Abstract:

BACKGROUND: Greece experienced an unprecedented increase in HIV cases among drug injectors in 2011 after economic crisis. Network-level factors are increasingly understood to drive HIV transmission in emerging epidemics. METHODS: We examined the relationship between networks, risk behaviors, and HIV serostatus among 1404 people who inject drugs in Athens, Greece. We generated networks using the chain-referral structure within a large HIV screening program. Network proportions, the proportion of a respondent's network with a given characteristic, were calculated. Multiple logistic regression models were used to assess the relationship between network proportions and individual HIV seroprevalence, injection frequency and unprotected sex. RESULTS: Of note, 1030 networks were generated. Respondent HIV seroprevalence was associated with greater proportions of network members who were HIV infected (ie, those with >/= 50% of network members HIV positive vs. those with no network members HIV positive) (AOR: 3.11; 95% CI: 2.10 to 4.62), divided drugs (AOR: 1.60; 95% CI: 1.10 to 2.35), or injected frequently (AOR: 1.50; 95% CI: 1.02 to 2.21). Homelessness was the only sociodemographic characteristic associated with a risk outcome measure--high-frequency injecting (AOR: 1.41; 95% CI: 1.03 to 1.93). These associations were weaker for more distal second- and third-degree networks and not present when examined within random networks. CONCLUSIONS: Networks are an independently important contributor to the HIV outbreak in Athens, Greece. Network associations were strongest for the immediate network, with residual associations for distal networks. Homelessness was associated with high-frequency injecting. Prevention programs should consider including network-level interventions to prevent future emerging epidemics.

Notes:

Tsang, Michelle ASchneider, John ASypsa, VanaSchumm, PhilNikolopoulos, Georgios KParaskevis, DimitriosFriedman, Samuel RMalliori, MeniHatzakis, AngelosengR01 DA033875/DA/NIDA NIH HHS/R21 MH098768/MH/NIMH NIH HHS/P30 DA011041/DA/NIDA NIH HHS/DP1 DA034989/DA/NIDA NIH HHS/R01DA033875/DA/NIDA NIH HHS/1R21MH098768/MH/NIMH NIH HHS/Research Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov't19992015/06/27 06:00J Acquir Immune Defic Syndr. 2015 Aug 1;69(4):499-508. doi: 10.1097/QAI.0000000000000665.