Introduction
Chlamydia is a common sexually transmitted disease caused by bacteria called Chlamydia trachomatis.
Chlamydia trachomatis has a number of
serovars and causes many different human infections.
- Eye: trachoma; inclusion conjunctivitis
- Genital tract: lymphogranuloma venereum, non-gonococcal urethritis, cervicitis, salpingitis
- Respiratory tract: pneumonia
Chlamydia trachomatis immunotypes D- Kare is isolated in about 50% of cases of non-gonococcal urethritis and cervicitis by appropriate techniques.
Clinical features
- Chlamydial infection are asymptomatic, but when an
incubation period can be determined, it is usually about 10-20 days - Co-infection with gonococci and chlamydiae is common
- C. trachomatis is an important cause of non gonococcal urethritis in males, and in females
cervicitis, salpingitis, or pelvic inflammatory disease - Urethral or cervical discharge tends to be less painful, less purulent, and watery in chlamydial compared with gonococcal infection
- On physical examination, the cervix may show contact bleeding in addition to the discharge
- A patient with urethritis or cervicitis and absence of gram-negative diplococci on Gram
stain and of N. gonorrhoeae on culture is assumed to have chlamydial infection
Complications
- Epididymo-orchitis and sterility in males.
- Pelvic inflammatory disease (PID) and infertility in females.
- Adverse pregnancy outcomes.
- Conjunctivitis and pneumonia in the newborn
Differential diagnoses
- Other causes of urethral and vaginal discharge (e.g Gonorrhoea)
Investigations
- Microscopy, culture and sensitivity (of discharge)
- Direct immunofluorescence assay
- Enzyme-linked immunoassay
- DNA probe test
- Ligase chain reaction (LCR)
Treatment objectives
- Eliminate the organism in the patient and sexual partner(s)
- Prevent re-infection
- Prevent complications
- Counsel and screen for possible co-infection with HIV so that appropriate management can be instituted
Drug therapy
Recommended regimen
- Doxycycline 100 mg orally, every 12 hours for 7 days
Or:
- Azithromycin 1 g orally, in a single dose
Chlamydial infection during pregnancy
Recommended regimen:
- Erythromycin 500 mg orally every 6 hours for 7 days
Or:
- Amoxycillin 500 mg orally every 8 hours for 7 days
Neonatal chlamydial conjunctivitis
This typically has an incubation period of 10-14 days compared to 2-3 days for gonococcal opthalmia
Recommended regimen:
- Erythromycin syrup 50 mg/kg per day orally, every 6 hours for 14 days
Alternative regimen:
- Trimethoprim 40 mg with sulfamethoxazole 200 mg orally, every 12 hours for 14 days
Note
- There is no evidence that additional
therapy with a topical agent provides further benefit - If inclusion conjunctivitis recurs after therapy has been completed, erythromycin treatment should be reinstituted for 2 weeks
- It is important to treat the mother and her sexual partner
Notable adverse drug reactions, caution and contraindications
Doxycycline and tetracycline
- Caution in patients with hepatic impairment, systemic lupus erythematosus and myasthenia gravis
- Antacids, aluminium, calcium, iron,
magnesium and zinc salts, and milk
decrease the absorption of tetracyclines - Deposition of tetracyclines in growing bones and teeth (by binding to calcium) causes staining and occasionally dental hypoplasia
- It should not be given to children under 12 years, or to pregnant or breast-feeding women
- With the exception of doxycycline,
tetracyclines may exacerbate renal failure and should not be given to patients with kidney disease - It may cause nausea, vomiting and diarrhoea; hypersensitivity reactions.
- Headache and visual disturbances may indicate benign intracranial hypertension
- There can be candidal superinfection with prolonged therapy
Azithromycin and Erythromycin
- Erythromycin estolate is contraindicated during pregnancy because of drug related hepato-toxicity; only erythromycin base or erythromycin ethylsuccinate should be used
- Erythromycin should not be taken on an empty stomach.
- Caution in persons with arrhythmias
- Infants should be followed up for
symptoms and signs of infantile
hypertrophic pyloric stenosis (has been reported in infants less than 6 weeks exposed to this drug)
Amoxicillin
- Caution where there is a history of allergy
- Erythematous rashes common in
glandular fever, cytomegalovirus
infection, acute or chroni lymphocytic leukaemia with pityriasis rosea, and allopurinol use
Prevention
- Counselling, Compliance, Condom use and Contact treatment.