[Drug-induced Stevens-Johnson syndrome in a patient with AIDS]

The Stevens-Johnson syndrome is a severe potentially life-threatening form of the erythema multiforme, affecting both skin and mucous membranes. We present a case of a 49-year-old male patient with AIDS who developed a Stevens-Johnson syndrome while being treated with pyrimethamine, sulfadiazine and phenytoin for cerebral toxoplasmosis. Further diagnostic evaluation of this dangerous cutaneous affection may prove difficult for several reasons. In particular, in patients with AIDS who are more susceptible for adverse drug reactions and who are simultaneously receiving a variety of drugs with a considerable potential of cutaneous side effects, therapy cannot be withhold for lack of therapeutic alternatives. Moreover, the low lymphocyte count in this case may have made reliable testing with lymphocyte transformation studies impossible. The evaluation and the differential diagnosis of the drug-induced Stevens-Johnson syndrome are discussed. Especially long- and moderately long-acting sulfonamides belong to the most important agents that can cause a drug-induced Stevens-Johnson syndrome. The pathogenesis and the risk factors for cutaneous hypersensitivity reactions in HIV-infected patients are only poorly understood. These kind of reactions, however, seem to occur more often in patients with a more advanced immunodeficiency.

Antiretroviral penetration into the CNS and incidence of AIDS-defining neurologic conditions

OBJECTIVE The link between CNS penetration of antiretrovirals and AIDS-defining neurologic disorders remains largely unknown.METHODS: HIV-infected, antiretroviral therapy-naive individuals in the HIV-CAUSAL Collaboration who started an antiretroviral regimen were classified according to the CNS Penetration Effectiveness (CPE) score of their initial regimen into low (<8), medium (8-9), or high (>9) CPE score. We estimated "intention-to-treat" hazard ratios of 4 neuroAIDS conditions for baseline regimens with high and medium CPE scores compared with regimens with a low score. We used inverse probability weighting to adjust for potential bias due to infrequent follow-up.RESULTS: A total of 61,938 individuals were followed for a median (interquartile range) of 37 (18, 70) months. During follow-up, there were 235 cases of HIV dementia, 169 cases of toxoplasmosis, 128 cases of cryptococcal meningitis, and 141 cases of progressive multifocal leukoencephalopathy. The hazard ratio (95% confidence interval) for initiating a combined antiretroviral therapy regimen with a high vs low CPE score was 1.74 (1.15, 2.65) for HIV dementia, 0.90 (0.50, 1.62) for toxoplasmosis, 1.13 (0.61, 2.11) for cryptococcal meningitis, and 1.32 (0.71, 2.47) for progressive multifocal leukoencephalopathy. The respective hazard ratios (95% confidence intervals) for a medium vs low CPE score were 1.01 (0.73, 1.39), 0.80 (0.56, 1.15), 1.08 (0.73, 1.62), and 1.08 (0.73, 1.58).CONCLUSIONS: We estimated that initiation of a combined antiretroviral therapy regimen with a high CPE score increases the risk of HIV dementia, but not of other neuroAIDS conditions.

Cancer risk and use of protease inhibitor or nonnucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy: the d: a: d study.

