Syringe sharing among people who inject drugs in Tijuana: before and after the Global Fund

Introduction. Needle and syringe programs (NSP) reduce syringe sharing and HIV transmission among people who inject drugs (PWID). However, their effectiveness relies on sufficient individual and population level coverage. In Tijuana, Mexico, the Global Fund (GF) supported NSP during 10/2011-12/2013, but withdrew funds at the end of 2013 following Mexico's re-classification as an upper-middle income country. Objective. We tested the hypothesis of higher NSP access and lower receptive syringe sharing among PWID in Tijuana during the GF support period compared to pre-GF initiation and post-GF withdrawal. Method. We used data from an ongoing cohort study of PWID in Tijuana (03/2011-10/2015) to implement a segmented regression analysis investigating changes in the self-reported probability of NSP access, reported difficulty in finding sterile syringes and receptive syringe sharing before GF initiation and after GF discontinuation. Results. We found a large significant increase in the probability of NSP access (+.07) and decrease in receptive syringe sharing (-.23) right after GF initiation, which continued over the GF period. Subsequently, we found a significant decline in NSP access (-.05) and an increase in receptive syringe sharing (+.02) right after post-GF withdrawal, which continued thereafter. Discussion and conclusion. We demonstrated significant temporal changes in NSP access and receptive syringe sharing among PWID in Tijuana after GF initiation and withdrawal consistent with our hypothesis. Coordinated efforts with local authorities are needed to sustain major coverage NSP in settings receiving GF or external aid to guarantee continuity of harm reduction services and prevent reinside in risk behaviors associated with HIV transmission.