People with Type O blood are twice as likely to be bitten by mosquitoes as those with Type A.

A landmark study published in the Journal of Medical Entomology by researcher Yoshikazu Shirai and his team at the Institute of Pest Control Technology in Chiba, Japan, examined the landing preferences of Aedes albopictus, commonly known as the Asian tiger mosquito. The researchers found that mosquitoes landed on Type O individuals nearly twice as often as they did on Type A individuals. This preference is linked to the specific saccharides or sugars that different blood types secrete through the skin and sweat.About 80% of the human population are classified as 'secretors.' These individuals possess a specific gene that allows them to broadcast their ABO blood type antigens through bodily fluids like saliva and perspiration. Mosquitoes use highly sensitive olfactory receptors to detect these chemical markers from distances of up to 100 feet. For a mosquito, these signals serve as a reliable indicator of the nutritional quality of the host's blood.While Type O is the clear favorite, Type B blood falls in the middle of the spectrum regarding attractiveness. Beyond blood type, other factors like carbon dioxide output, body temperature, and the presence of lactic acid also play significant roles in how mosquitoes choose their victims. However, when all other variables are equal, the chemical signature of Type O blood remains a primary attractant for several mosquito species. This evolutionary preference helps the insects identify the most efficient meal for egg production.