AUTHORS: Bethany K Sederdahl, MPH, MD, and Anthony Sciscione, DO
Definition
Genital infection with Chlamydia trachomatis (CT) is the most prevalent sexually transmitted disease in the U.S. In women, chlamydia infection can result in cervicitis, acute urethral syndrome, endometritis, and pelvic inflammatory disease. These infections can, in turn, lead to ectopic pregnancy, infertility, and chronic pelvic pain (see “Pelvic Inflammatory Disease”). In men, CT infection may cause mucopurulent discharge, urethritis, epididymitis, and prostatitis. Newborns born via an infected birth canal are at risk for conjunctivitis and pneumonia. A majority of the men and women affected with CT are asymptomatic. Thus, screening tests play a very important role in detection of this infection to initiate treatment, impede disease sequelae, and prevent further transmissions.1,2
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Epidemiology & Demographics
- C. trachomatis is the most commonly reported sexually transmitted disease in the U.S., with more than 1.5 million cases reported to the Centers for Disease Control and Prevention (CDC) in 2020. This represents a decreased in reported cases with 1.8 million cases reported in 2019. Rather than a decrease in disease, this is believed to represent lack of access to outpatient testing and treatment during the COVID-19 pandemic.2
- Regardless, because many cases of CT infection are asymptomatic and likely remain undiagnosed.
- Age is a strong predictor for risk of CT infection. Individuals less than 25 yr old are the largest age group affected by C. trachomatis; 61% of reported chlamydia infections were among individuals ages 15 to 24 yr.2
- Chlamydia conjunctivitis occurs in 18% to 44% of infants, and chlamydial pneumonia occurs in 3% to 16% of infants who are delivered by mothers with untreated CT infection at the time of delivery.3
- Pelvic inflammatory disease develops in 10% to 15% of women with untreated CT infections.3
- Untreated CT increases a person’s risk of acquiring HIV.3
- In men, 15% to 55% of nongonococcal urethritis cases are caused by C. trachomatis.
- Anorectal chlamydia infection can occur in partners who engage in anal sex and is more common among men who have sex with men.3
- Table E1 summarizes clinical characteristics of common C. trachomatis infections.
TABLE E1 Clinical Characteristics of Common Chlamydia trachomatis Infections
| Infection | Symptoms and Signs | Presumptive Diagnosis | Definitive Diagnosis | Treatment | |
|---|---|---|---|---|---|
| Men | Nongonococcal urethritis | Urethral discharge, dysuria | Urethral leukocytosis; no gonococci seen | Urine or urethral NAAT | Doxycycline, 100 mg PO bid, for 7 days |
| Epididymitis | Unilateral epididymal tenderness, swelling; pain; fever, presence of NGU | Urine or urethral NAAT | Urethral leukocytosis; pyuria on urinalysis | STI likely: Ceftriaxone 500 mg (1 g for individuals weighing >150 kg) IM plus doxycycline, 100 mg PO bid, for 10 days | |
| If enteric organisms are suspected: | |||||
| Ceftriaxone, 500 mg (1 g for individuals weighing >150 kg) IM, plus levofloxacin, 500 mg bid for 10 days | |||||
| Proctitis (non-LGV) | Rectal pain, discharge and bleeding; history of receptive anal intercourse | ≥1 PMN/OIF on rectal Gram stain; no gonococci seen | Urine or urethral NAAT; rectal culture or NAAT | Ceftriaxone, 500 mg (1 g for individuals weighing >150 kg) IM, plus Doxycycline, 100 mg PO bid, for 7 days | |
| Lymphogranuloma venereum proctitis | Painful, tender inguinal lymphadenopathy, fever | “Groove sign” | Urine, urethral, lymph node or rectal NAAT; rectal or lymph node culture; LGV-specific testing if available | Doxycycline, 100 mg PO bid, for 21 days | |