BACKGROUND The association between combination antiretroviral therapy (cART) and cancer risk, especially regimens containing protease inhibitors (PIs) or nonnucleoside reverse transcriptase inhibitors (NNRTIs), is unclear. METHODS Participants were followed from the latest of D:A:D study entry or January 1, 2004, until the earliest of a first cancer diagnosis, February 1, 2012, death, or 6 months after the last visit. Multivariable Poisson regression models assessed associations between cumulative (per year) use of either any cART or PI/NNRTI, and the incidence of any cancer, non-AIDS-defining cancers (NADC), AIDS-defining cancers (ADC), and the most frequently occurring ADC (Kaposi sarcoma, non-Hodgkin lymphoma) and NADC (lung, invasive anal, head/neck cancers, and Hodgkin lymphoma). RESULTS A total of 41,762 persons contributed 241,556 person-years (PY). A total of 1832 cancers were diagnosed [incidence rate: 0.76/100 PY (95% confidence interval: 0.72 to 0.79)], 718 ADC [0.30/100 PY (0.28-0.32)], and 1114 NADC [0.46/100 PY (0.43-0.49)]. Longer exposure to cART was associated with a lower ADC risk [adjusted rate ratio: 0.88/year (0.85-0.92)] but a higher NADC risk [1.02/year (1.00-1.03)]. Both PI and NNRTI use were associated with a lower ADC risk [PI: 0.96/year (0.92-1.00); NNRTI: 0.86/year (0.81-0.91)]. PI use was associated with a higher NADC risk [1.03/year (1.01-1.05)]. Although this was largely driven by an association with anal cancer [1.08/year (1.04-1.13)], the association remained after excluding anal cancers from the end point [1.02/year (1.01-1.04)]. No association was seen between NNRTI use and NADC [1.00/year (0.98-1.02)]. CONCLUSIONS Cumulative use of PIs may be associated with a higher risk of anal cancer and possibly other NADC. Further investigation of biological mechanisms is warranted.

Sports after Busy Work: Work-Related Cognitive Failure Corresponds to Risk Bearing Behaviors and Athletic Injury

Although employees are encouraged to take exercise after work to keep physically fit, they should not suffer injury. Some sports injuries that occur after work appear to be work-related and preventable. This study investigated whether cognitive failure mediates the influence of mental work demands and conscientiousness on risk-taking and risky and unaware behaviour during after-work sports activities. Participants were 129 employees (36% female) who regularly took part in team sports after work. A structural equation model showed that work-related cognitive failure significantly mediated the influence of mental work demands on risky behaviour during sports (p < .05) and also mediated the directional link between conscientiousness and risky behaviour during sports (p < .05). A path from risky behaviour during sports to sports injuries in the last four weeks was also significant (p < .05). Performance constraints, time pressure, and task uncertainty are likely to increase cognitive load and thereby boost cognitive failures both during work and sports activities after work. Some sports injuries after work could be prevented by addressing the issue of work redesign.

Cultural capital and smoking in young adults: applying new indicators to explore social inequalities in health behaviour.

BACKGROUND Associations between social status and health behaviours are well documented, but the mechanisms involved are less understood. Cultural capital theory may contribute to a better understanding by expanding the scope of inequality indicators to include individuals' knowledge, skills, beliefs and material goods to examine how these indicators impact individuals' health lifestyles. We explore the structure and applicability of a set of cultural capital indicators in the empirical exploration of smoking behaviour among young male adults. METHODS We analysed data from the Swiss Federal Survey of Adolescents (CH-X) 2010-11 panel of young Swiss males (n = 10 736). A set of nine theoretically relevant variables (including incorporated, institutionalized and objectified cultural capital) were investigated using exploratory factor analysis. Regression models were run to observe the association between factor scores and smoking outcomes. Outcome measures consisted of daily smoking status and the number of cigarettes smoked by daily smokers. RESULTS Cultural capital indicators aggregated in a three-factor solution representing 'health values', 'education and knowledge' and 'family resources'. Each factor score predicted the smoking outcomes. In young males, scoring low on health values, education and knowledge and family resources was associated with a higher risk of being a daily smoker and of smoking more cigarettes daily. CONCLUSION Cultural capital measures that include, but go beyond, educational attainment can improve prediction models of smoking in young male adults. New measures of cultural capital may thus contribute to our understanding of the social status-based resources that individuals can use towards health behaviours.

