Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Panagiotis Vagenas is active.

Publication


Featured researches published by Panagiotis Vagenas.


Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2015

Alcohol use disorders negatively influence antiretroviral medication adherence among men who have sex with men in Peru

Enrico G. Ferro; Damian Weikum; Panagiotis Vagenas; Michael Copenhaver; Pedro Gonzales; Jesus Peinado; Robinson Cabello; Javier R. Lama; Jorge Sanchez; Frederick L. Altice

As international guidelines increase access to antiretroviral therapy (ART) globally, ART adherence becomes increasingly important to achieve HIV treatment as prevention (TasP) goals. In the concentrated HIV epidemic among men who have sex with men (MSM) and transgendered women (TGW) in Lima, Peru, the independent correlates of ART nonadherence were examined to inform treatment intervention priorities. Cross sectional survey of HIV-infected MSM and TGW who are engaged in clinical care in Lima, Peru. From June to August 2012, 302 HIV-infected Peruvian MSM/TGW from three clinical care sites were recruited using convenience sampling to participate in a cross-sectional computer-assisted adherence survey. Several standardized screening measures associated with ART nonadherence were examined in order to determine the independent correlates of optimal (≥90%) and perfect (100%) adherence, which were assessed using logistic regression. Of the 302 participants recruited, 263 (87.1%) were prescribed ART. Among those prescribed ART, 229 (87.1%) reported optimal and 146 (55.5%) reported perfect adherence. The prevalence of alcohol use disorders (AUD; 43.2%), alcohol dependence (5.3%), recent drug use (6.0%), and depression (44.5%) was high, and most participants had some evidence of neurocognitive impairment. Meeting criteria for having an AUD and depression were collinear (p < 0.001). On multivariate analysis, having an AUD was inversely related and the only independent correlate of optimal (AOR = 0.427; 95% CI = 0.187–0.976) and perfect (AOR = 0.552; 95% CI = 0.327–0.930) ART adherence. AUDs are highly prevalent among Peruvian HIV-infected MSM and contribute significantly to ART nonadherence. These findings support the need for screening and treating underlying AUDs. In order to meet HIV TasP goals, evidence-based strategies targeting AUDs are likely to directly improve ART adherence and indirectly improve overall individual health, HIV treatment engagement, and reduce transmission to sexual partners among this vulnerable and disproportionally affected population.


PLOS ONE | 2013

Screening for Drug and Alcohol Use Disorders and Their Association with HIV-Related Sexual Risk Behaviors among Men Who Have Sex with Men in Peru

Kaysia T. Ludford; Panagiotis Vagenas; Javier R. Lama; Jesus Peinado; Pedro Gonzales; Rene Leiva; Monica Pun; Jorge Sanchez; Frederick L. Altice

Background Perus HIV epidemic is concentrated among men who have sex with men (MSM). The contribution of alcohol use disorders (AUDs) to known high-risk behaviors associated with HIV transmission in this context has not been well characterized. Methods Between June and October 2011, 5,148 sexually active MSM were recruited using convenience sampling in five cities to participate in a cross-sectional bio-behavioral survey. Five high-risk sexual criteria previously associated with incident HIV infection in this setting were selected a priori as the dependent outcomes. Screening for AUDs used the validated Alcohol Use Disorders Identification Test (AUDIT) and AUDS were stratified by severity. Unadjusted and adjusted odds ratios (AOR) were computed to establish the independent correlates of the five dependent outcomes. Results The majority (62.8%) of participants met screening criteria for having an AUD, which were independently correlated with each of the following high-risk sexual risk behaviors in the previous 6 months: 1) >5 sexual partners [AOR = 1.76; (1.54–2.02)]; 2) sex with an HIV-infected partner [AOR = 1.29; (1.03–1.62)]; 3) having a sexually transmitted infection [AOR = 1.38; (1.13–1.68)]; 4) being a sex worker [AOR = 1.61; (1.40–1.87)]; and 5) unprotected sex during last encounter [AOR = 1.22; (1.09–1.38)]. Recent drug use was also correlated with having >5 sexual partners [AOR = 1.42 (1.19–1.71)], sex work [AOR = 1.97 (1.63–2.39)] and unprotected sex during last encounter [AOR = 1.31 (1.11–1.54)]. For each dependent variable, the association with AUDs significantly increased with increasing AUD severity. Conclusions AUDs are highly prevalent among MSM in Peru and are associated with increased HIV risk-taking behaviors that are associated with HIV transmission. Strategies that target problematic drinking such as medication-assisted therapy, behavioral counseling and structural interventions could potentially reduce risky behaviors and ultimately reduce HIV transmission among MSM in Peru.