| Women | Cervicitis | Mucopurulent cervical discharge; ectopy, easily induced bleeding | ≥20 PMN/OIF on cervical Gram stain | Urine or cervical NAAT | Doxycycline, 100 mg PO bid, for 7 days |
| Urethritis | Dysuria, frequency; no hematuria | Pyuria on UA; negative urine Gram stain and culture | Urine, cervical, or urethral NAAT | Doxycycline, 100 mg PO bid for 7 days | |
| Pelvic inflammatory disease | Lower abdominal pain, adnexal pain, cervical motion tenderness | Evidence of mucopurulent cervicitis | Urine or cervical NAAT | Outpatient: Ceftriaxone 500 mg IM as a single dose, plus doxycycline 100 mg PO bid for 14 days, with metronidazole, 500 mg PO bid for 14 days | |
| Adults | Conjunctivitis | Ocular pain, redness, discharge; simultaneous genital infection | Gram stain of conjunctival swab negative for bacterial pathogens; PMNs on smear | DFA or NAAT on conjunctival swab | Doxycycline, 100 mg PO bid for 7 days |
| Newborns | Conjunctivitis | Ocular pain, redness, discharge; simultaneous genital infection | Gram stain of conjunctival swab negative for bacterial pathogens; PMNs on smear | DFA or NAAT on conjunctival swab; vagina, rectum, pharynx also often positive | Erythromycin base 50 mg/kg/day, PO divided into four doses daily for 14 days; evaluate and treat parents as well |
| Pneumonia | Staccato cough, tachypnea, hyperinflation | Diffuse interstitial infiltrate, eosinophilia | Nasopharyngeal NAATs or culture; MIF serology (IgM) | Erythromycin base or ethylsuccinate 50 mg/kg/day, PO divided into four doses daily for 14 days; evaluate and treat parents as well |
bid, Twice daily; DFA, Direct fluorescent antibody; IgM, immunoglobulin M; IM, intramuscular; LGV, lymphogranuloma venereum; MIF, microimmunofluorescence; MSM, men who have sex with men; NAAT, nucleic acid amplification test; NGU, nongonococcal urethritis; OIF, oil immersion field; PMN, polymorphonuclear neutrophil; PO, by mouth; STI, sexually transmitted infection; UA, urinalysis.
From Bennett JE et al: Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, ed 8, Philadelphia, 2015, Saunders; updated with new treatment guidelines from the Centers for Disease Control and Prevention.
Physical Findings & Clinical Presentation
- Chlamydial infections are commonly asymptomatic. Clinical manifestations in symptomatic women affected with C. trachomatis may include vaginal discharge or irregular vaginal bleeding. Purulent discharge or cervicitis may be visualized on speculum examination. Easily induced endocervical bleeding can be noted on examination and is caused by inflammation of endocervical columnar epithelium. Untreated infection can ascend the reproductive tract, causing pelvic inflammatory disease. Clinical signs of pelvic inflammatory disease are cervical, uterine, or adnexal tenderness on examination. Complications of pelvic disease are ectopic pregnancy, infertility, and chronic pelvic pain.
- Symptoms in men may include dysuria or a mucopurulent penile discharge. A complication that can arise from CT infection in men is epididymitis, which manifests as unilateral testicular pain, hydrocele, or swelling of the epididymis. An untreated CT infection can also cause prostatitis in men. Prostatitis may present as urinary dysfunction, pain with ejaculation, and pelvic pain.
- Chlamydial conjunctivitis can be experienced by both men and women and is the result of conjunctiva exposed to infected genital secretions. CT infection can also cause proctitis or infection of the rectum in men and women. This usually presents with rectal pain, discharge, or bleeding. CT infection of the throat is usually asymptomatic in both men and women and not a usual cause of pharyngitis. Less frequent manifestations of CT infection may include perihepatitis (Fitz-Hugh-Curtis syndrome) or reactive arthritis (Reiter syndrome).
