Rapid diagnosis of Chlamydia trachomatis infection in patients attending an ophthalmic casualty department

High Frequency of Latent Conjunctival C. trachomatis, M. hominis, and U. urealyticum Infections in Young Adults with Dry Eye Disease

Aim. To determine the frequency of detection of conjunctival C. trachomatis (CT), M. hominis (MH), and U. urealyticum (UU) infections in young adults with dry eye disease (DED), since these infections may potentially produce the chronic subclinical inflammation characteristic of DED. Materials and Methods. The study included subjects of 25–45 years of age, divided into the DED (n = 114) and nondry eye control (n = 98) groups, with the diagnosis based on self-reported complaints, biomicroscopy, the Schirmer I test, and break-up time. All patients had conjunctival scrapings taken to detect CT, MH, and UU with direct fluorescent-antibody assay kits. Results. At least one of the three microorganisms was found in 87.7% of the DED patients versus 8.2% of the controls. Of all the DED patients, 63.2%, 50.8%, and 42.1% were found to be infected with CT, MH, and UU, respectively. Multiple pathogens were identified in 65% of the DED patients found to be infected. CT infection was detected in 6.1% of the controls. Conclusion. C. trachomatis, M. hominis, and U. urealyticum were detected with high frequency in the conjunctiva of young adults with DED and may be an important risk factor for DED in them.

Evaluation of five immunoassays for detection of Chlamydia psittaci in cloacal and conjunctival specimens from turkeys

Five commercially available immunoassays were evaluated for the detection of Chlamydia psittaci in cloacal and conjunctival swabs from industrially raised turkeys: IMAGEN (DAKO Diagnostics, Ely, Cambridgeshire, United Kingdom), Chlamydia CEL-VET IF (Cellabs, Brookvale, Australia), IDEIA (DAKO Diagnostics), CELISA (Cellabs), and CLEARVIEW (Unipath, Bedford, United Kingdom). Results were compared with isolation in Buffalo Green Monkey cells as a reference method. For the conjunctival samples, the sensitivities of the IMAGEN test, the Chlamydia CEL-VET IF test, the IDEIA, the CELISA, and the CLEARVIEW test were found to be 100, 66, 0, 0, and 0%, respectively, as compared to the reference test. Also for the conjunctival samples, the specificities of the IMAGEN test, the Chlamydia CEL-VET IF test, and the IDEIA were found to be 100, 11, and 92.8%, respectively. For the cloacal specimens, the sensitivities of the IMAGEN test, the Chlamydia CEL-VET IF test, the IDEIA, the CELISA, and the CLEARVIEW test were found to be 100, 93.3, 26.6, 0, and 53.3%, respectively. Also for the cloacal specimens, the specificities of the IMAGEN test, the Chlamydia CEL-VET IF test, the IDEIA, and the CLEARVIEW test were found to be 92, 12, 100, and 88%, respectively. The IMAGEN test was the most sensitive and specific direct chlamydia antigen detection test for cloacal and conjunctival samples from turkeys.

The use of polymerase chain reaction for the detection of chlamydial keratoconjunctivitis

Ocular swabs from 30 consecutive patients with follicular conjunctivitis were screened for Chlamydia trachomatis, herpes simplex virus, and adenovirus by a variety of laboratory techniques. For the detection of C. trachomatis, we compared two polymerase chain reaction methods, McCoy cell culture isolation, and the direct fluorescein-conjugated monoclonal antibody test. Four of 30 patients tested positive for C. trachomatis by using both conventional and biotinylated polymerase chain reaction methods. Two of the four patients were also McCoy cell culture-positive for C. trachomatis and one of four patients tested positive by using a fluorescein-conjugated chlamydial monoclonal antibody test. All four patients responded to oral antibiotic treatment. On follow-up testing, all four patients were polymerase chain reaction-negative, McCoy cell culture-negative, and fluorescein-conjugated antibody test-negative for C. trachomatis. The polymerase chain reaction appears to be an equally specific and more sensitive method than McCoy cell culture or fluorescein-conjugated antibody testing for the detection of C. trachomatis from ocular specimens.

