Key facts
- Every day, more than one million people between the ages of 15 and 49 in the world are infected with a curable sexually transmitted infection, most of which are asymptomatic.
- In 2020, it was estimated that 374 million people between the ages of 15 and 49 were infected with one of the following four curable STIs: chlamydia, gonorrhea, syphilis and trichomoniasis.
- In 2022, it is estimated that 8 million adults between the ages of 15 and 49 will be infected with syphilis.
- It is estimated that more than 500 million people between the ages of 15 and 49 years are infected with genital herpes simplex virus (herpes) (1) .
- HPV infection causes more than 311,000 deaths from cervical cancer annually (2) .
- In 2016, it was estimated that approximately 1 million pregnant women were infected with syphilis, resulting in more than 390,000 adverse birth outcomes (3).
- Sexually transmitted infections directly affect sexual and reproductive health due to stigma, infertility, cancers and pregnancy complications, and can increase the risk of HIV infection.
- Drug resistance is a major threat to reducing the burden of sexually transmitted infections worldwide.
Overview
There are more than 30 different types of bacteria, viruses and parasites that are known to be transmitted through sexual contact, including vaginal, anal or oral sex. Some sexually transmitted infections can also be transmitted from mother to child during pregnancy, childbirth and breastfeeding. Eight pathogens cause a significant spread of sexually transmitted infections. The following four infections are currently curable: syphilis, gonorrhea, chlamydia, and trichomoniasis. There are four other viral conditions: hepatitis B virus, herpes simplex virus, human immunodeficiency virus, and human papillomavirus.
Added to this are emerging outbreaks of new sexually transmitted infections such as monkeypox, Shigella sonnei, Neisseria meningitidis, Ebola and Zika, as well as the resurgence of neglected sexually transmitted disease infections such as syphilitic lymphogranulomatosis. These cases herald increasing challenges in providing adequate services to prevent and control sexually transmitted infections.
Scope of the problem
Sexually transmitted infections have a profound impact on sexual and reproductive health around the world.
More than one million cases of sexually transmitted infections occur daily. In 2020, the organization estimated that there would be 374 million new infections with one of the following four sexually transmitted infections: chlamydia (129 million cases), gonorrhea (82 million cases), syphilis (7.1 million cases), and trichomoniasis (156 million cases). It is estimated that more than 490 million people were living with herpes infection in 2016, and that 300 million women were infected with human papillomavirus, which is the leading cause of cervical cancer and anal cancer among men who have sex with men. . In addition, the organization's updated estimates indicate that 254 million people will live with hepatitis B in 2022.
Sexually transmitted infections can have serious consequences beyond the direct impact of the infection itself.
- Sexually transmitted infections, such as herpes, gonorrhea and syphilis, can increase your risk of contracting HIV.
- Transmission of sexually transmitted infections from mother to child can cause stillbirth, neonatal death, low birth weight, prematurity, sepsis, neonatal conjunctivitis, and congenital malformations.
- HPV infection causes cervical and other cancers.
- Hepatitis B caused just over 1 million deaths in 2022, with most of those deaths resulting from cirrhosis and hepatocellular carcinoma.
- Sexually transmitted infections, such as gonorrhea and chlamydia, are major causes of pelvic inflammatory disease and infertility in women.
Preventing sexually transmitted infections
Condoms, when used properly and consistently, provide one of the most effective means of preventing sexually transmitted infections, including HIV. Although these condoms are effective, they do not protect against sexually transmitted infections that cause sores outside the genitals (ie syphilis or genital herpes). When possible, a condom should be used during all vaginal and anal sex.
Safe and highly effective vaccines exist to prevent the following two types of sexually transmitted viral infections: hepatitis B and human papillomavirus. These vaccines represent a significant advance in the prevention of sexually transmitted infections. By the end of 2023, HPV vaccine had been included in routine immunization programs in 140 countries, most of them high- and middle-income countries. In order to eliminate cervical cancer, which is a public health problem in the world, the goals of high coverage of vaccination with the human papillomavirus vaccine, screening and treatment of precancerous lesions, and therapeutic management of cancer must be achieved by 2030, in addition to maintaining this high level of The coming decades.
Research on developing anti-herpes vaccines has reached advanced stages, with several candidate vaccines undergoing preliminary clinical trials. Increasing evidence suggests that the meningitis prophylaxis (MemB) vaccine provides protection against gonorrhea. More research is needed on vaccines against chlamydia, gonorrhea, syphilis and trichomoniasis.
Other vital medical interventions to prevent some sexually transmitted infections include voluntary medical adult male circumcision, microbicide use, and partner treatment. Trials are being conducted to evaluate the benefits of pre-exposure prophylaxis and post-exposure prophylaxis for sexually transmitted infections and their potential safety against antimicrobial resistance.
Diagnosis of sexually transmitted infections
Sexually transmitted infections are often asymptomatic. Symptoms when they appear can be non-specific.
Accurate tests for diagnosing sexually transmitted infections (using molecular technology) are widely used in high-income countries and are particularly useful for diagnosing asymptomatic infections. However, these tests are largely unavailable in low- and middle-income countries to diagnose chlamydia and gonorrhea. Even if they are available, they are often expensive and cannot be widely available. In addition, obtaining results often takes a long time, which leads to obstructed follow-up and failure to complete care or treatment.
In contrast, there are rapid and inexpensive tests to diagnose syphilis, hepatitis B, and HIV. Rapid testing for syphilis and rapid dual tests for HIV/syphilis are used in many resource-limited settings.
