Mortality from HIV and TB coinfections is higher in Eastern Europe than in Western Europe and Argentina

BACKGROUND AND OBJECTIVES: Tuberculosis (TB) is a leading cause of death in HIV-infected patients worldwide. We aimed to study clinical characteristics and outcome of 1075 consecutive patients diagnosed with HIV/TB from 2004 to 2006 in Europe and Argentina. METHODS: One-year mortality was assessed in patients stratified according to region of residence, and factors associated with death were evaluated in multivariable Cox models. RESULTS: At TB diagnosis, patients in Eastern Europe had less advanced immunodeficiency, whereas a greater proportion had a history of intravenous drug use, coinfection with hepatitis C, disseminated TB, and infection with drug-resistant TB (P < 0.0001). In Eastern Europe, fewer patients initiated TB treatment containing at least rifamycin, isoniazid, and pyrazinamide or combination antiretroviral therapy (P < 0.0001). Mortality at 1 year was 27% in Eastern Europe, compared with 7, 9 and 11% in Central/Northern Europe, Southern Europe, and Argentina, respectively (P < 0.0001). In a multivariable model, the adjusted relative hazard of death was significantly lower in each of the other regions compared with Eastern Europe: 0.34 (95% confidence interval 0.17-0.65), 0.28 (0.14-0.57), 0.34 (0.15-0.77) in Argentina, Southern Europe and Central/Northern Europe, respectively. Factors significantly associated with increased mortality were CD4 cell count less than 200 cells/microl [2.31 (1.56-3.45)], prior AIDS [1.74 (1.22-2.47)], disseminated TB [2.00 (1.38-2.85)], initiation of TB treatment not including rifamycin, isoniazid and pyrazinamide [1.68 (1.20-2.36)], and rifamycin resistance [2.10 (1.29-3.41)]. Adjusting for these known confounders did not explain the increased mortality seen in Eastern Europe. CONCLUSION: The poor outcome of patients with HIV/TB in Eastern Europe deserves further study and urgent public health attention.

HIV-related malignancies: A community-based study using a linkage of cancer registry and HIV registry data

Background. Increased incidence of cancer is documented in immunosuppressed transplant patients. Likewise, as survival increases for persons infected with the Human Immunodeficiency Virus (HIV), we expect their incidence of cancer to increase. The objective of this study was to examine the current gender specific spectrum of cancer in an HIV infected cohort (especially malignancies not currently associated with Acquired Immunodeficiency Syndrome (AIDS)) in relation to the general population.^ Methods. Cancer incidence data was collected for residents of Harris County, Texas who were diagnosed with a malignancy between 1975 and 1994. This data was linked to HIV/AIDS registry data to identify malignancies in an HIV infected cohort of 14,986 persons. A standardized incidence ratio (SIR) analysis was used to compare incidence of cancer in this cohort to that in the general population. Risk factors such as mode of HIV infection, age, race and gender, were evaluated for contribution to the development of cancer within the HIV cohort, using Cox regression techniques.^ Findings. Of those in the HIV infected cohort, 2289 persons (15%) were identified as having one or more malignancies. The linkage identified 29.5% of these malignancies (males 28.7% females 60.9%). HIV infected men and women had incidences of cancer that were 16.7 (16.1, 17.3) and 2.9 (2.3, 3.7) times that expected for the general population of Harris County, Texas, adjusting for age. Significant SIR's were observed for the AIDS-defining malignancies of Kaposi's sarcoma, non-Hodgkin's lymphoma, primary lymphoma of the brain and cancer of the cervix. Additionally, significant SIR's for non-melanotic skin cancer in males, 6.9 (4.8, 9.5) and colon cancer in females, 4.0 (1.1, 10.2) were detected. Among the HIV infected cohort, race/ethnicity of White (relative risk 2.4 with 95% confidence intervals 2.0, 2.8) or Spanish Surname, 2.2 (1.9, 2.7) and an infection route of male to male sex, with, 3.0 (1.9, 4.9) or without, 3.4 (2.1, 5.5) intravenous drug use, increased the risk of having a diagnosis of an incident cancer.^ Interpretation. There appears to be an increased risk of developing cancer if infected with the HIV. In addition to the malignancies routinely associated with HIV infection, there appears to be an increased risk of being diagnosed with non-melanotic skin cancer in males and colon cancer in females. ^

