reprodUCtIVe systeMs 323the only people who are not at risk of stds are those who
are celibate (never have sex) or who are in a long-term,
mutually monogamous relationship in which both partners
are disease-free. the following guidelines can help you
minimize your risk of acquiring or spreading an std.
- Use a latex condom during either genital or oral sex
to greatly reduce your risk of being exposed to hIV,
gonorrhea, herpes, and other diseases. with the
condom, use a spermicide that contains nonoxynol-9,
which may help kill virus particles. Condoms are
available for men and women. - limit yourself to one partner who also has sex only
with you. - Get to know a prospective partner before you have sex.
a friendly but frank discussion of your sexual histories,
including any previous exposure to an std, is very helpful. - If you decide to become sexually intimate, be alert to
the presence of sores, a discharge, or any other sign of
possible trouble in your partner’s genital area.
Parasites cause some STDs
Several animal parasites can be transmitted by close body
contact. One is pubic lice, also called crab lice or simply
“crabs” (Figure 16.19A). These tiny relatives of spiders usu-
ally turn up in the pubic hair, although they can make their
way to any hairy spot on the body. They cling to hairs and
attach their small, whitish eggs (“nits”) to the base of the
hair shaft. Itching and irritation can be intense when the
parasites bite into the skin and suck blood. Anti parasitic
drugs get rid of pubic lice.
Many microorganisms may live inside the vagina,
although its rather acidic pH usually keeps pathogens
in check. When certain vaginal infections do occur, they
can be transmitted to a sex partner during intercourse.
Any factor that alters the vagina’s usual chemistry (such
as taking an antibiotic) can trigger overgrowth of Candida
albicans, a type of yeast (a fungus) that often lives in the
vagina. A vaginal yeast infection, or candidiasis, causes a
“cottage cheesy” discharge and itching and irritation of the
vulva. A male may notice itching, redness, and flaky skin
on his penis. Yeast infections are easily treated by over-the-
counter and prescription medications, but both partners
may need to be treated to prevent reinfection.
Trichomonas vaginalis, a protozoan parasite (Figure
16.19B), can cause the severe vaginal inflammation called
trichomoniasis. The symptoms include a foul-smelling
vaginal discharge and burning and itching of the vulva.
An infected male may experience painful urination and
have a discharge from the penis, both due to an inflamed
urethra. Usually both partners are treated with antibiotics.
Figure 16.19 Animal parasites also cause STDs. A A crab
louse, magnified 120 times. Crab lice may be visible as moving
brownish dots. B The protozoan Trichomonas vaginalis, which
causes trichomoniasis.eight steps to safer sex
A
E. Gray/Science SourceGetty Images- avoid abusing alcohol and drugs.
studies show that alcohol and
drug abuse both are correlated
with unsafe sex practices. - learn about and be alert for
symptoms of stds. If you have
reason to think you have been
exposed, abstain from sex until
a medical checkup rules out
any problems. self-treatment
won’t help. see a doctor or visit
a clinic. - take all prescribed medication and don’t share it with
a partner. Unless both of you take a full course of
medication, your chances of reinfection will be great.
your partner may need to be treated even if he or she
does not have symptoms. - If you do become exposed to an std, avoid sex until
medical tests confirm that you are not infected.
16.11
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