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Biomedical subjects

Mark L Williams

Publications and source records attributed to Mark L Williams.

At least 19 recordsLinked to original sources
PubMed2007

Differences in HIV risk behaviors by gender in a sample of Tanzanian injection drug users.

This study investigated differences in drug use and sexual behaviors among from 237 male and 123 female heroin users in Dar es Salaam, Tanzania. Multivariate models of risk of needle sharing were estimated using multivariate logistic regression. Men were significantly older, more likely to inject only white heroin, share needles, and give or lend used needles to other injectors. Women were more likely to be living on the streets, have injected brown heroin, have had sex, have had a higher number of sex partners, and have used a condom with the most recent sex partner. Being male and earning less than US $46 in the past month were significant predictors of increased risk of needle sharing. Despite differences in sociodemographic, drug use, and sexual behaviors by gender, both male and female injectors in Dar es Salaam exhibit elevated risk of HIV infection associated with drug use.

Adult↗
PubMed2007

Factors associated with suboptimal antiretroviral therapy adherence to dose, schedule, and dietary instructions.

The purpose of this study was to assess the degree of suboptimal antiretroviral therapy adherence to dose, schedule, and dietary instructions and to examine the effects of extra-personal, intra-personal, and inter-personal factors on suboptimal adherence across the three types of instructions. Self-report and clinical data were collected from 193 sexually infected Swedish patients receiving ART. Effects of extra-personal, intra-personal, and inter-personal factors on suboptimal adherence were examined using multivariate logistic regression models. Suboptimal adherence to dose instructions was recorded in 12% of patients. Equivalent percentage for suboptimal adherence to schedule instructions was 37% and for suboptimal adherence to dietary instructions 58%. Anxiety was the only risk factor for suboptimal adherence to dose. Heavy pill burden was a risk factor for suboptimal adherence to schedule. Older age and HIV-related post-traumatic stress disorder (PTSD) symptoms decreased the risk of suboptimal adherence to schedule. No factors investigated had an effect on suboptimal adherence to dietary instructions. To improve adherence to dose and schedule instructions, clinicians caring for patients with HIV should assess and treat anxiety and be alert to HIV-related PTSD symptoms.

Adult↗
PubMed2006

A randomized control trial of Internet-delivered HIV prevention targeting rural MSM.

The Internet may be important for delivering human immunodeficiency virus (HIV) risk reduction to men who have sex with men (MSM) in rural areas. This randomized control trial (RCT) tested the acceptability and efficacy of an Internet-delivered HIV risk-reduction intervention. Two modules include a conversation between an HIV-negative man and an HIV-positive man, with interactive graphics. Ninety men were randomly assigned to intervention or wait-list control and 79% completed the study. An 'intent-to-treat' model was used. HIV/acquired immune deficiency syndrome (AIDS) knowledge, self-efficacy and outcome expectancies increased after participating in the intervention, and changes were maintained at 1-week follow-up. Participants said they would participate again. This RCT provides support for the acceptability and efficacy of the Internet for delivering HIV prevention messages to rural MSM.

Adolescent↗
PubMed2006

Prevalence of childhood sexual abuse among incarcerated males in county jail.

OBJECTIVE: The current study examined the prevalence and characteristics of childhood sexual abuse in a jailed-based population. METHODOLOGY: A retrospective, self-reported survey was administered over an 8-week period to a random sample of 100 men who were incarcerated in a county jail in Southeastern Texas. The survey included questions about childhood sexual experiences before and after puberty, drug history and use, and sexual risk-taking behaviors. RESULTS: Of the 100 male inmates who participated in this study, 59% reported experiencing some form of sexual abuse before puberty, and all such instances occurred before or at the age of 13 years. The first episode of childhood sexual abuse began at an average age of 9.6 years (SD = 2.4), and ended at an average age of 13.0 years (SD = 2.3). Kissing and touching without intercourse (64%) was the common pattern of sexual abuse experience reported. The total number of perpetrators was 165, with 10% male and 90% female. Friends (n = 72) and family (n = 56) were the most frequent perpetrators. CONCLUSION: Childhood sexual abuse may be more prevalent among inmates than among males in the general population. These results show a high percentage of inmates who report a history of childhood sexual abuse; this rate is higher than those reported by other studies for incarcerated males. The findings support the belief held by professionals in the criminal justice field that a significant number of incarcerated males may have been victims of sexual abuse.