Social Meets Molecular: Combining Phylogenetic and Latent Class Analyses to Understand HIV-1 Transmission in Switzerland

Switzerland has a complex human immunodeficiency virus (HIV) epidemic involving several populations. We examined transmission of HIV type 1 (HIV-1) in a national cohort study. Latent class analysis was used to identify socioeconomic and behavioral groups among 6,027 patients enrolled in the Swiss HIV Cohort Study between 2000 and 2011. Phylogenetic analysis of sequence data, available for 4,013 patients, was used to identify transmission clusters. Concordance between sociobehavioral groups and transmission clusters was assessed in correlation and multiple correspondence analyses. A total of 2,696 patients were infected with subtype B, 203 with subtype C, 196 with subtype A, and 733 with recombinant subtypes (mainly CRF02_AG and CRF01_AE). Latent class analysis identified 8 patient groups. Most transmission clusters of subtype B were shared between groups of gay men (groups 1-3) or between the heterosexual groups "heterosexual people of lower socioeconomic position" (group 4) and "injection drug users" (group 8). Clusters linking homosexual and heterosexual groups were associated with "older heterosexual and gay people on welfare" (group 5). "Migrant women in heterosexual partnerships" (group 6) and "heterosexual migrants on welfare" (group 7) shared non-B clusters with groups 4 and 5. Combining approaches from social and molecular epidemiology can provide insights into HIV-1 transmission and inform the design of prevention strategies.

Psychosocial aspects on the treatment of HIV-infection

Psychological and social factors have a deep impact on the treatment of HIV-infection, from the readiness to start antiretroviral therapy to treatment adherence over time. Among psychological factors, anxiety may affect HIV-infected persons in all stages of disease, from the disclosure of HIV diagnosis to the decision to start and maintain treatment. This is a lifelong challenge for both patients and doctors. Psychiatric comorbidities (depression, addiction) may enhance negative psychological effects of HIV. Among social factors, stigma and discrimination may occur in families and at work, leading to a loss of social support resulting in isolation and poverty. This may prevent HIV-positive individuals from seeking medical care. These aspects are particularly important in some groups of patients as injecting drug users and migrants. Acknowledgment and consideration of psychosocial factors are therefore essential for the long term success of antiretroviral therapy.

Loss to follow-up of HIV-infected women after delivery: The Swiss HIV Cohort Study and the Swiss Mother and Child HIV Cohort Study.

INTRODUCTION HIV-infected pregnant women are very likely to engage in HIV medical care to prevent transmission of HIV to their newborn. After delivery, however, childcare and competing commitments might lead to disengagement from HIV care. The aim of this study was to quantify loss to follow-up (LTFU) from HIV care after delivery and to identify risk factors for LTFU. METHODS We used data on 719 pregnancies within the Swiss HIV Cohort Study from 1996 to 2012 and with information on follow-up visits available. Two LTFU events were defined: no clinical visit for >180 days and no visit for >360 days in the year after delivery. Logistic regression analysis was used to identify risk factors for a LTFU event after delivery. RESULTS Median maternal age at delivery was 32 years (IQR 28-36), 357 (49%) women were black, 280 (39%) white, 56 (8%) Asian and 4% other ethnicities. One hundred and seven (15%) women reported any history of IDU. The majority (524, 73%) of women received their HIV diagnosis before pregnancy, most of those (413, 79%) had lived with diagnosed HIV longer than three years and two-thirds (342, 65%) were already on antiretroviral therapy (ART) at time of conception. Of the 181 women diagnosed during pregnancy by a screening test, 80 (44%) were diagnosed in the first trimester, 67 (37%) in the second and 34 (19%) in the third trimester. Of 357 (69%) women who had been seen in HIV medical care during three months before conception, 93% achieved an undetectable HIV viral load (VL) at delivery. Of 62 (12%) women with the last medical visit more than six months before conception, only 72% achieved an undetectable VL (p=0.001). Overall, 247 (34%) women were LTFU over 180 days in the year after delivery and 86 (12%) women were LTFU over 360 days with 43 (50%) of those women returning. Being LTFU for 180 days was significantly associated with history of intravenous drug use (aOR 1.73, 95% CI 1.09-2.77, p=0.021) and not achieving an undetectable VL at delivery (aOR 1.79, 95% CI 1.03-3.11, p=0.040) after adjusting for maternal age, ethnicity, time of HIV diagnosis and being on ART at conception. CONCLUSIONS Women with a history of IDU and women with a detectable VL at delivery were more likely to be LTFU after delivery. This is of concern regarding their own health, as well as risk for sexual partners and subsequent pregnancies. Further strategies should be developed to enhance retention in medical care beyond pregnancy.

