Jan 11, 2013 - Research

Genetic Armor in Flu Season

A sure way to make you more diligent about washing your hands is to read some coverage of what’s turning out to be the worst flu season in recent memory.


A lucky few of us, however, have defenses that go beyond trusty soap and water – our genes. Approximately 30 percent of people with European ancestry and 20 percent of those with African ancestry carry a mutation that gives them extra protection against the most common strains of norovirus.

Norovirus is one of the three flu or flu-like viruses now spreading across the globe during this sick season.

Flu Season

What makes this so bad is what the New York Times describes as “the convergence of three flu or flu-like epidemics” hitting all at once. These three illnesses include an unusually virulent flu virus,  a nasty norovirus, and a whooping cough outbreak that’s as bad as it’s been in 60 years. As the article indicates, this all happens “amid the normal winter highs for the many viruses that cause symptoms on the colds and flu spectrum.” It’s not a pretty picture for those who fret about getting ill.

The Centers for Disease Control (CDC) is a little less breathless in its description of flu season, but officials there are still heralding a warning.

According to the CDC’s Dr. Joe Bresee, “Reports of influenza-like illness (ILI) are nearing what have been peak levels during moderately severe seasons.” The CDC continues to recommend flu shots and antiviral medication when appropriate.

Norovirus Symptoms

So, let’s focus on the norovirus, which is sometimes described as the “stomach flu.” In reality, it isn’t the flu but “viral gastroenteritis.”

This nasty bug is hugely contagious and pretty unpleasant, with symptoms that include abdominal pain, vomiting, and diarrhea. It spreads quickly, especially in close quarters, and can rapidly rip through schools, retirement communities, and hospitals. This latest outbreak is hitting the US right as the flu is spreading. This particular strain hit England a few weeks ago, making more than a million people ill, according to the Guardian.

Genetic Protection

‘Some people may be safer than most during this illness. About 30 percent of people with European ancestry and about 20 percent with African ancestry carry the AA version of SNP rs601338 in the FUT2 gene. These lucky folks need not fear the most common strain of norovirus like the rest of us. They lack the molecules noroviruses use to enter the digestive tract cells.  It doesn’t mean they are bulletproof from getting sick, but they are protected against most norovirus strains. Unfortunately, very few people of Asian ancestry carry the resistant genetic variant.

Whether you belong to the fortunate ones who carry this extra genetic protection or not, it is still a good idea to keep washing your hands. If you haven’t already, you might also consider getting a flu shot if it is available.

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