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Background Understanding the sources of HIV transmission provides a basis for prioritizing HIV prevention resources in specific geographic regions and populations. This study estimated the number, proportion, and rate of HIV transmissions attributable to individuals along the HIV care continuum, within different HIV transmission risk groups in six US cities. Methods We used a dynamic, compartmental HIV transmission model that draws on racial/ethnic- and risk-behavior-specific linkage to HIV care and use of HIV prevention services from local, state and national surveillance sources. We estimated the rate and number of HIV transmissions attributable to individuals in the stage of acute undiagnosed HIV, non-acute undiagnosed HIV, HIV diagnosed but antiretroviral therapy (ART) naive, off ART, and on ART, stratified by HIV transmission group for the 2019 calendar year. Results Individuals with undiagnosed non-acute HIV infection accounted for the highest proportion of total transmissions in every city, ranging from 36.8% [26.7%-44.9%] in New York City to 64.9% [47.0%-71.6%] in Baltimore. Individuals who had discontinued ART contributed to the second highest percentage of total infections in four of six cities. Individuals with acute HIV had the highest transmission rate per 100 person years, ranging from 76.4 [58.9-135.9] in Miami to 160.2 [85.7-302.8] in Baltimore. Conclusion These findings underline the importance of both early diagnosis and improved ART retention for ending the HIV epidemic in the US. Differences in the sources of transmission across cities indicate that localized priority-setting to effectively address diverse microepidemics at different stages of epidemic control is necessary.

BACKGROUND Adherence to antiretroviral therapy (ART) and sustained HIV suppression virtually eliminate HIV transmission, eg, having an undetectable viral load renders HIV untransmittable (U=U). Owing to the greatly reduced likelihood of HIV transmission when viral load is undetectable, we studied one behavioral ramification of adopting a U=U prevention strategy-not disclosing HIV status to sex partners. SETTING Cisgender men recruited through community outreach in the state of Georgia, USA. METHODS We examined HIV status disclosure to sex partners among 345 young (median age = 29 years) men receiving ART. Data were collected using computerized interviews, daily sexual behavior surveys over 28 days, unannounced pill counts for ART adherence, urine tests for drug use and urogenital health, and blood samples for HIV viral load. RESULTS One in 3 participants (34%) engaged in condomless anal/vaginal intercourse with an HIV-negative/unknown HIV status partner over 28 days. Average ART adherence was 76%, and one in 5 men had detectable HIV viral loads. Men who engaged in condomless sex with undisclosed partners demonstrated significantly less HIV disclosure to family and friends and had fewer enacted stigma experiences. Hierarchical regression models showed that endorsing U=U as a personal HIV prevention strategy predicted undisclosed condomless sex over and above substance use, HIV stigma experiences, disclosure to family and friends, ART adherence, and HIV viral load. CONCLUSIONS Interventions are needed to improve ART adherence and assist men living with HIV in their decisions to disclose HIV status to sex partners.

Background Biological and epidemiological evidence suggest that herpes simplex virus type 2 (HSV-2) elevates HIV acquisition and transmission risks. We improved previous estimates of the contribution of HSV-2 to HIV infections by using a dynamic transmission model. Setting World Health Organization regions. Methods We developed a mathematical model of HSV-2/HIV transmission among 15- to 49-year-old heterosexual, non-drug-injecting populations, calibrated using region-specific demographic and HSV-2/HIV epidemiological data. We derived global and regional estimates of the contribution of HSV-2 to HIV infection over 10 years [the transmission population-attributable fraction (tPAF)] under 3 additive scenarios, assuming: (1) HSV-2 increases only HIV acquisition risk (conservative); (2) HSV-2 also increases HIV transmission risk (liberal); and (3) HIV or antiretroviral therapy (ART) also modifies HSV-2 transmission risk, and HSV-2 decreases ART effect on HIV transmission risk (fully liberal). Results Under the conservative scenario, the predicted tPAF was 37.3% (95% uncertainty interval: 33.4%-43.2%), and an estimated 5.6 (4.5-7.0) million incident heterosexual HIV infections were due to HSV-2 globally over 2009-2018. The contribution of HSV-2 to HIV infections was largest for the African region [tPAF = 42.6% (38.0%-51.2%)] and lowest for the European region [tPAF = 11.2% (7.9%-13.8%)]. The tPAF was higher among female sex workers, their clients, and older populations, reflecting their higher HSV-2 prevalence. The tPAF was approximately 50% and 1.3- to 2.4-fold higher for the liberal or fully liberal scenario than the conservative scenario across regions. Conclusion HSV-2 may have contributed to at least 37% of incident HIV infections in the past decade worldwide, and even more in Africa, and may continue to do so despite increased ART access unless future improved HSV-2 control measures, such as vaccines, become available.

BACKGROUND Beliefs regarding responsibility for preventing HIV transmission may differ between individuals and their sexual partners. We assessed HIV prevention responsibility beliefs among men who have sex with men (MSM) participating in the 2017 National HIV Behavioral Surveillance survey. METHODS MSM were recruited using time-location sampling at clubs, bars, and street locations in San Francisco. HIV prevention responsibility beliefs were assessed on a four-point scale (1 = strongly disagree to 4 = strongly agree). Associations were assessed using generalizing estimating equations to adjust for behaviors within multiple partnerships. RESULTS A total of 316 HIV-negative men and 76 HIV-positive men reported on 1336 partnerships. HIV-negative compared with HIV-positive men had higher endorsement of mutual responsibility (mean 3.7 vs. 3.5; P < 0.01). Both groups had similar levels of endorsing responsibility on the HIV-negative or HIV-positive partner. HIV-positive men endorsing equal responsibility were more likely to know their partner's HIV status (P < 0.01) and less likely to have serodiscordant condomless anal intercourse (CAI) (P < 0.01) than men who did not endorse equal responsibility. HIV-negative men in partnerships with pre-exposure prophylaxis (PrEP) use were more likely to know their partner's HIV status (P = 0.02) and have serodiscordant CAI (P = 0.04) than men not in partnerships with PrEP use. CONCLUSIONS HIV-negative and HIV-positive men accept responsibility for preventing HIV. The finding that HIV-negative men in partnerships with PrEP use who engage in serodiscordant CAI is concerning because they are still at risk for other sexually transmitted infections, which are presently at elevated levels in San Francisco and other US cities.

Background Reducing HIV transmission using pre-exposure prophylaxis (PrEP) requires focussing on individuals at high acquisition risk, such as men who have sex with men with a history of nonoccupational post-exposure prophylaxis (nPEP). This study aims to characterize longitudinal trends in PrEP uptake and its determinants among nPEP users in Montreal. Methods Eligible attendees at Clinique medicale l'Actuel were recruited prospectively starting in October 2000 (nPEP) and January 2013 (PrEP). Linking these cohorts, we characterized the nPEP-to-PrEP cascade, examined the determinants of PrEP uptake after nPEP consultation using a Cox proportional-hazard model, and assessed whether PrEP persistence differed by nPEP history using Kaplan-Meier curves. Results As of August 2019, 31% of 2682 nPEP cohort participants had 2 or more nPEP consultations. Subsequent PrEP consultations occurred among 36% of nPEP users, of which 17% sought nPEP again afterward. Among 2718 PrEP cohort participants, 46% reported previous nPEP use. Among nPEP users, those aged 25-49 years [hazard ratio (HR) = 1.3, 95% confidence interval (CI): 1.1 to 1.7], with more nPEP episodes (HR = 1.4, 95% CI: 1.3 to 1.5), who reported chemsex (HR = 1.3, 95% CI: 1.1 to 1.7), with a sexually transmitted infection history (HR = 1.5; 95% CI: 1.3 to 1.7), and who returned for their first nPEP follow-up visit (HR = 3.4, 95% CI: 2.7 to 4.2) had higher rates of PrEP linkage. There was no difference in PrEP persistence between nPEP-to-PrEP and PrEP only participants. Conclusion Over one-third of nPEP users were subsequently prescribed PrEP. However, the large proportion of men who repeatedly use nPEP calls for more efficient PrEP-linkage services and, among those who use PrEP, improved persistence should be encouraged.

