A common parasite can decapitate human sperm − with implications for male fertility

Male fertility rates have been plummeting over the past half-century. An analysis from 1992 noted a steady decrease in sperm counts and quality since the 1940s. A more recent study found that male infertility rates increased nearly 80% from 1990 to 2019. The reasons driving this trend remain a mystery, but frequently cited culprits include obesity, poor diet and environmental toxins.

Infectious diseases such as gonorrhea or chlamydia are often overlooked factors that affect fertility…