AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Chlamydia trachomatis is an obligate, intracellular bacterium with 15 immunotypes, as follows: A-C cause trachoma (chronic conjunctivitis endemic in Africa and Asia); D-K, genital tract infections; and L1-L3, lymphogranuloma venereum (associated with genital ulcer disease in tropical countries). Chlamydia is the most commonly reported bacterial sexually transmitted disease (STD) in the United States and is one of the leading causes of infertility in women.

The US Preventive Services Task Force recommends the following¹: (1) screening for chlamydial infection in all sexually active nonpregnant young women aged 24 years or younger and for older nonpregnant women who are at increased risk; (2) screening for chlamydial infection in all pregnant women aged 24 years or younger and in older pregnant women who are at increased risk; and (3) not routinely screening for chlamydial infection in women aged 25 years or older, regardless of whether they are pregnant, if they are not at increased risk.

Pathophysiology

Infection of the genital tract is the most common clinical presentation. The incubation period is 1-3 weeks. Approximately 50% of infected males and 80% of infected females are asymptomatic, but infection may cause a mucopurulent cervicitis in females and urethritis in males. Ascending infection can result in pelvic inflammatory disease (PID) in women and is the most common cause of epididymitis in men younger than 35 years. Of women with PID, 5-10% develop perihepatitis (ie, Fitz-Hugh and Curtis syndrome).

Although patients with any sexually transmitted disease (STD) are at increased risk of co-infection with another STD, co-infection of chlamydia and gonorrhea is most common. Forty percent of women and 20% of men with chlamydial infection are co-infected with gonorrhea. Patients with chlamydia also have a higher frequency of Reiter syndrome (ie, urethritis, conjunctivitis, reactive arthritis) than the general population.

Lymphogranuloma venereum is rare in the US but is responsible for 10% of genital ulcer disease in tropical countries. Localized inguinal adenopathy and ulceration develop 2-12 weeks after exposure. Proctitis, rectal strictures, and lymphatic obstruction with secondary elephantiasis can occur in untreated disease.

Chlamydia is transmitted via the birth canal of an infected mother, and neonates exposed to chlamydia at birth may develop conjunctivitis 5-13 days later. C trachomatis immunotypes A-C, which are endemic in Africa, cause a chronic conjunctivitis.

C trachomatis is one of the most common causes of pneumonia in the newborn. Chlamydial infection develops in 60% of neonates born vaginally to infected mothers.

Frequency

United States

Approximately 4 million cases of chlamydial infection are reported per year in the United States, with an overall prevalence of 5%. At-risk groups (eg, sexually active adolescent girls) have a higher prevalence, with an incidence of 10%. A prevalence of chlamydia as high as 14% has been reported in African American females aged 18-26 years and 17% among females with a history of gonorrhea or chlamydia in the previous 12 months. In addition, approximately 100,000 neonates are exposed to chlamydia annually.

Mortality/Morbidity

Chlamydial infection is one of the leading causes of infertility in women. Other long-term problems caused by chlamydial infection include PID, chronic pelvic pain, and perihepatitis. Women with a chlamydial infection (especially serotype G) are at an increased risk of developing cervical cancer; risk is as high as 6.5 times greater than in women without infection. Untreated neonatal conjunctivitis can result in blindness.

Race

The disease is more common among minorities, lower socioeconomic groups, and people living in urban areas than in the general population.

Sex

Women are more likely to be asymptomatic than men (80% vs 50%). However, women are more likely to develop long-term complications (eg, PID, infertility).

Age

Prevalence rates are highest in adolescent girls (>10%).

