Recent months have seen numerous schools across the country closed due to norovirus outbreaks. Often referred to as the “stomach flu,” norovirus causes watery diarrhea, mild fever, and projectile vomiting, which is highly effective for spreading the virus.
Norovirus is highly contagious and spreads rapidly in confined spaces, such as schools or cruise ships. While most people recover within 24 to 48 hours, it is a significant cause of childhood illness. Tragically, in developing countries, it claims nearly 50,000 child lives annually.
Interestingly, not all individuals are equally susceptible to norovirus. Your blood type plays a crucial role in determining whether you will fall ill.
Why is Norovirus So Challenging to Eliminate?
As a microbiologist, I personally experienced a norovirus outbreak on a rafting trip down the Grand Canyon. The lack of proper sanitation facilities made the situation more difficult. Despite everyone recovering within a few days, it highlighted the resilience of norovirus.
Norovirus is resistant to common disinfectants and can survive over a wide range of temperatures, from freezing to 145 degrees Fahrenheit, the highest temperature in a typical dishwasher. It can remain on human hands and surfaces for days, posing a constant threat of spreading.
The Influence of Blood Type on Norovirus Infection
When norovirus is ingested, it attaches to and infects cells lining the small intestine. The ability to do this depends on the specific sugars, or oligosaccharides, present on the surface of these cells—a pattern largely determined by your blood type.
Blood types are categorized as A, B, AB, or O, each defined by the presence or absence of certain oligosaccharide structures on red blood cells. These same structures also appear on intestinal cells, which norovirus uses to latch onto and infect cells.
Notably, the presence of the H1-antigen is essential for the attachment of many norovirus strains. Individuals lacking this antigen, which comprises about 20% of the European-derived population, show resistance to many strains of norovirus.
Blood type can further modify the binding capabilities of norovirus. People with A, AB, and O blood types can attach additional sugars to their H1-antigen, potentially increasing susceptibility to certain strains.
