Chlamydia trachomatis causes trachoma (serotypes A, B, Ba and C) and also genital infections (serotypes D to K) and disease Lymphogranuloma venereum (serotypes L1 to L3).

Infection with genital serotypes D to K can cause isolated episodes of ophthalmia neonatorum in infants or inclusion conjunctivitis in adults. The incubation period for adult inclusion conjunctivitis is 4-12 days.

Genital serotypes do not cause trachoma blindness since they do not enter stable transmission cycles within communities. Serotypes D to K occasionally cause subacute follicular conjunctivitis but conjunctival scarring is rare.

Usually, adult inclusion conjunctivitis is observed in young sexually active people. It is most common in persons aged 15-35 years.

Diagnosis of adult inclusion conjunctivitis depends upon clinical presentation and laboratory diagnosis.

Women with chlamydial infection often have a concomitant urethritis or vaginal discharge secondary to chronic vaginitis and/or cervicitis. Men may have symptomatic or asymptomatic urethritis.

Often, history of patient reveals that this condition has been going on for several weeks. Usually, bacterial infections run a much shorter clinical course of one to two weeks only.

Adult inclusion conjunctivitis usually presents as unilateral (less commonly bilateral) conjunctival redness with mucopurulent discharge, papillary hypertrophy and a predominant follicular conjunctivitis. Untreated disease has a chronic remittent course and may last for months together.

Knowledge of duration of symptoms, any prior treatment taken and recent and not-so-recent history of sexual exposure is important in diagnosis.

Clinical features:

Patient may have tender enlarged pre-auricular lymph node.

Slit-lamp examination by an eye-specialist is required.

Ocular clinical features may include:-

-       Inferior tarsal conjunctival follicles.

-       Papillary hypertrophy and injection in superior tarsal conjunctiva.

-       Keratitis (may develop during second week after onset). Corneal involvement includes:

Superficial punctate keratitis.

Small marginal or central infiltrates.

Sub-epithelial infiltrates (tend to be more peripheral).

Superior limbus pannus.

-       Limbal swelling.

-       Iritis (may develop in late stages of disease).

Laboratory diagnosis:

-       Nucleic acid amplification tests (NAATs): Nucleic acid amplification test is the best laboratory technique, of which polymerase chain reaction (PCR) is an example.

NAATs have high sensitivity and specificity but are expensive and not widely available.

-       Giemsa cytology: Giemsa cytology is microscopic examination of stained conjunctival scrapings for basophilic intra-cytoplasmic epithelial inclusion bodies (Halberstaedter-Prowazek bodies). This test is highly specific but has low sensitivity.

-       Chlamydial culture: Chlamydial cultures may be obtained from conjunctiva.

-       Direct fluorescent antibody (DFA) assay: Direct fluorescent antibody assay of conjunctival smears is less sensitive than NAATs.

-       Enzyme immunoassay (EIA): Enzyme immunoassay of conjunctival smears is also less sensitive than NAATs

-       Serum immunoglobulin G (IgG) titers: Serum immunoglobulin G (IgG) titers may be obtained against chlamydia species.

Adult inclusion conjunctivitis should be differentiated from conditions like:

-       Trachoma.

-       Epidemic kerato-conjunctivitis.

-       Superior limbic kerato-conjunctivitis.

-       Allergic conjunctivitis.

-       Bacterial conjunctivitis.

-       Viral conjunctivitis.

-       Molluscum contagiosum.

-       Complications of contact lens use.

Management should be carried out under medical supervision.

Adult inclusion conjunctivitis is usually self-limiting.

To prevent re-infection, all sexual partners should be treated simultaneously. All sexual partners should also be examined for other sexually transmitted diseases such as gonorrhoea, syphilis and Human immunodeficiency virus (HIV). It is prudent to treat all members of the household with antibiotics. There should be abstinence from sexual activity until the course of treatment is complete.

The goal of pharmacotherapy is to reduce morbidity and to prevent any complications.

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathological organisms.

Conjunctivitis is usually an ocular manifestation of a sexually transmitted uro-genital infection. Therefore, adult inclusion conjunctivitis does not respond and topical use of antibiotic is relatively not effective.

Patients should be followed-up for about 2-6 weeks after initiation of treatment, depending upon the severity of initial symptoms.

Treatment consists of:

-       Systemic antibiotics: Systemic antibiotics are usually recommended for about 3-6 weeks. Systemic oral antibiotics such as erythromycin, azithromycin, tetracycline or doxycycline may be used.

‘Single-dose azithromycin should be considered as equally reliable treatment option, comparing to long-term alternative regimens for adult inclusion conjunctivitis. Patients should wait for one week, until first signs of significant regression become obvious and should consider approximately one month to total relief. Follicles could be reasonably used as a key sign for clinical assessment of treatment success’ (http://reference.medscape.com/medline/abstract/24047438 ).

Tetracyclines are avoided in children less than seven years of age and in women who are pregnant or are breastfeeding the babies.

-       Topical antibiotics: Topical antibiotics are relatively ineffective.

Prognosis:

Prognosis is usually good if treatment is initiated early and the entire course of antibiotics is completed. Re-infection is very common and is due to non-treatment of infected sexual partners or acquisition from a new partner. Therefore, all sexual partners should be treated.

Untreated chlamydial infection can lead to pelvic inflammatory disease and scarring of fallopian tubes in women, causing infertility/sterility or ectopic pregnancy. Chlamydial salpingitis and tubo-ovarian abscess may rupture and lead to peritonitis. Chlamydia is an indirect cause of mortality from ectopic pregnancies.

Complications of adult inclusion conjunctivititis may be:

Systemic complications:

-       Urethritis, vaginitis and mucopurulent cervicitis in females.

-       Pelvic inflammatory disease (PID).

-       Perihepatitis (Fitz-Hugh-Curtis syndrome) in women with PID.

-       Urethritis in males.

-       Epididymitis in males.

-       Co-infection with another sexually transmitted disease like gonorrhoea.

-       Reiter syndrome (syndrome of urethritis, conjunctivitis and reactive arthritis) may be associated with chlamydial infection.

Ocular complications:

In adult inclusion conjunctivitis secondary to genital tract infection, there is not the same likelihood of re-infection. Thus, conjunctival scarring is rarely a complication of adult inclusion conjunctivitis, although micro-pannus (superficial fibrovascular proliferation that extends 1-2 mm beyond normal vascular arcade) and micro-ulceration of the cornea following punctate keratitis may rarely take place.

Iritis may develop in late stages of disease.

To prevent adult inclusion conjunctivitis, patients should follow safe sexual practices.

Patients should be educated about the risks of sexually transmitted diseases.