Many parents of young children are aware of a virus called RSV, and the word being circulated is that this is a dangerous virus, now very widespread.

Is it dangerous?  Is it widespread?

And why is this winter disease happening in the summer?

To answer these urgent questions, we take a look at the RSV epidemic happening now, a winter epidemic in the middle of summer.

What is RSV?

At its most essential, RSV is the common cold.   As most know, common colds are infections caused by viruses, the common cold viruses.  All these viruses cause the same pattern of basic symptoms- runny nose, sore throat, and cough, with fevers and aches and malaise.

There are actually many viruses that cause the common cold, because any virus that attacks the nose, throat, and lungs, causes the same problems from our nose getting runny, our throat hurting and our sore lungs coughing.

Take a look at this list of viruses that can cause the common cold:

• Rhinovirus
• The old coronaviruses (they are mostly about 8,000! years old), not COVID
• RSV
• Influenza viruses
• Parainfluenza viruses
• Adenoviruses
• and others

We won’t talk about all the viruses that cause the common cold, but we will note that 3 of them cause the vast majority of our colds.  Rhinoviruses are THE common cold virus, causing more than the other, but the old coronaviruses and RSV cause most of the rest.

So, to our question, what is RSV?

RSV stands for a very technical term:

Respiratory

Syncytial

Virus

The Respiratory and Virus words make sense, after all it cause so many colds, it is obvious it is a respiratory virus.  But what about Syncytial?  This word simply means that if the virus infects dozens of cells lining your nose or throat or lung, it will merge those cells.   The word syncytium simply means merged cells.  This helped doctors determine if RSV was present before we could detect its signature proteins, just look at a swab of nasal or throat cells under the microscope and see if the cells lining the nose or throat had been merged.

The merger itself is not too important, no matter the virus, any on that above list will do, viruses destroy the cells it infects.  Whether it merges the cells first or not doesn’t matter, once the virus makes a zillion copies and pops the cells, those cells are gone.

In sum, RSV is one of the 3 most common viruses that cause the common cold.

When does RSV attack us?

For most of recorded history, RSV has been a seasonal attacker, only appearing in the US in the winter, showing up in the fall, disappearing in the spring, peaking in the winter.  We almost have never seen RSV in the summer.

In that way, it is very much like the influenza virus, which appears every winter too and is almost never seen in the summer.  The influenza virus this summer is totally absent, as it always is.

But not RSV, it raging across our community, and has for all this summer.  Seeing RSV raging in the summer is like seeing tulips bloom through the ice of January.  It never happens.  If you saw tulips blooming in the dark frozen depths of winter you would stop and wonder.  It is very, very strange.

The appearance of a full epidemic of RSV in summer is indeed very, very strange.  No one knows how this happened.  But here are some thoughts

First, no one knows how viruses, the tiniest forms of life, manage to appear and disappear in regular rhythm across years for centuries, right on time every year.  Again, take the influenza virus.  Around Ohio, it appears every December and disappears every April, every year, like clockwork.  Every year.   That means in June, no states have large cases of influenza.  But in December, the virus appears suddenly in every state.  How does a virus appear across continents within a few weeks, at the same time, every year, and then fully disappear across continents in a few weeks, at the same time, every year?  No one has any idea, but I find it one of the most interesting phenomena of life.

Second, the regular sequence of all respiratory viruses the winter of 2020-21 was dramatically disrupted.  The measures we took to stop COVID failed, but those same measures succeeded in doing something never done before- they stopped the transmission of all those common cold viruses on that list.  For the first time in over 10,000 years, we had no winter influenza epidemic, we had no RSV epidemic, we had no (old) coronavirus epidemic this winter.  We had no common cold epidemics this winter!  It is astounding!!

Third, since this sort of global interruption of the movement of winter seasonal cold viruses has never happened before in recorded history, we have NO idea how that will change the pattern of how these viruses travel in and out of continents going forward.  For example, no one knows how the influenza, the flu, epidemic of this winter will run.  We do have one surprise in hand, the winter in summer epidemic of RSV we are living through right now.

Is RSV a virus or disease, how bad is it to get RSV?

The main point to keep in mind here is that RSV is not a disease, it is a virus, the name of a particular species of viruses.

Take a look at that list of viruses that cause common colds above.  Each and every one of them can cause mild colds and each and every one of them can cause severe respiratory illnesses.

What matters most to me, and to you, is whether your child’s respiratory viral infection is mild or severe, not the name of the virus.

Say I tested your child for RSV when they felt perfectly well and it came back positive, it would not change the fact that they feel fine, and would not predict they would get very ill at all.  It simply means a virus called RSV is in their nose or throat, that is all.

Now on that list, it is fair to say that the RSVs and the influenza viruses do cause severe respiratory illnesses more often than the others, but all of them do.  So should your child ever be tested for RSV and come out positive, please keep in mind that the only thing that matters at that moment is how bad their infection is.  If they have RSV and are only experiencing a bit of a sniffle and a mild cough, then there is nothing to worry about.

Of course, if a child has RSV and is severely ill, that is a great cause for concern, but so it is if they are severely ill with rhinovirus, influenza virus, or any other viral infection.

Is there a vaccine for RSV?

No, and none are in sight.  RSV turns out to be like strep in that both can happen over and over and over again.  Many people never really develop good immunity after infection with either germ, so it makes it hard for a vaccine to be created that would offer immunity.

How long are you contagious if you have RSV?

All cold viruses are contagious, otherwise we could never catch them.

RSV is typically contagious for a week, but in one group that gets a lot of RSV, infants, the virus can be contagious for a month.

What are the best practices for isolation and quarantine for RSV?

Except in unusual circumstances, such as very severe disease or the exposure of someone with significant medical fragility, none.

Prior to COVID we never isolated people in the general population with colds, RSV or otherwise.  We never did for 2 very good reasons that remain compelling today:

1. For most colds, and clearly for infants with RSV, you are contagious for 3-4 weeks.  It is simply impossible to quarantine for a month for every cold.
2. Cold viruses, including RSV, are nearly universal.  Short of the sort of population wide lockdown we had the spring of 2020, cold viruses, including RSV just are too widespread to stop the spread.  Nearly everyone gets colds, so if you isolate or quarantine your child for a cold for the whole time they are contagious, you will likely have no impact.  The only path to stop the spread is for an entire population to isolate, which we hopefully will not be doing too frequently.

Bottom Lines

1. RSV is the name of a species of virus, it is not an illness.
2. RSV is one of many viruses that cause common colds, ear infections, wheezy bronchiolitis, viral pneumonias, the full range of respiratory viral infections.
3. RSV, like all cold viruses, can cause mild cold symptoms, or every severe respiratory infections.  Therefore, what really matters when your child has a cold is how sick they are, not the name of the virus.
4. If your child is ever diagnosed with or exposed to RSV, the only question that matters is how sick they are.  If not very ill, or not ill at all, all is well, no worries.  RSV tends to cause mild illness.  But RSV is also well known for making many kids more severely ill, and severe illness is always cause for concern and medical attention.
5. RSV is contagious, typically for a week, but in young children for a month.
6. We do not isolate or quarantine for colds or viral respiratory infections, with the exception of COVID.  Because, with the exception of COVID, cold viruses are everywhere, typically cause little harm over time, and remain contagious for as long as a month.

One Sentence TAKEAWAY:  We are experiencing winter-time RSV in the summer, be sure to keep all attention on how ill your child is, not the name of the virus, when it comes to RSV

To your health,
Dr. Arthur Lavin