SEXUAL TRANSMISSION OF HIV

Transmission through sexual contact accounts for 75 to 85 percent of the nearly 28 million infections with the human immunodeficiency virus (HIV) that have occurred so far.1 The probability of infection through sexual contact, although it varies greatly, appears to be lower than that of infection through other routes of exposure (Figure 1). The variability observed among and within routes of HIV exposure depends partly on the viral dose and also on whether the virus is transmitted directly into the blood or onto a mucous membrane. In addition, these differences are influenced by a variety of host factors, including both factors common to all routes of exposure and those unique to sexual transmission. HIV infectivity is the average probability of transmission to another person after that person is exposed to an infected host. Infectivity plus two other parameters — the duration of infectiousness and the average rate at which susceptible people change sexual partners — determines whether the epidemic grows or slows.12 On a population level, all three corners of the classic epidemiologic triangle — host-related factors (susceptibility and infectiousness), environmental factors (the social, cultural, and political milieu), and agent factors (HIV type 1) determine HIV infectivity. Host-related and environmental factors can amplify the epidemic through their dual effect on infectivity and the rate of sexual-partner change. Although the entire triangle is key to understanding infectivity, our article focuses on the epidemiology and biology of the host-related factors that affect the sexual transmission of HIV

High Levels of Human Immunodeficiency Virus Type 1 in Blood and Semen of Seropositive Men in Sub-Saharan Africa

High levels of human immunodeficiency virus type 1 (HIV-1) replication, as reflected in HIV-1 RNA concentrations in blood and semen, probably contribute to both rapid disease progression and enhanced sexual transmission. Semen and blood were collected from 49 Malawian and 61 US and Swiss (US/Swiss) HIV-1.seropositive men with similar CD4 cell counts and no urethritis or exposure to antiretroviral drugs. Median seminal plasma and blood plasma HIV-1 RNA concentrations were > 3-fold (P = .034) and 5-fold (P = .0003) higher, respectively, in the Malawian men. Similar differences were observed in subsets of the Malawian and US/Swiss study groups matched individually for CD4 cell count (P = .035 and P <.002, respectively). These observations may help explain the high rates of HIV-1 sexual transmission and accelerated HIV-1 disease progression in sub-Saharan Afric

Complete Genome Sequences of Cluster A Mycobacteriophages BobSwaget, Fred313, KADY, Lokk, MyraDee, Stagni, and StepMih

Seven mycobacteriophages from distinct geographical locations were isolated, using Mycobacterium smegmatis mc2155 as the host, and then purified and sequenced. All of the genomes are related to cluster A mycobacteriophages, BobSwaget and Lokk in subcluster A2; Fred313, KADY, Stagni, and StepMih in subcluster A3; and MyraDee in subcluster A18, the first phage to be assigned to that subcluster

Diversity and scale: Genetic architecture of 2068 traits in the VA Million Veteran Program

One of the justifiable criticisms of human genetic studies is the underrepresentation of participants from diverse populations. Lack of inclusion must be addressed at-scale to identify causal disease factors and understand the genetic causes of health disparities. We present genome-wide associations for 2068 traits from 635,969 participants in the Department of Veterans Affairs Million Veteran Program, a longitudinal study of diverse United States Veterans. Systematic analysis revealed 13,672 genomic risk loci; 1608 were only significant after including non-European populations. Fine-mapping identified causal variants at 6318 signals across 613 traits. One-third (n = 2069) were identified in participants from non-European populations. This reveals a broadly similar genetic architecture across populations, highlights genetic insights gained from underrepresented groups, and presents an extensive atlas of genetic associations

Physical and Sexual Violence During Pregnancy and After Delivery: A Prospective Multistate Study of Women With or at Risk for HIV Infection

Objectives. We sought to describe and compare prevalence rates of and risk factors for violence against women during pregnancy and postpartum. Methods. Physical and sexual violence and violence risk factors were assessed during late pregnancy and 6 months postpartum in a prospective study of pregnant women with (n=336) and without (n=298) HIV in 4 US states. Results. Overall, 10.6% of women reported having experienced violence, 8.9% during pregnancy and 4.9% after delivery. Of these women, 61.7% were abused only during their pregnancy, 21.7% were repeatedly abused, and 16.7% were abused only after their delivery. Sexual violence rarely occurred in the absence of physical violence. The strongest predictor of violence was engaging in bartered sex (adjusted odds ratio [OR]=5.54; 95% confidence interval [CI] =2.0, 15.4). Other predictors included frequent changes in residence (adjusted OR=1.57; 95% CI=1.1, 2.2), financial support from family or partners (adjusted OR=0.42; 95% CI=0.2, 0.8), and HIV diagnosis during current pregnancy (adjusted OR=0.30; 95% CI=0.1, 0.7). Conclusions. Women more commonly experienced violence during than after their pregnancy, but violence was best predicted by socioeconomic and behavioral indicators whose influence did not vary over time

