A sexually transmitted infection (STI) that almost disappeared is back — with a vengeance. The medieval STI can silently but significantly increase the risk of heart attack, stroke and dangerous swelling of the aorta, the body’s largest blood vessel, a large new study found. Once nearly eradicated in the 1990s thanks to safer sexual practices, cases of syphilis are on the rise due to decreased condom use, less screening and pandemic-related disruptions in healthcare access. A major STI can silently but significantly increase the risk of heart attack, stroke and dangerous swelling of the aorta, the body’s largest blood vessel. DJ Creative Studio – stock.adobe.com The bacterium Treponema pallidum causes syphilis, which can spread through contact with infectious sores during vaginal, anal or oral sex. The infection progresses through four stages — primary, secondary, latent and tertiary — if it’s not treated with antibiotics.…