BACKGROUND Gay and bisexual men with undiagnosed HIV contribute disproportionately to HIV transmission in Australia. METHODS In 2014 and 2018, we recruited men at gay venues and events in Sydney. Participants self-completed surveys and provided oral fluid samples for HIV testing. We calculated the prevalence of HIV and undiagnosed infection, and assessed changes in behavior, HIV testing, and the use of pre-exposure prophylaxis. We weighted the samples to adjust for differences in where participants were recruited between rounds. Two-sample tests of proportion were used to compare prevalence estimates and χ tests to assess differences between the samples. RESULTS In 2014, 944 men were recruited, and 890 men were recruited in 2018. In 2014, the weighted estimate of HIV prevalence was 6.1% [95% confidence intervals (CI): 4.6 to 7.6], of which 13.8% (95% CI: 5.0 to 22.7) was undiagnosed. In 2018, weighted HIV prevalence was 6.4% (95% CI: 4.8 to 8.0), of which 5.3% (95% CI: 0.5 to 11.1) was undiagnosed. Between 2014 and 2018 among all participants, men reporting at least 10 recent casual partners increased from 22.3% to 27.7% (P = 0.008), condomless anal intercourse with casual partners in the previous 6 months increased from 23.9% to 37.3% (P < 0.001), and sexually transmitted infection diagnoses in the previous year increased from 14.4% to 27.5% (P < 0.001). HIV testing and the use of pre-exposure prophylaxis in the previous 6 months increased from 49.6% to 56.3% (P = 0.004) and 2.0%-21.0% (P < 0.001), respectively. CONCLUSIONS Repeated, bio-behavioral surveillance suggests the prevalence of undiagnosed HIV remains low in Sydney, despite gay and bisexual men reporting more casual sex partners, condomless sex, and sexually transmitted infections.

BACKGROUND Understanding geographic patterns of HIV transmission is critical to designing effective interventions. We characterized geographic proximity by transmission risk and urban-rural characteristics among people with closely related HIV strains suggestive of potential transmission relationships. METHODS We analyzed US National HIV Surveillance System data of people diagnosed between 2010 and 2016 with a reported HIV-1 partial polymerase nucleotide sequence. We used HIV TRAnsmission Cluster Engine (HIV-TRACE) to identify sequences linked at a genetic distance of ≤0.5%. For each linked person, we assessed median distances between counties of residence at diagnosis by transmission category and urban-rural classification, weighting observations to account for persons with multiple linked sequences. RESULTS There were 24,743 persons with viral sequence linkages to at least one other person included in this analysis. Overall, half (50.9%) of persons with linked viral sequences resided in different counties, and the median distance from persons with linked viruses was 11 km/7 miles [interquartile range (IQR), 0-145 km/90 miles]. Median distances were highest for men who have sex with men (MSM: 14 km/9 miles; IQR, 0-179 km/111 miles) and MSM who inject drugs, and median distances increased with increasing rurality (large central metro: 0 km/miles; IQR, 0-83 km/52 miles; nonmetro: 103 km/64 miles; IQR, 40 km/25 miles-316 km/196 miles). CONCLUSION Transmission networks in the United States involving MSM, MSM who inject drugs, or persons living in small metro and nonmetro counties may be more geographically dispersed, highlighting the importance of coordinated health department efforts for comprehensive follow-up and linkage to care.

BACKGROUND In the United States, young men (aged 13-24 years) who have sex with men (MSM) bear a disproportionate burden of HIV. Transmission among MSM has been found to be disassortative by age. METHODS We analyzed HIV-1 pol sequences reported to the US National HIV Surveillance System from MSM with HIV diagnosed during 2009-2016. Using an HIV genetic transmission network, we identified persons with closely related viruses (ie, genetic distance ≤1.5%) and used multivariable logistic regression to examine changes from 2009-2012 to 2013-2016 in proportions of MSM linked to young MSM who were >5 years older or of the same race/ethnicity. RESULTS Among 9510 young MSM linked to another MSM with a closely related virus, 37% linked to an older MSM and 62% linked to an MSM of the same race/ethnicity. Comparing 2013-2016 with 2009-2012, we found increases in linkage of older MSM to young MSM, with the most substantial increases seen in Hispanic/Latinos aged 13-19 [adjusted prevalence ratio (APR) = 1.31, 95% confidence interval (CI) = 1.11 to 1.56] and blacks aged 13-19 (APR = 1.23, CI = 1.06 to 1.41) and 20-24 years (APR = 1.14, CI = 1.02 to 1.28). By contrast, change in linkage patterns among racial/ethnic groups was unremarkable. CONCLUSIONS We found evidence of increased age mixing among MSM with respect to HIV transmission over time, which coincides temporally with changes in partner-seeking behavior such as increased use of mobile applications. These findings indicate the importance of social factors on HIV sexual and transmission networks and suggest that prevention efforts need to effectively reach MSM of all ages.

Background Nearly all population-level research showing positive associations between age-disparate partnerships and HIV acquisition among adolescent girls and young women (AGYW) has classified age disparity as ≥5 or ≥10 years. We describe variations in 1-year risk of HIV infection after exposure to sexual partner(s) of continuous age disparities. Methods Longitudinal data from the HPTN 068 randomized trial in South Africa were used to estimate 1-year risk of HIV infection at various age pairings. The parametric g-formula was used to estimate risk at up to 5 annual time points, stratified by maximum partner age difference, maximum partner age, and AGYW age. Results AGYW reported an older partner in 86% of 5351 age pairings. The 1-year risk of HIV infection rapidly increased with maximum partner age difference among girls ages 13-14 years, from 0·01 with a same-age partner, to 0·21 with a partner 10 years older, and 0·24 with a partner 15 years older. A gradual increase occurred among AGYW ages 15-16 years, up to 0·13 with a partner 15 years older, and 0·09 among AGYW 17-18 years with partners 8-11 years older. Risk of HIV infection among AGYW ages 19-21 years remained relatively constant across maximum partner age differences. Conclusions Age differences between AGYW and their sexual partners have a greater effect on HIV-risk infection in younger compared with older AGYW. Considering both the age of an AGYW and her sexual partners provides granular insight into identifying key groups for HIV transmission prevention efforts.

Background: Sexual partners are the primary source of incident HIV infection among adolescent girls and young women (AGYW) in sub-Saharan Africa. Identifying partner types at greatest risk of HIV transmission could guide the design of tailored HIV prevention interventions. Methods: We conducted a secondary analysis of data from AGYW (aged 13-23 years) enrolled in a randomized controlled trial of cash transfers for HIV prevention in South Africa Annually, AGYW reported behavioral and demographic characteristics of their 3 most recent sexual partners, categorized each partner using prespecified labels, and received HIV testing. We used latent class analysis (LCA) to identify partner types from reported characteristics, and generalized estimating equations to estimate the relationship between both LCA-identified and prespecified partner types and incident HIV infection. Results: Across 2140 AGYW visits, 1034 AGYW made 2968 partner reports and 63 AGYW acquired HIV infection. We identified 5 LCA partner types, which we named monogamous HIV-negative peer partner; one-time protected in-school peer partner; out-ofschool older partner; anonymous out-of-school peer partner; and cohabiting with children in-school peer partner. Compared to AGYW with only monogamous HIV-negative peer partners, AGYW with out-of-school older partners had 2.56 times the annual risk of HIV infection (95% confidence interval: 1.23 to 5.33), whereas AGYW with anonymous out-of-school peer partners had 1.72 times the risk (95% confidence interval: 0.82 to 3.59). Prespecified partner types were not associated with incident HIV. Conclusion: By identifying meaningful combinations of partner characteristics and predicting the corresponding risk of HIV acquisition among AGYW, LCA-identified partner types may provide new insights for the design of tailored HIV prevention interventions.