Journal of Acquired Immune Deficiency Syndromes | 2009

Tonsillar application of AT-2 SIV affords partial protection against rectal challenge with SIVmac239.

Panagiotis Vagenas; Vennansha G. Williams; Michael Piatak; Julian W. Bess; Jeffrey D. Lifson; James Blanchard; Agegnehu Gettie; Melissa Robbiani

Background:Although mucosal responses are important for preventing infections with HIV, the optimal strategies for inducing them remain unclear. To evaluate vaccine strategies targeting the oral mucosal lymphoid tissue inductive sites as an approach to provide immunity at distal sites, we vaccinated healthy macaques via the palatine/lingual tonsils with aldrithiol 2 (AT-2) inactivated Simian immunodeficiency virus (SIV)mac239, combined with CpG-C immunostimulatory oligonucleotide (CpG-C ISS-ODN, C274) as the adjuvant. Methods:Macaques received 5 doses of C274 or control ODN C661 and AT-2 SIV on the tonsillar tissues every 6 weeks before being challenged rectally with SIVmac239, 8 weeks after the last immunization. Results:Although no T-cell or B-cell responses were detected in the blood before challenge, antibody (Ab) responses were detected in the rectum. Immunization with AT-2 SIV significantly reduced the frequency of infection compared with nonimmunized controls, irrespective of adjuvant. In the vaccinated animals that became infected, peak viremias were somewhat reduced. SIV-specific responses were detected in the blood once animals became infected with no detectable differences between the differently immunized groups and the controls. Conclusion:This work provides evidence that vaccine immunogens applied to the oral mucosal associated lymphoid tissues can provide benefit against rectal challenge, a finding with important implications for mucosal vaccination strategies.


Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2015

Communication Technology Use and mHealth Acceptance among HIV-infected Men who have Sex with Men in Peru: Implications for HIV Prevention and Treatment

Archana Krishnan; Enrico G. Ferro; Damian Weikum; Panagiotis Vagenas; Javier R. Lama; Jorge Sanchez; Frederick L. Altice

The HIV epidemic in Peru is concentrated among men who have sex with men (MSM). Given that MSM have been documented as early adopters of emerging technology, we examined communication technology access and utilization, and mobile health (mHealth) acceptance among Peruvian MSM and transgender women (TGW) in order to gauge opportunities for mHealth-enabled HIV interventions. A convenience sample of 359 HIV-infected MSM and TGW recruited from three sites in Lima, Peru completed standardized assessments of alcohol use disorders (AUDs), risky sexual behavior, and antiretroviral therapy (ART) adherence along with self-constructed measures of communication technology access and utilization, and mHealth acceptance. Most participants (86%) had daily access to any cell phone, including smartphones (30%). The most frequent communication activities were receiving and making calls, and receiving and sending text messages using cell phones. On a 5-point Likert scale, participants expressed interest in using mHealth for medication reminders (M = 3.21, SD = 1.32) and engaging in anonymous online interactions with health professionals to discuss HIV-related issues (M = 3.56, SD = 1.33). Importantly, no significant differences were found in communication technology use and mHealth acceptance among participants with AUDs, depression, and suboptimal ART adherence, all of which are associated with poor HIV treatment outcomes. Findings show support for implementing mHealth-based intervention strategies using cell phones to assess and reduce HIV-risk behaviors among HIV-infected MSM and TGW.


Journal of Substance Abuse Treatment | 2014

An evaluation of hepatic enzyme elevations among HIV-infected released prisoners enrolled in two randomized placebo-controlled trials of extended release naltrexone

Panagiotis Vagenas; Angela Di Paola; Maua Herme; Thomas M. Lincoln; Daniel J. Skiest; Frederick L. Altice; Sandra A. Springer

Extended-release naltrexone (XR-NTX), an approved treatment for opioid or alcohol dependence, is a once-monthly injectable formulation of naltrexone. Hepatotoxicity concerns have limited its use, necessitating further investigation. This study aims to examine hepatic enzyme levels in participants of 2 randomized placebo-controlled trials (RCTs) of XR-NTX. Hepatic transaminases were measured in 85 patients enrolled in RCTs of XR-NTX among HIV-infected prisoners, transitioning to the community and receiving treatment for either dependence on alcohol (52.9%), opioids (44.7%) or both (16.5%). Baseline characteristics included HCV co-infection (55.7%), antiretroviral therapy (81%), mental illness (39%) and receiving psychiatric medications (34.1%). Levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) were not statistically different between persons randomized to placebo (N=24) and XR-NTX (N=61) arms. These results confirm that XR-NTX is safe to use among opioid and alcohol dependent HIV-infected released prisoners receiving ART with high rates of co-morbid HCV infection and mental illness.


