Evaluations of enzyme-linked immunosorbent assay procedure for determining specific Epstein-Barr virus serology and of rapid test kits for diagnosis for infectious mononucleosis.

Using the results of Epstein-Barr virus-specific immunofluorescence serology as the "gold standard," we found that the sensitivities of the five rapid test kits varied from 78 to 84% and specificities varied from 89 to 100%. Enzyme-linked immunosorbent assay-determined specific Epstein-Barr virus antibody profiles had a sensitivity and specificity of 98.6 and 95.5%, respectively.

The risk of acquiring Lyme disease or babesiosis from a blood transfusion.

To determine the risk of acquiring Lyme disease or babesiosis from blood transfusion, serum was collected before and 6 weeks after patients received multiple transfusions during cardiothoracic surgery and antibodies to Borrelia burgdorferi and Babesia microti were measured. Of 155 subjects, 149 received 601 total units of packed red blood cells (PRBC) and 48 received 371 total units of platelets. No patient developed clinical or serologic evidence of Lyme disease; 1 (who received 5 units of PRBC) developed clinical and serologic evidence of babesiosis. The risk of acquiring Lyme disease from a transfused unit of PRBC was 0 (95% confidence interval [CI], 0-0.5%) and from a transfused unit of platelets was 0 (95% CI, 0-0.8%); the same risks for babesiosis were 0.17% (95% CI, 0.004%-0.9%) and 0 (95% CI, 0-0.8%), respectively. The risk of acquiring either Lyme disease or babesiosis from a blood transfusion in Connecticut is very low.

Asymptomatic calcified herniated thoracic disks: CT recognition.

Among 270 CT scans of the thorax obtained over a 7-month period, four patients (1.5%) with calcified herniated thoracic disks were identified. Each of these patients presented with abnormal chest radiographs and had a CT examination for evaluation of suspected malignancy. None showed any signs or symptoms of thoracic spinal cord compression. The clinical significance of incidental thoracic disk protrusions is unknown. It may be that these patients are at risk for the later development of symptomatic disk disease.

Comparative evaluation of three commercial tests for detection of heterophile antibody in patients with infectious mononucleosis.

Infectious mononucleosis (IM) is caused by the Epstein-Barr virus. Commonly used laboratory tests used for diagnosis of IM include a screening test based on the observation that horse erythrocytes are agglutinated by the Paul-Bunnell antibody found in the serum of patients with IM. This study evaluated two latex agglutination (LA) kits for IM, Monolatex (Wampole Laboratories) and Immunoscan-IM (American MicroScan) (formerly Monogen; Biokit, S.A.), and compared them with Monospot (Ortho Diagnostic Systems) results on 220 patient sera. Discrepancies in the three test results were resolved with complete Epstein-Barr virus antibody profiles. They indicated that any of the three kits tested can be successfully used as a screening test for IM. The advantage of the LA kits is that no differential absorption step is necessary. When discrepancies were resolved, sensitivity and specificity of both LA kits were greater than 93%.

Rapid detection of Chlamydia trachomatis by an enzyme immunoassay method.

Chlamydia trachomatis has been shown to be a major cause of sexually transmitted diseases in the United States. An enzyme immunoassay (Abbot Laboratories) has been developed that detects chlamydial antigen directly in the urogenital specimens of patients. We have evaluated specimens from 1,074 patients belonging to one of three risk groups. Three swabs were collected from each patient--one each for Neisseria gonorrhoeae, chlamydia cell culture, and enzyme immunoassay. When compared with cell culture, the sensitivity and specificity of the enzyme immunoassay for symptomatic males and females attending a sexually transmitted disease clinic was 82% and 100%, and 91.3% and 95.0%, respectively. A moderate risk group, consisting of female patients seen at either urology or gynecology clinics for genitourinary symptoms was also evaluated. The sensitivity and specificity of the test on this group was 96% and 96.7%. A population of females at low risk were also screened for chlamydial infection. In this group, the sensitivity and specificity of the enzyme immunoassay was 89.3% and 93.2%, respectively. This rapid test is a highly specific and sensitive procedure for the detection of chlamydial antigen in genital specimens from high risk female patients as well as symptomatic males.

Considerations in the laboratory diagnosis of antibiotic-associated gastroenteritis.

Clostridium difficile has been shown to be the major cause of antibiotic-associated gastroenteritis in both humans and experimental animals. During the past few years an increasing number of laboratories have attempted to detect, isolate, and identify this organism and its toxin from clinical samples. Direct visualization of C. difficile in patient specimens using immunofluorescent microscopy has been proposed. The major disadvantage of this method was its lack of specificity due to crossreaction with other clostridial species. Attempts to absorb the antisera with crossreacting strains also failed. Laboratory diagnosis of C. difficile in clinical specimens has relied on either culture using one or more selective media or on the detection of specific cytotoxin in stool filtrates. Until recently the cytotoxicity assay was the only procedure available for the routine detection of cytotoxin and, as a result, has limited this test to laboratories with access to tissue culture facilities. As a result, there has been much interest in the development of immunochemical methods for the detection of C. difficile toxins. We originally reported on the detection of C. difficile toxin in stool filtrates using counterimmunoelectrophoresis. We examined 140 fecal specimens submitted for C. difficile toxin assay by counterimmunoelectrophoresis, using both unabsorbed and absorbed antitoxin, tissue culture, and bacterial culture. Using tissue culture assay as the reference method, the sensitivity of counterimmunoelectrophoresis and counterimmunoelectrophoresis-absorbed was 100% and the specificity 63.0% and 77.5%, respectively. Enzyme immunosorbent assays for the detection of toxin A from C. difficile have also been reported, however, at the present time they do not appear to be as sensitive as the cytotoxicity assay for toxin B (cytotoxin).(ABSTRACT TRUNCATED AT 250 WORDS)