Large CI, but a convincingly high odds-ratio that 'high deadspace' syringes increase transmission: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654245/ https:/

Large CI, but a convincingly high odds-ratio that 'high deadspace' syringes increase transmission: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654245/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654245/ Lab testing shows less transmission with less deadspace (up to a point: thick gauge needles were all detectable): https://www.liebertpub.com/doi/abs/10.1089/aid.2016.0023 https://www.liebertpub.com/doi/abs/10.1089/aid.2016.0023 This sounds quite substantial (33% vs. 1.4%), but there's room for confounders: http://www.injectingadvice.com/v4/index.php/articles/equipment/157-how-syringe-type-effects-hiv-risk http://www.injectingadvice.com/v4/index.php/articles/equipme... Overall it seems quite effective.