Showing papers by "Myron S. Cohen published in 2003"

Population-based study of chlamydial infection in China: a hidden epidemic.

Abstract: ContextSexually transmitted diseases are increasing rapidly in China. Surveillance data imperfectly indicate current prevalence and risk factors.ObjectivesTo estimate the prevalence of genital chlamydial and gonococcal infections and to describe patterns of infection by subgroup and behavioral patterns.Design, Setting, and ParticipantsA national stratified probability sample of 3426 Chinese individuals (1738 women and 1688 men) aged 20 to 64 years, who were interviewed between August 1999 and August 2000, completed a computer-administered survey, and provided a urine specimen (69% total participation rate).Main Outcome MeasurePositive test result for chlamydial or gonococcal infections.ResultsThe overall prevalence per 100 population of chlamydial infection was 2.6 (95% confidence interval [CI], 1.6-4.1) for women and 2.1 (95% CI, 1.3-3.3) for men. For gonococcal infection, the overall prevalence per 100 population was 0.08 (95% CI, 0.02-0.4) for women and 0.02 (95% CI, 0.005-0.1) for men. Risk factors for chlamydial infection among men aged 20 to 44 years were unprotected sex with a commercial sex worker (odds ratio [OR], 8.24; 95% CI, 3.51-19.35), less education (OR, 7.20; 95% CI, 2.31-22.37), and recent sex with their spouse or other steady partner (OR, 7.73; 95% CI, 2.70-22.10). Among women aged 20 to 44 years, risk factors for chlamydial infection were having less education (OR, 2.82; 95% CI, 1.01-7.91) and living in a city (OR, 3.46; 95% CI, 1.67-7.18) or along the southern coast (OR, 2.16; 95% CI, 1.29-3.63) and having a spouse or other steady sexual partner who earned a high income (OR, 2.85; 95% CI, 1.11-7.29), who socialized often (OR, 2.79; 95% CI, 1.08-7.19), or who traveled less than 1 week per year (OR, 5.40; 95% CI, 1.44-20.3).ConclusionsThe prevalence of chlamydial infection in China is substantial. The patterns of infection suggest potential avenues for intervention.

Addition of treatment for trichomoniasis to syndromic management of urethritis in Malawi: a randomized clinical trial.

Abstract: Background: Male urethritis is generally treated syndromically but failure of empirical treatment is common. Goal: The study goal was to evaluate the addition of metronidazole to the syndromic management of urethritis in Malawi in a randomized clinical trial. Study Design: Men with urethritis were randomized to receive either 2 g of metronidazole by mouth or placebo in addition to standard care for urethritis (i.e. a single intramuscular dose of 240 mg gentamicin and 100 mg doxycycline twice daily for 7 days). The primary endpoints of the study included measurement of the effects of treatment on Trichomonas vaginalis signs and symptoms of urethritis and the concentration of HIV RNA in semen in dually infected subjects. Results: The overall prevalence of T vaginalis was 17.3% (71/411) and treatment with metronidazole cleared 95% of culture-positive infections compared with 54% clearance among men receiving placebo (P = 0.006). Prevalence of persistent urethritis was observed in approximately 16% of both groups at the end of 1 week (29/179 of those receiving metronidazole versus 29/187 in the placebo group; P = 0.86). For a subset of HIV-infected men with trichomoniasis the seminal plasma HIV RNA concentration was lower than in a group of HIV-positive control subjects (P = 0.052). Conclusion: In areas with a high prevalence of trichomoniasis the addition of metronidazole to the syndromic management of male urethritis can eliminate infection with T vaginalis and may help to reduce the transmission of HIV. Such treatment should be strongly considered as part of empirical therapy for urethritis in men in Malawi and places where T vaginalis infection in men is common. (authors)

Estimating correlation by using a general linear mixed model: evaluation of the relationship between the concentration of HIV-1 RNA in blood and semen.