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• All patients
• • May have a history of STDs
  • Dysuria
  • Yellow mucopurulent discharge from the urethra
• Women
• • Intermenstrual or postcoital bleeding
  • Lower abdominal pain
  • Fever (in PID)
  • No symptoms in 80%
• Men
• • Unilateral pain and swelling of the scrotum
  • Fever
  • Asymptomatic in 50%
• Neonates
• • Injected conjunctivae
  • Mucopurulent discharge from eyes
  • Bilateral involvement of the eyes

Physical

• Men may have any, all, or none of the following:
• • Mucopurulent urethral discharge
  • Unilateral epididymal tenderness and swelling
  • Mucopurulent rectal discharge (from anal intercourse)
• Women may have any, all, or none of the following:
• • Mucopurulent cervical or vaginal discharge
  • Cervical motion tenderness
  • Adnexal tenderness
  • Lower abdominal tenderness
  • Upper right quadrant abdominal tenderness (Fitz-Hugh and Curtis syndrome)
  • Mucopurulent rectal discharge (from anal intercourse)
• Neonates - Bilateral purulent conjunctivitis
• Lymphogranuloma venereum
• • Localized inguinal adenopathy or buboes
  • Genital ulceration
  • "Groove sign" - Separation of inguinal and femoral lymph nodes by the inguinal ligament (15-20% of patients)

Causes

• Chlamydial transmission usually is caused by sexual contact through oral, anal, or vaginal intercourse. The incubation period is 1-3 weeks.
• Neonatal infection may occur secondary to passage through the birth canal of an infected mother. Two thirds of infants born to mothers with chlamydia develop an infection.
• Specific risk factors include multiple sexual partners, a new sexual partner, lack of barrier contraceptive, and co-infection with another STD.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Cell culture
• • Used to isolate and culture the organism
  • Fifty to 90% sensitivity; 99% specificity
  • Expensive because of the expertise and lab requirements
  • Unsuitable for large numbers of patients (eg, in the emergency department)
  • Difficult to culture the organism; many false-negative results
• Direct fluorescent antibody
• • Laboratory assay test for C trachomatis
  • Fifty to 80% sensitivity; 99% specificity
  • Labor intensive; requires skilled personnel
  • Method of choice for confirmation of other assays
• Nucleic acid amplification techniques
• • Detection of chlamydial DNA using specific probes
  • Eighty to 92% sensitivity; 99% specificity (No difference in urine specimen vs genital specimen for men; urine tests may be less sensitive than genital swab for women)
  • Expensive compared to enzyme immunoassays, but urine test is now becoming more cost effective
• Enzyme immunoassay
• • Laboratory assay for C trachomatis
  • Forty to 60% sensitivity; 99% specificity
  • Inexpensive
  • Automatable
  • Suitable for large numbers because it is automatable and cost-effective
  • Most commonly used test for chlamydia in the emergency department and outpatient clinics
• Tests to identify other STDs
• Pregnancy test: Test patients at risk for STDs for pregnancy as well.

Imaging Studies

• An ultrasound may be performed to look for tubo-ovarian abscess.

Other Tests

• Complete blood count can be performed for suspected PID.
• Consider HIV testing, as co-infection is not uncommon.
• Consider performing a Pap smear on women, as risk of cervical cancer is increased 6.5 fold.
• Consider testing partners for chlamydia.

Procedures

• Collect specimens from urethra, endocervix, rectum, or conjunctivae.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Emergency Department Care

• Begin antibiotic therapy as soon as possible. Consider compliance, cost, and potential adverse effects.
• Consider treatment for possible gonorrhea co-infection (see Gonorrhea).
• Send specimens from sites of infection to the lab for culture.
• Perform a pregnancy test; this can alter antibiotic treatment and patient follow-up care.
• Provide information and counseling to prevent future STDs and consider referral for HIV testing.
• Encourage the patient to abstain from sexual intercourse until after treatment and testing of all partners is completed.

Consultations

• Consult obstetrics/gynecology for any patient with severe PID and any pregnant patient with chlamydial infection.
• Consult ophthalmology for patients with chlamydial conjunctivitis.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goals of pharmacotherapy are to reduce morbidity and prevent complications.

Drug Category: Antibiotics

The Centers for Disease Control and Prevention (CDC) recommends azithromycin and doxycycline as first-line drugs for the treatment of chlamydial infection. Medical treatment with these agents is 95% effective. Second-line drugs (eg, erythromycin, sulfa) are less effective and have more adverse effects.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Hospitalization is recommended for PID with any of the following factors:
• • Tubo-ovarian abscess
  • Pregnancy
  • Failure of outpatient treatment
  • Immunodeficiency
  • Severe abdominal pain
  • Inability to tolerate PO medications
  • Perihepatitis

Further Outpatient Care

• Recheck patients with PID in 1-2 days for signs of clinical improvement.
• All patients should receive follow-up care with a primary care provider to reduce risk of further infection and to screen for cervical cancer.
• Test for chlamydial cure is not necessary unless the patient thinks he or she may have been reinfected.

