ResearchProjects

Half or more of HIV transmission events may occur within the period of high infectivity (and often high risk behavior) that can last 11 months or more after a person is initially infected. The study sought to develop effective intervention techniques against HIV transmission among drug users and their community members during the recent infection period. It evaluated ways to locate individuals who had been recently infected, and of finding members within their drug-using and other social networks and venues.  This group was tested for acute and for recent infection, alerted to the probability that their networks contained highly-infectious members, and educated in ways to minimize their chances of getting infected. In addition, the project developed and evaluated ways to reduce stigmatization of those newly-infected with HIV.

Abstract on NIH RePORTER

Puleo J, Buchanan A, Katenka N, Halloran ME, Friedman SR, Nikolopoulos G (2024).
Assessing spillover effects of medications for opioid use disorder on HIV risk behaviors among a network of people who inject drugs
Stats, 7 (2), 549-575. doi: 10.3390/stats7020034.

Lee T, Buchanan AL, Katenka NV, Forastiere L, Halloran ME, Friedman SR, Nikolopoulos G (2023).
Estimating causal effects of HIV prevention interventions with interference in network-based studies among people who inject drugs
Annals of Applied Statistics, 17 (3), 2165-2191. doi: 10.1214/22-aoas1713. PMCID: PMC10798667.

Lee Y, Buchanan AL, Ogburn EL, Friedman SR, Halloran ME, Katenka NV, Wu J, Nikolopoulos G (2023).
Finding influential subjects in a network using a causal framework
Biometrics, 79 (4), 3715-3727. doi: 10.1111/biom.13841. PMCID: PMC10423748.

Buchanan AL, Katenka N, Lee Y, Wu J, Pantavou K, Friedman SR, Halloran ME, Marshall BDL, Forastiere L, Nikolopoulos GK (2023).
Methods for assessing spillover in network-based studies of HIV/AIDS prevention among people who use drugs
Pathogens, 12 (3), 326. doi: 10.3390/pathogens12020326. PMCID: PMC9967280.

Hadjikou A, Pantavou K, Pavlitina E, Pavlopoulou ID, Economou M, Christaki E, Lamnisos D, Kostaki EG, Paraskevis D, Schneider J, Talias M, Friedman SR, Nikolopoulos GK (2021).
Sociometric risk network structure, HIV prevalence, and drug injection-related norms among people who inject drugs (PWID) in Athens, Greece
Substance Use and Misuse, 56 (8), 1190-1201. doi: 10.1080/10826084.2021.1914103.

Hadjikou A, Pavlopoulou ID, Pantavou K, Georgiou AN, Williams LD, Christaki E, Voskarides K, Lavranos G, Lamnisos D, Pouget ER, Friedman S, Nikolopoulos GK (2021).
Drug injection-related norms and high-risk behaviors of people who inject drugs in Athens, Greece
AIDS Research and Human Retroviruses, 37 (2), 130-138. doi: 10.1089/AID.2020.0050. PMCID: PMC8020521.

Vasylyeva TI, Zarebski A, Smyrnov P, Williams LD, Korobchuk A, Liulchuk M, Zadorozhna V, Nikolopoulos G, Paraskevis D, Schneider J, Skaathun B, Pybus OG, Friedman SR (2020).
Phylodynamics helps to evaluate the impact of an HIV prevention intervention
Viruses, 12 (4), 469. doi: 10.3390/v12040469 . PMCID: PMC7232463.

Korobchuk A, Davtyan H, Denisiuk O, Zachariah R, Nikolopoulos GK, Paraskevis D, Skaathun B, Schneider J, Vasylyeva TI, Williams LD, Smyrnov P, Friedman SR (2019).
People with high HIV viral load within risk networks: Who are these people and who refers them best?
Journal of Infection in Developing Countries, 13 (7S), 103S-110S. doi: 10.3855/jidc.11273. PMCID: PMC6779172.

Psichogiou M, Giallouros G, Pantavou K, Pavlitina E, Papadopoulou M, Williams LD, Hadjikou A, Kakalou E, Skoutelis A, Protopapas K, Antoniadou A, Boulmetis G, Paraskevis D, Hatzakis A, Friedman SR, Nikolopoulos GK (2019).
Identifying, linking, and treating people who inject drugs and were recently infected with HIV in the context of a network-based intervention
AIDS Care, 31 (11), 1376-1383. doi: 10.1080/09540121.2019.1601671. PMCID: PMC6818705.

Schueler K, Ferreira M, Nikolopoulos G, Skaathun B, Paraskevis D, Hatzakis A, Friedman SR, Schneider JA (2019).
Pre-exposure prophylaxis (PrEP) awareness and use within high HIV transmission networks
AIDS and Behavior, 23 (7), 1893-1903. doi: 10.1007/s10461-019-02411-0. PMCID: PMC6800107.

