Viruses and Health: Not all bad?

In medicine, especially in pediatrics, we tend to treat all viruses as if they’re all bad, all the time.  Might we be treating "illnesses" that are actually beneficial to their hosts?

The most common reasons for visits to pediatrician’s offices are all related to viral infections.  Colds, coughs, ear infections, fevers – an overwhelming percentage are viral.  The bulk of after-hours phone calls I get are also along these lines.  Parents are panicked about infections.  And why not?  When you read in the news about flesh-eating strep or staph infections (MRSA), deaths from flu, hospitalizations from rotavirus – how could a parent not freak out?  Our society has developed a veritable army of over-the-counter and prescription soldiers to fight the evil viruses that lurk among us.  I’m playing this up, of course, and I do understand that viral infections can contribute to serious illness, including cancer and neurological disability.  However, reports today on the harm of viral TREATMENTS got me to thinking – is the cure worse than the cause?  And are some viral infections actually good for us?

From the FDA MedWatch:

1. Long-Acting Hydrocodone-Containing Cough Product (marketed as Tussionex Pennkinetic Extended-Release Suspension)

[Posted 03/11/2008] FDA informed healthcare professionals of
life-threatening adverse events and death in patients, including
children, who have received Tussionex Pennkinetic Extended-Release
Suspension (Tussionex). Tussionex is
contraindicated for use in patients less than 6 years of age because of
their susceptibility to life-threatening and fatal respiratory
depression.

2. Tamiflu (oseltamivir phosphate)

[Posted 03/04/2008, UPDATED 03/04/2008] Roche and FDA informed
healthcare professionals of neuropsychiatric events associated with the
use of Tamiflu, in patients with influenza.The label has been revised
as follows: Influenza can be associated with a variety of neurologic
and behavioral symptoms which can include events such as
hallucinations, delirium, and abnormal behavior, in some cases
resulting in fatal outcomes.

So, a medication prescribed for colds and coughs can be fatal, and an anti-flu medication is associated with severe neurological adverse effects, including death.  Clearly, in these cases, the treatment is worse than the disease.  This is one of the lessons in "treating" childhood illness – and for all of medicine – first, do no harm – right?  Yes, these illnesses can be uncomfortable or even severe.  But in the vast majority of cases, children, when left to their own devices, heal quite nicely. 

And might some viruses actually be better left alone? 

Researchers at Washington University / St. Louis reported these findings last year:
      

ST. LOUIS . – Mice with chronic herpes virus infections can better
resist the bacterium that causes plague and a bacterium that causes one
kind of food poisoning, researchers report in this week’s Nature.

Scientists at Washington University School of Medicine in St. Louis
attributed the surprising finding to changes in the immune system
triggered by the long-term presence of a latent herpes virus infection.
In latent viral infections, the virus is present for the lifetime of
the host in a relatively quiescent form that does not cause overt
symptoms.

While presenting their results, researchers
stressed that they did not want to minimize or in any way disregard the
human suffering and health risks caused by disease-causing herpes
infections. But they noted that several strains of herpes viruses found
in much of the human population remain symptom-free throughout the
host’s lifetime.

"Our results suggest that we should look at whether humans receive
similar advantages from these and other chronic infections that do not
cause active disease," says senior author Herbert W. "Skip" Virgin,
M.D., Ph.D., head of the Department of Pathology and Immunology. "If
so, that has public health implications because we would want to very
carefully weigh the risks and benefits of eliminating a virus that our
bodies have established a symbiotic relationship with."

And from Johns Hopkins:

PHILADELPHIA — Researchers have found a way to activate Epstein-Barr
viruses inside tumors as a way to identify patients whose infection can
then be manipulated to destroy their tumors. They say this strategy
could offer a novel way of treating many cancers associated with
Epstein-Barr, including at least four different types of lymphoma and
nasopharyngeal and gastric cancers.

In both of these cases, it appears that viral infections may indeed confer some sort of protection or health benefit to the host.  Is this true in all circumstances?  Of course not.  But the converse – that these viruses are always a health threat in all people, is equally unlikely.  It behooves us to be very, very careful when considering eradicating viruses from our bodies, particularly when the cure is potentially worse than the infection.