Strengthening the Reporting of Observational Studies in Epidemiology for respondent-driven sampling studies: "STROBE-RDS" statement.

OBJECTIVES Respondent-driven sampling (RDS) is a new data collection methodology used to estimate characteristics of hard-to-reach groups, such as the HIV prevalence in drug users. Many national public health systems and international organizations rely on RDS data. However, RDS reporting quality and available reporting guidelines are inadequate. We carried out a systematic review of RDS studies and present Strengthening the Reporting of Observational Studies in Epidemiology for RDS Studies (STROBE-RDS), a checklist of essential items to present in RDS publications, justified by an explanation and elaboration document. STUDY DESIGN AND SETTING We searched the MEDLINE (1970-2013), EMBASE (1974-2013), and Global Health (1910-2013) databases to assess the number and geographical distribution of published RDS studies. STROBE-RDS was developed based on STROBE guidelines, following Guidance for Developers of Health Research Reporting Guidelines. RESULTS RDS has been used in over 460 studies from 69 countries, including the USA (151 studies), China (70), and India (32). STROBE-RDS includes modifications to 12 of the 22 items on the STROBE checklist. The two key areas that required modification concerned the selection of participants and statistical analysis of the sample. CONCLUSION STROBE-RDS seeks to enhance the transparency and utility of research using RDS. If widely adopted, STROBE-RDS should improve global infectious diseases public health decision making.

Non-sexual household transmission of HCV infection: A cohort study

Objective. This study was designed to determine the prevalence and incidence of HCV infection among non-sexual household contacts of HCV-infected women and to describe the association between HCV infection and potential household risk factors in order to examine whether non-sexual household contact is a route of transmission for HCV infection. ^ Methods. A baseline prevalence survey included 409 non-sexual household contacts of 241 HCV-infected index women in the Houston area from 1994 to 1997. A total of 470 non-sexual household contacts with no evidence of HCV infection at baseline investigation were re-assessed approximately three years after baseline enrollment. Information on potential risk factors was collected through face to face interviews and blood samples were tested for anti-HCV with ELISA-2 and Matrix/RIBA-2. The relationships between HCV infection and potential risk factors were examined by using univariate and multivariate logistic regression analyses. ^ Results. The overall prevalence of anti-HCV positivity among 409 non-sexual household contacts was 4.4%. The highest prevalence of anti-HCV was found in parents (19.5%), followed by siblings (8.1%) and other relatives (5.6%); the children had the lowest prevalence of anti-HCV (1.2%). The univariate analysis showed that IDU, blood transfusion, tattoos, sexual contact with injecting drug users, more than 3 sexual partners in a lifetime, history of a STD, incarceration, previous hepatitis, and contact with hepatitis patients were significantly associated with HCV infection, however, sharing razors, nail clippers, toothbrushes, gum, food or beds with HCV-infected women, and history of dialysis, health care job, body piercing, and homosexual activities were not. Multivariate analysis found that IDU (OR = 221.7 with 95% CI of 22.8 to 2155.7) and history of a STD (OR = 11.7 with 95% CI of 1.2 to 113.1) were the only variables significantly associated with HCV infection. No such associations remained for other risk factors. The three-year cumulative incidence of anti-HCV among 352 non-sexual household contacts of HCV-infected women was zero. ^ Conclusion. This study has provided no evidence that non-sexual household contact is a likely route of transmission for HCV infection. The risk of sharing razors, nail clippers, toothbrushes, gum, food and/or beds with HCV-infected women is not evident and has not been shown to be the likely mode for HCV spread among family members. This study does suggest that IDU is the likely route of transmission for most HCV infection. Association also has been shown independently with a history of STD. The prevalence of anti-HCV among non-sexual household contacts was low. Exposure to common parenteral risk factors and sexual transmission between sexual partners may account for HCV spread among household members of HCV-infected persons. ^

