Encyclopedia of Health and Medicine

gonorrhea 329
may recommend CESAREAN SECTION (surgical delivery)
for women whose infections are active
(symptomatic) near the time of delivery to prevent
this.
Risk Factors and Preventive Measures
Because HSV-2 infection is so prevalent, all sexually
active people are at risk for genital herpes.
Uninfected people who are in monogamous relationships
with uninfected sexual partners have the
lowest risk for infection; uninfected people who
have multiple sexual partners or who are in relationships
with sexual partners who have genital
herpes have the highest risk for infection. At present
the most effective means of prevention among
sexually active adults is abstinence during outbreaks
and barrier protection such as latex condoms
during all sexual activity. Barrier protection
is not absolute, however, as the HSV-2 virus may
infect nerve cells at the skin’s surface that the condom
does not cover.
The antiviral medication valacyclovir significantly
reduces viral shedding, slowing but not
entirely preventing transmission of genital herpes.
This preventive measure is most effective in
monogamous relationships in which one person
has HSV-2 and the other does not. Clinical studies
are under way to evaluate a vaccine for genital
herpes.
See also CHLAMYDIA; COLD SORE; CONTRACEPTION;
GONORRHEA; HUMAN PAPILLOMAVIRUS (HPV); LYMPH
NODE; OCULAR HERPES; SEXUAL HEALTH; SEXUALLY
TRANSMITTED DISEASE (STD) PREVENTION; SEXUALLY
TRANSMITTED DISEASES (STDS); SYPHILIS.
giardiasis An illness resulting from INFECTION
with the protozoan Giardia lamblia (also called Giardia
intestinalis). Giardia are abundant in fresh
water throughout the United States; infection
occurs through drinking contaminated water. The
PROTOZOA infect the SMALL INTESTINE of humans and
animals and can survive for extended periods
without a host. The most common means of infection
is through swallowing water in recreational
settings, such as lakes, rivers, and streams. Fountains,
swimming pools, and hot tubs that lack
proper chlorination also may harbor Giardia. Giardiasis
also spreads through fecal contamination by
direct contact, such as by changing diapers, and
can occur as a FOODBORNE ILLNESS spread through
poor FOOD SAFETY practices.
Symptoms develop after an incubation period
of 7 to 10 days and include DIARRHEA, excessive
FLATULENCE (gas), abdominal discomfort, and NAU-
SEA. The diarrhea is watery and has a greasy
appearance. Some people also experience fatigue,
loss of APPETITE, and rapid weight loss. It is also
possible to have giardiasis and have no symptoms.
Stool samples examined under the microscope
typically contain both cysts and trophozoites, the
immature and mature forms, respectively, of the
Giardia. Treatment is ANTIBIOTIC MEDICATIONS and
ANTIFUNGAL MEDICATIONS. The course of illness runs
four to six weeks with treatment, after which
most people recover without complications or
residual consequences. Without treatment giardiasis
may persist for six to eight weeks, with gradual
though complete recovery.
MEDICATIONS TO TREAT GIARDIASIS
albendazole
furazolidone
metronidazole
nitazoxanide
paromomycin
tinidazole
See also AMEBIASIS; BABESIOSIS; DRINKING WATER
STANDARDS.
gonorrhea A sexually transmitted disease (STD)
resulting from INFECTION with the bacterium Neisseria
gonorrhoeae. N. gonorrhoeae infects 350,000
Americans each year, though public health officials
believe another 350,000 people have gonorrhea
that goes undiagnosed because they do not
know they are infected. Gonorrhea is highly contagious
and passes among sexual partners through
vaginal intercourse, anal intercourse, or oral sex.
People who have multiple sex partners have
increased risk for gonorrhea as well as other STDs.
Gonorrhea is a public health concern of great
magnitude worldwide because a number of strains
of N. gonorrhoeae have become resistant to the
ANTIBIOTIC MEDICATIONS used to treat the infection.
Symptoms and Diagnostic Path
Gonorrhea has a 2- to 10-day INCUBATION PERIOD
(time from exposure to symptoms) though often
causes no symptoms, especially in women. Symptoms
that do occur tend to be generalized and