Avalanche risk assessment - a multi-temporal approach, results from Galtür, Austria

Snow avalanches pose a threat to settlements and infrastructure in alpine environments. Due to the catastrophic events in recent years, the public is more aware of this phenomenon. Alpine settlements have always been confronted with natural hazards, but changes in land use and in dealing with avalanche hazards lead to an altering perception of this threat. In this study, a multi-temporal risk assessment is presented for three avalanche tracks in the municipality of Galtür, Austria. Changes in avalanche risk as well as changes in the risk-influencing factors (process behaviour, values at risk (buildings) and vulnerability) between 1950 and 2000 are quantified. An additional focus is put on the interconnection between these factors and their influence on the resulting risk. The avalanche processes were calculated using different simulation models (SAMOS as well as ELBA+). For each avalanche track, different scenarios were calculated according to the development of mitigation measures. The focus of the study was on a multi-temporal risk assessment; consequently the used models could be replaced with other snow avalanche models providing the same functionalities. The monetary values of buildings were estimated using the volume of the buildings and average prices per cubic meter. The changing size of the buildings over time was inferred from construction plans. The vulnerability of the buildings is understood as a degree of loss to a given element within the area affected by natural hazards. A vulnerability function for different construction types of buildings that depends on avalanche pressure was used to assess the degree of loss. No general risk trend could be determined for the studied avalanche tracks. Due to the high complexity of the variations in risk, small changes of one of several influencing factors can cause considerable differences in the resulting risk. This multi-temporal approach leads to better understanding of the today's risk by identifying the main changes and the underlying processes. Furthermore, this knowledge can be implemented in strategies for sustainable development in Alpine settlements.

Essentials from the 2015 European AIDS Clinical Society (EACS) guidelines for the treatment of adult HIV-positive persons.

BACKGROUND The European AIDS Clinical Society (EACS) guidelines are intended for all clinicians involved in the care of HIV-positive persons, and are available in print, online, and as a free App for download for iPhone and Android. GUIDELINE HIGHLIGHTS The 2015 version of the EACS guidelines contains major revisions in all sections; antiretroviral treatment (ART), comorbidities, coinfections and opportunistic diseases. Among the key revisions is the recommendation of ART for all HIV-positive persons, irrespectively of CD4 count, based on the Strategic Timing of AntiRetroviral Treatment (START) study results. The recommendations for the preferred and the alternative ART options have also been revised, and a new section on the use of pre-exposure prophylaxis (PrEP) has been added. A number of new antiretroviral drugs/drug combinations have been added to the updated tables on drug-drug interactions, adverse drug effects, dose adjustment for renal/liver insufficiency and for ART administration in persons with swallowing difficulties. The revisions of the coinfection section reflect the major advances in anti-hepatitis C virus (HCV) treatment with direct-acting antivirals with earlier start of treatment in individuals at increased risk of liver disease progression, and a phasing out of interferon-containing treatment regimens. The section on opportunistic diseases has been restructured according to individual pathogens/diseases and a new overview table has been added on CD4 count thresholds for different primary prophylaxes. CONCLUSIONS The diagnosis and management of HIV infection and related coinfections, opportunistic diseases and comorbidities continue to require a multidisciplinary effort for which the 2015 version of the EACS guidelines provides an easily accessable and updated overview.

Incidence of AIDS-Defining and Other Cancers in HIV-Positive Children in South Africa: Record Linkage Study.

BACKGROUND Little is known on the risk of cancer in HIV-positive children in sub-Saharan Africa. We examined incidence and risk factors of AIDS-defining and other cancers in pediatric antiretroviral therapy (ART) programs in South Africa. METHODS We linked the records of five ART programs in Johannesburg and Cape Town to those of pediatric oncology units, based on name and surname, date of birth, folder and civil identification numbers. We calculated incidence rates and obtained hazard ratios (HR) with 95% confidence intervals (CI) from Cox regression models including ART, sex, age, and degree of immunodeficiency. Missing CD4 counts and CD4% were multiply imputed. Immunodeficiency was defined according to World Health Organization 2005 criteria. RESULTS Data of 11,707 HIV-positive children were included in the analysis. During 29,348 person-years of follow-up 24 cancers were diagnosed, for an incidence rate of 82 per 100,000 person-years (95% CI 55-122). The most frequent cancers were Kaposi Sarcoma (34 per 100,000 person-years) and Non Hodgkin Lymphoma (31 per 100,000 person-years). The incidence of non AIDS-defining malignancies was 17 per 100,000. The risk of developing cancer was lower on ART (HR 0.29, 95%CI 0.09-0.86), and increased with age at enrolment (>10 versus <3 years: HR 7.3, 95% CI 2.2-24.6) and immunodeficiency at enrolment (advanced/severe versus no/mild: HR 3.5, 95%CI 1.1-12.0). The HR for the effect of ART from complete case analysis was similar but ceased to be statistically significant (p=0.078). CONCLUSIONS Early HIV diagnosis and linkage to care, with start of ART before advanced immunodeficiency develops, may substantially reduce the burden of cancer in HIV-positive children in South Africa and elsewhere.