Kostaki EG, Frampton D, Paraskevis D, Pantavou K, Ferns B, Raffle J, Grant P, Kozlakidis Z, Hadjikou A, Pavlitina E, Williams LD, Hatzakis A, Friedman SR, Nastouli E, Nikolopoulos GK (2019).
Near full-length genomic sequencing and molecular analysis of HIV-infected individuals in a network-based intervention (TRIP) in Athens, Greece: Evidence that transmissions occur more frequently from those with high HIV-RNA
Current HIV Research, 16 (5), 345-353. doi: 10.2174/1570162X17666190130120757. PMCID: PMC6446520.

Williams LD, Korobchuk A, Pavlitina E, Nikolopoulos GK, Skaathun B, Schneider J, Kostaki EG, Smyrnov P, Vasylyeva TI, Psichogiou M, Paraskevis D, Morgan E, Hadjikou A, Downing MJ, Hatzakis A, Friedman SR (2019).
Experiences of stigma and support reported by participants in a network intervention to reduce HIV transmission in Athens, Greece; Odessa, Ukraine; and Chicago, Illinois
AIDS and Behavior, 23 (5), 1210-1224. doi: 10.1007/s10461-019-02402-1. PMCID: PMC6511315.

Williams LD, Kostaki E, Pavlitina E, Paraskevis D, Hatzakis A, Schneider J, Smyrnov P, Hadjikou A, Nikolopoulos GK, Psichogiou M, Friedman SR (2018).
Pockets of HIV non-infection within highly-infected risk networks in Athens, Greece
Frontiers in Microbiology, 9, 1825. doi: 10.3389/fmicb.2018.01825. PMCID: PMC6117409.

Morgan E, Skaathun B, Nikolopoulos GK, Paraskevis D, Williams LD, Smyrnov P, Friedman SR, Schneider JA (2019).
A network intervention to locate newly HIV infected persons within MSM networks in Chicago
AIDS and Behavior, 23 (1), 15-20. doi: 10.1007/s10461-018-2202-6. PMCID: PMC6784826.

Friedman SR, Williams L, Young AM, Teubl J, Paraskevis D, Kostaki E, Latkin C, German D, Mateu-Gelabert P, Guarino H, Vasylyeva TI, Skaathun B, Schneider J, Korobchuk A, Smyrnov P, Nikolopoulos G (2018).
Network research experiences in New York and Eastern Europe: Lessons for the Southern US in understanding HIV transmission dynamics
Current HIV/AIDS Reports, 15 (3), 283-292. doi: 10.1007/s11904-018-0403-2. PMCID: PMC6010197.

Kostaki EG, Pavlitina E, Williams L, Magiorkinis G, Schneider J, Skaathun B, Morgan E, Psichogiou M, Daikos GL, Sypsa V, Smyrnov P, Korobchuk A, Malliori M, Hatzakis A, Friedman SR, Paraskevis D (2018).
Molecular analysis of HIV-1 infected individuals in a network-based intervention (TRIP): Phylogenetics identify HIV-1 infected individuals with social links
Journal of Infectious Diseases, 218 (5), 707-715. doi: 10.1093/infdis/jiy239. PMCID: PMC6057507.

Smyrnov P, Williams LD, Korobchuk A, Sazonova Y, Nikolopoulos GK, Skaathun B, Morgan E, Schneider J, Vasylyeva TI, Friedman SR (2018).
Risk network approaches to locating undiagnosed HIV cases in Odessa, Ukraine
Journal of the International AIDS Society, 21 (1), e25040. doi: 10.1002/jia2.25040. PMCID: PMC5810318.

Paraskevis D, Kostaki E, Nikolopoulos GK, Sypsa V, Psichogiou M, Del Amo J, Hodges-Mameletzis I, Paraskeva D, Skoutelis A, Malliori M, Williams L, Friedman SR, Daikos GL, Hatzakis A (2017).
Molecular tracing of the geographical origin of HIV-1 infection and patterns of epidemic spread among migrants who inject drugs in Athens
Clinical Infectious Diseases, 65 (12), 2078-2084. doi: 10.1093/cid/cix717. PMCID: PMC5850526.

Nikolopoulos GK, Katsoulidou A, Kantzanou M, Rokka C, Tsiara C, Sypsa V, Paraskevis D, Psichogiou M, Friedman S, Hatzakis A (2017).
Evaluation of the limiting antigen avidity EIA (LAg) in people who inject drugs in Greece
Epidemiology and Infection, 145 (2), 401-412. doi: 10.1017/S0950268816002417. PMCID: PMC6824880.

