Sexual Partner Concurrency Among Partners Reported by MSM with Recent HIV Infection

Assessing transmission attribution risk from simulated sequencing data in HIV molecular epidemiology

BACKGROUND

HIV molecular epidemiology (ME) is the analysis of sequence data together with individual-level clinical, demographic, and behavioral data to understand HIV epidemiology. The use of ME has raised concerns regarding identification of the putative source in direct transmission events. This could result in harm ranging from stigma to criminal prosecution in some jurisdictions. Here we assessed the risks of ME using simulated HIV genetic sequencing data.

METHODS

We simulated social networks of men-who-have-sex-with-men, calibrating the simulations to data from San Diego. We used these networks to simulate consensus and next-generation sequence (NGS) data to evaluate the risks of identifying direct transmissions using different HIV sequence lengths, and population sampling depths. To identify the source of transmissions, we calculated infector probability and used phyloscanner software for the analysis of consensus and NGS data, respectively.

RESULTS

Consensus sequence analyses showed that the risk of correctly inferring the source (direct transmission) within identified transmission pairs was very small and independent of sampling depth. Alternatively, NGS analyses showed that identification of the source of a transmission was very accurate, but only for 6.5% of inferred pairs. False positive transmissions were also observed, where one or more unobserved intermediaries were present when compared to the true network.

CONCLUSION

Source attribution using consensus sequences rarely infers direct transmission pairs with high confidence but is still useful for population studies. In contrast, source attribution using NGS data was much more accurate in identifying direct transmission pairs, but for only a small percentage of transmission pairs analyzed.

Substance use and variation in sexual partnership rates among young MSM and young transgender women: Disaggregating between and within-person associations

BACKGROUND

Substance use has been extensively linked to sexual behavior and HIV/STI risk among men who have sex with men (MSM) and transgender women (TW). However, the impact of specific substances and on specific partnership types is not well characterized. The current study seeks to estimate the association between specific substances and partnership rates while carefully disaggregating between and within-person associations to characterize the nature of these associations and inform prevention interventions.

METHODS

Using data from a longitudinal cohort (n = 1159) of young MSM (YMSM) and young TW (YTW), we utilized a series of hybrid mixed effect models to estimate the associations between substance use (i.e., heavy episodic drinking [HED], marijuana, cocaine, ecstasy, methamphetamine, poppers, prescription stimulant, prescription painkiller, and prescription depressants) and partnerships (i.e., one-time, casual, and main).

RESULTS

Results from multivariable models indicated people using substances had higher one-time (HED, poppers) and casual (HED, methamphetamine, poppers) partnership rates. In addition, participants reported higher rates of one-time (HED, ecstasy, methamphetamine, poppers) and casual partners (HED, marijuana, cocaine, methamphetamines, poppers) during periods of substance use.

CONCLUSION

These findings confirm that the highest rates of sexual activity occur among YMSM-YTW using substances during periods of substance use. Yet, these findings should caution researchers against simplistic generalizations as these associations differ across substance and partnership types. Efforts to promote the health of MSM-YTW who use substances should carefully consider this complexity as interventions accounting for the unique cultural context of substance use in these populations are most likely to be successful.

NK cells from Men Who Have Sex with Men at high risk for HIV-1 infection exhibit higher effector capacity

Despite being under constant exposure to HIV-1, some individuals do not show serological or clinical evidence of infection and are known as HESN (HIV-Exposed Seronegative). Multiple studies in different HESN cohorts have linked the NK cells as a correlate of resistance; however, little is known about the role of these cells in Men Who Have Sex with Men (MSM) with high risk sexual behaviors. We evaluated a general overview of activation and effector features of NK cells of MSM co-cultured with LT CD4+ HIV+ in which MSM at high risk of HIV-1 infection (HR-MSM) exhibit higher capacity to eliminate infected cells, reduced percentages of CD69+ cells when compared to MSM at low risk of infection (LR-MSM). In addition, we found that, despite the lower levels of CD69+ NK cells on HR-MSM group, within this population, higher percentages of CD69+ IFN-γ+ and CD69+ NKG2D+ NK cells were found together with higher levels of RANTES and Granzyme B production with higher antiviral capacity, resulting in a lower concentration of p24 protein and p24+ CD4+ T cells. Altogether, this information suggests that NK cells of MSM could impact the capacity to face the viral infection.