Neighborhood and Individual Sociodemographic Characteristics Associated with Disparities in Adult Obesity and Perceptions of the Home Food Environment

Purpose: Multiple studies have demonstrated significant disparities in the relationship between individual sociodemographic characteristics and risk of overweight or obesity. However, little information is available for assessing the complex associations among being overweight or obese with neighborhood and individual sociodemographic factors and the measured and perceived community food environment. Methods: Using 2014 national evaluation data from 20 communities (analyzed 2015–2016) that participated in the U.S. Centers for Disease Control and Prevention Community Transformation Grants Program, we used multilevel multivariable models to assess associations among factors at the individual, census tract, and county levels with being overweight or obese and with the perceived home food environment. Results: Individual level factors (age, sex, race/ethnicity, household income, and education) were significantly associated with the likelihood of being overweight or obese in every model tested. Census tract level poverty and education were significantly associated with the likelihood of being overweight or obese in univariate but not multivariable analyses. Perceived community food environment was a significant predictor of the perceived home food environment; the objective measure of county-level grocery store access was not. Neither perceived nor objective community food environment measures were significantly associated with overweight/obesity in multivariable analyses. Conclusion: Individual-level sociodemographic characteristics are more strongly associated with obesity-related outcomes than are area-level measures. Future interventions designed to address health equity issues in obesity among underserved populations may benefit from focusing on nutrition education tailored to individuals, to encourage purchase and consumption of healthy food. Improving healthy food availability in underserved communities may also be critical for nutrition education to have a meaningful impact

Barriers to universal prenatal HIV testing in 4 US locations in 1997.

OBJECTIVES: We determined rates of prenatal HIV testing and investigated barriers to testing. METHODS: We surveyed 1362 representative parturient women from 7 hospitals in 4 locations of the United States. RESULTS: Overall, 89.9% of women reported being offered HIV testing and 69.6% reported being tested. Proportions of women not offered testing differed by location (range = 5.2%-16.3%), as did proportions not tested (range = 12.2%-54.4%). Among women who perceived that their clinicians had not recommended testing, 41.7% were tested, compared with 92.8% of women who perceived a strong recommendation (P < .05). Private insurance for prenatal care was also associated with not being tested. Women gave multiple reasons for not being tested, most commonly not being at risk, having been tested recently, and the test's not being offered or recommended, cited by 55.3%, 39.1% and 11.1% of women, respectively. CONCLUSIONS: Although most parturient women were offered a prenatal HIV test and got tested, testing proportions did not reach national goals and differed significantly by location and payment status. Concern about testing consequences was not a major barrier. Perception of clinicians' recommendations strongly influenced testing. Changing provider practices will be essential to implementing universal prenatal HIV testing

New Mother\u27s Knowledge and Attitudes About Perinatal Human Immunodeficiency Virus infection

Objectives: To assess new mothers’ attitudes toward perinatal human immunodeficiency virus (HIV) testing, their knowledge about perinatal HIV, and their trust of government and scientists. Methods: In a cross-sectional survey of 1362 postpartum women at four United States locations in 1997, a standardized interview was administered to new mothers 24–48 hours postpartum to determine their HIV test acceptance, attitudes, and knowledge. Results: Seventy-five percent of women who were offered HIV tests reported being tested. Although 95% of women were aware of perinatal HIV transmission, only 60% knew that HIV can be transmitted through breast-feeding, and only 51% knew of medication to prevent perinatal transmission. Eighty-four percent of women thought that all pregnant women should be tested for HIV, and 60% thought that prenatal HIV testing should be legally mandated. Twenty percent of women indicated mistrust of government and scientists regarding origins of HIV and potential cures for AIDS. Knowledge about perinatal transmission was unrelated to receipt of prenatal HIV tests. When other factors were controlled for, mistrust was not significantly associated with getting tested. Conclusion: Incomplete knowledge of prevention of perinatal HIV transmission and mistrust were prevalent among new mothers. Knowledge deficits or mistrust did not appear to reduce reported prenatal test rates, but our data suggest that future public health efforts need to educate women about methods of preventing perinatal HIV transmission and at enhancing their trust in the public health system