses circulating on Long Island for the National Respiratory Enteric Viral Surveillance System, a program of the CDC.
The national surveillance system monitors the geographic circulation patterns of numerous human viral pathogens, including RSV, human parainfluenza viruses and human metapneumovirus, a relative newcomer that was first identified in 2001.
Viral agents isolated among patients at NUMC, a large institution with a diverse patient population, are illustrative of the types of viruses causing infections in the region, Leonardi said.
He added that it is important to monitor circulating viruses at both the local and national levels because it keeps health officials apprised of trends in infectious respiratory diseases.
Viruses circulate through populations in countless chains of coughing, sneezing, touching contaminated objects, and even shaking hands. Aside from inoculations against the flu, there are no vaccines or medications for many of the bugs on the move in winter.
“That’s why it’s so important to wash your hands, because you inadvertently touch your nose or mouth and many of these viruses are spread through droplets,” he said of secretions that can taint unwashed hands and surfaces.
Door knobs, keyboards, telephones, public restroom faucets and a wide range of commonly touched items can serve as vectors of infection. Simple modes of transmission, he said, can result in waves of viral spread.
Although Leonardi has seen an uptick in RSV in recent weeks, he is not calling the trend an epidemic.
“Epidemic is a scary word,” Leonardi said.
The word, however, doesn’t frighten Dr. Deborah Friedman, a specialist in pediatric intensive care and a professor of pediatrics at New York Medical College in Westchester County.
Friedman also is a spokeswoman for a consortium of hospital labs that monitor RSV statewide. She said the viral infection has reached epidemic levels elsewhere in New York, and because viruses are unpredictable, it is anyone’s guess where the infectious agent will next cause outbreaks.
“The epidemic at the current time is in New York City. Of course, these things change quickly. So we can assume that the epidemic will be spreading,” said Friedman, who is part of RSVAlert. The service relies on information from 23 laboratories throughout the state known as the Core Based Statistical Group. No Long Island hospitals are in the consortium.
“RSV is a very common infection and very contagious,” Friedman said. “It’s not unusual to catch it. In fact, almost all children have had an RSV infection by the time they are 2.” Federal scientists are working on a vaccine.
In its early stages, the infection is not easily distinguished from the common cold, but usually causes an infection deeper in the lungs than the common cold’s adeno- and rhinoviruses. Clogged nasal passages, congested cough and other upper respiratory symptoms are hallmarks of those pathogens.
RSV symptoms include a dry cough and low-grade fever, but more serious, occasionally life-threatening RSV infections have affected children born prematurely, or those whose health was compromised by other medical conditions.
“Babies who have serious heart disease or serious lung conditions are the ones who are hospitalized,” Friedman said.
Dr. Roy Steigbigel, an infectious disease specialist who holds the title of Distinguished Service Professor at Stony Brook University School of Medicine, said without molecular tests to reveal a pathogen’s biological signature, it’s not easy to say which wintertime virus is infecting a patient.
“Clinically it is not that easy to differentiate them,” Steigbigel said, because they all produce similar symptoms, at least initially. “We need the [laboratory] data, and without it, there’s no way to be certain. That’s why so many people get a diagnosis of a flu-like infection.”