When to Monitor CD4 Cell Count and HIV RNA to Reduce Mortality and AIDS-Defining Illness in Virologically Suppressed HIV-Positive Persons on Antiretroviral Therapy in High-Income Countries: A Prospective Observational Study.

OBJECTIVE To illustrate an approach to compare CD4 cell count and HIV-RNA monitoring strategies in HIV-positive individuals on antiretroviral therapy (ART). DESIGN Prospective studies of HIV-positive individuals in Europe and the USA in the HIV-CAUSAL Collaboration and The Center for AIDS Research Network of Integrated Clinical Systems. METHODS Antiretroviral-naive individuals who initiated ART and became virologically suppressed within 12 months were followed from the date of suppression. We compared 3 CD4 cell count and HIV-RNA monitoring strategies: once every (1) 3 ± 1 months, (2) 6 ± 1 months, and (3) 9-12 ± 1 months. We used inverse-probability weighted models to compare these strategies with respect to clinical, immunologic, and virologic outcomes. RESULTS In 39,029 eligible individuals, there were 265 deaths and 690 AIDS-defining illnesses or deaths. Compared with the 3-month strategy, the mortality hazard ratios (95% CIs) were 0.86 (0.42 to 1.78) for the 6 months and 0.82 (0.46 to 1.47) for the 9-12 month strategy. The respective 18-month risk ratios (95% CIs) of virologic failure (RNA >200) were 0.74 (0.46 to 1.19) and 2.35 (1.56 to 3.54) and 18-month mean CD4 differences (95% CIs) were -5.3 (-18.6 to 7.9) and -31.7 (-52.0 to -11.3). The estimates for the 2-year risk of AIDS-defining illness or death were similar across strategies. CONCLUSIONS Our findings suggest that monitoring frequency of virologically suppressed individuals can be decreased from every 3 months to every 6, 9, or 12 months with respect to clinical outcomes. Because effects of different monitoring strategies could take years to materialize, longer follow-up is needed to fully evaluate this question.

HIV incidence estimates and HIV/AIDS concurrent diagnosis in Houston/Harris County