BACKGROUND HIV's capacity to escape immune recognition by Human Leukocyte Antigen (HLA) is a core component of HIV pathogenesis. A better understanding of the distribution of HLA Class I in HIV-infected patients would improve our knowledge of pathogenesis in relation to host HLA type, and could better improve therapeutic strategies against HIV. MATERIALS AND METHODS 301-325 transmission pairs and 469-496 clusters were identified for analysis among Swiss HIV Cohort Study (SHCS) participants using HIV pol sequences from the drug resistance database. HLA Class I data was compiled at three specificity levels: four-digit, two-digit alleles, and HLA-B supertype. The analysis tabulated HLA-I homogeneity as two measures: the proportion of transmission pairs which are HLA-concordant as well as the average percentage of allele matches within all clusters. These measures were compared to the mean value across randomizations with randomly assorted individuals. RESULTS We repeated the analysis for different HLA classification levels and separately for HLA-A, -B, and -C. Subanalyses by risk group were performed for HLA-B. HLA-B showed significantly greater homogeneity in the transmission chains (2-digit clusters: 0.291 vs.0.251, p-value=0.009; supertype clusters: 0.659 vs. 0.611, p-value=0.002; supertype pairs: 0.655 vs. 0.608, p-value=0.014). Risk group restriction caused the effect to disappear for men-who-have-sex-with-men (MSM) but not other risk groups. We also examined if protective HLA alleles B27 and B57 were under- or overrepresented in the transmission chains, though this yielded no significant pattern. CONCLUSIONS The HLA-B alleles of patients within HIV-1 transmission chains segregate in homogenous clusters/pairs, potentially indicating preferential transmission among HLA-B concordant individuals.

Background: Sharing needles/syringes and sexual transmission are widely appreciated as means of HIV transmission among persons who inject drugs (PWIDs). London, Canada, is experiencing an outbreak of HIV among PWIDs, despite a large needle/syringe distribution program and low rates of needle/syringe sharing. Objective: To determine whether sharing of injection drug preparation equipment (IDPE) is associated with HIV infection. Methods: Between August 2016 and June 2017, individuals with a history of injection drug use and residence in London were recruited to complete a comprehensive questionnaire and HIV testing. Results: A total of 127 participants were recruited; 8 were excluded because of failure to complete HIV testing. The remaining 35 HIV-infected (cases) and 84 HIV-uninfected (controls) participants were assessed. Regression analysis found that sharing IDPE, without sharing needles/syringes, was strongly associated with HIV infection (adjusted odds ratio: 22.1, 95% confidence interval: 4.51 to 108.6, P < 0.001). Conclusions: Sharing of IDPE is a risk factor for HIV infection among PWIDs, even in the absence of needle/syringe sharing. Harm reduction interventions to reduce HIV transmission associated with this practice are urgently needed.

Concentration of antiretroviral (ARV) drug found in plasma, and amounts of drug excreted into breastmilk, may affect HIV viral load and potentially perinatal HIV transmission.In this cohort study with 2-phase sampling, we included mothers randomized to postpartum maternal ARVs or daily infant nevirapine during 28 weeks of breastfeeding in the Breastfeeding, Antiretrovirals, and Nutrition study. Among these, we included all mothers who transmitted HIV to their infants between 2 and 28 weeks and 15% of mothers who did not (n = 27 and 227, respectively). Spearman correlation coefficients (r) were used to assess the correlation between maternal plasma and breastmilk ARV concentration. Associations between the median effective drug concentration (EC50) and detectable maternal viral load (plasma:40 copies per milliliter, breastmilk:56 copies per milliliter) were assessed using mixed-effects models. Cox models were used to estimate the association between maternal or infant plasma drug concentration and breastmilk HIV transmission from 2 to 28 weeks.All ARV compounds exhibited substantial correlations between maternal plasma and breastmilk concentrations (r: 0.85-0.98, P-value0.0001). Having plasma drug concentration above the EC50 was associated with lower odds of having detectable HIV RNA [maternal plasma odds ratio (OR) 0.64, 95% confidence interval (CI): 0.45 to 0.91; breastmilk OR 0.22, 95% CI: 0.14 to 0.35] and a reduced rate of breastmilk HIV transmission (hazard ratio 0.40, 95% CI: 0.18 to 0.93). Having breastmilk drug concentration above the EC50 was also associated with lower odds of having detectable maternal HIV RNA (plasma OR 0.62, 95% CI: 0.45 to 0.85; breastmilk OR 0.42, 95% CI: 0.29 to 0.59).Ensuring adequate drug concentration is important for viral suppression and preventing breastmilk HIV transmission.

BACKGROUND: Detecting recent and rapid spread of HIV can help prioritize prevention and early treatment for those at highest risk of transmission. HIV genetic sequence data can identify transmission clusters, but previous approaches have not distinguished clusters of recent, rapid transmission. We assessed an analytic approach to identify such clusters in the United States. METHODS: We analyzed 156,553 partial HIV-1 polymerase sequences reported to the National HIV Surveillance System and inferred transmission clusters using two genetic distance thresholds (0.5% and 1.5%) and two time periods for diagnoses (all years and 2013–2015, i.e., recent diagnoses). For rapidly growing clusters (with ≥5 diagnoses during 2015), molecular clock phylogenetic analysis estimated the time to most recent common ancestor for all divergence events within the cluster. Cluster transmission rates were estimated using these phylogenies. RESULTS: A distance threshold of 1.5% identified 103 rapidly growing clusters using all diagnoses and 73 using recent diagnoses; at 0.5%, 15 clusters were identified using all diagnoses and 13 using recent diagnoses. Molecular clock analysis estimated that the 13 clusters identified at 0.5% using recent diagnoses had been diversifying for a median of 4.7 years, compared with 6.5–13.2 years using other approaches. The 13 clusters at 0.5% had a transmission rate of 33/100 person-years, compared with previous national estimates of 4/100 person-years. CONCLUSIONS: Our approach identified clusters with transmission rates 8 times those of previous national estimates. This method can identify groups involved in rapid transmission and help programs effectively direct and prioritize limited public health resources.

BACKGROUND: Pre-exposure prophylaxis (PrEP) uptake has been slow among African American men who have sex with men (AAMSM) in the United States. We used an agent-based model (ABM) to simulate race-specific PrEP coverage to estimate their impact on racial disparities in HIV incidence among MSM in Atlanta, Georgia. METHODS: An ABM was constructed to simulate HIV transmission in a dynamic network of 10,000 MSM over ten years, beginning in 2015. We modeled a base scenario with estimated PrEP coverage of 2.5% among AAMSM and 5.0% among white MSM (WMSM). We then compared HIV incidence over ten years and calculated a disparity ratio of AAMSM to WMSM incidence rates across varying PrEP scale-up scenarios, with equal and unequal coverage among AAMSM and WMSM. RESULTS: Assuming current coverage remains constant, the model predicts HIV incidence rates of 2.95 and 1.76 per 100 person-years among AAMSM and WMSM respectively, with a disparity ratio of 1.68. If PrEP coverage were to increase six-fold without addressing inequities in PrEP uptake, the model predicts incidences of 2.65 and 1.34, corresponding to a mean decrease of 10.4% and 24.0% in HIV incidence, respectively. This stronger benefit for WMSM increased the disparity ratio to 1.98. Equal PrEP coverage among AAMSM and WMSM resulted in lower incidence rates overall with lower disparity ratios. CONCLUSION: Lower uptake among AAMSM relative to WMSM may limit the population-level impact of PrEP use among AAMSM, which may ultimately culminate in wider racial disparities in HIV incidence among MSM.

