The Skinny on STIs and Male Infertility
How many sexually transmitted infections (STIs) are there right
now in the U.S.? Believe it or not, 110,000,000! That’s double the number
of folks that get the flu each year. Talk about an epidemic! Not only that,
but 20,000,000 new STIs are diagnosed each year. Fully half of these
infections occur in 15- to 24-year-olds.
Unfortunately, most studies examining STIs and fertility
focus on females and not males. But there is some knowledge about how STIs
impact the fertility
potential of men. Might be good to know which ones can impair male
fertility, don’tcha think?
What Goes Around
A dozen or more STIs are known. Their incidence varies
widely by geographic area. In the U.S., 8 common STIs and 2 rare, episodic ones
merit discussion. Among them, 4 are caused by bacteria and are curable, 1 is a
parasite (also curable) and 5 are viruses that aren’t curable but are
controllable. Here are the Top 10 pesky little bugs.
Top 10 STIs in the U.S.
- HPV (human papilloma virus or condyloma; 14
million new cases annually). Alternatively called “venereal warts,” they are
associated with cervical and penile cancers, but not male infertility. A
preventative vaccine is available for teenagers.
- Chlamydia trachomatis (2.8 million cases).
In women, chlamydia infections can block tubes and cause infertility. In men,
blockages have not been demonstrated, but many studies show impaired sperm
motility and DNA fragmentation either due to inflammation or
- Trichomonas vaginalis (1.1 million cases)
has no proven association with male fertility but this flagellated parasite has
been linked to lower sperm motility. Treatable with antibiotics.
- Gonorrhea (820,000 cases) is a bacterial
infection that causes nasty urethritis and potentially epididymitis which
could lead to interruption or blockage
of sperm flow during ejaculation and result in male sterility.
- Herpes simplex virus (HSV, 776,000 cases)
causes painful genital pimples but has no well described association with male
infertility. Its effect on developing babies in infected mothers is profound,
- Syphilis (55,400 cases). Early infections are
marked by genital ulcers followed by neurological symptoms if untreated. Before
the age of antibiotics, it was a common cause of dementia. There is no reported
toxic effect of syphilis on sperm, but if untreated, infertility can result
from inflammation, scarring and blockage of
the epididymis and testis.
- HIV (41,400 cases) is associated with
reduced semen quality and male infertility, but really only if the infection
progresses to the point of weight loss and immunodeficiency.
- Ureaplasma urealyticum and Mycoplasma (common)
are tiny bacteria that cling to sperm and may impair sperm motility and function.
They are typically found in <1% of asymptomatic infertile men.
- Zika virus (rare) can be transmitted
sexually during epidemics with devastating effects on fetal development but no
clear effects on male fertility. However, Zika-infected male mice have been
shown to be vulnerable to testicular infections and sterility.
- Ebola virus (very rare) is transmitted
sexually and that can cause problems much worse than fertility, including
So, that’s the scoop on STIs and male infertility. Some are feared
and others simply frightening. Remember, you and your partners carry your
entire sexual history with you during every encounter. The best way to prevent
this cause of male infertility is to practice safe sex. Every time. Treatment
is good, but prevention is ideal.
This article first appeared on Dr. Turek’s blog.