Adolescent↗
PubMed2006

HIV/AIDS and injection drug use in the neighborhoods of Dar es Salaam, Tanzania.

This study examines the intersection between needle-sharing practices and HIV recovered from used syringes collected from 73 heroin injection drug users (IDUs) in Dar es Salaam, Tanzania, between October 2003 and January 2004. To extract blood residue, syringes were flushed and 10 microliters of solution mixed with 120 microliters of a latex solution was placed on a Capillus HIV-1/2 slide. Thirty-five (57%) of the useable syringes tested positive for HIV antibodies. Results varied significantly: 90% of syringes tested HIV positive in a mixed-income neighborhood 2 kilometers from the city center: 0% of syringes tested HIV positive in the outlying areas. In addition, semistructured interviews were conducted with 51 IDUs. The interviews were content coded, and codes were collapsed into emergent themes regarding syringe-use practices. Injecting is a recent practice, particularly among heroin users in neighborhoods far from the city center. Sharing syringes has resulted in a high proportion of used syringes containing HIV-positive blood residue. Geographic distance is an indicator of recent adoption of IDU in neighborhoods and correlates strongly with the distribution of syringes containing HIV-positive blood residue.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Virtual and physical venues as contexts for HIV risk among rural men who have sex with men.

Rural men who have sex with men (MSM) have few identifiable venues in which to congregate and meet potential sex partners. The Internet provides a venue for rural MSM to meet, and this is potentially troubling because studies of urban MSM suggest that HIV risk is higher for men who date online. The goals of this study were to identify venues where rural MSM meet their sexual partners and to examine their association with high-risk sexual practices. Six hundred sixty-three predominantly single, gay, Caucasian MSM completed an online survey of their sexual activities. Results showed that the Internet and bars were the most popular venues for meeting sex partners. Highest rates of risk behaviors were associated with Internet dating and venues in which immediate sexual encounters typically occur, suggesting that prevention in rural areas should target multiple-risk environments.

Adolescent↗
PubMed2006

Psychological correlates of trading sex for money among African American crack cocaine smokers.

This article compares demographic characteristics, sexual practices, and psychosocial status among 193 African American female crack cocaine users who currently, previously, or never traded sex for money. Current traders were less likely to have a main sexual partner, more likely to have a casual sexual partner, and more likely to smoke larger quantities of crack. There was a significant trend towards current traders reporting lower self-esteem, greater depression and anxiety, poorer decision-making confidence, more hostility, less social conformity, greater risk taking behaviors, and more problems growing up, compared to previous and never traders. These differences suggest that interventions should address self-esteem, risk-taking practices, depression and anxiety as well as other psychosocial factors.

Adolescent↗
PubMed2006

An investigation of concurrent sex partnering in two samples of drug users having large numbers of sex partners.

The objective of this study was to quantitatively measure the nature of concurrent sex partnering in two samples of drug users having large numbers of sex partners. The purpose of this study was to measure concurrent sex partnering and overlap in concurrent sex partners in two samples of drug users in which some or all participants were trading sex-for-money. Two samples having large numbers of sex partners were used to conduct the analyses: drug-using male sex workers (MSW) and male and female crack cocaine smokers (CS) having vaginal sex. To reflect the quality of concurrent partnering, three measures were used: the proportion of the samples having concurrent partners; the proportions of the samples having intimate, casual, and sex-for-money of partners; and overlap in concurrent partners. Proportions of each sample having concurrent partners were essentially the same. However, the kinds of concurrent partners and overlap in concurrent partners were significantly different. Concurrent partners in the MSW sample were mostly sex-for-money or sex-for-drugs partners. Most concurrent partners in the CS sample were initimate or casual sex partners. Overlap in concurrent partners was also significantly different. The measure of overlap for the CS sample was three times higher than that of the MSW sample. These data suggest that concurrent sex partnering in the two samples, beyond the proportion having concurrent partners, was different. The patterns of concurrent sex partners in each sample may reflect different reasons for engaging in concurrent partnering. Different reasons for engaging in concurrent partnering may also be reflected in different overlap scores between the two samples. Efforts should be made in future studies to better capture the complexities of concurrent partnering and to examine the implications of these for disease spread and control.

