Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection.

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results.

[Epidemiology and laboratory diagnostics of legionellae]. / A legionellák epidemiológiája és laboratóriumi diagnosztikája.

The severe pulmonary disease caused by the inhalation of the different Legionella species is called Legionella pneumonia, while the name of the pulmonary disease caused by the most common Legionella (L. pneumophila) is Legionnaires' disease. Another type of disease caused by legionellae is Pontiac fever with influenza-like symptoms. Legionella spp. are facultative intracellular parasites. They survive within both monocytes in the human organism and amebae in the environment. To prevent and control the occurrence of legionelloses, legionellae should be surveyed and detected in the environmental (water pipes, air-conditioning systems, cooling towers, respiratory equipments, etc.) and clinical (blood, bronchoalveolar lavage, sputum, abscess, etc.) samples. Laboratory diagnosis is complicated by the limitations of the available assays. Thus, it is proposed that the microbiological laboratory diagnosis should be based on the simultaneous application of at least three methods (culturing [on BCYE medium], followed by biochemical assays, serology, molecular biologic methods, such as polymerase chain reaction [PCR], direct demonstration [immunofluorescence microscopy], antigen determination are the most important ones) and on the simultaneous demonstration from three different samples (e.g. lower respiratory tract secretions, sputum, urine, blood culture, serum, moreover, water samples from all potential infectious sources, sediment of hot water tanks, as well as swab samples of faucets and shower heads). The advantage of PCR is that is gives reliable results in one day, in contrast to conventional culturing. However, its sensitivity can not be improved by increasing the sample volume, and neither can it give quantitative results nor can it produce strains for epidemiologic studies, contrary to the method of culturing. It is concluded that PCR and culturing do complement, but do not substitute each other.

Molecular genetic and traditional methods for detection of Mycobacterium tuberculosis complex (discrepancy analysis).

In the past six and half years, 862 different clinical samples [sputum, bronchoalveolar lavage, thorax puncture, cerebrospinal fluid and skin samples] were tested by Gen-probe amplified Mycobacterium tuberculosis direct test (MTD) or ligase chain reaction (LCR) or polymerase chain reaction (PCR). 239 parallel clinical samples were cultivated, and some samples were stained with Ziehl-Neelsen staining. 1-4 samples were tested per patient. 29 (12.13%) samples were positive and 177 (74.05%) samples were negative with both cultivation and molecular genetic methods. 2 (0.83%) samples were positive only on cultivation, and 31 (12.97%) samples were positive only with the molecular diagnostic methods. The differences are undoubtedly explained by the sensitivity of the molecular diagnostic methods.

Epidemiological study of Chlamydia trachomatis infection in pregnant women in Hungary.

A multicentre survey was carried out in order to determine the prevalence and risk factors of Chlamydia trachomatis infection in the pregnant population in Hungary. The nucleic acid hybridisation method (PACE 2 Gen-Probe) was applied for the examination of C trachomatis. The overall average prevalence of C trachomatis cases during an 18 month survey on 6161 pregnant women was 5.87%. There were significant differences in the proportions of chlamydial infection in the different survey centres, and also in the different age groups and the different family status groups. The perinatal mortality rate exhibited a significantly higher prevalence (8.52%) among C trachomatis positive than among negative patients (2.03%). In the anamnestic histories of C trachomatis infected patients, the frequency of premature uterine activity was 8.13%, in contrast with 5.18% in the non-infected group (p < 0.05). We suggest that all pregnant women be tested for C trachomatis infection.

Prevalence of Chlamydia trachomatis infection in a low-risk population in Hungary.

BACKGROUND AND OBJECTIVE: Chlamydia trachomatis is the leading cause of nongonococcal urethritis and cervicitis in women. Because of the recent increases in the numbers of new cases and severe consequences, there is an urgent demand for the introduction of sensitive and specific rapid diagnostic methods. GOAL: A multicenter examination involving seven centers was sponsored by the Hungarian Ministry of Health and Welfare in order to provide a survey of Chlamydia trachomatis in the gravid population. 6,161 women were tested between 1994 to 1995. STUDY DESIGN: The seven centers were selected with regard to different aspects, from developed and less developed areas in the capital, two large provincial towns, and various other provincial regions reflecting either an industrial or an agricultural background. The nucleic acid hybridization method (PACE 2 Gen-Probe, San Diego, CA) was introduced in this low-risk population for the examination of Chlamydia trachomatis. In one center, a further two methods, antigen detection by ELISA (SYVA, CA) and cultivation on the McCoy cell line (staining with SYVA FITC-labeled antichlamydia monoclonal antibody), were applied. RESULTS: International surveys and experience indicate that the proportion of the population threatened by Chlamydia trachomatis is above 10%. The overall average incidence of Chlamydia trachomatis cases in this low-risk gravid population was 5.74%. The data from the different centers ranged between 1.6% and 9.7%. The chlamydia-infected Hungarian gravid population is below the critical 10%, but there is one Hungarian county where the value is close to 10%. CONCLUSIONS: In this provincial, industrial area, the number of unmarried and divorced gravida in a low economic situation is disproportionately high. For this disadvantaged population, permanent Chlamydia trachomatis screening was suggested. In the other centers, screening of pregnant women for Chlamydia trachomatis and the treatment of positive cases and their partners were suggested for pathological gravida with preterm labor and preterm rupture of the membranes.