Daily pre-exposure prophylaxis and event-driven pre-exposure prophylaxis (PrEP) are efficacious in reducing HIV transmission among men who have sex with men (MSM). We analyzed baseline data from a PrEP demonstration project "Be-PrEP-ared" in Antwerp, Belgium, to understand preferences for daily PrEP or event-driven PrEP among MSM at high risk of HIV and factors influencing their initial choice.Cross-sectional data from an open-label prospective cohort study, using mixed methods. Participants who preregistered online were screened for eligibility and tested for sexually transmitted infections (STIs). Eligible participants chose between daily PrEP and event-driven PrEP and reported on behavioral data through an electronic questionnaire. In-depth interviews were conducted with a selected subsample. Bivariate associations were examined between preferred PrEP regimens and sociodemographic factors, sexual behavior, and STIs at screening.In total, 200 participants were enrolled between October 2015 and December 2016. Self-reported levels of sexual risk-taking before enrollment were high. STI screening revealed that 39.5% had at least 1 bacterial STI. At baseline, 76.5% of participants preferred daily PrEP and 23.5% event-driven PrEP. Feeling able to anticipate HIV risk was the most frequent reason for preferring event-driven PrEP. Regimen choice was associated with sexual risk-taking behavior in the past 3 months. Almost all participants (95.7%) considered it likely that they would change their dosing regimen the following year.Event-driven PrEP was preferred by 23.5% of the participants, which better suits their preventive needs. Event-driven PrEP should be included in PrEP provision as a valuable alternative to daily PrEP for MSM at high risk of HIV.

HIV-1 RNA load is the best biological predictor of HIV transmission and treatment response. The rate of virologic suppression among key subpopulations can guide HIV prevention programs.The Botswana Combination Prevention Project performed a population-based household survey among adults in 30 communities in Botswana. Data collected included knowledge of HIV-positive status, antiretroviral therapy (ART) coverage, and virologic suppression (HIV-1 RNA ≤400 copies per milliliter). Individuals aged 16-29 years were considered young adults.Among 552 young people living with HIV enrolled with RNA load data and ART status available, 51% (n = 279) had undetectable HIV-1 RNA, including 54% of young women and 32% of young men [sex prevalence ratio (PR): 0.53; 95% confidence interval (CI): 0.43 to 0.80; P0.001]. Compared with older adults (30-64 years old), young HIV-infected adults were significantly less likely to have undetectable HIV-1 RNA (PR: 0.65; 95% CI: 0.59 to 0.70; P0.0001), including both men (PR: 0.43; 95% CI: 0.34 to 0.56; P0.0001) and women (PR: 0.67; 95% CI: 0.62 to 0.74; P0.0001). Among a subset of people living with HIV receiving ART, young adults also were less likely to have undetectable HIV-1 RNA load than older adults (PR: 0.93; 95% CI: 0.90 to 0.95; P =0.0001). Analysis of the care continuum revealed that inferior HIV diagnosis and suboptimal linkage to care are the primary reasons for low virologic suppression among young adults.Young adults in Botswana are significantly less likely to have undetectable HIV-1 RNA load compared with older adults. In the era of broad scale-up of ART, interventions able to diagnose young adults living with HIV and link them to effective therapy are urgently needed.

BACKGROUND Alcohol consumption has frequently been purported as a driver of condomless sex and HIV transmission, but to date, experimental evidence for the causal risk-taking impact of alcohol among HIV-positive populations is lacking. The present experiment sought to determine whether acute alcohol consumption has a direct causal impact on condomless sex intentions among HIV-positive men-who-have-sex-with-men (MSM), and to assess whether alcohol's impact differs between MSM who are HIV-positive versus HIV-negative. METHODS In a randomized controlled alcohol administration experiment, HIV-positive and HIV-negative MSM were brought into a specialized barroom laboratory and randomly assigned to beverage consumption condition: alcohol (target blood alcohol concentration = 0.080%), placebo alcohol (target blood alcohol concentration = 0.000%), or water (control). Participants then underwent a video-based sexual arousal manipulation (sexually aroused/nonaroused) and indicated their intentions to engage in condom-protected and condomless sexual acts in a standardized paradigm. The primary outcome entailed intentions to engage in condomless receptive and condomless insertive anal sex. RESULTS A total of 282 MSM (141 HIV-positive; 141 HIV-negative) completed experimental procedures. MSM who received alcohol reported significantly stronger intentions to engage in condomless sex than those who received placebo alcohol or water (F(1,274) = 9.43, P = 0.002). The impact of alcohol did not differ between HIV-positive and HIV-negative MSM (F(1,274) = 1.86, P = 0.174). CONCLUSIONS The present investigation entailed the first risk-focused alcohol administration experiment to involve an HIV-positive sample, and results demonstrated that consuming alcohol had an independent, causal impact on intentions to engage in sexual behaviors that can result in HIV transmission. Findings strongly suggest that alcohol-focused initiatives should be incorporated into HIV prevention efforts.

Evaluate the incidence and predictors of HIV acquisition from outside partners in serodiscordant couples. Demographic, behavioral, and clinical exposures were measured quarterly in a cohort of serodiscordant cohabiting couples in Zambia from 1995-2012 (n=3049). Genetic analysis classified incident infections as those acquired from the study partner (linked) or acquired from an outside partner (unlinked). Factors associated with time to unlinked HIV infection were evaluated using multivariable Cox proportional hazards regression stratified by gender. There were 100 unlinked infections in couples followed for a median of 806 days. Forty-five infections occurred in women (1.85/100 couple-years [CY]; 95%CI:1.35-2.47). Risk of female unlinked infection (vs. non-seroconverting females) was associated with reporting being drunk weekly/daily vs. moderate/non-drinkers at baseline (aHR=5.44;95%CI:1.03-28.73), genital ulcers (aHR=6.09;95%CI:2.72-13.64) or genital inflammation (aHR=11.92;95%CI:5.60-25.37) during follow-up adjusting for age, years cohabiting, income, contraceptive use, previous pregnancies, history of sexually transmitted infections (STI), and condomless sex with study partner. Fifty-five infections occurred in men (1.82/100 CY;95%CI:1.37-2.37). Risk of male unlinked infection was associated with genital inflammation (aHR=8.52;95%CI:3.82-19.03) or genital ulceration (aHR=2.31;95% CI:2.05-8.89), reporting =>1 outside sexual partner (aHR=3.86;95%CI:0.98-15.17) during follow-up, and reporting being drunk weekly/daily vs. moderate/non-drinkers at baseline (aHR=3.84;95%CI=1.28-11.55), controlling for age, income, circumcision status, and history of STI. Predictors of unlinked infection in serodiscordant relationships were alcohol use, genital inflammation, and ulceration. Causes of genital inflammation and ulceration should be screened for and treated in HIV-negative individuals. Counseling on risk of alcohol use and sex with outside partners should be discussed with couples where one or both are HIV-negative, including in counseling on use of pre-exposure prophylaxis to prevent HIV acquisition in the HIV-negative partner. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Delaying HIV care initiation may lead to greater morbidity, mortality, and further HIV transmission. Rural residence may be associated with delayed diagnosis and linkage to care, with negative clinical outcomes.To examine the association between rural patient residence and CD4 cell count at HIV care initiation in a large HIV clinical cohort in the Southeastern United States.We included HIV-infected patients who initiated care between 1996 and 2012 with a geocodable address and no previous history of HIV clinical care. Patient residence was categorized as urban or rural using United States Department of Agriculture Rural Urban Commuting Area codes. Multivariable linear regression models were fit to estimate the association between patient residence and CD4 cell count at HIV care initiation.Among 1396 patients who met study inclusion criteria, 988 had a geocodable address. Overall, 35% of patients resided in rural areas and presented to HIV care with a mean CD4 cell count of 351 cells/mm (SD, 290). Care initiation mean CD4 cell counts increased from 329 cells/mm (SD, 283) in 1996-2003 to 391 cells/mm (SD, 292) in 2008-2012 (P = 0.006). Rural in comparison with urban patients presented with lower CD4 cell counts with an unadjusted and adjusted mean difference of -48 cells/mm [95% confidence interval, -86 to -10) and -37 cells/mm (95% confidence interval: -73 to -2), respectively, consistently observed across calendar years.HIV care initiation at low CD4 cell counts was common in this Southeastern US cohort and more common among rural area residents.