Interventions to reduce sexual risk behavior in African American men

The purpose of this review was to describe characteristics of interventions that have been conducted for African American men and identify similarities and differences between interventions for subpopulations of African American men. Of the 473 studies identified through database searching, 8 studies met the eligibility criteria for this review. Target populations within these studies included heterosexual men, homosexual and bisexual men, persons with mental health problems, and injection and non-injection drug users. Little variation was found in the theories and methods used in interventions for different target populations. However, several different behavioral determinants were addressed within these interventions. Although interventions for drug users generally did not exclude individuals based on sexual orientation, these interventions were able to address HIV sexual risk behavior in heterosexual, homosexual, and bisexual-identified men. Given these findings, multi-faceted approaches to HIV prevention are recommended in order to reduce HIV risk in African American men.^

Internet as a medium to seek partners among men who have sex with men

While there are reports of developing sexual relationships on the Internet (I) among MSM, there are few reports that have examined the process of developing sexual relationships on the I and comparing to that in real life (IRL). This study examines the process to provide insight into how MSM make decisions about courtship, engages in negotiations for sex, and choose sexual partners and examines the comparative sexual risks taken between I vs. IRL negotiation. This self-selected convenience sample at a national level (n=1001) of MSM recruited through the I, systematically explored the different steps, the process of courtship in a flow chart of I and IRL dating to portray the process of filtering, courtship and/or negotiation for sex. Risk behaviors in both environments are presented along with interactions that create predictable sequences or "scripts". These sequences constitute 'filtering' and 'sexual positioning'. Differences between I & IRL suggest discussion of HIV/STD status to have consistent differences for all variables except 'unprotected sex' meaning no condom use. There was more communication on the I in regards to self revealing information or variables relating to reducing risks which enable 'filtering' (including serosorting). Data indicate more steps in the I process, providing more complex, multiple steps to filter and position with regard not only to HIV/STD risk but also to negotiate position for complementary sexual interest. The study established a pattern of MSM's courtships or negotiation for sex and a pattern of acquisition, and more I negotiation. Data suggest negotiation opportunities which could lend to intervention to advise people how to negotiate safely. ^ Previous studies have reviewed MSM and drug use. This is a study to review the process of drug use associated with sexual behavior regarding the Internet (I) and in real life (IRL) using a self-selected, convenience sample of MSM (n=1001) recruited nation-wide through the Internet. Data on MSM and drugs illustrate the Internet being used as a tool to filter for drug use among MSM. MSM's drug use in both environments highlights the use of sexual performance drugs with an IRL pursuit of intimacy or negotiation for sex. IRL encounters were more likely to involve drug use (both recreational and sexual performance-enhancing) than Internet encounters. This may be due to more IRL meetings occurring at bars, clubs or parties where drug use is a norm. Compared with IRL, the Internet may provide a venue for persons who do not want to use drugs to select partners with similar attitudes. This suggests that filtering may be occurring as part of the internet negotiation. Data indicated that IRL persons get drunk/high before having sex in past 60 days significantly more often than Internet participants. Age did not alter the pattern of results. Thus drug filtering is really not recreational drug filtering or selecting for PNP, but appears to be situationally-based. Thus, it should perhaps be seen as another form of filtering to select drug-free partners, rather than using the Internet to specifically recruit and interact with other recreational drug users. ^

An analysis of the effects of a peer mentor program and other factors on HIV patients' retention in care and clinical outcomes at Thomas Street Health Clinic, Houston Texas

Research examining programs designed to retain patients in health care focus on repeated interactions between outreach workers and patients (Bradford et al. 2007; Cheever 2007). The purpose of this study was to determine if patients who are peer-mentored at their intake exam remain in care longer and attend more physicians' visits than those who were not mentored. Using patients' medical records and a previously created mentor database, the study determined how many patients attended their intake visit but subsequently failed to establish regular care. The cohort study examined risk factors for establishing care, determined if patients lacking a peer mentor failed to establish care more than peer mentor assisted patients, and subsequently if peer mentored patients had better health outcomes. The sample consists of 1639 patients who were entered into the Thomas Street Patient Mentor Database between May 2005 and June 2007. The assignment to the mentored group was haphazardly conducted based on mentor availability. The data from the Mentor Database was then analyzed using descriptive statistical software (SPSS version 15; SPSS Inc., Chicago, Illinois, USA). Results indicated that patients who had a mentor at intake were more likely to return for primary care HIV visits at 90 and 180 days. Mentored patients also were more likely to be prescribed ART within 180 days from intake. Other risk factors that impacted remaining in care included gender, previous care status, time from diagnosis to intake visit, and intravenous drug use. Clinical health outcomes did not differ significantly between groups. This supports that mentoring did improve outcomes. Continuing to use peer-mentoring programs for HIV care may help in increasing retention of patients in care and improving patients' health in a cost effective manner. Future research on the effects of peer mentoring on mentors, and effects of concordance of mentor and patient demographics may help to further improve peer-mentoring programs. ^