American Journal of Men's Health | 2017

Men Who Have Sex With Men in Peru: Acceptability of Medication-Assisted Therapy for Treating Alcohol Use Disorders.

Shan-Estelle Brown; Panagiotis Vagenas; Kelika A. Konda; Jesse L. Clark; Javier R. Lama; Pedro Gonzales; Jorge Sanchez; Ann Duerr; Frederick L. Altice

In Peru, the HIV epidemic is concentrated in men who have sex with men (MSM) and transgender women (TGW). Multiple studies correlate alcohol use disorders (AUDs) with risky sexual behaviors among Peruvian MSM. Qualitative research was used to inform a clinical trial on the acceptability of medication-assisted therapies to assist management of AUDs and improve antiretroviral therapy (ART) adherence among MSM/TGW in Peru. Three focus groups involving HIV-infected or HIV-uninfected MSM/TGW (n = 26) with AUDs (AUDIT ≥ 8) were transcribed, translated from Spanish into English, and analyzed using thematic content analysis. Despite having an AUD, participants considered themselves “social” drinkers, minimized their drinking behaviors, and differed about whether or not alcohol problems could be treated. Participants expressed skepticism about medication for treating AUDs. Three concepts emerged as necessary components of a treatment program for alcohol problems: cost, family support, and the potential to drink less alcohol without attaining total abstinence. This study reveals important areas of education to increase potential acceptability of a medication for treating AUDs among MSM/TGW. Given the social conditions and knowledge base of the participants, medication-assisted therapies using naltrexone may be a beneficial strategy for MSM with AUDs.


Journal of Acquired Immune Deficiency Syndromes | 2012

Characterization of peripheral and mucosal immune responses in rhesus macaques on long-term tenofovir and emtricitabine combination antiretroviral therapy

Edith Jasny; Suzanne Geer; Ines Frank; Panagiotis Vagenas; Meropi Aravantinou; Andres M. Salazar; Jeffrey D. Lifson; Michael Piatak; Agegnehu Gettie; James Blanchard; Melissa Robbiani

Background:The goal of antiretroviral therapy (ART) is to suppress virus replication to limit immune system damage. Some have proposed combining ART with immune therapies to boost antiviral immunity. For this to be successful, ART must not impair physiological immune function. Methods:We studied the impact of ART (tenofovir and emtricitabine) on systemic and mucosal immunity in uninfected and simian immunodeficiency (SIV)–infected Chinese rhesus macaques. Subcutaneous ART was initiated 2 weeks after tonsillar inoculation with SIVmac239. Results:There was no evidence of immune dysregulation as a result of ART in either infected or uninfected animals. Early virus-induced alterations in circulating immune cell populations (decreased central memory T cells and myeloid dendritic cells) were detected, but normalized shortly after ART initiation. ART-treated animals showed marginal SIV-specific T-cell responses during treatment, which increased after ART discontinuation. Elevated expression of CXCL10 in oral, rectal, and blood samples and APOBEC3G mRNA in oral and rectal tissues was observed during acute infection and was down regulated after starting ART. ART did not impact the ability of the animals to respond to tonsillar application of polyICLC with increased CXCL10 expression in oral fluids and CD80 expression on blood myeloid dendritic cells. Conclusion:Early initiation of ART prevented virus-induced damage and did not impede mucosal or systemic immune functions.


Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2016

HIV-infected men who have sex with men, before and after release from jail: the impact of age and race, results from a multi-site study.

Panagiotis Vagenas; Alexei Zelenev; Frederick L. Altice; Angela Di Paola; Alison O. Jordan; Paul A. Teixeira; Paula M. Frew; Anne C. Spaulding; Sandra A. Springer

The US HIV/AIDS epidemic is concentrated among men who have sex with men (MSM). Black men are disproportionately affected by incarceration and Black MSM experience higher infection rates and worse HIV-related health outcomes compared to non-Black MSM. We compared HIV treatment outcomes for Black MSM to other HIV-infected men from one of the largest cohorts of HIV-infected jail detainees (N = 1270) transitioning to the community. Of the 574 HIV-infected men released, 113 (19.7%) self-identified as being MSM. Compared to other male subgroups, young Black MSM (<30 years old, N = 18) were significantly less likely: (1) before incarceration, to have insurance, access to an HIV healthcare provider, and use cocaine; (2) during incarceration, to receive a disease management intervention; and (3) in the 6 months post-release, to link to HIV care. Interventions that effectively link and retain young HIV-infected Black MSM in care in communities before incarceration and post-release from jail are urgently needed.


