Those who have followed my commentary on this winter’s epidemic of influenza virus infections in Real Answers know that for a truly vast majority of children who get infections with the influenza virus, the illness is mild.  Well over 99% of children who get infected with this virus recover without needing a stay in the hospital.  There are deaths, but the chance of that happening approaches one in a million.

Just this month, the leading journal of pediatric medicine, the AAP’s flagship journal, Pediatrics, published a detailed analysis of these rare, but infinitely tragic deaths.   http://pediatrics.aappublications.org/content/141/4/e20174313?etoc=

I thought it would be helpful to share what we have learned.  The bottom line, which I will mention up front, is that many of these deaths could have been prevented by the flu shot.

A Reminder on What is Influenza?

The confusion around the word flu is so deep, it is worth reminding everyone that there are two meanings to the word flu.

One has to do with being sick.  If someone has a mild viral respiratory infection, we typically say they have a cold.  If the illness is perceived as very nasty, we typically say they have the flu.  This has nothing to do with the species of virus causing the cold or flu.  Many, many species of virus cause the exact same range of respiratory illnesses.  One is indeed the influenza virus (typically only between December and April).  But there are many others:  RSV, rhinovirus, adenovirus, parainfluenza virus, you get the idea.

What we are talking about here is one species of virus, the influenza virus, the one that comes around December and leaves around April every year.   And this posting will go over the very tragic loss of life this one species of virus causes every winter.

How can the Influenza Virus Cause a Death?

Again, death from an infection with this virus is exceedingly rare in children, it happens about one in a million infections.  That makes this infection actually relatively safe compared to others.  To put it into perspective, bacterial meningitis causes death in 1 in 5-10 of those children infected.  The difference between 1 in 5 and 1 in a million is quite vast.

In the case of influenza, it appears that many of the deaths occur when the viral infection is compounded with another serious virus, such as RSV, or even more ominously, with an overwhelming bacterial infection, typically a staph or strep pneumonia.

This happens because all viral respiratory infections, including those from the influenza virus, make us sick by damaging the lining of our respiratory tissues, the tissues of our body that touch air.  These include the nose, throat, voice box, and lungs, and the surface of our eyes.  When a virus infects these linings, it literally burns off some of that lining, causing all the redness, swelling, and mucus production that make a cold a cold.  Look at the next pink eye you see, that is a viral infection made visible, and that redness and wateriness and mucus is what can be seen in the nose, throat, and lung with a cold.

When that lining gets burned, it opens the door to other germs.  Very, very fortunately, the body defends against this very, very well.  But in that one in a million instance, the dangerous bacteria get a foothold in the lung and cause an overwhelming pneumonia.

This is not such a rare event in the elderly.  Across the United States, a range of 12,000-60,000 people die every year from influenza virus infection.  Of that total, about 100-150 of these deaths are children, a very small number of the total.  Most of the thousands the virus kills are over age 65, the actual proportion is as much as 80%!

Characteristics of Deaths by Influenza Virus Infection in Children

The first characteristic is the overwhelming tragedy of such a loss.   Any such death is unbearable, to have this happen from an infection that causes so few deaths must make the enormity of the loss even greater.

The most striking characteristic of the 100-150 deaths by influenza virus every winter in childhood is that about half of these children were otherwise healthy, and 70% of them all did not get a flu shot.  It was also found that in the US only about 1/3 of pregnant women get the flu shot, and the authors believe the data establish that if a pregnant woman gets immunized, her infant will be less likely to get very ill from the influenza virus the winter after their birth.

What Can We Do to Drop the Number of Deaths in Childhood from the Influenza Virus

The authors of the review make it clear that if we want that number of 100-150 to go down there are some steps our nation can take that will do that:

1. Increase the number of children who get the flu shot.  Every child over 6 months able to get a flu shot should get one. This is the one step most likely to drop that 100-150 number.
2. Increase the number of pregnant women who get the flu shot.  This will protect very young infants from serious influenza virus infections.
3. Anyone with a cold, including all children, who develop signs their cold is no longer just a cold, should be seen and treated if a bacterial infection has begun.  The clearest signs this has happened are:  sudden worsening of the illness, pain, and trouble breathing when not coughing.  Fever itself, and yellow and green mucus, are not signs that a pneumonia has started, fever and colorful mucus are seen in the vast majority of all simple viral colds.
4. Tamiflu remains a bad idea for otherwise healthy children with influenza virus infection that does not require a stay in the hospital.  But for very ill children, and those hospitalized for this infection, even the tiny bit of benefit from Tamiflu may prove helpful and the considerable risks of its use reasonable.

BOTTOM LINES

1. The influenza virus can lead to serious illness, even death, but about 99.6% of these deaths are in older people, not children, thankfully.  
2.  The number of deaths from the influenza virus in childhood is about 100-150 or so every winter, for the typical seasonal influenza virus epidemics.  This makes death an extremely unlikely event, again thankfully, in childhood.  That chance is about 1 in a million, a rare event indeed.
3. Although very rare, there are things to do to make it rarer.  The top action that would drop the chance of tragedy is to make sure every child and pregnant woman gets a flu vaccine.  About 70% of children who die of this virus are not immunized for it.  Flu shots would clearly drop this number.
4. We need to end this disturbing post with a reminder, once again, that the influenza virus is a relatively very safe infection, the ultimate tragedy of death from its infections is very, very rare in childhood.

To your health!
Dr. Arthur Lavin