Ork 46 90 .648 Has pooled resources with somebody in network 44 90 .422 Injection drugs Cocaine Talwin & Ritalin Crack cocaine Morphine Crystal methamphetamine Heroin 71 34 27 45 17 23 131 106 38 57 22 30 .852,.001.233.018.247.173 Shared syringes after injection 31 85 .010 Solvent types Lacquer 78 4 Social Network Correlates of Solvent-Using IDU IDU Only No. Paint thinner Nail polish Gasoline Network size ]) 5.5 Solvent and IDU No. 31 43 61 5.9 P .258 IDU: Injection drug users; GLBTT: Gay, lesbian, bisexual, transgendered, and two-spirited; IQR: inter-quartile range. doi:10.1371/journal.pone.0088623.t001 This study is consistent with a previous 2003 study in our geographic setting, where an increased risk for HCV among SIDU was detected among Aboriginal IDU. The present study extends the literature by demonstrating that increased risk for HCV is observed irrespective of the Aboriginal status of users, although since 80% of the respondents were of Aboriginal descent, power may have been limited to detect a statistical difference. Unlike the previous study, our present results indicate that HIV infection was negatively associated with S-IDU status. Thus, although HIV and HCV can affect the same populations, our results demonstrate that the specific underlying transmission dynamics of each pathogen results in differences in who is actually infected. Furthermore, the increased likelihood of S-IDU having another active IDU in their network, in combination with more frequent syringe-sharing is potentially an Docosahexaenoyl ethanolamide example of micro-level and 23148522 macro-level factors combining to increase the likelihood of HCV transmission. That is, given the higher prevalence of HCV in IDU generally, and given the higher frequency of syringesharing among S-IDU, the ��per injection��risk of HCV transmission, when syringes are shared, may be elevated in our group of S-IDU, leading to the higher observed HCV prevalence. Other studies have identified a link between solvent use and risk of STBBIs; possible mechanisms, specific to solvent use include those related to an extremely marginalized and disadvantaged population, such as riskier sexual behavior, and unique risk networks with a high prevalence of pathogens including STBBIs. Studies examining mediating factors explaining the relationship between solvent use and STBBIs are much needed. Among IDU, differential risk for pathogens has been demonstrated widely. Factors such as drug choice, geographic setting and level of CASIN site vulnerability influence networks, interactions with members of the same or different sub-populations, and routines around drug preparation and equipment usage. Further work to refine the micro- and macro-level risks of SIDU, as well as their interactions with known risks is a worthy study endeavour. Solvent use is associated with individuals from the most socioeconomically disadvantaged populations, alongside a disproportionately higher burden of psychiatric and physical morbidities. The findings from this study align with literature demonstrating a higher burden of infectious diseases among solvent users. Although lifetime use of solvents has been estimated to be as high as 14% among youth in the United States, users who progress to habitual use are of particular concern. Why some progress to chronic use, despite overwhelming social stigma is not known. Given its association with socio-economic deprivation, and the near ubiquitous availability of solvents, it can be surmised that socio-economic vulnerability a.Ork 46 90 .648 Has pooled resources with somebody in network 44 90 .422 Injection drugs Cocaine Talwin & Ritalin Crack cocaine Morphine Crystal methamphetamine Heroin 71 34 27 45 17 23 131 106 38 57 22 30 .852,.001.233.018.247.173 Shared syringes after injection 31 85 .010 Solvent types Lacquer 78 4 Social Network Correlates of Solvent-Using IDU IDU Only No. Paint thinner Nail polish Gasoline Network size ]) 5.5 Solvent and IDU No. 31 43 61 5.9 P .258 IDU: Injection drug users; GLBTT: Gay, lesbian, bisexual, transgendered, and two-spirited; IQR: inter-quartile range. doi:10.1371/journal.pone.0088623.t001 This study is consistent with a previous 2003 study in our geographic setting, where an increased risk for HCV among SIDU was detected among Aboriginal IDU. The present study extends the literature by demonstrating that increased risk for HCV is observed irrespective of the Aboriginal status of users, although since 80% of the respondents were of Aboriginal descent, power may have been limited to detect a statistical difference. Unlike the previous study, our present results indicate that HIV infection was negatively associated with S-IDU status. Thus, although HIV and HCV can affect the same populations, our results demonstrate that the specific underlying transmission dynamics of each pathogen results in differences in who is actually infected. Furthermore, the increased likelihood of S-IDU having another active IDU in their network, in combination with more frequent syringe-sharing is potentially an example of micro-level and 23148522 macro-level factors combining to increase the likelihood of HCV transmission. That is, given the higher prevalence of HCV in IDU generally, and given the higher frequency of syringesharing among S-IDU, the ��per injection��risk of HCV transmission, when syringes are shared, may be elevated in our group of S-IDU, leading to the higher observed HCV prevalence. Other studies have identified a link between solvent use and risk of STBBIs; possible mechanisms, specific to solvent use include those related to an extremely marginalized and disadvantaged population, such as riskier sexual behavior, and unique risk networks with a high prevalence of pathogens including STBBIs. Studies examining mediating factors explaining the relationship between solvent use and STBBIs are much needed. Among IDU, differential risk for pathogens has been demonstrated widely. Factors such as drug choice, geographic setting and level of vulnerability influence networks, interactions with members of the same or different sub-populations, and routines around drug preparation and equipment usage. Further work to refine the micro- and macro-level risks of SIDU, as well as their interactions with known risks is a worthy study endeavour. Solvent use is associated with individuals from the most socioeconomically disadvantaged populations, alongside a disproportionately higher burden of psychiatric and physical morbidities. The findings from this study align with literature demonstrating a higher burden of infectious diseases among solvent users. Although lifetime use of solvents has been estimated to be as high as 14% among youth in the United States, users who progress to habitual use are of particular concern. Why some progress to chronic use, despite overwhelming social stigma is not known. Given its association with socio-economic deprivation, and the near ubiquitous availability of solvents, it can be surmised that socio-economic vulnerability a.