Makindo Medical Notes.com

At least 70% of women and 50% of men infected with chlamydia trachomatis are asymptomatic, and symptoms in men can be very mild.

About

• Cause a variety of different diseases depending on serotype
• Genital chlamydial infection can cause significant short and long-term morbidity. Complications of infection include pelvic inflammatory disease (PID), tubal infertility, ectopic pregnancy, epididymo-orchitis, and lymphogranuloma venereum (LGV).

Characteristics

• Obligate intracellular bacteria Not seen well on gram stain unable to make ATP and some amino acids
• Life cycle with extracellular elementary bodies (EB) resistant to drying and inert but infectious
• Intracellular reticulate body (RB) which is metabolically active and divides but is non-infectious

Life cycle

• EB bind to cells via specific cell receptors and enter by endocytosis
• Within cells EBs replicated within phagosomes but lysosomal break down blocked
• Over hours EBs become RBs producing DNA, RNA and protein using cell ATP
• The RBs then become EBs and the cell lyses and they are released to infect more cells

Pathogenicity

• Serotype L1, L2, and L3: Cause the genital disease called lymphogranuloma venereum. Sub-Saharan Africa but increasing cases in London. Acute genital ulcer and 2 weeks later painful inguinal lymph nodes with scarring and even genital elephantiasis. The rectal infection causes severe proctitis with painful defaecation and purulent bloody discharge.
• Serotype D-K: Urethritis and Pelvic inflammatory disease, proctitis, epididymitis. Seen in young. Sexually transmitted infections
• Serotype D-K :Neonatal pneumonia. Chlamydia acquired in delivery. Rhinitis and staccato cough within weeks up to 6 months of birth. May be lung damage
• Serotype D-K : Neonatal inclusion conjunctivitis - acquired in delivery. Mucopurulent discharge is seen after birth.
• Serotype A-C:Trachoma/Conjunctivitis . The major cause of blindness in Africa and American Indians. Chlamydia invades conjunctival epithelium and causes chronic follicular keratoconjunctivitis. This leads to inturned eyelashes and eventually corneal scarring

Risk factors for chlamydia infection include

• Age under 25 years
• A new sexual partner
• More than one sexual partner in the last year
• Lack of consistent condom use
• Social deprivation

Screening

• Asymptomatic people who should be tested for chlamydia include:
• Sexual partners of those with proven or suspected chlamydial infection
• All sexually active people younger than 25 years of age, annually, or more frequently if they have changed their partner
• All people with concerns about a sexual exposure.
• Exposure was within the last two weeks, a test should be carried out at presentation and if negative, repeated two weeks after the exposure.
• People under the age of 25 years who have been treated for chlamydia in the previous three months
• People who have had two or more sexual partners in the previous 12 months
• All women seeking termination of pregnancy
• All men and women attending genito-urinary medicine clinics

Clinical

• Increased vaginal discharge
• Post-coital and intermenstrual bleeding
• Dysuria
• Lower abdominal pain
• Deep dyspareunia
• Suspect chlamydia in sexually active men with:
• Urethral discharge
• Dysuria
• Symptoms of rectal chlamydia include anal discharge and anorectal discomfort, although rectal infection is usually asymptomatic.
• Pharyngeal infections are usually asymptomatic.

Investigations

• Giemsa staining of media shows intracellular bodies
• Immunofluorescence can also show IC bodies
• Antigen detection and Serology
• PCR to detect chlamydial RNA or DNA are sensitive and specific

Sensitivities

• Doxycycline, Azithromycin, Tetracycline (not in children/pregnant/breastfeeding)
• Erythromycin

Management:

• Refer GUM for contact tracing and commence either
• Doxycycline 100mg twice daily for 7 days If intolerant to tetracyclines. Doxycycline contraindicated in pregnancy and breast-feeding
• Azithromycin 1g single starting dose (2x500mg tablets), then 500mg daily for 2 days (off-label dose)
• Erythromycin 500mg twice daily for 14 days or 500mg four times daily for 7 days
• Amoxicillin 500mg three times a day for 7 days