Sypsa V, Psichogiou M, Paraskevis D, Nikolopoulos G, Tsiara C, Paraskeva D, Micha K, Malliori M, Pharris A, Wiessing L, Donoghoe M, Friedman S, Des Jarlais D, Daikos G, Hatzakis A (2017).
Rapid decline in HIV incidence among persons who inject drugs during a fast-track combination prevention program after an HIV outbreak in Athens
Journal of Infectious Diseases, 215 (10), 1496-1505. doi: 10.1093/infdis/jix100. PMCID: PMC5853582.

Nikolopoulos GK, Pavlitina E, Muth SQ, Schneider J, Psichogiou M, Williams LD, Paraskevis D, Sypsa V, Magiorkinis G, Smyrnov P, Korobchuk A, Vasylyeva TI, Skaathun B, Malliori M, Kafetzopoulos E, Hatzakis A, Friedman SR (2016).
A network intervention that locates and intervenes with recently HIV-infected persons: The Transmission Reduction Intervention Project (TRIP)
Scientific Reports, 6, 38100. doi: 10.1038/srep38100. PMCID: PMC5137009.

Hatzakis A, Sypsa V, Paraskevis D, Nikolopoulos G, Tsiara C, Micha K, Panopoulos A, Malliori M, Psichogiou M, Pharris A, Wiessing L, van de Laar M, Donoghoe M, Heckathorn DD, Friedman SR, Des Jarlais DC (2015).
Design and baseline findings of a large-scale rapid response to an HIV outbreak in people who inject drugs in Athens, Greece: The ARISTOTLE programme
Addiction, 110 (9), 1453-1467. doi: 10.1111/add.12999. PMCID: PMC4854521.

Nikolopoulos GK, Fotiou A, Kanavou E, Richardson C, Detsis M, Pharris A, Suk JE, Semenza JC, Costa-Storti C, Paraskevis D, Sypsa V, Malliori MM, Friedman SR, Hatzakis A (2015).
National income inequality and declining GDP growth rates are associated with increases in HIV diagnoses among people who inject drugs in Europe: A panel data analysis
PLoS One, 10 (4), e0122367. doi: 10.1371/journal.pone.0122367. PMCID: PMC4398461.

Nikolopoulos GK, Sypsa V, Bonovas S, Paraskevis D, Malliori-Minerva M, Hatzakis A, Friedman SR (2015).
Big events in Greece and HIV infection among people who inject drugs
Substance Use and Misuse, 50 (7), 825-838. doi: 10.3109/10826084.2015.978659. PMCID: PMC4498974.

Tsang MA, Schneider JA, Sypsa V, Schumm P, Nikolopoulos GK, Paraskevis D, Friedman SR, Malliori M, Hatzakis A (2015).
Network characteristics of people who inject drugs within a new HIV epidemic following austerity in Athens, Greece
Journal of Acquired Immune Deficiency Syndromes, 69 (4), 499-508. doi: 10.1097/QAI.0000000000000665. PMCID: PMC4484886.

Vasylyeva TI, Friedman SR, Magiorkinis G (2015).
Prevention of early HIV transmissions might be more important in emerging or generalizing epidemics
Proceedings of the National Academy of Sciences of the United States of America, 112 (13), E1515. doi: 10.1073/pnas.1424168112. PMCID: PMC4386368.

Sypsa V, Paraskevis D, Malliori M, Nikolopoulos GK, Panopoulos A, Kantzanou M, Katsoulidou A, Psichogiou M, Fotiou A, Pharris A, Van De Laar M, Wiessing L, Des Jarlais D, Friedman SR, Hatzakis A (2015).
Homelessness and other risk factors for HIV infection in the current outbreak among injection drug users in Athens, Greece
American Journal of Public Health, 105 (1), 196-204. doi: 10.2105/AJPH.2013.301656. PMCID: PMC4145040.

Vasylyeva TI, Friedman SR, Smyrnov P, Bondarenko K (2015).
A new approach to prevent HIV transmission: Project Protect intervention for recently infected individuals
AIDS Care, 27 (2), 223-228. doi: 10.1080/09540121.2014.947913. PMCID: PMC4524562.

Friedman SR, Downing MJ, Smyrnov P, Nikolopoulos G, Schneider JA, Livak B, Magiorkinis G, Slobodianyk L, Vasylyeva TI, Paraskevis D, Psichogiou M, Sypsa V, Malliori MM, Hatzakis A (2014).
Socially-integrated transdisciplinary HIV prevention
AIDS and Behavior, 18 (10), 1821-1834. doi: 10.1007/s10461-013-0643-5. PMCID: PMC4004719.