Showing papers by "Myron S. Cohen published in 2002"

Development and Validation of a PCR-Based Enzyme-Linked Immunosorbent Assay with Urine for Use in Clinical Research Settings To Detect Trichomonas vaginalis in Women

Abstract: Trichomonas vaginalis infection is highly prevalent worldwide and is associated with poor birth outcomes and enhanced human immunodeficiency virus transmission. Traditional detection methods rely on microscopic examination of vaginal specimens (wet mount) and culture, which can be insensitive and time-consuming. More than 3,000 women attending two sexually transmitted disease clinics were enrolled in this cross-sectional study to evaluate urine-based PCR for detection of T. vaginalis using a combined reference standard of wet mount and culture from vaginal swab. The prevalence of trichomoniasis in the population was 16.7% (502 of 3,009 women) using the reference standard. PCR with urine combined with agarose gel-based detection was 66.9% sensitive and 98.3% specific compared to the reference standard. Detection of PCR products using an unlabeled enzyme-linked immunosorbent assay (ELISA) improved the sensitivity to 86.4%, but specificity fell to 86.1%. Using a digoxigenin-labeled ELISA for detection of amplified T. vaginalis DNA from urine, the sensitivity and specificity of the PCR improved to 90.8 and 93.4%, respectively, compared to wet mount or culture from vaginal swabs. For clinical research settings in which vaginal specimens are not available and culture conditions are not feasible, urine-based PCR-ELISA may be useful for the detection of trichomoniasis in women.

Can antiretroviral therapy be used to prevent sexual transmission of human immunodeficiency virus type 1

Abstract: Approximately 5 million people annually are newly infected with human immunodeficiency virus (HIV) Although education, behavior modification, and promotion of condom use are effective transmission-prevention measures, the severity of the pandemic demands that all possible prevention strategies be explored Antiretroviral therapy has the potential to decrease sexual transmission of HIV type 1 by reducing levels of HIV RNA and thus decreasing the risk that infected persons will transmit the disease or by its use as preexposure or postexposure prophylaxis In this article, we explore the rationale for using antiretroviral therapy to prevent sexual transmission of HIV, as well as the limitations of this approach

Pharmacokinetic and Pharmacodynamic Investigation of Efavirenz in the Semen and Blood of Human Immunodeficiency Virus Type 1–Infected Men

Abstract: Therapeutic concentrations of antiretroviral agents in seminal plasma (SP) may reduce virus burden and influence sexual transmission of human immunodeficiency virus (HIV) type 1. This study compared the pharmacokinetic, pharmacodynamic, and dose responses of efavirenz (EFV) in SP versus those in blood plasma (BP). A total of 431 BP samples and 157 SP samples were obtained over a period of 40 days, from 9 EFV-naive men (i.e., men about to receive EFV for the first time) and from 12 EFV-experienced men (i.e., men already receiving EFV as part of an antiretroviral regimen). Overall, median EFV exposure in SP was 3.4% (range, 2.0%-5.0%) of that in BP. However, all EFV concentrations in SP were >/=40-fold higher than the wild-type IC(90) (IC(90)(WT)) for HIV-1. During the dosing interval, no single SPrcolon;BP EFV-concentration ratio was significantly predictive of the absolute measure of exposure in SP. By day 40, HIV-1 RNA in SP was undetectable in 8 (89%) of 9 EFV-naive men and remained undetectable in 10 (83%) of 12 EFV-experienced men. In SP, EFV reaches concentrations above the HIV-1 IC(90)(WT) throughout the dosing interval. EFV-containing regimens effectively suppress HIV-1 RNA in SP.

Quantification of Chlamydia trachomatis Elementary Bodies in Urine by Ligase Chain Reaction

Abstract: Modification of the standard Chlamydia trachomatis ligase chain reaction (LCR) detection assay resulted in a quantitative test. Sample rates from C. trachomatis standards ranging from 32 to 1,048,576 elementary bodies (EB)/ml of urine exhibited a linear correlation with concentration. Quantitative LCR (qLCR) was used to measure the number of EB per milliliter in 158 urine samples from women in Madagascar that tested positive for C. trachomatis by the standard LCR detection assay. C. trachomatis concentrations displayed an apparent bimodal distribution, with approximately one-third of samples (37%) in a peak ranging from 32 to 1,015 EB/ml (median = 297 EB/ml) and the remainder (63%) in a grouping with relatively higher concentrations, ranging from 1,086 to 218,670 EB/ml (median = 7,389 EB/ml). qLCR will be useful for studies of chlamydial infection aimed at understanding the associations of organism burden with clinical manifestations and transmission.

Laboratory diagnosis of sexually transmitted infections in women with genital discharge in Madagascar: implications for primary care.

Abstract: Women seeking care in Madagascar for genital discharge (n = 1,066) were evaluated for syphilis seroreactivity; bacterial vaginosis (BV) and trichomoniasis. Chlamydial infection was assessed by ligase chain reaction (LCR) and by direct immunofluorescence (IF); gonorrhoea by direct microscopy, culture and LCR. Leucocytes were determined in endocervical smears and in urine using leucocyte esterase dipstick (LED). Gonococcal isolates were tested for minimal inhibitory concentrations. BV was found in 56%, trichomoniasis in 25%, and syphilis in 6% of the women. LCR detected gonorrhoea in 13% and chlamydial infection in 11% of the women. Detection of Gram(-) intracellular diplococci in endocervical smears, and gonococcal culture were respectively 23% and 57% sensitive and 98% and 100% specific compared to LCR. Chlamydia antigen detection by IF was 75% sensitive and 77% specific compared to LCR. Leucocytes in endocervical smears and LED testing lacked precision to detect gonococcal and chlamydial infections. Of 67 gonococcal strains evaluated, 19% were fully susceptible to penicillin, 33% to tetracycline; all were susceptible to ciprofloxacin, ceftriaxone, and spectinomycin. Patients who present with genital discharge in Madagascar should be treated syndromically for gonococcal and chlamydial infections and screened for syphilis. Gonorrhoea should be treated with ciprofloxacin.

Traitement syndromique des infections a` gonocoques et aChlamydia chez les femmes venues consulter dans un service de soins de santeprimaires pour des pertes vaginales: la prise de decision

Abstract: Resume Le traitement syndromique des infections a gonocoques et a Chlamydia chez les femmes venues chercher des soins dans des dispensaires ou les ressources sont limitees, tel qu’il est recommande par l’OMS et mis en œuvre dans de nombreux pays en developpement, suppose que l’on trouve un juste milieu entre sous-traitement et surtraitement. Le present article recense les facteurs entrant en ligne de compte dans le choix des strategies adaptees au traitement syndromique en pareil cas ; en font partie les aspects generaux de la prise de decision et les inconvenients de l’approche rationnelle. L’article expose les consequences positives et negatives du traitement ou de l’abstention therapeutiques decides selon un algorithme specifique permettant de detecter une infection avec une precision donnee (sensibilite, specificite et valeur predictive). Les autres aspects reconnus de la prise de decision sont lies a l’execution de cette derniere – stabilite des facteurs de risque en fonction du temps, du lieu et du responsable de cette execution, acceptabilite par les parties interessees et contraintes liees a l’environnement. Il est necessaire d’examiner comme base de discussion les algorithmes de traitement etablis selon des criteres empiriques et de les evaluer conjointement avec les faits, les options et les arguments presentes par les divers partenaires.