Machekera Shepherd, Boas Peniel, Temu Poruan, Mosende Zimmbodilion, Lote Namarola, Kelly-Hanku Angela, Mahiane S Guy, Glaubius Robert, Rowley Jane, Gurung Anup, Korenromp Eline
Government of Papua New Guinea, National Department of Health, AOPI Center, Waigani Drive, PO Box, 5896, Port Moresby, Papua New Guinea.
World Vision International, Ruta Place, Morata St, Gordons. P.O Box 4254, Boroko, National Capital District, Port Moresby, Papua New Guinea.
Infect Dis Model. 2021 Mar 20;6:584-597. doi: 10.1016/j.idm.2021.03.004. eCollection 2021.
Papua New Guinea (PNG) has among the highest rates of sexually transmitted infections (STIs) globally and is committed to reducing their incidence. The Syphilis Interventions Towards Elimination (SITE) model was used to explore the expected impact and cost of alternative syphilis intervention scale-up scenarios.
SITE is a dynamical model of syphilis transmission among adults 15-49 years. Individuals are divided into nine groups based on sexual behaviour and into six stages of infection. The model was calibrated to PNG using data from routine surveillance, bio-behavioural surveys, research studies and program records. Inputs included syphilis prevalence, risk behaviours, intervention coverage and service delivery unit costs. Scenarios compared different interventions (clinical treatment, contact tracing, syphilis screening, and condom promotion) for incidence and cost per infection averted over 2021-2030.
Increasing treatment coverage of symptomatic primary/secondary-stage syphilis cases from 25-35% in 2020 to 60% from 2023 onwards reduced estimated incidence over 2021-2030 by 55%, compared to a scenario assuming constant coverage at 2019-2020 levels. The introduction of contact tracing in 2020, assuming 0.4 contacts per symptomatic person treated, reduced incidence over 2021-2030 by 10%. Increasing screening coverage by 20-30 percentage points from the 2019-2020 level reduced incidence over 2021-2030 by 3-16% depending on the target population. Scaling-up clinical, symptom-driven treatment and contact tracing had the lowest cost per infection averted, followed by condom promotion and periodic screening of female sex workers and men who have sex with men.
PNG could considerably reduce its syphilis burden by scaling-up clinical treatment and contact tracing alongside targeted behavioural risk reduction interventions. SITE is a useful tool countries can apply to inform national STI programming and resource allocation.
巴布亚新几内亚（PNG）的性传播感染（STIs）发病率在全球居高不下，该国致力于降低其发病率。梅毒消除干预措施（SITE）模型被用于探究扩大梅毒干预措施规模的不同方案的预期影响和成本。
SITE是一个关于15至49岁成年人梅毒传播的动态模型。个体根据性行为被分为九组，根据感染阶段分为六个阶段。该模型利用常规监测、生物行为调查、研究和项目记录的数据进行校准，以符合巴布亚新几内亚的情况。输入数据包括梅毒患病率、风险行为、干预覆盖率和服务提供单位成本。各方案比较了不同干预措施（临床治疗、接触者追踪、梅毒筛查和推广使用避孕套）在2021年至2030年期间避免感染的发病率和成本。
将有症状的一期/二期梅毒病例的治疗覆盖率从2020年的25%-35%提高到2023年起的60%，与假设维持在2019-2020年水平的覆盖率不变的方案相比，预计2021年至2030年期间发病率降低55%。假设每例接受治疗的有症状患者追踪0.4个接触者，2020年引入接触者追踪措施后，2021年至2030年期间发病率降低10%。将筛查覆盖率在2019-2020年水平基础上提高20-30个百分点，2021年至2030年期间发病率降低3%-16%，具体取决于目标人群。扩大临床症状驱动治疗和接触者追踪措施，每避免一例感染的成本最低，其次是推广使用避孕套以及对女性性工作者和男男性行为者进行定期筛查。
巴布亚新几内亚可以通过扩大临床治疗和接触者追踪措施，同时采取针对性的降低行为风险干预措施，大幅减轻梅毒负担。SITE是各国可用于为国家性传播感染规划和资源分配提供参考的有用工具。
