++
Chlamydia trachomatis is the leading bacterial pathogen
of sexually transmitted infections worldwide. Sexually transmitted
infections are discussed in Chapter 233, including
a detailed discussion of the diagnosis and management of nongonococcal
urethritis, epididymitis, and endocervitis. In 1999, the World Health Organization (2001) estimated
that 92 million new cases of C trachomatis infections
occurred globally.28-30 In the United States in
2006, there were 1,030,911 chlamydia diagnoses reported to the CDC.29 However,
it is estimated that there are as many as 2.8 million new cases
of C trachomatis infection each year because the
majority of cases go undiagnosed.29-30 Most infected
men and women are asymptomatic and are diagnosed from either routine
screening or as a result of a known infected partner. Men usually
do not have long-term complications from infection but are important
in continued transmission as carriers. Women are at greater risk
for complications because most infections are initially asymptomatic
and unrecognized. If the infection is not diagnosed and treated,
severe complications including pelvic inflammatory disease (PID),
ectopic pregnancy, and infertility can occur. Therefore, C
trachomatis infections present an enormous public health
problem throughout the world. Although the highest age-specific
rates of chlamydia were in females 15 to 19 years of age (2862.7
cases per 100,000 females), followed by females 20 to 24 years of
age (2797.0 cases per 100,000 females) these higher rates compared
to men reflect increased detection from higher rates of screening
in women.29 Given the high prevalence of Chlamydia
in women 15 to 24 years of age, the CDC recommends annual chlamydia screening
for all sexually active women who are younger than 26 years of age (eFig. 259.1).30
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Clinical Features, Treatment,
and Prevention by Site
+++
Infections of
the Genital Tract
+++
Nongonococcal
Urethritis
++
Nongonococcal urethritis in the male is a common sexually transmitted
disease caused by C trachomatis in 15% to
55% of cases.30 The presumptive diagnosis
is made by examining the urethral discharge and excluding gonorrhea
by smear and culture; or by rapid tests using ligase or nucleic
acid amplification technique (polymerase chain reaction) testing
of urine for C trachomatis. The definitive diagnosis
is made by culturing chlamydia from a urethral specimen.
++
The treatment of choice for chlamydial urethritis is azithromycin
1 g orally in a single dose or doxycycline 100 mg orally twice a
day for 7 days.30 Erythromycin, ofloxacin, or levofloxacin
are alternative drugs. Successful treatment requires that the sexual
partners of the patient be treated as well.
++
Epididymitis, an important complication of urethritis in young
men, may be caused by Neisseria gonorrhea or Chlamydia trachomatis and
is treated with a 10-day course of oral doxycycline twice daily
for the chlamydia and ceftriaxone 250 mg IM in a single dose for
gonorrhea. A 10-day course of ofloxacin or levofloxacin can also
be used.30
+++
Female Genital
Tract Infections
++
In most women, chlamydial infections are asymptomatic, but women
with C trachomatis can present with endocervical
erosions, a mucopurulent cervical exudate, or urethritis.30 In
addition, chlamydial infection is a common cause of PID in sexually
active adolescents and women. Diagnosis depends on demonstration
of C trachomatis in a cervical specimen either by culture or the
rapid direct slide immunofluorescence method using monoclonal antibodies. Nucleic
acid amplification tests (NAATs) can also be used and are able to
detect small amounts of chlamydial nucleic acid by a urine sample,
or a urethral or endocervical swab. Treatment for uncomplicated
female genital tract infections includes doxycycline, 100 mg orally
twice daily for 7 days or 1 gram of azithromycin given orally in
a single dose (Table 233-2).30 Azithromycin,
erythromycin, or amoxicillin is recommended for treatment in pregnant
women (eTable 259.2).30 Sexual
partners must also be treated to prevent reinfection.