Prevalence of Mollicutes among men who have sex with men and transgender women aged 15 to 19 years in Salvador, North-eastern Brazil

BACKGROUND

Some species of Mollicutes have been associated with different pathologies of the urogenital tract in humans, with a high prevalence among adult men who have sex with men (MSM) and transgender women (TGW). However, few studies have been performed to investigate its prevalence among adolescents. In this study, we estimated the initial prevalence of Mycoplasma genitalium (MG), Mycoplasma hominis (MH), Ureaplasma urealyticum (UU), and Ureaplasma parvum (UP); the rate of misdiagnosis at different anatomical sites; and the associated factors with positive tests for Mollicutes among MSM and TGW aged 15 to 19 years enrolled in the PrEP1519 study.

METHODS

PrEP-1519 is the first study to investigate the effectiveness of pre-exposure prophylaxis for human immunodeficiency virus among adolescent MSM and TGW aged 15 to 19 in Latin America. Oral, anal, and urethral swabs were taken from 246 adolescents upon enrolment in the study to detect MG, MH, UU, and UP by quantitative polymerase chain reaction (qPCR). Bivariate and multivariate analyses were conducted by Poisson regression and 95% confidence intervals (95% CI) were estimated.

RESULTS

The prevalence of Mollicutes was 32.1%. UU was the most prevalent species (20.7%), followed by MH (13.4%), MG (5.7%), and UP (3.2%); 67.3% of the positive samples would have been missed if only urethral samples had been taken. Receptive anal sex (prevalence ratio [PR] = 1.79; 95% CI = 1.07-3.01) and clinical suspicion of sexually transmitted infection (PR = 1.62; 95% CI = 1.01-2.61) were factors associated with the detection of Mollicutes in general. Group sex (PR = 1.98; 95% CI = 1.12-3.50) and receptive anal sex (PR = 2.36; 95% CI = 0.95-5.86) were associated with the detection of Mycoplasma spp. No sociodemographic, clinical, or behavioural variable was significantly associated with the detection of Ureaplasma spp.

CONCLUSIONS

A high prevalence of Mollicutes was observed among adolescent MSM and TGW, especially at extragenital sites. Further research is required to understand the epidemiological profile of high-risk adolescents in different regions and contexts, and to investigate the pathogenesis of Mollicutes in the oral and anal mucosa before routine screening can be recommended in clinical practice.

Sex-Positivity, Medical Mistrust, and PrEP Conspiracy Beliefs Among HIV-Negative Cisgender Black Sexual Minority Men in Atlanta, Georgia

Because the public health response to the disproportionate HIV burden faced by Black sexual minority men (BSMMM) has focused on sexual risk reduction and disease prevention, other vital components of sexual health (e.g., intimacy, pleasure, benefits of sex) have been often overlooked. Sex-positive describes a more open, holistic approach toward sex and sexuality that prioritizes these other components, though such an approach is rarely applied to BSMM's sexual health. For sex-positive BSMM, risk/preventive discourse may foster or exacerbate medical mistrust as a reaction to the dissonance between how these men view sexual health and how the medical establishment views it, which may discourage sexual healthcare-seeking. We assessed sex-positivity and its association with medical mistrust and PrEP conspiracy beliefs among 206 HIV-negative cisgender BSMM in Atlanta, Georgia. We performed exploratory factor analytic procedures on responses to a sex-positivity scale, followed by multivariable linear regressions to determine sex-positivity's associations with medical mistrust and PrEP conspiracy beliefs. We extracted two sex-positivity factors: sexual freedom (α = 0.90), reflecting openness toward casual sex and rejection of sexual mores, and essence of sex (α = 0.77), reflecting the intimate, relational, and pleasurable qualities of sex. Sexual freedom was independently associated with perceived provider deception (β = 0.19, CI = 0.04, 0.34). Essence of sex was independently associated with PrEP conspiracy beliefs (β = 0.16, CI = 0.02, 0.31) and marginally associated with perceived provider deception (β = 0.14, CI = - 0.00, 0.29). Healthcare providers and public health practitioners may cultivate greater trust with BSMM by incorporating a sex-positive approach into patient/participant interactions, clinical decision-making, and interventions. Improving access to sexual pleasure acknowledges BSMM's right to optimal, holistic sexual health.

