BackgroundIn the absence of interventions and breast-feeding, the in utero transmission rate of human immunodeficiency virus (HIV) is estimated to be 10%–15%, and the role that amniotic fluid (AF) ...plays in this is unclear ObjectivesLevels of cytomegalovirus (CMV) in AF and levels of HIV-1 in AF, maternal blood, and fetal cord blood were assessed Study designWe enrolled 23 HIV-1–positive women with healthy, singleton pregnancies who underwent elective cesarean section (CS) at full term. The Roche Amplicor HIV-1 Monitor test (version 1.5) was used for determination of maternal plasma VLs. The NASBA Nuclisens assay was used for determination of VLs in other samples. To determine the feasibility of detecting viral infections in AF, CMV polymerase chain reaction DNA extraction was performed on the AF samples by use of the QIAamp DNA kit ResultsHIV-1 RNA was not detected in either AF or fetal cord blood. CMV was detected in 4 AF samples. Maternal CD4+ T cell counts were 158–654 cells/mL (mean, 405 cells/mL). The maternal plasma VLs ranged from below detectable limits to 169,990 copies/mL (mean, 33,700 copies/mL) ConclusionsIn the absence of medical complications and before labor, AF collected during elective CS from women who had received either zidovudine or nevirapine during late-stage pregnancy was free of HIV
Nearly 30% of pregnant women in South Africa are estimated to be HIV seropositive, yet adherence to guidelines for the prevention of mother-to-child transmission of HIV (PMTCT) is often low. A pilot ...study was developed to see whether PMTCT services provided by the South African Government could be enhanced by the Mamekhaya program, a combination of the mothers2mothers peer-mentoring program and a culturally adapted cognitive-behavioral intervention (CBI) from the USA. Pregnant women attending two maternity clinics offering PMTCT in Gugulethu and Vanguard Townships, Cape Town, South Africa, were invited to participate in the study. Women at the intervention site (Gugulethu) received the support of a mentor mother and also attended an eight-session Mamekhaya CBI. At the control site (Vanguard), women received standard services provided by midwives and counselors. Baseline assessments were completed by all participants at enrollment (n=160), and follow-ups were completed six months later by 44% of participants. Self-reports of adherence to PMTCT practices were high across both sites (90% or more engaging in the core practices). Women at the Mamekhaya site showed significantly greater improvement in establishing social support and reducing depression scores than women at the control site. Mamekhaya participants also showed trends for better attendance at follow-up medical visits, and greater improvements in positive coping. The greatest effect of the Mamekhaya program was to increase HIV knowledge scores, particularly with regard to understanding the meaning and importance of viral load and CD4 test results. Results from this pilot study show promise that augmenting basic PMTCT services with mentor mothers and a culturally adapted CBI can be effective in conveying information and in improving the emotional outlook and hopefulness of HIV-positive pregnant women in South Africa.
A decision analysis model, from a health care system perspective, was used to assess the cost-effectiveness of HIV rescreening during late pregnancy to prevent perinatal HIV transmission in South ...Africa, a country with high HIV prevalence and incidence among pregnant women. Because new HIV prenatal prophylactic and pediatric antiretroviral therapy (ART) regimens are becoming more widely available, the study was carried out with different combinations of the two. With an estimated HIV incidence during pregnancy of 2.3 per 100 person-years, HIV rescreening would prevent additional infant infections and result in net savings when zidovudine plus single-dose nevirapine or single-dose nevirapine is used for perinatal HIV prevention, and ART was available to treat perinatally HIV-infected children. The cost savings were robust over a wide range of parameter values when ART was available to treat perinatally HIV-infected children but were more sensitive to variations around the baseline when ART was not available. The minimum time interval between the initial and repeat screens would be from 3 to 18 weeks, depending on prophylactic and treatment regimens, for HIV rescreening to be cost saving. Overall, HIV rescreening late in pregnancy in high-prevalence, resource-limited settings such as South Africa would be a cost-effective strategy for reducing mother-to-child transmission.