Several other rapid tests are being developed to diagnose sexually transmitted infections, and these tests could improve the diagnosis and treatment of these cases, especially in resource-limited settings.
Treatment of sexually transmitted infections
There is currently an effective treatment for many sexually transmitted infections.
- Three types of bacterial STIs (chlamydia, gonorrhea and syphilis) and one parasitic STI (trichomoniasis) can generally be treated with single-dose antibiotic regimens.
- For herpes and HIV, the most effective treatments available are antivirals, which can modify the course of the disease, although they cannot cure it.
- For hepatitis B virus, antivirals can help fight the virus and slow the rate of liver damage.
Antimicrobial resistance of sexually transmitted infections (STIs), especially gonorrhea, has increased rapidly in recent years and has limited treatment options. The gonococcal antiresistance surveillance program has shown high rates of resistance to many antibiotics, including quinolones, azithromycin, and broad-spectrum cephalosporins, which are “last-stage” treatments (3) .
Antimicrobial resistance also exists in other sexually transmitted infections, such as Mycoplasma genitalium, but is not systematically monitored.
Therapeutic management of sexually transmitted infections
Low- and middle-income countries rely on identifying persistent, easily recognizable signs and symptoms to guide treatment, without laboratory testing. This approach - syndrome-based management - is often based on clinical algorithms and allows health workers to diagnose a specific infection based on observable symptoms (eg vaginal or urethral discharge, anogenital ulcers, etc.). Syndromic-based management is easy, ensures rapid same-day treatment, and avoids the need for expensive or unavailable diagnostic tests in symptomatic patients. However, this approach may lead to overtreatment or missed treatment because most infections are asymptomatic. Therefore, WHO recommends that countries strengthen syndrome-based management by gradually incorporating laboratory tests to support diagnosis. In settings where quality-assured molecular assays are available, treatment of sexually transmitted infections based on laboratory testing is recommended. Furthermore, screening strategies for sexually transmitted infections are necessary for people at higher risk, such as sex workers, men who have sex with men, adolescents in some settings, and pregnant women.
Treating sexual partners is an important component of the management of sexually transmitted infections in order to stop infection and prevent recurrence.
Control the spread of infection
Behavior change is a complex challenge
Despite tremendous efforts to identify simple interventions that can reduce risky sexual behaviors, behavior change remains a complex challenge.
Information, education and counseling can improve an individual's ability to recognize symptoms of sexually transmitted infections and increase the likelihood of seeking care and encouraging their sexual partner to seek care as well. Factors such as lack of public awareness, lack of training among health workers, and long-standing stigma about sexually transmitted infections remain barriers to broader and more effective implementation of these interventions.
Health services for examining and treating sexually transmitted infections are still weak
People seeking testing and treatment for sexually transmitted infections face multiple problems, including limited resources, stigma, poor quality of services, and often having to spend out of pocket.
Marginalized populations most at risk of sexually transmitted infections – such as sex workers, men who have sex with men, people who use drugs, prison populations, mobile populations, and adolescents in countries with a high HIV burden - often do not have access to appropriate sexual health services. Human immunodeficiency.
Science, technology and innovation services are often neglected and underfunded in many places. These problems lead to difficulties in providing diagnostic tests to detect asymptomatic infections, a shortage of trained staff, limited laboratory capacity and a limited supply of appropriate medicines.
Organization's response
Our work is currently guided by the Global Health Sector Strategy on HIV, viral hepatitis and sexually transmitted infections , 2022-2030. In this context, the organization does the following:
- Establish global goals, norms and standards for the prevention, screening and treatment of sexually transmitted infections;
- Providing support for estimating the incidence of sexually transmitted infections and their economic burden and strengthening surveillance;
- Monitoring antigonorrhoea resistance globally;
- Lead the development of a global plan for research into sexually transmitted infections, including the development of additional diagnostic tests, vaccines and medicines for gonorrhea and syphilis.
In fulfilling its mission, the organization also supports countries in the following areas:
- Develop national strategic plans and guidelines;
- Creating an enabling environment that allows individuals to discuss sexually transmitted infections, adopt safer sex practices, and seek treatment;
- Expanding primary prevention (provision and use of condoms, etc.);
- Increase the integration of services for sexually transmitted infections into primary health care services;
- Increasing access to quality, person-centred care for people with sexually transmitted infections;
- Facilitating the accreditation of point-of-care tests;
- Strengthen and scale up health interventions to make an impact, such as vaccination against hepatitis B and human papillomavirus, and syphilis screening in priority populations;
- Strengthening capacity to monitor trends in sexually transmitted infections;
- Monitoring gonorrhea resistance and response.
the reviewer
- James C, Harfouche M, Welton NJ, et al. Herpes simplex virus: global infection prevalence and incidence estimates, 2016. Bull World Health Organ. 2020;98(5):315-329.
- Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018 Nov;68(6):394-424. Epub 2018 Sep 12. Erratum in: CA Cancer J Clin. 2020 Jul;70(4):313.
- Unemo M, Lahra MM, Escher M, Eremin S, Cole MJ, Galarza P, Ndowa F, Martin I, Dillon JR, Galas M, Ramon-Pardo P, Weinstock H, Wi T. WHO global antimicrobial resistance surveillance (GASP/GLASS) ) for Neisseria gonorrhoeae 2017-2018: a retrospective observational study. Lancet Microbe 2021; 2: e627–36
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