INTRODUCTION The Philippines has seen rapid increases in HIV prevalence among people who inject drugs. We study 2 neighboring cities where a linked HIV epidemic differed in timing of onset and levels of prevalence. In Cebu, prevalence rose rapidly from below 1% to 54% between 2009 and 2011 and remained high through 2013. In nearby Mandaue, HIV remained below 4% through 2011 then rose rapidly to 38% by 2013. OBJECTIVES We hypothesize that infection prevalence differences in these cities may owe to aspects of social network structure, specifically levels of network clustering. Building on previous research, we hypothesize that higher levels of network clustering are associated with greater epidemic potential. METHODS Data were collected with respondent-driven sampling among men who inject drugs in Cebu and Mandaue in 2013. We first examine sample composition using estimators for population means. We then apply new estimators of network clustering in respondent-driven sampling data to examine associations with HIV prevalence. RESULTS Samples in both cities were comparable in composition by age, education, and injection locations. Dyadic needle-sharing levels were also similar between the 2 cities, but network clustering in the needle-sharing network differed dramatically. We found higher clustering in Cebu than Mandaue, consistent with expectations that higher clustering is associated with faster epidemic spread. CONCLUSIONS This article is the first to apply estimators of network clustering to empirical respondent-driven samples, and it offers suggestive evidence that researchers should pay greater attention to network structure's role in HIV transmission dynamics.

BACKGROUND Early antiretroviral therapy (ART) initiation in HIV-infected infants significantly improves survival but is often delayed in resource-limited settings. Adding HIV testing of infants at birth to the current recommendation of testing at age 4-6 weeks may improve testing rates and decrease time to ART initiation. We modeled the benefit of adding HIV testing at birth to the current 6-week testing algorithm. METHODS Microsoft Excel was used to create a decision-tree model of the care continuum for the estimated 1,400,000 HIV-infected women and their infants in sub-Saharan Africa in 2012. The model assumed average published rates for facility births (42.9%), prevention of mother-to-child HIV transmission utilization (63%), mother-to-child-transmission rates based on prevention of mother-to-child HIV transmission regimen (5%-40%), return of test results (41%), enrollment in HIV care (52%), and ART initiation (54%). We conducted sensitivity analyses to model the impact of key variables and applied the model to specific country examples. RESULTS Adding HIV testing at birth would increase the number of infants on ART by 204% by age 18 months. The greatest increase is seen in early ART initiations (543% by age 3 months). The increase would lead to a corresponding increase in survival at 12 months of age, with 5108 fewer infant deaths (44,550, versus 49,658). CONCLUSION Adding HIV testing at birth has the potential to improve the number and timing of ART initiation of HIV-infected infants, leading to a decrease in infant mortality. Using this model, countries should investigate a combination of HIV testing at birth and during the early infant period.

Supplemental Digital Content is Available in the Text., Introduction: Women in sub-Saharan Africa face a 2-fold higher risk of HIV acquisition during pregnancy and postpartum and the majority do not know the HIV status of their male partner. Home-based couple HIV testing for pregnant women can reduce HIV transmission to women and infants while increasing antiretroviral therapy (ART) coverage in men. However, the cost-effectiveness of this program has not been evaluated. Methods: We modeled the health and economic impact of implementing a home-based partner education and HIV testing (HOPE) intervention for pregnant women and their male partners in a region of Western Kenya (formally Nyanza Province). We used data from the HOPE randomized clinical trial conducted in Kisumu, Kenya, to parameterize a mathematical model of HIV transmission. We conducted an in-country microcosting of the HOPE intervention (payer perspective) to estimate program costs as well as a lower cost scenario of task-shifting to community health workers. Results: The incremental cost of adding the HOPE intervention to standard antenatal care was $31–37 and $14–16 USD per couple tested with program and task-shifting costs, respectively. At 60% coverage of male partners, HOPE was projected to avert 6987 HIV infections and 2603 deaths in Nyanza province over 10 years with an incremental cost-effectiveness ratio (ICER) of $886 and $615 per disability-adjusted life year averted for the program and task-shifting scenario, respectively. ICERs were robust to changes in intervention coverage, effectiveness, and ART initiation and dropout rates. Conclusions: The HOPE intervention can moderately decrease HIV-associated morbidity and mortality by increasing ART coverage in male partners of pregnant women. ICERs fall below Kenya's per capita gross domestic product ($1358) and are therefore considered cost-effective. Task-shifting to community health workers can increase intervention affordability and feasibility.

Introduction: Male partner HIV testing has been recognized as an important component of prevention of mother-to-child HIV transmission. Scheduled home-based couple HIV testing may be an effective strategy to reach men. Methods: Women attending their first antenatal visit at Kisumu County Hospital in Kenya were randomized to home-based education and HIV testing within 2 weeks of enrollment (HOPE) or to written invitations for male partners to attend clinic (INVITE). Male partner HIV testing and maternal child health outcomes were compared at 6 months postpartum. Results: Of 1101 women screened, 620 were eligible and 601 were randomized to HOPE (n = 306) or INVITE (n = 295). At 6 months postpartum, male partners were more than twice as likely [relative risk (RR) = 2.10; 95% CI (CI): 1.81 to 2.42] to have been HIV tested in the HOPE arm [233 (87%)] compared with the INVITE arm [108 (39%)]. Couples in the HOPE arm [192 (77%)] were 3 times as likely (RR = 3.17; 95% CI: 2.53 to 3.98) to have been tested as a couple as the INVITE arm [62 (24%)] and women in the HOPE arm [217 (88%)] were also twice as likely (RR = 2.27; 95% CI: 1.93 to 2.67) to know their partner's HIV status as the INVITE arm [98 (39%)]. More serodiscordant couples were identified in the HOPE arm [33 (13%)] than in the INVITE arm [10 (4%)] (RR = 3.38; 95% CI: 1.70 to 6.71). Maternal child health outcomes of facility delivery, postpartum family planning, and exclusive breastfeeding did not vary by arm. Conclusions: Home-based HIV testing for pregnant couples resulted in higher uptake of male partner and couple testing, as well as higher rates of HIV status disclosure and identification of serodiscordant couples. However, the intervention did not result in higher uptake of maternal child health outcomes, because facility delivery and postpartum family planning were high in both arms, whereas exclusive breastfeeding was low. The HOPE intervention was successful at its primary aim to increase HIV testing and disclosure among pregnant couples and was able to find more serodiscordant couples compared with the invitation-only strategy. Trial Registration: Clinicaltrials.gov registry: NCT01784783.

Background: Effective retention of HIV-infected mothers and their infants is fraught with multiple challenges, resulting in loss across the continuum of prevention of mother-to-child HIV transmission (PMTCT) care and missed opportunities to offer life-saving HIV prevention and treatment. Methods: The Mother Infant Retention for Health study is an individual-randomized study evaluating the effectiveness of active patient follow-up compared with standard of care on the combined outcome of attrition of HIV-infected women and their infants at 6 months postpartum. Lay counselors administered the active patient follow-up package of interventions, including individualized health education, use of flip charts during clinic visits, and at home, phone and short message service appointment reminders, active phone and physical tracking of patients immediately after missed clinic visits, and individualized retention and adherence support. Results: Use of study visits to indicate participant progression along the PMTCT cascade highlights the nature of loss among women and infants in PMTCT care because of issues such as pregnancy complications, infant deaths, and transfer out. Delay in implementation of Option B+, unanticipated slow enrollment, a health-care worker strike, rapid HIV test kit shortages, and changes in national PMTCT guidelines necessitated several modifications to the protocol design and implementation to ensure successful completion of the study. Conclusions: Flexibility when operationalizing an implementation science study is critical in the context of the shifting landscape in a noncontrolled “real-world” setting. Trial Registration: Clinicaltrials.gov NCT01962220.