Abstract: Estimating the correlation coefficient between two outcome variables is one of the most important aspects of epidemiological and clinical research. A simple Pearson's correlation coefficient method is usually employed when there are complete independent data points for both outcome variables. However, researchers often deal with correlated observations in a longitudinal setting with missing values where a simple Pearson's correlation coefficient method cannot be used. General linear mixed models (GLMM) techniques were used to estimate correlation coefficients in a longitudinal data set with missing values. A random regression mixed model with unstructured covariance matrix was employed to estimate correlation coefficients between concentrations of HIV-1 RNA in blood and seminal plasma. The effects of CD4 count and antiretroviral therapy were also examined. We used data sets from three different centres (650 samples from 238 patients) where blood and seminal plasma HIV-1 RNA concentrations were collected from patients; 137 samples from 90 different patients without antiviral therapy and 513 samples from 148 patients receiving therapy were considered for analysis. We found no significant correlation between blood and semen HIV-1 RNA concentration in the absence of antiviral therapy. However, a moderate correlation between blood and semen HIV-1 RNA was observed among subjects with lower CD4 counts receiving therapy. Our findings confirm and extend the idea that the concentrations of HIV-1 in semen often differ from the HIV-1 concentration in blood. Antiretroviral therapy administered to subjects with low CD4 counts result in sufficient concomitant reduction of HIV-1 in blood and semen so as to improve the correlation between these compartments. These results have important implications for studies related to the sexual transmission of HIV, and development of HIV prevention strategies.

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

Abstract: Trichomonas vaginalis infection is highly prevalent worldwide and is associated with urethritis, prostatitis, and urethral strictures in men. However, the natural history and importance of T. vaginalis in men are poorly understood, in part because of difficulties in diagnosing infection. Traditional detection methods rely on culture and wet-mount microscopy, which can be insensitive and time consuming. Urethral swabs are commonly used to detect T. vaginalis in men, but discomfort from specimen collection is a barrier to large studies. One thousand two hundred twenty-five Malawian men attending sexually transmitted disease and dermatology clinics were enrolled in this cross-sectional study to validate detection by urine-based PCR-enzyme-linked immunosorbent assay (ELISA) with urine and urethral swab culture as the reference standard. This assay for detection of amplified T. vaginalis DNA in first-catch urine (< or = 30 ml) performed with a sensitivity of 92.7%, a specificity of 88.6%, and an adjusted specificity of 95.2% compared to culture of urethral swabs or urine sediment. For clinical research settings in which urethral swabs are not available and culture is not feasible, the urine-based PCR-ELISA may be useful for detection of trichomoniasis in men.

Human Immunodeficiency Virus Type 1 RNA in Breast-Milk Components

Abstract: We conducted the present study to determine which of the 4 components of breast milk (whole milk, skim milk, lipid layer, and breast-milk cells) had the highest sensitivity and concentration of human immunodeficiency virus (HIV) type 1 RNA burden and to determine biological correlates to these factors. The probability of detection of HIV (sensitivity) and the concentration of HIV-1 RNA were both associated with the choice of milk component, CD4(+) cell count, concentration of blood serum HIV-1 RNA, and the presence of breast inflammation. Whole milk demonstrated higher sensitivity and mean concentration than any other single component. Sensitivity was enhanced by analyzing all 4 components of breast milk.

Distribution of the CCR5 gene 32-base pair deletion and CCR5 expression in Chinese minorities.

Abstract: China has an ethnically diverse population. Genetic differences may contribute to disparities in the efficiency of HIV transmission. To further characterize this risk, we examined the HIV-related genetic diversity in the predominant Han Chinese and in six minority groups. We searched for the delta32-CCR5 mutation, a common cause of relative HIV resistance in the white population. In addition, CCR5 receptor expression was measured. Blood samples were obtained from adults belonging to the Han, Meng, Zang, Weiwuer, Zhuang, Yi, and Dai ethnic groups. Polymerase chain reaction analysis was performed on genomic DNA samples. Surface expression of CCR5 on peripheral blood mononuclear cells was measured by flow cytometry. One-way ANOVA was used to determine mean statistical differences. Samples from 10 members of each minority were examined. A delta32-CCR5 heterozygote phenotype was detected in one Weiwuer subject, but no mutations were found in the other 69 subjects studied. The mean CCR5 expression of cells harvested from the Dai minority was greater than that of cells from all other minorities studied, for both CD3+CCR5+ and CD4+CCR5+ sets (p < .01, one-way ANOVA). The delta32-CCR5 mutation seems to be rare in most Han Chinese and the minority populations studied. CCR5 expression appears to be greater in the Dai minority than in the other minorities investigated. The mechanism for this increased expression requires further study.