++
++
Data from a randomized controlled trial of chlamydia screening
in a managed care setting suggested that screening programs can
lead to a reduction in the incidence of PID by as much as 60%.31 As
with other inflammatory sexually transmitted infections, chlamydia
infection can facilitate the transmission of HIV infection. In addition,
pregnant women infected with chlamydia can pass the infection to
their infants during delivery, potentially resulting in neonatal
ophthalmia and pneumonia.
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Lymphogranuloma
Venereum
++
Lymphogranuloma venereum is a sexually transmitted chlamydial
disease caused by serovars L1 to L3. The incidence of this disease
has declined in the United States, but it is still quite prevalent
in tropical and subtropical areas.32 Tender, unilateral
inguinal or femoral lymphadenopathy is the most common clinical
manifestation of LGV among heterosexual men.30,32 Women
and homosexually active men may have proctocolitis or involvement
of perirectal or perianal lymphatic tissues resulting in fistulas
and strictures.32 The disease is rare in children
and infrequently seen in adolescents.
++
LGV can manifest as acute or chronic disease because it is a
disease of the lymphatic tissue.33First, there
is a primary lesion, which is transient and clinically mild, usually
appears as a papule or a shallow ulcer on the penis or vaginal wall, and
generally heals without scar formation (eFig.
259.2). Systemic manifestations can include fever, chills,
and anorexia. In the secondary stage, occurring 2 to 6 weeks after
the primary lesion, there is pronounced lymphadenitis or lymphadenopathy
in the inguinal area (Fig. 259-1). The nodes
are large and often fluctuant, forming buboes. This stage of disease
is found predominantly in males. In the tertiary stage, which is
not necessarily preceded by lymphadenopathy, there is a chronic
inflammatory response with fibrosis which can result as strictures
in the anal, rectal, and vaginal areas. Once suspected,
the diagnosis can be best confirmed by complement-fixation or microimmunofluorescence
tests, using the specific antigens. The treatment of choice is doxycycline
100 mg orally twice a day for 21 days (eTable
259.3).30 For children less than 8 years of
age, erythromycin base (2 grams per day in 4 divided doses for 21
days) is recommended.32Some experts recommend
a 1 gram dose of azithromycin weekly for 3 weeks; however, there
are minimal data using this regimen.32
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++
++
+++
Perinatally
Transmitted Infections
++
C trachomatis can be transmitted to newborns and
can cause
purulent conjunctivitis and pneumonia. Notably, 50% to
75% of infants born to infected mothers become infected
at one or more sites including the conjunctiva, nasopharynx, vagina,
and rectum.33-35 The most frequent site of perinatally
acquired chlamydia infection in neonates is the nasopharynx with
rates as high as 70% in exposed infants. Furthermore, in
those with nasopharyngeal infection, chlamydia pneumonia develops
in 30% of infants.35
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Newborn Inclusion
Conjunctivitis
++
Acute purulent conjunctivitis in the newborn, also known as inclusion
blenorrhea, has an incubation period from 5 to 12 days.32 There
is a watery discharge from the eyes that becomes progressively more
purulent, with swelling of the eyelids. Left untreated, lymphoid
follicles and a membranous conjunctivitis can develop and persist
for weeks or months. The conjunctivitis should be distinguished
from other pyogenic bacterial infections (N gonorrhoeae and S
aureus,) and from chemical conjunctivitis resulting from
silver nitrate prophylaxis. N gonorrhoeae conjunctivitis
typically occurs in the first 2 to 5 days after birth, whereas chlamydia
conjunctivitis occurs later. It may be difficult to distinguish
between the two clinically.
++
Conjunctival cultures on blood and chocolate agar media will
identify bacterial pathogens. The most useful diagnostic method
is examination of Giemsa-stained conjunctival scrapings for inclusion
bodies. Because chlamydia are obligate intracellular agents, the conjunctivae
must be scraped rather than swabbed to obtain an adequate specimen.
The infection can also be diagnosed by culture, immunofluorescence,
or enzyme-linked immunosorbent assay (ELISA).
