How do mumps cause infertility?

Mumps & Fertility. The mumps virus infects the salivary and parotid glands in the mouth. About 20% of pubertal boys or men will also get a very painful mumps infection in the testicles, called mumps orchitis. The virus can destroy the testicular tissue leading to infertility and low testosterone levels. The mumps vaccine has been available since 1967 and is recommended for just about everyone.
Testicular Infection. Mumps may infect the testes for some reason. The inflammation resulting may cause permanant damage to the tissue affecting sperm production. Another reason to immunize.