The purpose of this dissertation was to estimate HIV incidence among the individuals who had HIV tests performed at the Houston Department of Health and Human Services (HDHHS) public health laboratory, and to examine the prevalence of HIV and AIDS concurrent diagnoses among HIV cases reported between 2000 and 2007 in Houston/Harris County. ^ The first study in this dissertation estimated the cumulative HIV incidence among the individuals testing at Houston public health laboratory using Serologic Testing Algorithms for Recent HIV Seroconversion (STARHS) during the two year study period (June 1, 2005 to May 31, 2007). The HIV incidence was estimated using two independently developed statistical imputation methods, one developed by the Centers for Disease Control and Prevention (CDC), and the other developed by HDHHS. Among the 54,394 persons who tested for HIV during the study period, 942 tested HIV positive (positivity rate=1.7%). Of these HIV positives, 448 (48%) were newly reported to the Houston HIV/AIDS Reporting System (HARS) and 417 of these 448 blood specimens (93%) were available for STARHS testing. The STARHS results showed 139 (33%) out of the 417 specimens were newly infected with HIV. Using both the CDC and HDHHS methods, the estimated cumulative HIV incidences over the two-year study period were similar: 862 per 100,000 persons (95% CI: 655-1,070) by CDC method, and 925 per 100,000 persons (95% CI: 908-943) by HDHHS method. Consistent with the national finding, this study found African Americans, and men who have sex with men (MSM) accounted for most of the new HIV infections among the individuals testing at Houston public health laboratory. Using CDC statistical method, this study also found the highest cumulative HIV incidence (2,176 per 100,000 persons [95%CI: 1,536-2,798]) was among those who tested in the HIV counseling and testing sites, compared to the sexually transmitted disease clinics (1,242 per 100,000 persons [95%CI: 871-1,608]) and city health clinics (215 per 100,000 persons [95%CI: 80-353]. This finding suggested the HIV counseling and testing sites in Houston were successful in reaching high risk populations and testing them early for HIV. In addition, older age groups had higher cumulative HIV incidence, but accounted for smaller proportions of new HIV infections. The incidence in the 30-39 age group (994 per 100,000 persons [95%CI: 625-1,363]) was 1.5 times the incidence in 13-29 age group (645 per 100,000 persons [95%CI: 447-840]); the incidences in 40-49 age group (1,371 per 100,000 persons [95%CI: 765-1,977]) and 50 or above age groups (1,369 per 100,000 persons [95%CI: 318-2,415]) were 2.1 times compared to the youngest 13-29 age group. The increased HIV incidence in older age groups suggested that persons 40 or above were still at risk to contract HIV infections. HIV prevention programs should encourage more people who are age 40 and above to test for HIV. ^ The second study investigated concurrent diagnoses of HIV and AIDS in Houston. Concurrent HIV/AIDS diagnosis is defined as AIDS diagnosis within three months of HIV diagnosis. This study found about one-third of the HIV cases were diagnosed with HIV and AIDS concurrently (within three months) in Houston/Harris County. Using multivariable logistic regression analysis, this study found being male, Hispanic, older, and diagnosed in the private sector of care were positively associated with concurrent HIV and AIDS diagnoses. By contrast, men who had sex with men and also used injection drugs (MSM/IDU) were 0.64 times (95% CI: 0.44-0.93) less likely to have concurrent HIV and AIDS diagnoses. A sensitivity analysis comparing difference durations of elapsed time for concurrent HIV and AIDS diagnosis definitions (1-month, 3-month, and 12-month cut-offs) affected the effect size of the odds ratios, but not the direction. ^ The results of these two studies, one describing characteristics of the individuals who were newly infected with HIV, and the other study describing persons who were diagnosed with HIV and AIDS concurrently, can be used as a reference for HIV prevention program planning in Houston/Harris County. ^

Psychosocial predictors of HIV testing behaviors among high risk heterosexuals

Though a lot of progress has been made in the treatment, prevention, and in increasing the knowledge and awareness of HIV/AIDS, the CDC reports that over 21% of the people infected with HIV are unaware of their HIV serostatus. Thirty-one percent of people infected with HIV are diagnosed late in the disease progression, often too late to prevent the transmission or the progression of HIV to AIDS. CDC has set a goal to increase by the year 2010, the number of people aware of the HIV serostatus by 5%. ^ This study examined the association between decision-making and risk-taking (assessed using the decision-making confidence and risk-taking scales of the Texas Christian University Self Rating Form) and HIV testing behaviors within a population of heterosexuals at risk for HIV infections living in Harris County, Texas (N=923). Data used in the study was obtained during the first cycle of the National HIV Behavioral Surveillance among heterosexuals at risk for HIV infection (NHBS-HET1), conducted from October, 2006 to June, 2007. Eighty percent of the study population reported testing for HIV at some point in their lives. The results showed that individuals who scored high (>3.3) on the decision-making confidence scale of the TCU/SRF were more likely to be tested for HIV when compared to those who scored low on the scale (OR= 2.02, 95% CI= 1.44–2.84), and that individuals who score low on the risk-taking scale of the TCU/SRF were more likely to have been tested for HIV when compared to those who scored high on the scale (OR= 1.65, 95% CI= 1.2–2.31). Several demographic factors were also assessed for their association with HIV testing behaviors. Only sex was found to be associated with HIV testing. ^ The findings suggest that risk-taking and decision-making are predictors of HIV testing behaviors such as prior HIV testing within heterosexuals living in high-risk areas of Houston, Texas, and that intervention designed to improve the risk-taking and decision-making attributes of this population might improve HIV testing within this population.^