Substance Use & Misuse | 2017

A Qualitative Assessment of Alcohol Consumption and Sexual Risk Behaviors Among Men Who Have Sex With Men and Transgender Women in Peru

Panagiotis Vagenas; Shan-Estelle Brown; Jesse L. Clark; Kelika A. Konda; Javier R. Lama; Jorge Sanchez; Ann Duerr; Frederick L. Altice

ABSTRACT Background: Peruvian men who have sex with men (MSM) and transgender women (TGW) experience the double burden of a highly concentrated HIV epidemic with a high prevalence of alcohol use disorders (AUDs). Recent research has associated both with risky sexual behaviors, including unprotected sex, having multiple sexual partners, engaging in sex work, having recent sexually transmitted infections, and having HIV-infected partners. AUDs have also been associated in MSM/TGW with being unaware of HIV+ status. Objectives: This study aims to further examine issues associated with alcohol consumption, HIV infection, and risk behaviors in a qualitative analysis of focus groups conducted with MSM/TGW in Peru. Methods: A total of 26 MSM/TGW participants with AUDs participated in three semi-structured focus groups in Lima, Peru. Content analysis was facilitated by software, and specific themes were elucidated. Results: Participants described their drinking patterns, including the types of alcoholic drinks they consumed. They depicted drinking frequently and over multiple-day sessions. Problematic drinking behaviors were described, as well as the perceived characteristics of alcohol dependence. Interestingly, HIV-infected participants who were prescribed antiretroviral therapy did not believe that their drinking affected their medication adherence. These insights can aid in the design of future interventions aiming to reduce problematic drinking as well as HIV-related risk behaviors and, subsequently, HIV incidence. Conclusions: Peruvian MSM/TGW exhibit problematic drinking, which may be associated with risky sexual behaviors and HIV transmission. Interest in reducing alcohol consumption was high, suggesting the need for targeted behavioral and pharmacological interventions.


Sexual Health | 2017

Active syphilis and its association with HIV and sexual risk behaviours in a multicity sample of men who have sex with men and transgender women in Peru

Lia N. Pizzicato; Panagiotis Vagenas; Pedro Gonzales; Javier R. Lama; Monica Pun; Jorge Sanchez; Frederick L. Altice

Background Syphilis in Peru is heavily concentrated in men who have sex with men (MSM) and transgender women (TGW). The aim of the present study was to understand the risk factors for active syphilis infection among MSM and TGW in Peru. METHODS Independent correlates suggestive of active syphilis infection were examined to better understand risk factors for syphilis in MSM and TGW, with separate analyses conducted based on location and among TGW. In 2011, 5101 MSM and TGW completed both self-report surveys and HIV and syphilis testing in five Peruvian cities. RESULTS Overall, 261 (5.1%) MSM and TGW met the criteria for active syphilis, with higher prevalence in Lima than elsewhere (7.0% vs 3.0%) and in TGW than in MSM (10.7% vs 4.2%). Significant independent correlates of active syphilis infection differed greatly by location. In Lima, they included being HIV-infected (aware or unaware of status), being a TGW, being a high school graduate, engaging in receptive anal intercourse, no recent sex with a female partner and having had any symptomatic sexually transmissible infection, including syphilis, in the previous 6 months. Outside Lima, the independent correlates included being HIV-infected and unaware of status, engaging in recent sex work, no recent sex with a female partner and age 35-44 years. Among TGW, independent correlates of active syphilis included being HIV-infected (aware or unaware of status), a recent syphilis diagnosis in the previous 6 months and recent drug use. CONCLUSION The findings of the present study support the need not only for combined HIV and syphilis screening, but also for increased screening and treatment of syphilis in MSM and TGW populations. Stratified analyses suggest different syphilis epidemics throughout the country and in TGW, yet being HIV-infected and aware were consistently associated with active syphilis, suggesting higher syphilis risk in HIV-infected MSM and TGW.

Collaboration


Dive into the Panagiotis Vagenas's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Javier R. Lama

Asociación Civil Impacta Salud y Educación

View shared research outputs
Top Co-Authors

Avatar

Jorge Sanchez

Asociación Civil Impacta Salud y Educación

View shared research outputs
Top Co-Authors

Avatar

Pedro Gonzales

Asociación Civil Impacta Salud y Educación

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Agegnehu Gettie

Aaron Diamond AIDS Research Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge