1. Predictors of Initiating Needle Exchange Program Utilization During its Implementation and Expansion in Tijuana, Mexico
Hello, my name is Alicia Vera. The title of my presentation is “Predictors of Initiating Needle Exchange Program Utilization During its Implementation and Expansion in Tijuana, Mexico”. To orient you to its location, Tijuana Mexico is situated on Mexico’s northwestern border with the United States, across from San Diego, California (USE POINTER TO SHOW LOCATION)

2. Authors Steffanie A. Strathdee, PhD Remedios Lozada, MD
Carlos Magis-Rodriguez, MD, PhD
Daniela Abramovitz, MS
Alicia Vera, MPH
Jorge Alvelais MD,
Kimberly Brouwer, PhD
Robin Pollini, MPH, PhD
Thomas L Patterson, PhD
Proyecto El Cuete and PrevenCasa
I would especially like to acknowledge our binational research team, led by Dr. Steffanie Strathdee, researchers from the University of California San Diego, Pro-COMUSIDA and Prevencasa, ISESALUD and CENSIDA.

3. Background
Needle exchange programs (NEPs) have reduced incidence and prevalence of HIV infection and needle sharing in most international settings.
NEPs reduce circulation of contaminated syringes and provide access to ancillary services (e.g., screening for HIV, HCV, TB) and referrals to drug treatment and care.
Nation-wide implementation of NEPs has been slower in Mexico compared to other countries, but this is changing.
By way of background, it is well established that needle exchange programs (NEPs) can reduce the incidence and prevalence of HIV and other blood borne infections, by reducing the circulation time of potentially contaminated syringes in the community.
NEPs also play a pivotal role in providing access to crucial ancillary services that differ depending on their availability, legality, cost, and the cultural context.
In Mexico, nation-wide implementation of NEPs has been slower compared to some countries, but this is now changing.

4. NEPs in Mexico: A Calendar of Events
Late 1980’s: First NEP began
Cd Juárez, CH. by Programa Compañeros,AC
Unofficially sanctioned by state government
2004: 2nd NEP implemented in Tijuana, BC
2006: CENSIDA’s national recommendations supporting NEPs
2007: B.C. Secretary of Health endorses NEPs
Rapid scale-up in Tijuana to >100,000 syringes
NEPs now offered in 6 Mexican states
This slide provides a snapshot of describing the scale-up of NEPs in Mexico.
In the late 1980’s the first NEP was implemented by an NGO called Programa Companeros in Ciudad Juarez, Chihuahua. We are fortunate to have the founder of this organization, Rebeca Ramos, as our chairperson here today. Until the mid-2000s, this NEP was the only one to exist in all of Mexico.
Around 2004, Pro-Comusida and Prevencasa implemented a small NEP in Tijuana. Both these NEPs were unofficially sanctioned by their state governments.
In 2005, CENSIDA published national guidelines endorsing harm reduction and NEPs, championed by Dr. Carlos Magis.
Most recently, in 2007 the Secretary of Health of Baja California, Dr. Jose Bustamente, officially endorsed NEPs, allowing for rapid scale-up in Tijuana, through which >100,000 syringes were exchanged last year, and across Mexico, NEPs are now operating in at least 6 states. We are fortunate that Dr. Bustamente is presenting a poster at this meeting that describes attitudes of stakeholders towards harm reduction in Tijuana.

5. Here is a photo of the mobile NEP vans, outfitted by CENSIDA and different state health ministries, which are called condonetas

6. Objective
To study uptake and predictors of initiating NEP among injection drug users (IDUs) during its recent expansion in Tijuana.
The objective of this presentation is to describe uptake and predictors of initiating NEP among injection drug users (IDUs) during its recent expansion in Tijuana.

7. Methods: Proyecto El Cuete
Prospective cohort of 1056 IDUs:
Respondent Driven Sampling
Eligibility
18 or older
Inject illicit drugs within prior month
Reside in Tijuana
Sample restricted to non-NEP users at baseline
Weighted Poisson regression with generalized estimating equations used to identify predictors of initiating NEP use at six-month follow-up, accounting for correlation between recruiter and recruits
Proyecto El Cuete began as a series of studies, which is now a prospective study of IDUs in Tijuana that was initiated in 2006 ‘Cuete is slang for syringe’.
The sample was recruited using respondent driven sampling, recruiting those who were 18 or older, who had injected drugs within the last month, and who currently live in Tijuana.
To identify predictors of NEP uptake, the sample was restricted to persons who did not use NEPs at baseline.
Weighted Poisson regression was conducted with GEEs to identify predictors of NEP initiation between the baseline and 6 month follow-up interview, accounting for the correlation between recruiter and recruits.