The influence of HIV/AIDS on the association between genital human papillomavirus and cervical cancer in HIV/AIDS infected women: A literature review

Background: With over 440 million cases of infections worldwide, genital HPV is the most frequent sexually transmitted infection. There are several types including high risk types 16, 18, 58 and 70 among others, which are known to cause cervical cell abnormality and if persistent, can lead to cervical cancer which globally, claims 288,000 lives annually. 33.4 million people worldwide are currently living with HIV/AIDS, with 22.4 million in sub-Saharan Africa where 70% of the female population living with HIV/AIDS is also found. Similar risk factors for HPV, cervical cancer and HIV/AIDS include early age at sexual debut, multiple sexual partners, infrequent condom use, history of STI and immune-suppression. ^ Objectives: To describe the role of HPV in cervical cancer development, to describe the influence of HIV/AIDS on HPV and in the development of cervical cancer and to describe the importance of preventive measures such as screening. ^ Methods: This is a literature review where data were analyzed qualitatively and a descriptive narrative style used to evaluate and present the information. The data came from searches using Pub Med, Cochrane Library, EBSCO Medline databases as well as websites such as the CDC and WHO. Articles selected were published in English over the last 10 years. Keywords used included: 'HPV, cervical cancer and HIV', 'HIV and HPV', 'HPV and cervical cancer', 'HPV infection', 'HPV vaccine', 'genital HPV', 'HIV and cervical cancer', 'prevalence of HIV and cervical cancer' and 'prevalence of cervical cancer'. ^ Results: Women with HIV/AIDS have multiple HPV types, persistent infection, are more likely to present with cervical neoplasia and are at higher risk for cervical cancer. Research also shows that HIV could affect the transmissibility of HPV and that HPV itself could also increase the susceptibility to HIV acquisition. ^ Conclusion: HIV, genital HPV and cervical cancer are all preventable. Need to emphasize programs that aim to increase HIV/AIDS, HPV and cervical cancer awareness. Stress importance of behavior modification such as frequent use of condoms, decreased sexual partners and delayed first intercourse. Facilitate programs for screening and treating HPV, male circumcision, effective management of HAART and HPV vaccination.^

Is family medicine meeting the HIV/AIDS challenge? A national survey of family physicians' beliefs, clinical competence, and experience regarding HIV disease

A national sample of family physicians was surveyed to (1) assess family physicians' beliefs about the human immunodeficiency virus (HIV) and individuals at risk for infection, their clinical competence regarding HIV-related issues, and their experiences with HIV disease; (2) present conclusions to the American Academy of Family Physicians (AAFP) to effect the development of an early clinical care protocol and a continuing medical education curriculum; and (3) collect base-line data for use in the evaluation of an early clinical care protocol and a continuing medical education curriculum, in the case that such programs are developed and disseminated. After considering retired or deceased respondents, of the 2,660 physicians surveyed, 1,678 (63.7%) responded. The resulting sample was representative of the active members of the AAFP. About 77% of the respondents were unable to accurately identify the universal precautions for blood and body fluids to prevent occupational transmission of HIV or hepatitis B virus (HBV). Residency trained and board certified physicians expressed fewer "external constraints," such as fear of losing patients, obviating them from providing treatment to individuals with HIV disease (p =.004 and p $<$.001, respectively). These physicians also manifested fewer "internal constraints" to the provision of HIV treatment, such as fear of becoming infected (p $<$.001 and p =.012, respectively). Residency trained physicians also expressed a greater comfort with discussing sexually-related topics with their patients than did non-residency trained physicians (p $<$.001). There were 67.1% of the physicians surveyed who reported never providing treatment to an individual with HIV disease. Residency trained and board certified physicians expressed a greater likelihood to provide treatment to HIV-infected patients (p $<$.001) than non-residency trained and non-board certified physicians.^ Among the various primary care specialties, family medicine is especially vulnerable to the current challenges of HIV/AIDS. These challenges are augmented by the epidemiologic pattern that characterizes AIDS. For the past several years, we have seen AIDS in this country assume a similar pattern to that seen in most other countries; HIV is becoming increasingly prevalent in the heterosexual population as well as in locations removed from metropolitan centers. This current phase of the epidemic generates greater pressures upon primary care physicians, particularly family physicians, to become better acquainted with the means to provide early care to HIV/AIDS patients and to prevent HIV/AIDS among their patients. Family medicine is especially appropriate for providing care to HIV patients because family medicine involves treatment to all age groups and conditions; other primary care specialties focus on limited patient populations or specific conditions. Family physicians should be armed with the expertise to confront HIV/AIDS. However, family physicians' clinical competence and experience with HIV is not known. The data collected in this survey describes their competencies, attitudes, and experiences. ^