Objective: Early initiation of antiretroviral treatment (ART) at CD4+ cell count greater or equal to 500 cells per microliter reduces morbidity and mortality in HIV-infected adults. We determined the proportion of HIV-infected people with high viral load (VL) for whom transmission prevention would be an additional benefit of early treatment. Design: A randomly selected subset of a nationally representative sample of HIV-infected adults in Swaziland in 2012. Methods: Eight to 12 months after a national survey to determine adult HIV prevalence 1067 of 5802 individuals identified as HIV-infected were asked to participate in a follow-up cross-sectional assessment. CD4+ cell enumeration VL measurements and ART status were obtained to estimate the proportion of currently untreated adults and of the entire HIV-infected population with high VL (greater than or equal to 1000 copies/mL) whose treatment under a test-and-treat or VL threshold eligibility strategy would reduce HIV transmission. Results: Of the 927 (87% of 1067) participants enrolled 466 (50%) reported no ART use. Among them 424 (91%) had VL greater than or equal to 1000 copies per milliliter; of these 148 (35%) were eligible for ART at the then existing CD4+ count threshold of less than 350 cells per microliter; an additional 107 (25%) were eligible with expanded CD4+ criterion of less than 500 cells per microliter; and 169 (40%) remained ART ineligible. Thus 36% of the 466 currently untreated and 18% of the total 927 had high VL yet remained ART ineligible under a CD4+ criterion of less than 500 cells per microliter. Conclusions: A test-and-treat or VL threshold for treatment eligibility is necessary to maximize the HIV transmission prevention benefits of ART. Copyright © 2015 Wolters Kluwer Health Inc.

BACKGROUND: Incident syphilis among HIV-infected persons indicates the ongoing behavioral risk for HIV transmission. Detectable viral loads (VLs) among coinfected cases may amplify this risk. METHODS: Primary and secondary cases reported during 2009–2010 from 4 US sites were crossmatched with local HIV surveillance registries to identify syphilis case-persons infected with HIV before or shortly after the syphilis diagnosis. We examined HIV VL and CD4 results collected within 6 months before or after syphilis diagnosis for the coinfected cases identified. Independent correlates of detectable VLs (≥200 copies/mL) were determined. RESULTS: We identified 1675 cases of incident primary or secondary syphilis among persons with HIV. Median age was 37 years; 99.5% were men, 41.1% were African American, 24.5% were Hispanics, and 79.9% of the HIV diagnoses were made at least 1 year before syphilis diagnosis. Among those coinfected, there were no VL results reported for 188 (11.2%); of the 1487 (88.8%) with reported VL results, 809 (54.4%) had a detectable VL (median, 25,101 copies/mL; range, 206–3,590,000 copies/mL). Detectable VLs independently correlated with syphilis diagnosed at younger age, at an sexually transmitted disease clinic, and closer in time to HIV diagnosis. CONCLUSIONS: More than half of syphilis case-persons identified with HIV had a detectable VL collected within 6 months of the syphilis diagnosis. This suggests virologic and active behavioral risk for transmitting HIV.

Background: Shortages of health workers and large number of HIV-infected persons in Africa mean that time to provide antiretroviral therapy (ART) adherence and other messages to patients is limited. Methods: Using time–motion methodology, we documented the intensity and nature of counseling delivered to patients. The study was conducted at a rural and an urban HIV clinic in western Kenya. We recorded all activities of 190 adult patients on ART during their return clinic visits to assess type, frequency, and duration of counseling messages. Results: Mean visit length for patients at the rural clinic was 44.5 (SD = 27.9) minutes and at urban clinic was 78.2 (SD = 42.1) minutes. Median time spent receiving any counseling during a visit was 4.07 minutes [interquartile range (IQR), 1.57–7.33] at rural and 3.99 (IQR, 2.87–6.25) minutes at urban, representing 11% and 8% of total mean visit time, respectively. Median time patients received ART adherence counseling was 1.29 (IQR, 0.77–2.83) minutes at rural and 1.76 (IQR, 1.23–2.83) minutes at urban (P = 0.001 for difference). Patients received a median time of 0.18 (0–0.72) minutes at rural and 0.28 (IQR, 0–0.67) minutes at urban clinic of counseling regarding contraception and pregnancy. Most patients in the study did not receive any counseling regarding alcohol/substance use, emerging risks for ongoing HIV transmission. Conclusions: Although ART adherence was discussed with most patients, time was limited. Reproductive counseling was provided to only half of the patients, and “positive prevention” messaging was minimal. There are strategic opportunities to enhance counseling and information received by clients within HIV programs in resource-limited settings.

OBJECTIVES Reports showed that Saudi Arabia has low prevalence of HIV/AIDS despite increasing influx of foreign nationals from countries with high risk of HIV. Knowledge and stigmatizing attitudes of health care workers contribute to difficulties of people living with HIV/AIDS (PLWHA) accessing prevention, care, and treatment services. Nothing is known about stigma and discrimination about PLWHA in Saudi Arabia. DESIGN We assessed knowledge of Saudi Arabian doctors about HIV and their attitudes toward PLWHA using a cross-sectional study design. METHOD In this study, 1483 doctors completed a self-administered questionnaire. RESULT Knowledge scores and stigma index were computed from responses to relevant statements in the questionnaire. Stigmatizing attitudes of contact, reproductive rights, blaming, and judgmental were identified. HIV knowledge was a significant predictor of high stigma. Doctors' year of medical practice, status/specialty, and location of practice in Saudi Arabia were major predictors of HIV knowledge. CONCLUSIONS Evidence of poor knowledge of HIV suggests the need for further training of health workers on HIV transmission mode.

BACKGROUND: Coital dilution the reduction in the coital frequency per partner when an additional ongoing partner is added may reduce the transmission potential of partnership concurrency for HIV and other sexually transmitted infections. Empirical estimates of dilution especially dilution of sexual acts unprotected by condoms are needed to inform prevention research. METHODS: Sexually active adults in Accra Ghana were recruited in a multistage household probability sample. Degree (number of ongoing partners) total acts and unprotected acts were measured retrospectively for each month in the past year through an event history calendar. Random-effects negative binomial models estimated the association between degree and coital frequency. RESULTS: Compared with person-months with a single partner (monogamy) 2.06 times as many total acts and 1.94 times as many unprotected acts occurred in months with 2 partners. In months with 3 partners 2.90 times as many total acts and 2.39 times as many unprotected acts occurred compared with monogamous months. Total acts but not unprotected acts also declined with partnership duration. CONCLUSIONS: No dilution was observed for total acts with up to 3 concurrent partners but a small amount of dilution was observed for unprotected acts for months with multiple concurrencies. This suggests moderate selective condom use in months with multiple concurrencies. The implications of the observed dilution for future HIV transmission must be investigated with mathematical models.

Objective: Treatment as prevention depends on retaining HIVinfected patients in care. We investigated the effect on HIV transmission of bringing patients lost to follow up (LTFU) back into care. Design: Mathematical model. Methods: Stochastic mathematical model of cohorts of 1000 HIVinfected patients on antiretroviral therapy based on the data from 2 clinics in Lilongwe Malawi. We calculated cohort viral load (sum of individual mean viral loads each year) and used a mathematical relationship between viral load and transmission probability to estimate the number of new HIV infections. We simulated 4 scenarios: "no LTFU" (all patients stay in care) "no tracing" (patients LTFU are not traced) "immediate tracing" (after missed clinic appointment) and "delayed tracing" (after 6 months). Results: About 440 of 1000 patients were LTFU over 5 years. Cohort viral loads (million copies/mL per 1000 patients) were 3.7 [95 prediction interval (PrI) 2.9 4.9] for no LTFU 8.6 (95 PrI 7.3 10.0) for no tracing 7.7 (95 PrI 6.2 9.1) for immediate and 8.0 (95 PrI 6.7 9.5) for delayed tracing. Comparing no LTFU with no tracing the number of new infections increased from 33 (95 PrI 29 38) to 54 (95 PrI 47 60) per 1000 patients. Immediate tracing prevented 3.6 (95 PrI 23.3 to 12.8) and delayed tracing 2.5 (95 PrI 25.8 to 11.1) new infections per 1000. Immediate tracing was more efficient than delayed tracing: to 116 and 142 tracing efforts respectively were needed prevent 1 new infection. Conclusions: Tracing of patients LTFU enhances the preventive effect of antiretroviral therapy but the number of transmissions prevented is small. © 2013 by Lippincott Williams Wilkins.

