The first biobehavioral survey (BBS) among people who inject drugs (PWID) was conducted in three towns in Zambia from November 2021 to February 2022. The BBS estimated the prevalence of HIV, recent HIV infection, active syphilis, hepatitis B (HBV), hepatitis C (HCV), HIV viral load suppression (VLS), and risk behaviors, as well as progress towards the UNAIDS 95-95-95 targets. The population size of PWID was also estimated. The BBS was led by ICAP at Columbia University, in collaboration with the Zambia National HIV/AIDS/STI/TB Council (NAC) and the Tropical Diseases Research Centre (TDRC), with support from the United States Centers for Disease Control and Prevention (CDC).

Major conclusions from the survey include:

• The prevalence of HIV among all PWID was highest in Ndola (21.3%), compared to Livingstone (12.2%), and Lusaka (7.3%).
• Although small sample sizes limit the reliability of the 95-95-95 target estimation, findings suggest both successes and gaps in the progress towards the global targets.
• The percentage of PWID living with HIV who were aware of their HIV status was less than 95% across the three sites (Livingstone:73.8%; Lusaka: 65.6%; Ndola: 61.9%).
• Among PWID living with HIV who were aware of their HIV status, ART coverage was highest in Livingstone (100%) and Ndola (100%), compared to Lusaka (82.4%). These estimates should be interpreted with caution due to small denominators.
• Among PWID living with HIV and on ART, the prevalence of viral load suppression was highest in Livingstone (100.0%), followed by Ndola (84.3%) and Lusaka (73.5%). These estimates should be interpreted with caution due to small denominators.
• Active syphilis prevalence was highest among PWID in Ndola (10.8%) compared to Livingstone (3.7%) and Lusaka (4.2%).
• The prevalence of HBV was lowest among PWID in Livingstone (1.9%) compared to Lusaka (4.5%) and Ndola (2.6%).
• Among HIV-negative PWID who had ever heard of PrEP, a minority had ever taken PrEP (range: 14.1%–23.3%).
• The majority of PWID in Livingstone (57.3%) and Ndola (67.2%) had shared needles in the last six months, compared to 29.0% in Lusaka.