Literature review of estimation of prevalence rate of HIV/AIDS in India using population survey and sentinel surveillance based data

HIV/AIDS is a treatable although incurable disease that presents immense challenges to those infected including physical, social and psychological effects. As of 2009, an estimated 2.4 million people were living with HIV or AIDS in India, 0.3% of the country's population. In India, it is difficult to not only treat but also to track because it is associated with socio-economic factors such as illiteracy, social biases, poor sanitation, malnutrition and social class. Nevertheless, it is important to know the prevalence of HIV/AIDS for several reasons. At the individual level, the quality of life of people living with HIV/AIDS is markedly lower than their counterparts without the disease and is associated with challenges. At the community level, it is important to identify high risk groups, monitor prevention efforts, and allocate appropriate resources to target programs for the reduction of transmission of HIV. ^

Prevalence of Staphylococcus aureus colonization among high-risk HIV populations

Staphylococcus aureus is a common microorganism in humans, typically colonizing the nasopharynx, skin and other mucosal surfaces. It is among the most frequent causes of clinically-significant bacterial infections accounting for increased morbidity and mortality among individuals with HIV/AIDS. Evidence of higher colonization rates among high-risk HIV populations have been observed however, prevalence estimates have varied. Additionally, behavioral, biological, and/or environmental factors that may account for these high colonization rates are not understood. Previous literature on clinic-based surveys were subject to considerable biases. Additionally, representative samples of high-risk HIV populations were difficult to obtain due in part to an underrepresentation of individuals who may not regularly obtain health care. ^ The main objective of this project is to determine the prevalence of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant (MRSA) nasal colonization in two populations: 1) men who have sex with men (MSM) and 2) injection drug users (IDU). Both of these populations are included in the third round of the National HIV Behavioral Surveillance System (NHBS) in Houston, Texas. ^ In the NHBS-MSM3 study, logistic regression was used to report odds ratios and 95% confidence intervals (CI). For the NHBS-IDU3 study, to account for the lack of independence between samples, the method of generalized estimating equations was utilized to report adjusted odds ratios and 95% CI. The NHBS-MSM3 study enrolled 202 participants with a MSSA colonization rate of 26.7% and MRSA rate of 3%. In the NHBS-IDU3 study, 18.4% were nasally colonized with MSSA and 5.7% were nasally colonized with MRSA. Among the NHBS-MSM3 population, high-risk sexual practices were associated with colonization. For the NHBS-IDU3 population, age, marital status, employment status, and the presence of scabs, were associated with colonization status when controlling for size of recruitment network. In multivariate GEE analyses, the use of antiretroviral medications and age remained significantly associated with S. aureus nasal colonization when controlling for size of recruitment network and gender. In both studies, a significantly higher than expected S. aureus and MRSA colonization rate was observed as compared to colonization rates described for the general population. However, these estimates were moderate in comparison to reported clinic-based MSM and IDU S. aureus colonization findings. This study validates substantial prevalence differences and biases that may exist with data collected from clinic-based MSM and IDU. The prevalence of MSSA and MRSA nasal colonization did not differ significantly with respect to HIV status among NHBS-MSM3/NHBS-IDU3 participants. Continued examination on the effects of S. aureus colonization and infection should be examined longitudinally to confirm additional community-based determinants in populations that are disproportionately affected.^