HIV Transmission Potential and Sex Partner Concurrency: Evidence for Racial Disparities in HIV Risk Among Gay and Bisexual Men (MSM)

We determined whether racial disparities in HIV infection among gay and bisexual men (MSM) may be partially explained by racial differences in the HIV transmission potential (i.e. mixing of people living with HIV and people not living with HIV or of unknown HIV serostatus) and density (i.e. sex partner concurrency) of sexual networks. Data included a behavioral survey, testing for HIV, and an egocentric sexual network survey. Mixed effects logistic regressions were used for hypothesis testing. Black (vs. non-Black) MSM were more likely to not know their partner's HIV serostatus (21.8% vs. 9.6%). Similar proportions reported sex partner concurrency (67.1% vs. 68.0%). In adjusted analyses, among Black MSM, sex partner concurrency significantly increased the odds of an HIV transmission potential partnership (TPP), and this association was not significant among non-Black indexes. The association between an HIV TPP and sex partner concurrency may help explain persistent racial disparities in HIV prevalence.

The effects of intimate relationship characteristics on unprotected anal intercourse among same-sex male couples in China: a dyadic analysis using the actor-partner interdependence model

BACKGROUND

Unprotected anal intercourse (UAI) within the context of concurrent sexual relationship are prevalent among men who have sex with men (MSM) who have regular male sex partners and it aggravates the risk of HIV infection among this community. The aim of this study was to assess the effect of intimate relationship characteristics on UAI among MSM couples at the dyadic level.

METHODS

Two hundred four MSM couples were recruited from a HIV testing clinic from April 2017 to April 2018 in Guangzhou, China. The actor-partner interdependence model (APIM) was applied for dyadic analysis. Each MSM couple was divided into the insertive role and the receptive role according to their regular anal sex role. In this context, actor effect is the impact of an MSM's intimate relationship characteristics on his own UAI, and partner effect is the impact of his partner's intimate relationship characteristics on his UAI.

RESULTS

Of the 408 participants, 58.82% had UAI with regular male sex partner (UAI-RP) and 8.09% had concurrent UAI. Intimate relationship characteristics were associated with concurrent UAI, but not associated with UAI-RP. For the receptive role, his relationship investment exerted significant actor and partner effects on concurrent UAI (AOR actor = 1.31, P < 0.001; AOR partner = 1.17, P < 0.001). Meanwhile, receptive role's violence experience within relationship exerted significant actor effects on his own concurrent UAI (AOR actor = 6.43, P = 0.044).

CONCLUSIONS

Relationship investment and violence experience influenced concurrent UAI among MSM couples and it varied in different sex roles. Additional assistance on empowerment, relationship therapy and sexual agreement is urgently needed to reduce their high possibility on engagement of HIV-related risk behaviors.

Substance use treatment partially mitigates association between methamphetamine use and STI risk: findings from the NSDUH cohort

BACKGROUND

In recent years, both methamphetamine use and STIs have been on the rise in the USA. In this analysis, we sought to ascertain whether the risk of STIs and HIV among methamphetamine users was moderated on the basis of participation in substance use treatment programmes.

METHODS

Data came from the National Survey on Drug Use and Health, 2015-2019. Among adult participants, survey-weighted logistic regression analyses were used to assess the relationship between past year methamphetamine use and risk of HIV and STIs, stratified by methamphetamine treatment utilisation and adjusted for demographic and other risk factors.

RESULTS

Among participants in the analytic sample (n=210 392), 1862 (0.9%) reported past year methamphetamine use, 566 (0.3%) reported receiving treatment for its use, 5471 (2.6%) tested positive for any STI in the past year and 395 (0.2%) for HIV ever in their lifetime. Past year methamphetamine use was associated with increased risk of STIs among those who did not receive treatment (adjusted OR=3.628; 95% CI 2.75 to 4.92). Significant moderation was also present between past-year methamphetamine use, risk of STI, and substance use treatment.

CONCLUSION

In this analysis, we demonstrated a strong relationship between methamphetamine use and risk of STIs that differed based on receipt of substance use treatment. These findings suggested that integrated STI and substance use treatment programmes may yield substantial public health benefits.

Exploration of the Complex Relationships Among Multilevel Predictors of PrEP Use Among Men Who Have Sex with Men in the United States

To explore the relationships among individual-, social-, and contextual- (state-level characteristics, including LBGTQ + and racial inequality) level factors and PrEP use. A cross-sectional survey was conducted in 2015-2016 among a geographically diverse group of men who have sex with men (MSM). Survey data was linked to publicly available state-level data based on participant zip code. Multivariable multilevel logistic regression was used to explore the association between multilevel variables and PrEP use. Of 4165 HIV-negative MSM, 13.4% were taking PrEP. In the regression analysis, several demographic and behavioral factors were associated with higher odds of PrEP use. Importantly, after adjusting for individual- and social-level factors, residents of states with high LGBTQ + equality had significantly higher odds of taking PrEP (OR 1.57; 95% CI 1.119, 2.023) compared to low equality states. LGBTQ + inequality between states may hinder PrEP use. States may need to take proactive measures to reduce LGBTQ + inequality as this may negatively impact the ability to reach the federal administration's stated goal to end the HIV epidemic in the US.

