C h a p t e r 4 1
Sexually Transmitted Infections
1059
Diagnosis andTreatment
Diagnosis is based on the history of sexual exposure
and symptoms. The presence of
N
.
gonorrhea
may be
confirmed by identification of the organism on a gram
stain or culture, but more rapid testing that can be done
from a urine sample is becoming preferred. While cul-
ture remains the gold standard, detection by NAATs is
possible using urine and urethral swab specimens.
29
The
sensitivity of these tests is similar to that of culture, and
they are cost effective in high-risk populations.
Updated recommendations from the U.S. Preventive
Services Task Force (USPSTF) suggest that clinicians
screen for gonorrhea in all sexually active men and
women who are at increased risk for infection (i.e.,
younger than 25 years of age, new or multiple sexual
partners, inconsistent condom use, sex work, men who
have sex with men, or drug use).
31
Testing for other STIs,
particularly syphilis and chlamydial infection, is sug-
gested at the time of examination. Pregnant women are
routinely screened at the time of their first prenatal visit;
high-risk populations should have repeat cultures during
the third trimester. Neonates are routinely treated with
various antibacterial agents applied to the conjunctiva
within 1 hour of birth to protect against undiagnosed
gonorrhea and other diseases.
Strains of
N. gonorrhoeae
that are resistant to penicil-
lin, tetracycline, and quinolone are prevalent worldwide,
and strains with other kinds of antibiotic resistance con-
tinue to evolve and spread. The current treatment recom-
mendation to combat penicillin- and tetracycline-resistant
strains is ceftriaxone or cefixime in a single injection.
28,29
While a single injection of cefixime is still the standard
treatment, some strains of
N. gonorrhoeae
have begun
to show resistance to this dose. At this time the organ-
ism is responding to higher dosing (up to 1 gm) of cefix-
ime. Because gonorrhea and chlamydia frequently occur
together, treatment of cefixime should be followed with
azithromycin or doxycycline for chlamydia. All sex part-
ners within 60 days prior to discovery of the infection
should be contacted, tested, and treated. Test of cure is
not required with observed single-dose therapy. Patients
are instructed to refrain from intercourse until therapy is
completed and symptoms are no longer present.
4
Syphilis
After declining every year from 1990 to 2000, the rates
of primary and secondary syphilis have been increas-
ing.
32,33
The CDC estimates that 55,400 people in the
United States develop syphilis each year.
32
Increased
rates were primarily in men, with men who have sex
with men being particularly affected.
32
There has also
been an increase in congenital syphilis.
32,33
Etiology and Pathogenesis
Syphilis is caused by a spirochete,
Treponema pallidum.
9,10
T. pallidum
is spread by direct contact with an infectious
moist lesion, usually through sexual intercourse. Bacteria-
laden secretions may transfer the organism during kissing
or intimate contact. Skin abrasions provide another pos-
sible portal of entry. There is rapid transplacental trans-
mission of the organism from the mother to the fetus after
16 weeks’ gestation, so that active infection in the mother
during pregnancy can produce congenital syphilis in the
fetus. Untreated syphilis can cause prematurity, stillbirth,
and congenital defects and active infection in the infant
(Fig. 41-8). Because the manifestations of maternal syphi-
lis may be subtle, testing for syphilis is mandatory in all
pregnancies. Once treated for syphilis, a pregnant woman
usually is followed throughout pregnancy by repeat test-
ing of serum titers.
The clinical disease is divided into three stages: primary,
secondary, and tertiary. Primary syphilis is character-
ized by the appearance of a chancre at the site of expo-
sure.
9,32–34
Chancres typically appear within 3 weeks of
exposure but may incubate for 1 week to 3 months. The
primary chancre begins as a single, indurated, buttonlike
papule up to several centimeters in diameter that erodes
to create a round or oval clean-based ulcerated lesion on
an elevated base. These lesions usually are painless and
located at the site of sexual contact. Primary syphilis is
readily apparent in the male, where the lesion is on the
scrotum or penis (Fig. 41-9). Although chancres can
develop on the external genitalia in females, they are more
common on the vagina or cervix, and primary syphilis
therefore may go untreated. There usually is an accompa-
nying regional lymphadenopathy. The infection is highly
FIGURE 41-8.
Infant who presented with congenital facial
syphilitic lesions. (From the Centers for Disease Control and
Prevention Public Health Image Library. No. 3503. Courtesy of
Dr. Joseph Caldwell.)