++
Topical treatment of neonatal conjunctivitis is not recommended
because local eye treatment does not prevent or clear nasopharyngeal carriage
and, thus, the further risk of developing pneumonia or repeated
episodes of conjunctivitis.35
++
Optimal management is oral erythromycin, 50 mg/kg per
day in 4 divided doses daily for 14 days.30 Because
treatment is not 100% effective, a second course may be
needed.32
++
Attempts to provide prophylaxis through antibiotic regimens administered
topically to the eyes shortly after delivery has not been 100% effective
with either erythromycin or tetracycline because neither eliminates
nasopharyngeal colonization and further risk for pneumonia. Prevention
can be achieved only by identifying and treating pregnant women prior
to delivery.
+++
Chlamydial Pneumonia
of Infancy
++
C trachomatis pneumonia usually occurs during
an infant’s first 4 months of life. Chlamydial pneumonia
is seen in 30% of infants with nasopharyngeal infection.34,35 The
classic symptoms of chlamydial pneumonia of infancy include a staccato
cough that worsens over time; nasal obstruction; and a respiratory exam
showing tachypnea or rales, but no wheezing.36 Fever
is usually not present (eTable 259.4).37 The infant may appear mildly to moderately
ill. On chest radiological imaging, hyperinflation with bilateral
interstitial infiltrates is the classic finding. The recommended
treatment is azithromycin (20 mg/kg orally once daily for 3
days) or erythromycin base or ethylsuccinate(50
mg/kg per day in 4 divided doses) for 14 days.30,32 The
diagnosis of chlamydial pneumonia (or conjunctivitis) in a neonate
is clear evidence of maternal infection, and thus the mother and
her partner should be treated.
++
++
Trachoma is responsible for about 3% of blindness worldwide
along with cataracts, glaucoma, and diabetic retinopathy. Approximately
1.3 million people worldwide are blind from trachoma, and 84 million people
have active trachoma infection.38,39 The global
distribution is shown in eFigure 259.2. Trachoma
is caused by Chlamydia trachomatis which spreads
through contact with eye discharge from the infected person (on
towels, handkerchiefs, fingers, etc.) and through transmission by
eye-seeking flies. It is associated with poverty and unsanitary living
conditions. In hyperendemic areas active disease is most common
in pre-school children with prevalence rates as high as 60–90%.
++
Active trachoma starts as the presence of follicles on the tarsal
conjunctiva.40 The follicles heal with necrosis
and cause severe conjunctival scarring. This in turn produces lacrimal
stenosis, lid distortion, and entropion and trichiasis. The chronic
keratoconjunctivitis then progresses to severe scarring of the cornea
and finally to blindness. The end result occurs after many years
of active disease. The World Health Organization (WHO) developed
a grading system including at least 2 of the following 4 criteria
to diagnose trachoma: lymphoid follicles on the upper tarsal conjunctiva,
typical conjunctival scarring, vascular pannus, and limbal follicles.39,40 (See: http://www.who.int/ncd/vision2020_actionplan/documents/Simplifiedgradingoftrachoma.PDF, accessed August 8, 2010.)
++
The diagnosis of trachoma is usually clinical but can be confirmed
by examining conjunctival scrapings with a Giemsa stain or immunofluorescence
demonstrating the infective particles. Chlamydia can also be cultured.
Serologic tests are not very helpful, but they are important epidemiologic
tools to assess prevalence.
++
The World Health Organization (WHO) has a goal of globalelimination
of blindness attributable to trachoma by 2020 by utilizing 4 preventionand
treatment methods: surgery for trichiasis, antibiotics, face
washing, and environmental improvement(SAFE).
Antibiotic treatment is prolonged either with topical antibiotics
or oral agents.32 Mass antibiotic treatment with
azithromycin once or twice ayear or topical tetracycline
twice daily for 6 weeks areeffective in treating
large populations in areas of high endemicity.41The treatment
and control of trachoma are complex and involve important international health
issues as outlined in the WHO trachoma control guide for program
managers available at: http://www.who.int/blindness/publications/tcm%20who_pbd_get_06_1.pdf(accessed
August 8, 2010).