Papua New Guinea lacks data characterising the sexual health needs of younger key populations (KP): female sex workers (FSW) and commercially and sexually exploited girls (CSE), men who have sex with men (MSM), and transgender women (TGW). Biobehavioural surveys among KP were conducted in three cities. We conducted unweighted and weighted analysis for sample and population proportions, respectively. Variables associated with younger versus older age (15-24 versus ≥25 years) were included in the multivariable analysis. Younger FSW/CSEG had greater odds of having both Neisseria gonorrhoea and Chlamydia trachomatis (aOR:3.2, 95%CI 2.0-5.0), or having either infection (aOR:2.2, 95%CI 1.2-4.1) than older peers. They also had lower odds of having tested for HIV (aOR: 0.6, 95%CI 0.4-0.8). Younger MSM/TGW had greater odds of paying for sex in the <6 months (aOR:2.2, 95%CI: 1.5-3.1) and of having been paid for sex (aOR:1.6, 95%CI 1.1-2.4) than their older peers (≥25 years). Younger MSM/TGW had lower odds of having contact with a peer educator ≤12 months (aOR:0.6, 95%CI 0.4-0.9) and having tested for HIV (aOR:0.6, 95%CI: 0.4-0.9). All key populations have substantial sexual health needs, but those of younger members are greatest. Younger key populations would likely benefit from health services designed specifically for them.
Keywords: Pacific; SDG 3: good health and well-being; SDG 5: gender equality; Surveillance; differentiated services; key populations; young people.