Adult↗
PubMed2006

HIV prevention and street-based male sex workers: an evaluation of brief interventions.

The purpose of this study was to evaluate the acceptability and the comparative efficacy of brief HIV risk reduction interventions to increase condom use during paid anal sex by street-based male sex workers (MSWs). Of the 399 street-based MSWs who participated in the evaluation of acceptability, 112 participated in the evaluation of efficacy. Acceptability was evaluated by assessing completion rates. Intervention efficacy was assessed across two brief interventions, a "standard" and a "standard-plus" interventions. The primary outcome of concern was condom use during paid anal sexual encounters. In addition to this variable, changes in drug use, needle use, condom use beliefs, and condom use intention were also assessed. Results showed that almost two thirds of MSWs enrolled in a brief intervention completed it. Completion rates varied by age, race/ethnicity, sexual orientation, and HIV status. Condom use during paid anal sex increased postintervention. In addition, condom use intentions, positive condom use outcome expectations, and condom use normative expectations increased preintervention to postintervention. However, there were no significant differences between the standard and the standard-plus brief interventions in any of the outcomes measured. Brief interventions to reduce the HIV risks are acceptable to MSWs and are efficacious for reducing unprotected anal sex during paid sexual encounters.

Adolescent↗
PubMed2006

The impact of a situationally focused individual human immunodeficiency virus/sexually transmitted disease risk-reduction intervention on risk behavior in a 1-year cohort of Nigerian military personnel.

Human immunodeficiency virus (HIV) and sexually transmitted disease (STD)-related risks in peacekeeping troops is a concern when they are stationed in areas of high HIV prevalence. We carried out an assessment of a situationally focused individual HIV/STD reduction intervention (where avoidance of risk situations, as well as risk behaviors, are emphasized) in one Nigerian military unit (N = 1,222), with a comparable unit from the same service as a waiting list control (N = 987). The intervention consisted of a possible five modules that were presented to groups of up to 50 personnel. Data were collected on reported sexual behaviors, condom beliefs, sexual risk behaviors with casual partners, and number of interventions attended. Data indicated significant increases in reported condom use with casual partners and positive condom beliefs at 6- and 12-month follow-up. Risk behavior was reduced 30% from baseline at 6 months and 23% from baseline at 12 months. There was also a significant dose-response effect for number of interventions attended. These data suggest that relatively brief situationally focused individual interventions are effective in military and West African contexts in reducing HIV/STD risk behaviors.

Adolescent↗
PubMed2005

Spatial bridging in a network of drug-using male sex workers.

This study sought to determine whether drug-using male sex workers (MSWs) spatially bridge sexual networks across cities and to determine whether the behaviors of MSWs who bridge differ from the behaviors of those who do not. Data were collected from 42 MSWs in Houston, Texas, between May 2003 and February 2004. Spatial bridging was defined as having traded sex for money in another city before traveling to and trading in Houston. Cities bridged by MSWs were geographically plotted and were primarily located in the Gulf Coast and in Florida. Slightly less than half of MSWs were identified as spatially bridging from one city to another. A significantly higher proportion of MSWs who bridged cities were homosexual (55% vs. 23%) and HIV positive (31% vs. 5%). Those who bridged cities used marijuana and injected drugs more frequently and had significantly more male sex partners than MSWs who did not bridge cities. Despite the small sample size, this study found that many drug-using MSWs spatially bridge sexual networks in cities where they trade sex for money.

Adult↗
PubMed2005

A history of drug use and childhood sexual abuse among incarcerated males in a county jail.

This study explored the relationship between childhood sexual abuse and drug use among incarcerated males. A retrospective, self-reported survey was administered over an 8-week period (September and October 2001) to a random sample of 100 men who were incarcerated in a county jail. The survey included questions about childhood sexual experiences before and after puberty, drug history and use, and sexual risk-taking behaviors. Overall, 59% of this sample of male inmates reported some form of childhood sexual abuse, and all such instances occurred before or at the age of 13. Statistically significant relationships were found between drug use and childhood sexual abuse, with those who experienced childhood sexual abuse reporting drug use at percentages as much as 30% higher than those denying histories of childhood sexual abuse.

Adolescent↗
PubMed2005

The social/sexual environment of gay men residing in a rural frontier state: implications for the development of HIV prevention programs.