Association of age with healthcare needs and engagement among Nigerian men who have sex with men and transgender women: cross-sectional and longitudinal analyses from an observational cohort

INTRODUCTION

Young men who have sex with men (MSM) and transgender women (TGW) face stigmas that hinder access to healthcare. The aim of the study was to understand age-related determinants of healthcare needs and engagement among MSM and TGW.

METHODS

The TRUST/RV368 cohort provides integrated prevention and treatment services for HIV and other sexually transmitted infections (STIs) tailored to the needs of sexual and gender minorities. MSM and TGW aged ≥16 years in Abuja and ≥18 years Lagos, Nigeria, completed standardized behavioural questionnaires and were tested for HIV, Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) every three months for up to 18 months. Logistic regression was used to estimate adjusted odds ratios (aORs) for associations of age and other factors with outcomes of interest upon enrolment, including HIV care continuum steps - HIV testing, ART initiation and viral suppression <1000 copies/mL. Cox proportional hazards models were used to calculate adjusted hazard ratios (aHRs) for associations with incident infections.

RESULTS

Between March 2013 and February 2019, 2123 participants were enrolled with median age 23 (interquartile range 21 to 27) years. Of 1745 tested, 865 (49.6%) were living with HIV. HIV incidence was 11.6/100 person-years [PY], including 23.1/100PY (95% CI 15.5 to 33.1) among participants aged 16 to 19 years and 23.8/100 PY (95% CI 13.6 to 39.1) among TGW. Compared to participants aged ≥25 years, those aged 16 to 19 years had decreased odds of prior HIV testing (aOR 0.40 [95% CI 0.11 to 0.92]), disclosing same-sex sexual practices to healthcare workers (aOR 0.53 [95% CI 0.36 to 0.77]) and receiving HIV prevention information (aOR 0.60 [95% CI 0.41 to 0.87]). They had increased odds of avoiding healthcare (aOR 1.94 [95% CI 1.3 to 2.83]) and engaging in transactional sex (aOR 2.76 [95% CI 1.92 to 3.71]). Age 16 to 19 years was independently associated with increased incidence of HIV (aHR 4.09 [95% CI 2.33 to 7.49]), NG (aHR 3.91 [95% CI 1.90 to 8.11]) and CT (aHR 2.74 [95% CI 1.48 to 5.81]).

CONCLUSIONS

Young MSM and TGW demonstrated decreased healthcare engagement and higher incidence of HIV and other STIs as compared to older participants in this Nigerian cohort. Interventions to address unique obstacles to healthcare engagement by adolescents and young adults are needed to curb the spread of HIV and other STIs among MSM and TGW in Nigeria.

NK Cell Activity and CD57+/NKG2Chigh Phenotype Are Increased in Men Who Have Sex With Men at High Risk for HIV

Introduction

The HIV-exposed seronegative (HESN) status is for individuals who remain seronegative despite repeated exposure to HIV. One of the main cohorts within this group is men who have sex with men (MSM). Studies of this cohort have revealed different immunological and genetic mechanisms that can explain the phenomenon of natural HIV resistance. NK cells' higher effector capacity is related to natural resistance to HIV. Besides, a new population of NK cells with adaptive features was described recently. These cells are increased in some HESN cohorts and appear to be involved in better control of viral replication in primarily HIV-infected subjects. The present study evaluated the role of NK cells in the natural resistance to HIV-1 infection in MSM.

Methodology

Phenotypic and functional features were evaluated in NK cells from two groups of MSM, at different risks of HIV infection, according to the number of sexual partners. The production of IFN-γ and β-chemokines was included in the analysis, as well as the cytotoxic capacity and adaptive NK cell frequency. Genetic features, such as HLA and KIR allele frequencies, were also explored.

