Latent Risk Subtypes Based on Injection and Sexual Behavior Among People Who Inject Drugs in Rural Puerto Rico.

BACKGROUND: People who inject drugs (PWID) in Puerto Rico engage in high levels of injection and sexual risk behavior, and they are at high risk for HIV and hepatitis C (HCV) infection, relative to their US counterparts. Less is known, however, about the clustering of risk behavior conducive to HIV and HCV infection among rural Puerto Rican communities. OBJECTIVES: The purpose of this study was to examine concurrent injection and sexual risk subtypes among a rural sample of PWID in Puerto Rico. METHODS: Data were drawn from a respondent-driven sample collected in 2015 of 315 PWID in 4 rural communities approximately 30-40 miles from San Juan. Latent class analysis (LCA) was used to examine risk subtypes using 3 injection and 3 sexual risk indicators. In addition, demographic and other PWID characteristics were examined as possible predictors of latent class membership. RESULTS: Four LCA subtypes were identified: low risk (36%), high injection/low sexual risk (22%), low injection/high sexual risk (20%), and high risk (22%). Younger age and past year homelessness predicted high risk latent class membership, relative to the other classes. In addition, daily speedball use predicted membership in the high injection/low sexual risk class, relative to the low risk and low injection/high sexual risk classes. CONCLUSION/IMPORTANCE: The findings suggest ways in which PWID risk clusters can be identified for targeted interventions.

Rural and urban injection drug use in Puerto Rico: Network implications for human immunodeficiency virus and hepatitis C virus infection.

Understanding the short- and long-term transmission dynamics of blood-borne illnesses in network contexts represents an important public health priority for people who inject drugs and the general population that surrounds them. The purpose of this article is to compare the risk networks of urban and rural people who inject drugs in Puerto Rico. In the current study, network characteristics are drawn from the sampling "trees" used to recruit participants to the study. We found that injection frequency is the only factor significantly related to clustering behavior among both urban and rural people who inject drugs.

Using Network Sampling and Recruitment Data to Understand Social Structures Related to Community Health in a Population of People Who Inject Drugs in Rural Puerto Rico.

OBJECTIVE: This research examined the social network and recruitment patterns of a sample of people who inject drugs (PWIDs) in rural Puerto Rico, in an attempt to uncover systematic clustering and between-group social boundaries that potentially influence disease spread. METHODS: Respondent driven sampling was utilized to obtain a sample of PWID in rural Puerto Rico. Through eight initial "seeds", 317 injection drug users were recruited. Using recruitment patterns of this sample, estimates of homophily and affiliation were calculated using RDSAT. RESULTS: Analyses showed clustering within the social network of PWID in rural Puerto Rico. In particular, females showed a very high tendency to recruit male PWID, which suggests low social cohesion among female PWID. Results for (believed) HCV status at the time of interview indicate that HCV+ individuals were less likely to interact with HCV- individuals or those who were unaware of their status, and may be acting as "gatekeepers" to prevent disease spread. Individuals who participated in a substance use program were more likely to affiliate with one another. The use of speedballs was related to clustering within the network, in which individuals who injected this mixture were more likely to affiliate with other speedball users. CONCLUSION: Social clustering based on several characteristics and behaviors were found within the IDU population in rural Puerto Rico. RDS was effective in not only garnering a sample of PWID in rural Puerto Rico, but also in uncovering social clustering that can potentially influence disease spread among this population.