CHLAMYDIAL INFECTIONS

Chlamydiae are obligate intracellular bacteria, which are unable to generate their ATP for metabolic activity and hence, depend on host cells for energy. Two species are important in humans—C.

Clinically, it present as atypical pneumonia, with dis­proportionately less clinical signs than X-ray findings.

Diagnosis depends on serology, i.e. IgM titers gt;1:16 on immunofluorescence test. Tissue-cultures from nasopharynx, sputum or bronchoalveolar lavage are confirmatory but rarely possible.

Treatment of choice is PO erythromycin/clarithromycin for 10 days or azithromycin for 5 days, in usual doses.

C. trachomatis infections in children are almost always caused by its trachoma biovar, though another lympho­granuloma biovar is responsible for a rare STD in adults, i.e. lymhphogranuloma venerum.

Clinical spectrum of trachoma biovar in children varies with age and mode of infection and includes:

• Trachoma (Ch 27.1.4),

• Genital infections, and

• Neonatal disease (conjunctivitis or pneumonia) in infected mothers.

Genital infections are acquired as sexually transmitted disease in adolescents or sexually-abused children. These infections may be asymptomatic or present as urethritis or epididymitis in males; and cervicitis, salpingitis or pelvic inflammatory disease in females.

Neonatal infection is acquired during vaginal delivery through infected birth canal, with premature rupture of membranes as a high-risk factor. While nasopharyngeal colonization is common, clinical disease usually presents with—(a) conjunctivitis, during 2^nd week of life, and/or

(b) atypical pneumonia at 1-3 months of age. Chlamydia is the leading cause of community-acquired neonatal conjunctivitis after control of gonococcal infections.

Diagnosis is mainly clinical, confirmed by demonstration of organisms in nasopharyngeal, ocular or genital smears, either on fluorescent antibody staining (characteristic inclusion bodies) or tissue-culture.

Treatment depends on the site and severity of infection, though PO erythromycin for 1-2 weeks, is the drug of choice in all cases, including newborns and for trachoma. WHO recommends single dose Azithromycin (PO 20 mg/kg) for treatment of Trachoma. Contacts, e.g. sexual partners and mother in neonatal case, should be treated simultaneously.

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