HIV transmission is common within men who have sex with men (MSM) couples; despite recommendations that MSM who engage in risky sexual behaviors get tested biannually/annually, little is known about the testing patterns of MSM while in a current primary relationship. This study compared demographic and relationship characteristics of groups of MSM with different testing patterns while in their primary relationships and assessed which factors were associated with regular or irregular testing. Two hundred seventy-five HIV-negative male couples/550 MSM were recruited online to complete a survey in 2011. Since the start of their relationship, 21% of MSM tested for HIV every 3, 4, or 6 months; 29% tested once a year; 30% tested only when they felt at risk for HIV; and 20% never tested for HIV. Bivariate analyses indicated that men who had never been tested while in their relationship were younger, less educated, had greater trust in their partner, and were less likely to be in a couple that had 1 or both men having had sex with someone else. In the multivariate analyses, testing at regular intervals was associated with higher education, having a sexual agreement, being in a couple that had 1 or both men having had sex with someone else, and having lower faith in trust toward the main partner. Findings suggest that many MSM's testing behaviors while in their primary relationship do not align with their risk profile. Trust seems to be a barrier to regular HIV testing, which may be addressed by encouraging MSM to negotiate clear sexual agreements with their primary partner.

Efforts to prevent the mother-to-child transmission (PMTCT) of HIV infection have encountered remarkable successes and considerable challenges around the globe. The reductions in vertical HIV transmission observed in Europe and North America have helped raise the possibility of the virtual elimination of new pediatric HIV infections and in turn an "AIDS-free generation". Yet in many resource-limited settings, preventable new pediatric infections continue to occur daily. Here, we consider what will be required to reach an end to the global pediatric HIV epidemic, and what we can hope for in the context of resurgent international interest. The science of PMTCT has advanced dramatically since the first evidence for the use of antiretroviral (ARV) drugs for PMTCT in 1994. The timing and causes of vertical transmission are now well understood, and this knowledge has led directly to highly efficacious PMTCT interventions based on the use of combination ARV regimens. The application of these interventions around the world has been uneven, however. Several African countries report good access to and uptake of PMTCT services and corresponding low rates of early mother-to-child transmission. However, limited population coverage of PMTCT programs with continued use of suboptimal ARV regimens still hamper prevention efforts in many other countries. Looking forward, reaching ambitious international targets to reduce pediatric HIV infections will require a combination of increased access to efficacious ARV regimens and strengthened health systems for maternal and child health, supported by continued strong political will and international attention.

BACKGROUND Engagement across the spectrum of HIV care can improve health outcomes and prevent HIV transmission. We used HIV surveillance data to examine these outcomes. METHODS San Francisco residents who were diagnosed with HIV between 2009 and 2010 were included. We measured the characteristics and proportion of persons linked to care within 6 months of diagnosis, retained in care for second and third visits, and virally suppressed within 12 months of diagnosis. RESULTS Of 862 persons included, 750 (87%) entered care within 6 months of diagnosis; of these, 72% had a second visit in the following 3-6 months; and of these, 80% had a third visit in the following 3-6 months. Viral suppression was achieved in 50% of the total population and in 76% of those retained for 3 visits. Lack of health insurance and unknown housing status were associated with not entering care (P < 0.01). Persons with unknown insurance status were less likely to be retained for a second visit; those younger than 30 years were less likely to be retained for a third visit. Independent predictors of failed viral suppression included age

Untreated substance use disorders (SUD) among HIV patients contribute to worse HIV care outcomes and increased HIV transmission. Although there are clinical and policy recommendations for integrated SUD and HIV treatment, payment issues including complex funding streams are a barrier.We assessed the availability of guideline-concordant medication-assisted therapies to treat alcohol, tobacco, and opioid dependence on state-administered AIDS Drug Assistance Programs (ADAPs), an important source of drug coverage for low-income HIV patients. We examined which medication-assisted therapies are most likely to be included on formularies and variation of these therapies across states.We reviewed state-specific ADAP formularies from 1997 to 2009 for the presence of guideline-concordant medication-assisted therapies to treat alcohol, tobacco, and opioid dependence.The most frequently included medication-assisted therapies were those to treat tobacco dependence, followed by opioid dependence. Few states covered alcohol dependence medications. In each year,10% of states covered all recommended medications and50% covered a partial formulary for at least 1 SUD.ADAPs could provide access to medication-assisted therapies for SUD for a significant number of HIV patients, but these medications have not been widely covered throughout the program's history. Increased availability of medication-assisted therapies through ADAP could facilitate integrated HIV and SUD care.

Cervicovaginal HIV level (CV-VL) influences HIV transmission. Plasma viral load (PVL) correlates with CV-VL, but discordance is frequent. We evaluated how PVL, behavioral, immunological, and local factors/conditions individually and collectively correlate with CV-VL.CV-VL was measured in the cervicovaginal lavage fluid (CVL) of 481 HIV-infected women over 976 person-visits in a longitudinal cohort study. We correlated identified factors with CV-VL at individual person-visits and detectable/undetectable PVL strata by univariate and multivariate linear regression and with shedding pattern (never, intermittent, persistent ≥3 shedding visits) in 136 women with ≥3 visits by ordinal logistic regression.Of 959 person-visits, 450 (46.9%) with available PVL were discordant, 435 (45.3%) had detectable PVL with undetectable CV-VL, and 15 (1.6%) had undetectable PVL with detectable CV-VL. Lower CV-VL correlated with highly active antiretroviral therapy (HAART) usage (P = 0.01). Higher CV-VL correlated with higher PVL (P0.001), inflammation-associated cellular changes (P = 0.03), cervical ectopy (P = 0.009), exudate (P = 0.005), and trichomoniasis (P = 0.03). In multivariate analysis of the PVL-detectable stratum, increased CV-VL correlated with the same factors and friability (P = 0.05), while with undetectable PVL, decreased CV-VL correlated with HAART use (P = 0.04). In longitudinal analysis, never (40.4%) and intermittent (44.9%) shedding were most frequent. Higher frequency shedders were more likely to have higher initial PVL [odds ratio (OR) = 2.47/log10 increase], herpes simplex virus type 2 seropositivity (OR = 3.21), and alcohol use (OR = 2.20).Although PVL correlates strongly with CV-VL, discordance is frequent. When PVL is detectable, cervicovaginal inflammatory conditions correlate with increased shedding. However, genital shedding is sporadic and not reliably predicted by associated factors. HAART, by reducing PVL, is the most reliable means of reducing cervicovaginal shedding.

Objective To identify demographic, behavioral, and psychological variables associated with being HIV positive unaware among black and Latino men who have sex with men (MSM). Methods Participants recruited in 3 cities completed a computer-assisted interview and were tested for HIV infection (OraSure Technologies, Bethlehem, PA). HIV-positive unaware MSM were compared with MSM who tested HIV negative in bivariate and multivariate analyses. Results Of 1208 MSM (597 black and 611 Latino), 11% were HIV-positive unaware (18% black; 5% Latino). In multivariate analysis of the Latino MSM, being HIV-positive unaware was associated with nongay identity, high perceived risk of currently being HIV positive, and belief that sex with other Latino men reduces HIV transmission risk. Among black MSM, being HIV-positive unaware was associated with gay identity, moderately higher income, having health insurance, sexuality disclosure to a current health care provider, fewer than 3 lifetime HIV tests, high perceived risk of testing HIV positive, and belief that sex with other black men reduces HIV transmission risk. Conclusions HIV prevention efforts should address misperceptions among those black and Latino MSM who believe that assortative (ie, intraracial) sexual mixing reduces risk of HIV infection. Our findings also revealed missed opportunities to diagnose black MSM with HIV infection who were already engaged in care and had disclosed their sexuality to their health care provider. Clinicians should offer HIV testing to all MSM, particularly black MSM, who disclose engaging in recent sex with other men to facilitate earlier diagnosis of HIV infection and reduce transmission risk to sexual partners.

