Correlation of the percent of positive Chlamydia trachomatis direct fluorescent antibody detection tests with the adequacy of specimen collection.

Chlamydia trachomatis is an obligate, intracellular parasite infecting the columnar and transitional cells lining the endocervix, uterus, fallopian tubes, rectum, urethra, and epididymis. We determined if the percent of specimens positive for C. trachomatis in the Microtrak Direct Specimen Test depended on the quality of specimens obtained. Female genital slides (649) were evaluated by the direct fluorescent antibody (DFA) test for the presence and numbers of (a) C. trachomatis elementary bodies and (b) columnar, transitional and squamous epithelial cells, and polymorphonuclear neutrophils (PMNs). Only 138 (21.3%) of the 649 slides were considered to be adequately taken, that is, containing columnar/transitional cells either alone or in conjunction with squamous cells and/or PMNs. Of the 138 adequate slides, 10 (7.2%) were C. trachomatis positive. However, 511 (78.7%) of the 649 slides were judged inadequate; 395 contained only squamous cells and/or PMNs, 19 were too thick to determine cell types, 46 contained only cell debris, and 51 contained neither cells nor debris. Only four (0.78%) of 511 were C. trachomatis positive. Thus adequate specimens containing columnar/transitional cells for C. trachomatis detection had a tenfold increase in the percent of positive results compared to inadequately collected specimens. By using the DFA test, one has the advantage of determining the adequacy of the specimens obtained as well as the presence of chlamydiae.

Prevalence of hepatitis C virus seropositivity among hospitalized US veterans.

BACKGROUND: Hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis in the United States and abroad. HCV antibody prevalences ranging from 10 to 90% have been reported in intravenous drug abusers, hemodialysis patients, and persons suffering from other liver diseases, whereas HCV seropositivity rates for volunteer-blood donor populations are generally under 1%. However no information has been available concerning the prevalence of HCV in general hospital populations in the United States. METHODS: We examined the rate of HCV seropositivity in 530 patients admitted to the Atlanta VA Medical Center between November 1993 and November 1994. The test population consisted of 400 random hospital admissions, 100 successive admissions to the surgical service, and 30 random admissions to the gastrointestinal service. Serum samples were assayed for HCV antibodies by a second generation EIA, and all repeat reactives were re-examined using a supplemental research assay to confirm the presence of HCV antibodies. Complete chart reviews were carried out on all HCV seropositive patients and on 100 HCV seronegative patients. RESULTS: Sixty-two of the 530 patients tested (11.7%) were repeatedly positive for HCV antibodies. Of these 62 repeat reactives, 56 (90.3%) were positive and 3 others (4.8%) indeterminate by the supplemental assay. The HCV seropositivity rate after supplemental testing was 11.8% for random admissions, 5.0% for surgical admissions, and 13.3% for patients admitted to the gastroenterology service. HCV-associated risk factors in HCV seropositive patients included a history of intravenous drug abuse, current or previous alcohol abuse, previous or concurrent liver disease, previous blood transfusions, hemodialysis, and multiple sex partners or unsafe sex. CONCLUSIONS: HCV infection may be more prevalent among hospitalized VA patients (and among other US hospital populations) than previously expected.

Human immunodeficiency virus type I. Infection among dentists.

The largest collection yet assembled of year-to-year data on the seroprevalence of antibody to HIV in practicing dentists confirms that dentists--along with other health care workers--remain at low risk for occupationally acquired HIV infection.

Human immunodeficiency virus: risk of exposure among health care workers at a southern urban hospital.

To assess the risk of exposure to the human immunodeficiency virus (HIV) among health care workers in a southern urban setting, random screening for antibodies to HIV was undertaken. Patients who were admitted for major trauma, for medical emergencies, or in labor were screened. Of 534 sera screened, 11 (2%) were seropositive. All but two of the seropositive patients were men. Rates were similar among black and white patients. Seven patients could be placed into an established risk group, but only one patient was known to have AIDS upon presentation to the emergency room. The mean age of seropositive individuals was 30.9 years; there were similar seroprevalence rates in each of four age groups among men. We conclude that there is a substantial risk of exposure to HIV in trauma and medical emergency centers; therefore all health care workers should practice universal barrier precautions whenever exposure to a patient's blood or body fluids is likely.

Analysis of implantation in assisted reproduction through the use of serial human chorionic gonadotropin measurements.

PURPOSE: Our purpose was to examine implantation of singleton pregnancies achieved following various assisted reproductive technologies (ARTs) through the appearance and rising titers of serum human chorionic gonadotropin (hCG) levels. METHODS: A total of 114 singleton pregnancies resulting from in vitro fertilization and intrauterine insemination was analyzed. Patients were divided into five groups according to the type of ovarian stimulation protocol [gonadotropin stimulation with/without the use of gonadotropin-releasing hormone agonist (GnRHa), long protocol, or flare-up technique] and to the day of embryo transfer (day 2 or day 3 after oocyte retrieval). Serial serum hCG levels were measured between 10 and 25 days after fertilization and log-transformed. Linear regression analyses were performed and extrapolated to hCG = 10 mIU/ml (hCG10), which was used as an estimate of detectable implantation. The slopes of the regression lines were used to estimate the rising speed of hCG. RESULTS: There were no significant differences in the days of hCG in maternal serum to reach 10 mIU/ml (implantation) or in the slopes of the regression lines for all five studied groups. CONCLUSIONS: The appearance of hCG in maternal serum was used to assess the time of clinically detectable implantation. Furthermore, because hCG production is a marker of trophoblastic activity, its serum doubling time was used as an indicator of embryo quality. Results showed that in various ART protocols with and without GnRHa, there were no significant differences in implantation time or embryo quality. Embryo development in early pregnancy follows a preprogrammed-timing schedule and depends mainly on the embryonic age of the healthy, successfully implanted conceptus.

Improved detection of antibodies to hepatitis C virus in dialysis patients using a second-generation enzyme immunoassay.

We tested serum samples from 99 patients undergoing maintenance hemodialysis for hepatitis C virus (HCV) antibodies using a first-generation, licensed anti-HCV enzyme immunoassay (EIA) and a second-generation anti-HCV EIA that detect three gene products c100-3, NS3, and core. Specimens that were repeatedly reactive by either or both screening assays were further evaluated by testing with supplemental EIAs and a dot blot immunoassay. There was 87.9% agreement between the licensed HCV EIA and the HCV EIA second generation. HCV EIA Second Generation detected 10 more positive specimens than HCV EIA, for an increase in detection from 33.3% (33/99) to 43.4% (43/99). We conclude that HCV EIA Second Generation improves detection of HCV infection in hemodialysis patients.