CONTEXT: The incidence and prevalence of HIV/AIDS is increasing among rural men who have sex with men (MSM). Yet little is known about the social/ sexual environment of rural frontier areas. PURPOSE: The purpose of this study was to assess the social/sexual environment of gay men living in rural areas and how this environment contributes to the development of HIV/AIDS prevention programs. METHODS: A qualitative study was conducted in Wyoming. In-depth guided interviews were conducted with 39 self-identified gay men. Data were analyzed for emergent themes using constant comparative analysis. FINDINGS: Four broadly related themes emerged. Participants perceive that they live in a hostile social environment in which the potential for becoming a target of violence is present. In order to cope with this social reality, men adopt strategies to assimilate into the predominant heterosexual culture and to look for sex partners. These, in turn, are related to their attitudes about HIV/AIDS and prevention activities. Notably, the Internet was discussed by participants as a means for men to connect to a larger gay society and look for sex partners and as a potential venue to HIV/AIDS prevention programs. CONCLUSIONS: Data provided a number of implications for developing HIV/AIDS prevention programs targeting rural MSM. Especially apparent was the need for programs to be mindful of the desire to keep one's sexual preferences shielded from public knowledge and the effect this may have on recruiting rural MSM to participate in prevention activities. The Internet, because men can access it privately, might provide a venue for prevention projects.

Adult↗
PubMed2005

Reported condom use and condom use difficulties in street outreach samples of men of four racial and ethnic backgrounds.

The epidemiology of the HIV/AIDS epidemic in the United States has focused research attention on lesbian, gay, bisexual and transgendered communities as well as on racial and ethnic minorities. Much of that attention has, however, been focused on specific racial and ethnic groups, and specific sexual minorities. We report on the results of a study that examined the association between condom use and partnership types among men from four major racial/ethnic groups. Self-reported data on sexual identity (homosexual, bisexual, and heterosexual) and condom use in the past three months were collected from 806 African Americans, Hispanic, Asian, and white men intercepted in public places in Houston, TX. Data indicated that condom use was lowest in African Americans and Hispanic men, bisexual men reported the highest levels of use, with heterosexual men reporting the lowest use. African Americans and Hispanic men reported generally that it was very difficult to use a condom during sexual contact, although the patterns for self-identified homosexual, heterosexual, and bisexual men varied across race/ethnicity. Homosexual African American men reported the least difficulty, and white homosexual men the most difficulty compared with heterosexual and bisexual peers. For homosexually identified men, there were considerable differences across race/ethnicity in the proportion of partners who never or rarely disagreed to use condoms, with Asians disagreeing least, and African Americans most. Within racial/ethnic groups, the levels of condom use and difficulty were similar for male and female partners, suggesting that it is sexual identity, rather than partner gender, that has impacted condom-use messages. These data suggest that racial/ethnic targeting of condom use is likely to be most efficacious in increasing condom use in men.

Adolescent↗
PubMed2004

Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples.

BACKGROUND: The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. METHODS: Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. RESULTS: Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft), and they were also those most likely to have injected drugs rather than administered them by any other route (p < 0.001). In addition, bisexual or homosexual identification was reported by more respondents in the sex exchange as primary source of income category. The number of sexual partners in the last three months followed a similar pattern, with those whose primary source of income was drug dealing or theft reporting relatively high partner numbers. CONCLUSIONS: These data suggest that social disadvantage is associated with HIV risk in part by its association with drug and sex work for survival, and offers one variable that may be associated with the concentration of disease among those at greatest disadvantage by having an illegal and unstable primary income source.

Journal Article↗
PubMed2003

Situational correlates of condom use in a sample of African-American drug users who are primarily crack cocaine users.

We studied the situational determinants of condom use for vaginal sex in 151 African-American crack cocaine users in Houston, Texas, using situational presentation (Sitpres) methodology, which uses hypothetical scenarios with randomly generated levels of eight variables across 10 scenarios that may impact the decision to use a condom. Multiple regression showed that variables associated with a high probability of using a condom were older age, how badly the partner wants to use a condom, and how badly the respondent wants vaginal sex. Crack craving or level of intoxication were not correlates. The Sitpres methodology was successfully used by these crack users and data indicated that it was sexual variables, rather than drug-associated variables, that were significantly associated with condom use.

Adolescent↗