The chlamydiae occupy a special place between bacteria and viruses.
- They are a large group of obligate intracellular organisms.
Chlamydia trachomatis has a number of serovars and causes many different human infections.
- Eye: trachoma; inclusion conjunctivitis
- Genital tract: lymphgranuloma venereum, non-gonococcal urethritis, salpingitis
- Respiratory tract: pneumonia
- trachomatis immunotypes D-K are isolated in about 50% of cases of non-gonococcal urethritis and cervicitis by appropriate techniques.
Infections 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 female’s 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 cervix and absence of gram-negative diplococcic on Gram stain and of N. gonorrhoeae on culture is assumed to have chlamydial infection.
Epididymo-orchitis and sterility in males.
Pelvic inflammatory disease (PID) and infertility in female.
Adverse pregnancy outcomes;
Conjunctivitis and pneumonia in the newborn.
Other causes of urethral and vaginal discharge (see Gonorrhoea).
Microscopy, culture and sensitivity (of discharge),
Direct immunofluorescence assay,
DNA probe test,
Ligase chain reaction (LCR),
Same as for gonococcal infection
Doxycycline 100mg orally, every 12 hours for 7 days.
Azithromycin 1 g orally, in a single dose.
Chlamydia infection during pregnancy
Erythromycin 500 mg orally every 6 hours for 7 days
Amoxycillin 500mg orally every 8 hours for 7 days.
Neonatal Chlamydia conjunctivitis
Typically has an incubation period of 10 -14 days compared to 2 – 3 days for gonococcal opthalmia.
Erythromycin syrup 50 mg/kg per day orally, every 6 hours for 14 days.
Trimethoprim 40 mg with sulfamethoxazole 200 mg orally, every 12 hours for 14 days.
Note: There is no evidence that additional therapy with topical agent provides future 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 Tetracycline.
- Deposition of tetracycline in growing bones and teeth (by binding to calcium) causes staining and occasionally dental hypoplasia.
- Should not be given to children under 12 years, or pregnant or breast feeding women.
- With the exception of doxycycline and minocycline, tetracycline may exacerbate renal failure and should not be given to patients with kidney disease
- May cause nausea, vomiting and diarrhoea hypersensitivity reactions. Headache and visual disturbances may indicate being intracranial hypertension.
- Candidal super infection 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).
- See ciprofloxacin – Gonorrhea
- Caution where there is a history of allergy
- Erythematous rashes common in glandular fever, cytomegalovirus infection, acute or chronic lymphocytic leukaemia with pityriasis rosea, and allopurinol use
- Condom use,
- Contact treatment.