Finding ways to leverage the substantial investment in prevention of mother-to-child transmission of HIV to address other maternal, neonatal, and child health threats is a priority. With increased emphasis on health systems strengthening and the integration of disease-specific initiatives within primary care, we propose three areas for consideration: 1) increased integration of service delivery; 2) adaptation of successful implementation models; and 3) a reconceptualization of the care continuums for prevention of mother-to-child HIV transmission and maternal, neonatal, and child health.

To investigate the relationship between male involvement in prevention of mother-to-child HIV transmission services and infant HIV acquisition and mortality, a prospective cohort study was undertaken between 1999 and 2005 in Nairobi, Kenya.HIV-infected pregnant women were enrolled and followed with their infants for 1 year with infant HIV DNA testing at birth, 1, 3, 6, 9, and 12 months postpartum. Women were encouraged to invite male partners for prevention counseling and HIV testing.Among 456 female participants, 140 partners (31%) attended the antenatal clinic. Eighty-two (19%) of 441 infants tested were HIV infected by 1 year of age. Adjusting for maternal viral load, vertical transmission risk was lower among women with partner attendance compared with those without [adjusted hazard ratio (aHR) = 0.56, 95% confidence interval (CI): 0.33 to 0.98; P = 0.042] and among women reporting versus not reporting previous partner HIV testing (aHR = 0.52, 95% CI: 0.32 to 0.84; P = 0.008). The combined risk of HIV acquisition or infant mortality was lower with male attendance (aHR = 0.55; 95% CI: 0.35 to 0.88; P = 0.012) and report of prior male HIV testing (aHR = 0.58; 95% CI: 0.34 to 0.88; P = 0.01) when adjusting for maternal viral load and breastfeeding.Including men in antenatal prevention of mother-to-child HIV transmission services with HIV testing may improve infant health outcomes.

HIV testing is the essential entry point for both treatment and prevention. The need to identify acute HIV infection (the period immediately after HIV acquisition, when persons are most infectious) and HIV-2 infection, which does not respond to many first-line antiretroviral agents, poses challenges for the traditional algorithm of Western blot confirmation after a repeatedly reactive antibody screening test. Immunoassays that detect antibodies earlier, tests for HIV RNA, and combination assays that screen simultaneously for both p24 antigen and HIV antibody are now approved for HIV diagnosis by the Food and Drug Administration. A revised testing algorithm can address the challenges posed by acute infection, HIV-2 infection, and the shortcomings of the Western blot. These new diagnostic strategies will allow earlier more accurate identification of infected persons so that they can benefit from effective treatment and also enhance abilities to focus prevention efforts where HIV transmission is most active.

HIV researchers have long appreciated the need to understand the social and behavioral determinants of HIV-related risk behavior, but the cumulative impact of individual behaviors on population-level HIV outcomes can be subtle and counterintuitive, and the methods for studying this are rarely part of a traditional social science or epidemiology training program. Mathematical models provide a way to examine the potential effects of the proximate biologic and behavioral determinants of HIV transmission dynamics, alone and in combination. The purpose of this article is to show how mathematical modeling studies have contributed to our understanding of the dynamics and disparities in the global spread of HIV. Our aims are to demonstrate the value that these analytic tools have for social and behavioral sciences in HIV prevention research, to identify gaps in the current literature, and to suggest directions for future research.

Background: HIV epidemics around the world have been linked to injection drug use. In many instances, the injected drugs are acidic. HIV-1 is known to be labile to acids, but its susceptibility to acids in the conditions in which illicit drugs are injected is unknown. Methods: We have combined data from ethnographic studies of injection drug use practices with laboratory virology to replicate and evaluate the effects of exposure to acids that are experienced during drug preparation and injection on HIV-1 viability. Results: Short exposures to the acids significantly reduced the likelihood of recovering viable HIV-1 once pH is reduced to 2.3, but acidic solutions did not totally eliminate infectious HIV-1 that might contaminate syringes or solutions being injected, even at the lowest pH tested (pH 1.7). Conclusions: Acidification of drugs, which is required for dissolving free-base formulations of drugs, can significantly reduce but not eliminate the likelihood that syringes previously used by HIV-1-infected injection drug users infect the next injector. Methamphetamines, which are manufactured under extremely acidic pHs, are unlikely to harbor viable HIV if stored or sold in contaminated injection equipment.

Bathhouses and sex clubs were identified as primary venues for HIV transmission during the original HIV epidemic. Because HIV incidence is increasing in some high-risk groups, their potential role in HIV transmission is being examined again. We present an extension of the Bernoulli process model of HIV transmission to incorporate subpopulations with different behaviors in sex acts, condom use, and choice of partners in a single period of time. With this model, we study the role that bathhouses and sex clubs play in HIV transmission using data from the 1997 Urban Men's Health Study. If sexual activity remains the same, we find that bathhouse closures would likely lead to a small increase in HIV transmission in the period examined by this study, although this impact is less than that which would be achieved through a 1% change in current condom use rates. If, conversely, bathhouse closure leads to a reduction of the sexual activity that was in the bathhouse by at least 2%, HIV transmission would be lowered.

BACKGROUND: Although syringe distribution is effective in preventing HIV transmission among injecting drug users (IDUs), there is little evidence on the required coverage to substantially reduce HIV transmission. METHODS: A mathematical model is developed to explore the relationship between the endemic HIV prevalence among IDUs and the coverage of syringe distribution. Data from IDU populations in the United Kingdom and Belarus are used to explore the implications of increasing coverage and the effect of changes in other behaviors. RESULTS: Projections suggest that there is a coverage threshold, which, if reached, could lead to substantial decreases in HIV prevalence. The threshold largely depends on the frequency that IDUs inject and (safely) reuse their syringes, and corresponds to less than 4 syringe-sharing events per IDU per month. Other factors, such as the injecting cessation rate and efficacy of syringe cleaning, only have substantial impact near threshold coverage levels. CONCLUSIONS: Our results support a policy of increasing the coverage of syringe distribution but highlight the difficulty in producing a universal coverage target. Great public health benefit could be conferred by encouraging the safe reuse of an IDU's own syringes and small stable injecting groups. Policies that discourage this will negate the impact of syringe distribution interventions.

The objectives were to study HIV risk behaviors in different population groups linkages to bridge populations and to examine factors affecting such behaviors and links. Ten population groups in 4 provinces were surveyed. Stratified random cluster sampling was used and interviews were conducted to provide information on sociodemographic characteristics mobility and risk behaviors. The groups surveyed were female sex workers (FSWs) household men and women youths in vocational training and men with high-mobility occupations (fishermen mototaxi drivers police military casino workers and deminers). The total number surveyed was 3848. The proportion reporting sex in the past year with FSWs differed sharply between male groups ranging from 20% to 51% in the high-mobility groups and 5% to 10% in the other groups. Noncommercial sex varied less by group. Consistent condom protection (always used condoms in the past 3 months) with FSWs was high (> 85% for most groups). However condom use was significantly less with noncommercial partners a high proportion of whom complained about a lack of condom availability. For the different male groups travel away from home > 1 month in the past year was a strong independent determinant of both sex with FSWs and noncommercial sex. Casual sex was more common in young unmarried men. Women in the general population did not report casual sex but 41% of them were worried about being infected by their husbands. The results suggest mobility is a strong determinant of casual sex. Although FSWs may still act as an important bridge for HIV transmission in Cambodia noncommercial sex is becoming increasingly important due to the relatively low condom use in such relationships. (authors)