The global burden of sexually transmitted infections (STIs) is high, with more than 30 pathogens, including bacteria, viruses and parasites, known to be transmitted through sexual contact. WHO estimates for 2020 indicate that there were 374 million new cases of curable STIs (gonorrhoea, chlamydia, syphilis and trichomoniasis) among people 15–49 years old. This includes 156 million new cases of trichomoniasis, 128.5 million new cases of chlamydia, 82.4 million new cases of gonorrhoea and 7.1 million new cases of syphilis, amounting to about 1 million new curable STIs every day. In 2022, the number of new syphilis cases increased to 8.0 million.

Chlamydia, caused by Chlamydia trachomatis, and gonorrhoea, caused by Neisseria gonorrhoeae, are the most common bacterial STIs worldwide and result in substantial morbidity and economic costs. Syphilis is a bacterial STI caused by Treponema pallidum that results in substantial morbidity and mortality. In addition, congenital syphilis can be devastating to a fetus if infection during pregnancy is not detected and treated sufficiently early in pregnancy. 

WHO has set ambitious targets in the recent global health sector strategies for HIV, viral hepatitis and STIs. To achieve these targets, such as a 90% reduction in both gonorrhoea and syphilis infections by 2030, the strategy emphasizes the importance of improving access to prevention, diagnostic and treatment services for people with STIs. These guidelines support the management of asymptomatic STIs. 

One challenge to responding to the burden of STIs is that these infections can be asymptomatic to a large and variable extent. In some individuals, such as biological women, gonococcal and chlamydial infections of the cervix can be asymptomatic in about 50–97% of cases. In anatomical sites other than the urethra and cervix, such as the anorectal and oropharyngeal sites, symptoms are usually minimal to absent in up to about 85% of cases.

Further, the treatment of people with STIs is complicated by the rapidly changing antimicrobial susceptibility patterns of various sexually transmitted pathogens, such as N. gonorrhoeae and Mycoplasma genitalium, to available antibiotics, with concerns about the eventual development of untreatable infections with serious sexual and reproductive health consequences. Asymptomatic STIs, especially in the pharynx or rectum, may be a reservoir for the selection of antimicrobial resistance when antimicrobial agents are given for other conditions but are below the minimal inhibitory concentration of the pre-existing STI pathogens. 

Antimicrobial resistance in N. gonorrhoeae has emerged for every drug available for empirical first-line treatment, with the extended-spectrum cephalosporin, ceftriaxone, currently being the last option in most countries. Certain antibiotics, including azithromycin, are at relatively high risk of selection of bacterial resistance, and use needs to be reserved for certain pathogens, including M. genitalium. 

These guidelines focus on the management of people with asymptomatic STIs by providing evidence-informed recommendations to screen for N. gonorrhoeae and C. trachomatis. These recommendations complement the WHO guidelines on syphilis screening among pregnant women, sex workers and men who have sex with men, syphilis self-testing and treponemal and non-treponemal testing; guidelines on STI partner services; guidelines on treatment of people with specific STIs (N. gonorrhoeae, C. trachomatis, M. genitalium, T. pallidum, Trichomonas vaginalis, bacterial vaginosis, Candida albicans, herpes simplex virus, human papillomavirus [genital warts]) and guidelines for the management of symptomatic STIs. All these guidelines will be included in the forthcoming WHO consolidated guidelines on STI prevention and care.

全球性传播感染（STIs）负担沉重，已知有超过30种病原体（包括细菌、病毒和寄生虫）可通过性接触传播。世界卫生组织（WHO）对2020年的估计表明，在15-49岁人群中，新发可治愈性STIs（淋病、衣原体感染、梅毒和滴虫病）病例达3.74亿例。这包括：1.56亿例新发滴虫病、1.285亿例新发衣原体感染、8240万例新发淋病以及710万例新发梅毒，相当于每天新增约100万例可治愈性STIs。2022年，新发梅毒病例数增至800万例。

由沙眼衣原体（Chlamydia trachomatis）引起的衣原体感染和由淋病奈瑟菌（Neisseria gonorrhoeae）引起的淋病是全球最常见的细菌性STIs，导致巨大的发病率和经济成本。由苍白螺旋体（Treponema pallidum）引起的梅毒是一种细菌性STI，导致显著的发病率和死亡率。此外，若孕期感染未被及时发现并在孕早期得到充分治疗，先天性梅毒可对胎儿造成毁灭性影响。

WHO在最近的全球卫生部门HIV、病毒性肝炎和STIs战略中制定了雄心勃勃的目标。为实现这些目标（例如到2030年将淋病和梅毒感染减少90%），该战略强调改善STIs感染者获得预防、诊断和治疗服务的重要性。本指南旨在支持无症状性传播感染的管理。

应对STIs负担的一个挑战是，这些感染在很大程度上且程度不一地呈现无症状。在一些个体中，例如女性，宫颈淋球菌和衣原体感染约50-97%的病例是无症状的。在尿道和宫颈以外的解剖部位（如肛门直肠和口咽部位），高达约85%的病例症状通常轻微或缺失。

此外，治疗STIs感染者变得复杂，原因是多种性传播病原体（如淋病奈瑟菌和生殖支原体Mycoplasma genitalium）对抗生素的抗菌药物敏感性模式快速变化，令人担忧最终可能出现无法治疗的感染，造成严重的性与生殖健康后果。无症状性STIs，特别是在咽部或直肠的感染，当因其他疾病使用抗菌药物但其浓度低于已存在的STI病原体的最低抑菌浓度（MIC）时，可能成为抗菌药物耐药性选择的储存库。

淋病奈瑟菌对可用于经验性一线治疗的每一种药物都已出现耐药性，其中超广谱头孢菌素头孢曲松（ceftriaxone）目前在大多数国家是最后的选择。某些抗生素（包括阿奇霉素）具有相对较高的选择细菌耐药性风险，其使用需要保留给特定病原体（包括生殖支原体）。

本指南侧重于无症状性传播感染者的管理，提供了筛查淋病奈瑟菌和沙眼衣原体的循证建议。这些建议是对以下WHO指南的补充：1.孕妇、性工作者和男男性行为者梅毒筛查、梅毒自我检测以及梅毒螺旋体和非梅毒螺旋体检测指南；2.性传播感染伴侣服务指南；3.特定性传播感染者（淋病奈瑟菌、沙眼衣原体、生殖支原体、苍白螺旋体、阴道毛滴虫Trichomonas vaginalis、细菌性阴道病、白色念珠菌Candida albicans、单纯疱疹病毒、人乳头瘤病毒（生殖器疣）]治疗指南；4.有症状性传播感染管理指南。

所有这些指南都将纳入即将发布的WHO性传播感染预防和关怀综合指南。