An immune dot-blot test for the diagnosis of ocular infection with Chlamydia trachomatis

We report a new simple non culture technique for the diagnosis of chlamydial eye disease. The immune dot-blot test (IDBT) detects chlamydial lipopolysaccharide (LPS) antigen which, after being trapped on nitrocellulose membrane, is detected by autoradiography with 125I-labelled genus specific monoclonal antibody. This test was evaluated over a two year period in adults and neonates, by comparing it to culture, serological detection of chlamydial antibodies and clinical features. We demonstrate that the IDBT is more than twice as sensitive as culture, and suggest that in order to achieve a reliable diagnosis of chlamydial eye infection an immunological test for chlamydial antigen should be used in preference to tests which detect the organisms themselves.

Laboratory survey of Chlamydia trachomatis ocular infections

The authors used immunofluorescence and immunoperoxidase tests to study a group of 101 patients with acute or chronic conjunctivitis, etiologically unrelated to conventional bacterial pathogens, and a control group of 30 healthy adults. Positive titers of IgG in serum and of IgA in lacrimal secretions against Chlamydia, detected by IPA, correlated with the identification of microorganisms by direct immunofluorescence. The use of both tests allows a precise evaluation of the stage of the infection and of its evolutive pattern.

Evaluation of three Chlamydia trachomatis immunoassays with an unbiased, noninvasive clinical sample

First-catch early morning urine samples from patients attending a genitourinary medicine clinic were tested by three different enzyme immunoassays. The results suggest significant differences in the sensitivities and specificities of the different assays. The direct visualization of elementary bodies in urine deposits by direct immunofluorescence was used as the "gold standard," using a monoclonal antibody with a different epitope specificity from those of antibodies used in the enzyme-linked immunosorbent assays. We report for the first time that urine specimens represent an unbiased sample, free of the inherent sampling errors associated with other genital specimens. We feel that urine is a valid specimen for use in any evaluation study of new assays directed towards the detection of Chlamydia trachomatis.

Epidemiology and diagnosis of acute conjunctivitis at an inner-city hospital

Chlamydia has been found to be the cause of a high percentage of cases of neonatal and chronic conjunctivitis in an inner-city population. To assess the etiology and epidemiology of acute conjunctivitis in this population, conjunctival scrapings were sampled from 45 patients presenting to an ocular emergency room; and replicate chlamydial, viral, and bacterial cultures and cytology tests were done. No cases of chlamydial conjunctivitis were diagnosed, although a viral etiology was established in 36% of the cases and a bacterial etiology in 40%. Twenty-four percent of the cases were not diagnosed. The authors recommend limiting the initial laboratory workup of patients with acute conjunctivitis to obtaining conjunctival smears for Gram and Giemsa staining. Chlamydial direct immunofluorescent monoclonal antibody (DFA) should be done if the patient is sexually active. Hyperacute conjunctivitis or acute conjunctivitis refractory to treatment mandates a more complete set of laboratory tests.

Detection of Chlamydia trachomatis by isolation in cell culture and enzyme amplified immunoassay

188 (139 female; 49 male) genital swabs from patients with urogenital complaints (greater than 6 weeks), 69 (33 female; 36 male) conjunctival swabs from patients with chronic conjunctivitis and 14 swabs from newborns with acute conjunctivitis were tested for the presence of Chlamydia trachomatis (Ct) by inoculation in cell culture and visualisation by indirect immunofluorescence (IFT) with a monoclonal antibody and enzyme immunoassay (ELISA). Of the 271 specimens 20 (7.4%) were Ct positive by cell culture (IFT) and 18 (6.6%) were positive by ELISA. In 184 (97.9%) urogenital specimens results between cell culture (IFT) and ELISA agreed. With ELISA 4 further genital specimens were found to be Ct positive. In 59 (85.5%) conjunctival swabs of patients with chronic conjunctivitis results between cell culture (IFT) and ELISA agreed. By inoculation of cell culture (IFT) 6 (8.7%) more Ct positive specimens could be identified which were negative in ELISA. There was complete agreement between positive and negative Ct detection with cell culture (IFT) and ELISA in the cases of acute conjunctivitis.