Racial disparities in CD4 counts at initial HIV-1 diagnosis: Analysis of the Adult Spectrum of HIV disease dataset and public health implications

Introduction. The HIV/AIDS disease burden disproportionately affects minority populations, specifically African Americans. While sexual risk behaviors play a role in the observed HIV burden, other factors including gender, age, socioeconomics, and barriers to healthcare access may also be contributory. The goal of this study was to determine how far down the HIV/AIDS disease process people of different ethnicities first present for healthcare. The study specifically analyzed the differences in CD4 cell counts at the initial HIV-1 diagnosis with respect to ethnicity. The study also analyzed racial differences in HIV/AIDS risk factors. ^ Methods. This is a retrospective study using data from the Adult Spectrum of HIV Disease (ASD), collected by the City of Houston Department of Health. The ASD database contains information on newly reported HIV cases in the Harris County District Hospitals between 1989 and 2000. Each patient had an initial and a follow-up report. The extracted variables of interest from the ASD data set were CD4 counts at the initial HIV diagnosis, race, gender, age at HIV diagnosis and behavioral risk factors. One-way ANOVA was used to examine differences in baseline CD4 counts at HIV diagnosis between racial/ethnic groups. Chi square was used to analyze racial differences in risk factors. ^ Results. The analyzed study sample was 4767. The study population was 47% Black, 37% White and 16% Hispanic [p<0.05]. The mean and median CD4 counts at diagnosis were 254 and 193 cells per ml, respectively. At the initial HIV diagnosis Blacks had the highest average CD4 counts (285), followed by Whites (233) and Hispanics (212) [p<0.001 ]. These statistical differences, however, were only observed with CD4 counts above 350 [p<0.001], even when adjusted for age at diagnosis and gender [p<0.05]. Looking at risk factors, Blacks were mostly affected by intravenous drug use (IVDU) and heterosexuality, whereas Whites and Hispanics were more affected by male homosexuality [ p<0.05]. ^ Conclusion. (1) There were statistical differences in CD4 counts with respect to ethnicity, but these differences only existed for CD4 counts above 350. These differences however do not appear to have clinical significance. Antithetically, Blacks had the highest CD4 counts followed by Whites and Hispanics. (2) 50% of this study group clinically had AIDS at their initial HIV diagnosis (median=193), irrespective of ethnicity. It was not clear from data analysis if these observations were due to failure of early HIV surveillance, HIV testing policies or healthcare access. More studies need to be done to address this question. (3) Homosexuality and bisexuality were the biggest risk factors for Whites and Hispanics, whereas for Blacks were mostly affected by heterosexuality and IVDU, implying a need for different public health intervention strategies for these racial groups. ^

Elimination of racial/ethnic Hepatitis B vaccination disparities in the US in the 2007--2008 National Health and Nutrition Examination Survey

Viral hepatitis is a significant public health problem worldwide and is due to viral infections that are classified as Hepatitis A, B, C, D, and E. Hepatitis B is one of the five known hepatic viruses. A safe and effective vaccine for Hepatitis B was first developed in 1981, and became adopted into national immunization programs targeting infants since 1990 and adolescents since 1995. In the U.S., this vaccination schedule has led to an 82% reduction in incidence from 8.5 cases per 100,000 in 1990 to 1.5 cases per 100,000 in 2007. Although there has been a decline in infection among adolescents, there is still a large burden of hepatitis B infection among adults and minorities. There is very little research in regards to vaccination gaps among adults. Using the National Health and Nutrition Examination Survey (NHANES) question "{Have you/Has SP (Study Participant)} ever received the 3-dose series of the hepatitis B vaccine?" the existence of racial/ethnic gaps using a cross-sectional study design was explored. In this study, other variables such as age, gender, socioeconomic variables (federal poverty line, educational attainment), and behavioral factors (sexual practices, self-report of men having sex with men, and intravenous drug use) were examined. We found that the current vaccination programs and policies for Hepatitis B had eliminated racial and ethnic disparities in Hepatitis B vaccination, but that a low coverage exists particularly for adults who engage in high risk behaviors. This study found a statistically significant 10% gap in Hepatitis B vaccination between those who have and those who do not have access to health insurance.^