The development of molecular subtyping for foodborne disease surveillance has significantly enhanced our ability to detect, investigate, and control common source outbreaks. Despite wide-scale use ...and many high profile outbreaks detected through enhanced foodborne disease surveillance, use and interpretation of molecular subtype data has been primarily intuitive. Efforts to develop interpretive guidelines have been based primarily on laboratory criteria with the relatively narrow goal of defining the likelihood of relatedness between strains. However, the significance of strain relatedness is context dependent, and additional factors are required for epidemiological inference. These factors have not been clearly defined, which has limited our ability to consistently interpret findings and effectively utilize the new tools. In this work, a theoretical framework was developed to describe the interrelationship of case definitions based on molecular or other classifications, the normal prevalence of disease or strain, frequency of exposure, specificity of exposure information, and number of cases in a common source outbreak setting. A computer model was developed to illustrate the impact of increasing case definition specificity and exposure prevalence on the association between illness and exposure. The model demonstrated that as the case definition in a case control study became more specific, measures of association increase and confidence intervals widened. Low prevalence exposures required less case definition specificity or fewer cases to reach significant association than high prevalence exposures. The model demonstrated that the optimum level of molecular subtype specificity is not fixed, but depended on the prevalence of the exposure, specificity of the exposure information, the number of available cases, and the question being asked. Furthermore, the sensitivity of exposure identification and the specificity of the exposure information have an impact on the ability to detect and resolve common source outbreaks in much the same manner as molecular subtyping. Using the key parameters identified, the inherent benefits and limitations of each of the currently available surveillance systems were compared for their ability to detect problems in the food supply. Interpretive guidelines for molecular subtype data were developed, and a practical guide to best practices was formulated.
Blood lead levels declined among Americans aged 1-74 y between the years 1976 and 1991 (National Health and Examination Survey NHANES III). In 1990, umbilical cord blood lead levels were surveyed ...among 223 women who gave birth in a Boston hospital obstetrical service. In a survey conducted 10 y earlier, women had a mean umbilical cord blood lead level of 6.56 μg/dl (standard deviation = 3.19). In another subgroup of 41 women who were 1-4 wk postpartum, bone lead levels were surveyed with a K-x-ray fluorescence instrument and by analysis of venous blood lead levels. In 1990, umbilical cord blood lead levels were very low (i.e., mean and median of 1.19 standard deviation = 1.32 and 1.0 μg/dl, respectively). In the subgroup of postpartum women, lead levels in cortical bone (i.e., tibia) and trabecular bone (i.e., patella) were also low (i.e., tibia mean and median of 4.5 standard deviation = 4.0 and 4 μg/g bone mineral, respectively; patella mean and median of 5.8 standard deviation = 4.5 and 5 μg/g, respectively). Maternal age was the only factor associated (i.e., borderline p = .076) with bone lead. Umbilical cord blood lead levels among women served by this Boston hospital from 1980 to 1990 declined dramatically, thus paralleling the National Health and Examination Survey. Bone lead levels were also low, but lead remains a reproductive hazard to women in select high-risk groups.
This article reviews retrospective data derived from Sharp The BirthPlace, San Diego for 1993–1994 and from the University of California, Irvine, Birthing Center for 1994 and compares these findings ...to data obtained from the National Birth Center Study (NBCS). The focus of this article is on intrapartum transfer rates from the two freestanding birth centers as a critical clinical indicator. Cause-specific transfer rates were calculated for eight clinical conditions. Data suggest that cause-specific intrapartum transfer rates are influenced by factors such as risk profile of the client population, distance to the referral center and mechanisms of transfer, definitions and diagnostic criteria used, and clinical practice guidelines. Reports from the literature, such as NBCS data, might serve as points of reference, but are likely not appropriate baseline indicators (benchmarks of “best practice”) for clinical events, against which individual performance can be measured; rather, these benchmarks should be individually defined, based on characteristics unique to each birth center.
A variety of species of bacteria are known to colonize human tumours
, proliferate within them and modulate immune function, which ultimately affects the survival of patients with cancer and their ...responses to treatment
. However, it is not known whether antigens derived from intracellular bacteria are presented by the human leukocyte antigen class I and II (HLA-I and HLA-II, respectively) molecules of tumour cells, or whether such antigens elicit a tumour-infiltrating T cell immune response. Here we used 16S rRNA gene sequencing and HLA peptidomics to identify a peptide repertoire derived from intracellular bacteria that was presented on HLA-I and HLA-II molecules in melanoma tumours. Our analysis of 17 melanoma metastases (derived from 9 patients) revealed 248 and 35 unique HLA-I and HLA-II peptides, respectively, that were derived from 41 species of bacteria. We identified recurrent bacterial peptides in tumours from different patients, as well as in different tumours from the same patient. Our study reveals that peptides derived from intracellular bacteria can be presented by tumour cells and elicit immune reactivity, and thus provides insight into a mechanism by which bacteria influence activation of the immune system and responses to therapy.
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