Chlamydial Infection (Other than Lymphogranuloma venereum)

Introduction

The chlamydiae occupy a special place between bacteria and viruses

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

C. trachomatis immunotypes D - K are isolated in about 50% of cases of non-gonococcal urethritis and cervicitis by appropriate techniques

Clinical features

Asymptomatic, but when an incubation period can be determined, it is usually about 10 - 20 days
Co-infection with gonococci and chlamydiae is common
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
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

Differential diagnoses

Investigations

Treatment goals

Drug treatment

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

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, contraindications and caution

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
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
May cause nausea, vomiting and diarrhoea; hypersensitivity reactions. Headache and visual disturbances may indicate benign intracranial hypertension
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)

Ofloxacin See ciprofloxacin- Gonorrhoea

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

Nigeria