Investigating the epidemic of heroin use in Dar es Salaam, Tanzania: Recognizing the issues of heroin smokers

Since heroin was introduced to East Africa during the 1980s, heroin use practices have changed rapidly in response to various internal and external pressures. The aim of this study was to identify and describe the population of heroin users and locations of heroin use in Dar es Salaam, Tanzania, in order to understand recent contexts of heroin use. The study took place between June 30 and August 19, 2011, in all three districts (Kinondoni, Ilala, and Temeke) of Dar es Salaam. We mapped sites using a Global Positioning System device, counted numbers of heroin users, and conducted informal interviews with heroin users. The mixed-methods analyses of the data included quantifying the basic demographic and aggregate information about the sites and heroin users, as well as qualitative analysis and coding of fieldnotes from observations and responses to interviews which was used to identify themes and characteristics of heroin users. ^ We identified a total of 150 sites and counted a total of 1046 male and 46 female non-injecting drug users and 78 male and 9 female injecting drug users (IDUs) of heroin. We found that social organization existed at some of the sites, with 31% (n=47) of sites reporting having a leader and 44% (n=66) of sites reporting mutual aid between users frequenting the site. We had difficulty locating IDUs and female drug users, and the majority of users we encountered were heroin smokers of kokteli, a mixture of heroin, cannabis, and/or tobacco which is smoked like a cigarette. ^ This research highlighted heroin smokers’ desire for access to drug treatment services. The current methadone-based medication assisted treatment (MAT) program is funded and operates as an HIV prevention program for IDUs to reduce HIV infection in this population and slow or stop the spread of a second wave of HIV infection in the general population. However, smokers perceived MAT to be primarily a drug use prevention or cessation program and felt unjustly neglected from the intervention, leading to a tense relationship with IDUs. From a public health standpoint, future interventions should include heroin smokers to prevent HIV transmission. ^

Retrospective analysis of Methicillin-Resistant Staphylococcus Aureus (MRSA) skin and Soft-Tissue Infections (SSTI) in a university hospital emergency department (ED)

Study Objective: Identify the most frequent risk factors of Community Acquired-MRSA (CA-MRSA) Skin and Soft-tissue Infections (SSTIs) using a case series of patients and characterize them by age, race/ethnicity, gender, abscess location, druguse and intravenous drug-user (IVDU), underlying medical conditions, homelessness, treatment resistance, sepsis, those whose last healthcare visit was within the last 12 months, and describe the susceptibility pattern from this central Texas population that have come into the University Medical Center Brackenridge (UMCB) Emergency Department (ED). ^ Methods: This study was a retrospective case-series medical record review involving a convenience sample of patients in 2007 from an urban public hospital's ED in Texas that had a SSTI that tested positive for MRSA. All positive MRSA cultures underwent susceptibility testing to determine antibiotic resistance. The demographic and clinical variables that were independently associated with MRSA were determined by univariate and multivariate analysis using logistic regression to calculate odds ratios (OR), 95% confidence intervals, and significance (p≤ 0.05). ^ Results: In 2007, there were 857 positive MRSA cultures. The demographics were: males 60% and females 40%, with the average age of 36.2 (std. dev. =13) the study population consisted of non-Hispanic white (42%), Hispanics (38%), and non-Hispanic black (18.8%). Possible risk factors addressed included using recreational drugs (not including IVDU) (27%) homelessness (13%), diabetes status (12.6%) or having an infectious disease, and IVDU (10%). The most frequent abscess location was the leg (26.6%), followed by the arm and torso (both 13.7%). Eighty-three percent of patients had one prominent susceptibility pattern that had a susceptibility rate for the following antibiotics: trimethoprim/sulfamethoxazole (TMP-SMX) and vancomycin had 100%, gentamicin 99%, clindamycin 96%, tetracycline 96%, and erythromycin 56%. ^ Conclusion: The ED is becoming an important area for disease transmission between the sterile hospital environment and the outside environment. As always, it is important to further research in the ED in an effort to better understand MRSA transmission and antibiotic resistance, as well as to keep surveillance for the introduction of new opportunistic pathogens into the population. ^

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.^