Results

High-risk MSM exhibit an increased frequency of fully mature and CD57+/NKG2Chigh NK cells. These individuals also show higher cytotoxic capacity and IFN-γ production in response to K562 stimuli. NK cells with a CD107a+/IFN-γ+ functional profile were found more frequently and displayed higher IFN-γ production capacity among high-risk MSM than among low-risk MSM. The protective allele HLA-B∗18 was only present in the high-risk MSM group as well as HLA-B∗ 39. The protective phenotype KIR3DL1/S1-HLA-B∗Bw4, in a homozygous state, was particularly abundant in the high-risk population. Notably, some of these functional features were related to higher frequencies of mature and CD57+/NKG2Chigh NK cells, which, in turn, were associated with a higher number of sexual partners.

Conclusion

The changes observed in the NK cell compartment can be driven by the magnitude of sexual exposure and immunological challenges of high-risk individuals, which could influence their resistance/susceptibility to HIV infection.

Lubricants and rectal douching: associations with rectal gonorrhea, chlamydia, and/or syphilis infection among men who have sex with men

Despite widespread prevalence of lubricant use and rectal douching for receptive anal intercourse (RAI) among men who have sex with men (MSM), research evaluating the association of these behaviors with sexually transmitted infections (STIs) is limited. This is an observational analysis of a longitudinal cohort of predominantly Black/Latino MSM in Los Angeles. Every six months from August 2014 to January 2018, participants received STI screening and surveys evaluating lubricant use, douching, substance use, and sexual risk behaviors. General estimating equations evaluated the association between consistent lubricant use and douching for RAI with positive rectal Neisseria gonorrhoeae, Chlamydia trachomatis, and/or syphilis (positive STI). Among 313 participants across 552 study visits, 16.5% (91/552) had positive STI. Consistent lubricant use was reported in 52.7% (243/552) and rectal douching in 57.6% (318/552) of study visits. Consistent lubricant use was associated with STI diagnosis (adjusted OR [AOR] 1.81; 95% CI 1.11-2.96; p = 0.018). Each episode of rectal douching before RAI was associated with 2% increased odds of positive STI (AOR 1.02; 95% CI 1.00-1.04; p = 0.041). Among this cohort of HIV-positive and high-risk HIV-negative MSM, lubricant use and douching was common and independently associated with an STI, suggesting the utility of prevention messaging around barrier methods/condoms for sexual encounters involving douching/lubricant use.

Syphilis associated with recreational drug use, depression and high-risk sexual behaviour in men who have sex with men: a case-control study in China

OBJECTIVE

We investigated syphilis prevalence among men who have sex with men (MSM) in China, as well as potential risk factors. Our principal hypothesis was that syphilis would be associated with the use of recreational drugs such as methamphetamines.

METHODS

From April to October 2013, we used several methods to recruit MSM in Qingdao, collecting demographic/behavioural information via self-administrated questionnaires. Trained health workers collected blood for the Treponema pallidum particle assay (TPPA) with positives confirmed by a toluidine red unheated serum test. We used an unmatched case-control study to identify factors that might predict syphilis infection using multivariable logistic regression.

RESULTS

We recruited 447 MSM who agreed to participate and who completed syphilis testing. Of 71 (15.9%) syphilis-positive MSM, 44 (62.0%) used drugs. Of 376 (84.1%) syphilis-negative MSM, 186 (49.5%) used drugs. We found a positive association with syphilis for any recreational drug use (crude OR (cOR) 1.7, 95 % CI 1.0 to 2.8), frequent methamphetamine use (cOR 2.4, 95% CI 1.1 to 5.3) and multiple drug use (adjusted OR (aOR) 3.4, 95% CI 1.3 to 9.2). Syphilis-positive men were more likely to have a higher physical depression score (aOR 5.2, 95% CI 1.1 to 24.4), be > 30 years old (aOR 2.7, 95% CI 1.5 to 4.8), report a prior STI (aOR 4.1, 95% CI 2.3 to 7.3) and report a sex party experience (aOR 2.2, 95% CI 1.1 to 4.4).

CONCLUSIONS

Recreational drug use, depression and high-risk sexual behaviours were associated with syphilis infection among MSM in China. Only a multifaceted approach is likely be effective in control of both syphilis and HIV .

A New Era of HIV Risk: It's Not What You Know, It's Who You Know (and How Infectious)

HIV is transmitted in social and sexual relationships, and HIV transmission risks, as well as protective actions, are evolving as HIV epidemics unfold. The current focus of HIV prevention is centered on antiretroviral medications used to reduce HIV infectiousness in persons already infected with HIV [treatment as prevention (TasP)]. The same medications used to treat infected persons can also be used by uninfected persons as pre-exposure prophylaxis (PrEP) to reduce the infectivity of HIV. Both PrEP and TasP are effective when adherence is high and individuals do not have co-occurring sexually transmitted infections. HIV prevention is most effective and efficient when delivered within sexual networks with high HIV prevalence. Specific network characteristics are recognized as important facilitators of HIV transmission; these characteristics include the degree of similarity among network members (homophily), gender role norms, and belief systems. Since 2011, HIV risk has been redefined based on infectiousness and infectivity, ushering in a new era of HIV prevention with the potential to end HIV epidemics.

