There is no evidence of increased rates of health-care-associated infections related to the wearing of neckties by health care professionals. There is weak evidence that neckties are contaminated with pathogenic (and nonpathogenic) bacteria.

Do neckties carry germs?

May 24, 2004 -- Dry clean frequently: Nearly half of all doctors' neckties carry disease-causing bacteria, a new study shows. They could spread infection among patients. It's a wake-up call for doctors and other medical personnel. While wearing a tie looks professional, frequent cleaning should be standard practice.

Are ties unsanitary?

Ties, however, “have been shown to be contaminated by pathogens…they are rarely laundered and play no part in patient care [2]” according to the United Kingdom Department of Health. As medical policy is primarily driven by evidence, studies have recently been performed to determine if neckties are dangerous fomites.