8. Results 85% male; median age: 37 years
76% migrants to Tijuana (of whom, half were deported from the US)
Overall, 85% were male, average age was 37, and three quarters had migrated to Tijuana. Among the migrants, half had been deported from the US.
This figure shows the baseline HIV prevalence among males, which was 4%, and females, which was higher at 10%. Despite relatively low prevalence, HIV incidence is roughly 2 per 100 person years.
HIV prevalence
HIV incidence

9. NEP Uptake Among IDUs in Tijuana, Mexico
At baseline, 20% of the cohort had ever used a NEP. Of the 618 IDUs who were eligible for the analysis of NEP predictors, 59% had used a NEP at follow-up.
N=1056
N=618

10. Did not initiate NEP (N=196)
Factors associated with NEP initiation among 618 IDUs in Tijuana, Mexico
Baseline Characteristics
Initiated NEP (N=284)
Did not initiate NEP (N=196)
p-value
Crude Odds Ratio
Median age (years) 37 39
0.02
0.99 per yr
Average monthly income ≥2500 pesos*
68%
78%
0.01
0.74
Mostly obtained syringes from pharmacies*
69%
80%
0.009
0.70
Receptive needle sharing*
36%
42%
0.18
0.81
Family members used drugs
39%
26%
0.003
1.36
Median # IDUs in social network 80 69
0.05
(per 10 persons)
Ever had sex with a male (men only)
32%
22%
0.03
Injected most often at shooting gallery*
29%
20%
1.34
Arrested for having track marks*
27%
17%
1.13
This slide shows factors associated with NEP uptake between baseline and follow-up.
As seen here, IDUs who started using NEP were younger, had lower incomes, and were less likely to obtain most of their syringes from pharmacies, where they can legally be purchased. On the other hand, they were just as likely to share needles.
They were more likely to have family members who used drugs, have larger numbers of IDUs in their social network, and among males, they were more likely to have had sex with men.
Additionally, IDUs who injected at shooting galleries most often, and those who reported being arrested for just having track marks by the police, were more likely to have started using the NEP.
* last 6 months

11. Factors independently associated with NEP initiation among IDUs in Tijuana, Mexico
Characteristics
Adj. Rate Ratio
95% CI
Individual level
Income ≥2500 pesos
0.66
Obtained syringe most often from pharmacist*
0.56
Obtained syringes most often from unsafe source*
0.36
Receptive needle sharing*
0.71
Social Influence
Family members ever used drugs
1.37
Size of social network (per 10 subjects)
1.01
Environmental level
Injected most often at shooting gallery*
1.54
Arrested for track marks*
1.38
Considering these factors simultaneously in a weighted Poisson regression model, those that were independently associated with initiating NEP are shown here. Variables with adjusted rate ratios LESS THAN ONE are inversely associated with NEP uptake. For example, having lower incomes, NOT primarily obtaining syringes at pharmacies, NOT getting most syringes from unsafe sources and NOT sharing needles were associated with starting to use NEPs.
On the other hand, having family members who used drugs, and having more IDUs in their social network were associated with NEP uptake.
Finally, injecting mostly at shooting galleries and having been recently arrested for having track marks was independently associated with starting to use NEPs.
* last 6 months

12. Discussion
Upon expansion, NEP uptake increased 3-fold over a 6 month period in Tijuana
Some, but not all high risk IDUs are being reached
Social networks may facilitate NEP uptake, but policing practices appear to be barriers
Results may not be generalizable to all IDUs in Tijuana, but high HIV incidence indicates an urgent need to continue NEP expansion and outreach
Need to work with police and pharmacists to reduce drug-related harms among IDUs who seek access to syringes through NEPs or pharmacies.
In summary, we found that NEP uptake increased 3-fold over a 6 month period, signaling that these programs are feasible, acceptable and much needed among IDUs in Tijuana.
Taken together, our analysis of predictors of NEP uptake suggests that some, but not all high risk IDUs are being reached.
Our results suggest that social networks of IDUs might facilitate NEP uptake through word of mouth, and that some IDUs who are afraid to carry syringes due to police pressure might seek out NEPs to avoid arrest.
Although our sample may not generalize to all IDUs in Tijuana or other Mexican cities, the rising HIV prevalence and incidence we are beginning to see in Tijuana (as well as Ciudad Juarez) indicates an urgent need to continue NEP expansion in Mexican cities where injection drug use is occurring.
There is also a commensurate need to work alongside with community members, police and pharmacists to ensure broader access to sterile syringes for IDUs, through both NEPs and pharmacies.

13. Acknowledgements UCSD CFAR Developmental Grant Funding
NIH Grants: K01DA020364, R01DA019829, RO1 MH065849
Staff from the PrevenCasa, AC, Patronato Pro- COMUSIDA, UCSD, and CIRAD
San Diego County Public Health Laboratory
Most importantly, the participants who gave of their time
In closing, I want to thank our funders, including the UCSD CFAR, NIDA and NIMH, as well as staff from our partner organizations and most of all, the participants in our study.