Deterrence/Prevention

• Condoms (barrier protection) should be used during sexual activities.
• Refer all sexual contacts for testing and treatment.
• Test for other STDs or refer patients for other STD testing.

Complications

• Infertility
• Urethral scarring in men
• PID
• Chronic pelvic pain
• Perihepatitis
• Cervical cancer

Prognosis

• Antibiotic treatment results are 95% effective for first-time therapy. Prognosis is excellent if treatment is initiated early and the entire course of antibiotics is completed.

Patient Education

• Counsel patients regarding the risk of other STDs and transmission of STDs.
• Inform patients of possible long-term risks and complications of their infection, including the possibility of infertility.
• Patients should avoid sexual contact until their treatment is completed and all partners also have been evaluated and treated.
• For excellent patient education resources, visit eMedicine's Sexually Transmitted Diseases Center. Also, see eMedicine's patient education articles Sexually Transmitted Diseases and Chlamydia.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to treat for co-infection with gonorrhea
• Failure to instruct patient to refer partners for evaluation
• Failure to recognize patients who need to be hospitalized for PID
• Failure to consider other differential diagnoses in patients with presumed PID

Special Concerns

• Treat all patients in whom chlamydial infection is strongly suspected with the appropriate antibiotic therapy. In a study by Yealy et al, as many as 47% of patients with a chlamydial infection seen initially in the ED were discharged without treatment.² Of these patients, only 13% were treated within 9 days.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

1. U.S. Preventive Services Task Force. Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. Jul 17 2007;147(2):128-34. [Medline]. [Full Text].
2. Yealy DM, Greene TJ, Hobbs GD. Underrecognition of cervical Neisseria gonorrhoeae and Chlamydia trachomatis infections in the emergency department. Acad Emerg Med. Oct 1997;4(10):962-7. [Medline].
3. Anttila T, Saikku P, Koskela P, et al. Serotypes of Chlamydia trachomatis and risk for development of cervical squamous cell carcinoma. JAMA. Jan 3 2001;285(1):47-51. [Medline].
4. CDC. Sexually transmitted diseases treatment guidelines 2002. Centers for Disease Control and Prevention. MMWR Recomm Rep. May 10 2002;51(RR-6):1-78. [Medline].
5. Darville T. Chlamydia trachomatis infections in neonates and young children. Semin Pediatr Infect Dis. Oct 2005;16(4):235-44. [Medline].
6. Datta SD, Sternberg M, Johnson RE, Berman S, Papp JR, McQuillan G. Gonorrhea and chlamydia in the United States among persons 14 to 39 years of age, 1999 to 2002. Ann Intern Med. Jul 17 2007;147(2):89-96. [Medline].
7. Jensen JS, Bjornelius E, Dohn B, Lidbrink P. Comparison of first void urine and urogenital swab specimens for detection of Mycoplasma genitalium and Chlamydia trachomatis by polymerase chain reaction in patients attending a sexually transmitted disease clinic. Sex Transm Dis. Aug 2004;31(8):499-507. [Medline].
8. Kelly JJ, Dalsey WC, McComb J, Njuki F. Follow-up program for emergency department patients with gonorrhea or chlamydia. Acad Emerg Med. Dec 2000;7(12):1437-9. [Medline].
9. Magid D, Douglas JM Jr, Schwartz JS. Doxycycline compared with azithromycin for treating women with genital Chlamydia trachomatis infections: an incremental cost-effectiveness analysis. Ann Intern Med. Feb 15 1996;124(4):389-99. [Medline].
10. Miller WC, Ford CA, Morris M, et al. Prevalence of chlamydial and gonococcal infections among young adults in the United States. JAMA. May 12 2004;291(18):2229-36. [Medline].
11. Stewart DP. Historical, physical, and laboratory characteristics of female ED patients with positive chlamydia and gonorrhea cultures. Am J Emerg Med. May 1996;14(3):336-7. [Medline].

Article Last Updated: Feb 15, 2008