Relational concurrency, stages of infection, and the evolution of HIV set point viral load

HIV viral load (VL) predicts both transmission potential and rate of disease progression. For reasons that are still not fully understood, the set point viral load (SPVL) established after acute infection varies across individuals and populations. Previous studies have suggested that population mean SPVL (MSPVL) has evolved near an optimum that reflects a trade-off between transmissibility and host survival. Sexual network structures affect rates of potential exposure during different within-host phases of infection marked by different transmission probabilities, and thus affect the number and timing of transmission events. These structures include relational concurrency, which has been argued to explain key differences in HIV burden across populations. We hypothesize that concurrency will alter the fitness landscape for SPVL in ways that differ from other network features whose impacts accrue at other times during infection. To quantitatively test this hypothesis, we developed a dynamic, stochastic, data-driven network model of HIV transmission, and evolution to assess the impact of key sexual network phenomena on MSPVL evolution. Experiments were repeated in sensitivity runs that made different assumptions about transmissibility during acute infection, SPVL heritability, and the functional form of the relationship between VL and transmissibility. For our main transmission model, scenarios yielded MSPVLs ranging from 4.4 to 4.75 log10 copies/ml, covering much of the observed empirical range. MSPVL evolved to be higher in populations with high concurrency and shorter relational durations, with values varying over a clinically significant range. In linear regression analyses on these and other predictors, main effects were significant (P < 0.05), as were interaction terms, indicating that effects are interdependent. We also noted a strong correlation between two key emergent properties measured at the end of the simulations-MSPVL and HIV prevalence-most clearly for phenomena that affect transmission networks early in infection. Controlling for prevalence, high concurrency yielded higher MSPVL than other network phenomena. Interestingly, we observed lower prevalence in runs in which SPVL heritability was zero, indicating the potential for viral evolution to exacerbate disease burden over time. Future efforts to understand empirical variation in MSPVL should consider local HIV burden and basic sexual behavioral and network structure.

Proportion and factors associated with recent HIV infection in a cohort of patients seen for care in Italy over 1996-2014: Data from the ICONA Foundation Study cohort

In Italy the prevalence of recent HIV infection (RHI) isn't currently monitored. Early diagnosis is crucial to allow introduction of antiretroviral therapy (cART) in the recent phase of infection. We aimed to estimate the proportion and the determinants of RHI among patients enrolled in the ICONA cohort; we explored differences in the median time from HIV diagnosis to cART initiation and in the viro-immunological response between RHI and Less Recent HIV infections (NRHI). We included antiretroviral-naïve HIV-positive patients enrolled in the cohort with documented dates of HIV-negative and positive antibodies tests, grouped in RHI (estimated date of seroconversion within 12 months of enrolment) and NRHI. Proportion of RHI and the trend of this proportion by calendar period (1996-2014) were investigated (Chi-square test). Logistic regression analysis was employed to identify factors associated with RHI. The time from seroconversion to cART initiation was compared in RHI and NRHI overall and after stratification by calendar period (survival analysis). We finally explored the time from starting cART to HIV-RNA <50 copies/mL and to CD4+ gain ≥200 cells/mmc by Cox regression. HIV seroconversion could be estimated for 2608/12,616 patients: 981/2608 (37.6%) were RHI. Proportion of RHI increased in recent calendar periods and was associated with younger age, baseline higher HIV-RNA and CD4+ count. There wasn't difference in the 2-year estimates of cART start between RHI and NRHI, regardless of calendar period. Rates and hazards of virological response were similar in RHI versus NRHI. RHI showed a 1.5-fold higher probability of CD4+ gain, also following adjustment for calendar period and cART regimen, and for age, HCV and smoking; the difference in probability was however attenuated after further controlling for baseline HIV-RNA and CD4+ T-cells. The increased proportion of RHI over time suggests that in recent years in Italy HIV infections are more likely to be detected earlier than before. The similar rates of cART introduction and viro-immunological response in RHI and NRHI probably reflect the efficacy of the modern cART regimens. An improvement of the prevention services is warranted to allow an early cART access, also in the perspective of therapy as prevention.