When you get the classic signs of a flu or cold—like a runny nose, sore throat, and fatigue—it’s easy to assume that's what you have. But there’s another virus out there that can cause also cause these symptoms: It’s called respiratory syncytial virus (RSV), and even if you've never heard of it before, there's a very good chance that you’ve actually had it in the past.
The virus is a common cause of illness in children—in fact, most children will have had an RSV infection by their second birthday, per the Centers for Disease Control and Prevention (CDC)—but it can affect people of all ages. And it’s possible for you to have had it without realizing it.
As with a mild cold or flu, respiratory syncytial virus symptoms usually include a runny nose, decrease in appetite, coughing, sneezing, fever, and wheezing, the CDC says. So, it can be tough to distinguish RSV from other upper respiratory infections at first glance. And, like those other illnesses, RSV can spread when an infected person coughs or sneezes. You can also get it from kissing the face of a child who has RSV.
Because of the overlap with the flu in both symptoms and timing, your doctor (or your child's) will have to be careful when figuring out a diagnosis.
RSV cases tend to spike at a certain times of year depending on where you live, and RSV season usually overlaps with flu season. For example, in 2016, RSV season started around mid-September to mid-November in various parts of the country, peaked anywhere from late December to mid-February 2017, and tapered off around mid-April to mid-May, according to CDC data.
If your doctor suspects that you have RSV, they’ll likely do an exam to check you for wheezing or other signs of lung irritation, the Mayo Clinic says. Still, that’s usually not enough to give you a proper diagnosis. "Just looking at a patient, you can't tell if they have the flu or RSV," William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells SELF.
That’s why your doctor will likely swab the inside of your mouth or nose to check for signs of the virus (and rule out something else, such as the flu), infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security, tells SELF. Sometimes you might also need a blood test to help rule out other disease or a chest X-ray to check for lung inflammation, the Mayo Clinic says.
Most people are able to recover from an RSV infection in a week or two, although some people may have more severe symptoms.
If you or your child has been diagnosed with RSV but seem otherwise OK, your doctor will likely recommend supportive care like over-the-counter pain and fever reducers, saline drops to help clear a stuffy nose, and drinking plenty of fluids, the Mayo Clinic says.
But RSV can also cause more severe infections, such as bronchiolitis (an inflammation of the small airways in the lungs) and pneumonia (an infection of the lungs). And young children, premature babies, the elderly, those with compromised immune systems, and those with other underlying health conditions are at a higher risk for these types of complications.
The link between RSV and bronchiolitis is especially strong, Daniel Ganjian, M.D., a pediatrician at Providence Saint John’s Health Center in Santa Monica, Calif., tells SELF. "Any child I see with bronchiolitis, I automatically test them for RSV," he says.
In more severe cases, a patient may be hospitalized for a few days if they’re having trouble breathing or are dehydrated, the CDC says. They may also need additional oxygen or even a breathing tube inserted and mechanical ventilation to make it easier for them to breathe.
Unfortunately, there isn’t a vaccine to protect against RSV, Dr. Adalja says. And, like the common cold, there’s only so much you can do to avoid it.
The virus can survive for several hours on hard surfaces like tables, doorknobs, and crib rails, the CDC says. So, you want to do your best to keep those areas clean, especially if someone in your home has been sneezing or coughing lately.
If you have a young child at home, a premature baby, or a child with a weakened immune system, ask people to stay away if they have cold- or flu-like symptoms, the CDC says. Otherwise, you’ll just want to do your best to avoid close contact with sick people, wash your hands often with soap and water, and avoid touching your face with unwashed hands.
There is a drug called palivizumab, which is a type of antibody, that may help prevent severe RSV illness in high-risk babies and children, like those who were born prematurely, have a congenital heart disease, or chronic lung disease, Dr. Adalja says. However, it can’t totally prevent RSV, or cure or treat children who already have it.
If your child has a cough but they seem otherwise fine and aren’t at a high risk for RSV complications, you’re probably OK to ride it out, Dr. Ganjian says. But if they’re not eating and drinking normally, their nostrils are flaring when they breathe, or they’re breathing faster than usual, it’s a good idea to get checked out by a doctor ASAP. And if you're having trouble breathing and it's not getting better, you should call your doctor, Dr. Schaffner says.
While RSV isn't well known to most people right now, that should change in the future. "Companies are working on better diagnostics for RSV, as well as better therapies and an RSV vaccine," Dr. Schaffner says. "This is going to be an important topic in the future."