STIs – Symptoms and Treatments

Information used has been taken from ECDC (see links) and WHO ‘Growing antibiotic resistance forces updates to recommended treatment for sexually transmitted infection’ News. August 2016.

General overview – trends in bacterial STIs

“Across European countries, there is currently large variability with regard to the extent and frequency of diagnostic procedures to detect sexually transmitted co-infections amongst MSM treated for HIV. The conditions allowing for STI outbreaks or epidemic spread, in terms of the numbers of individuals involved in high-risk sexual networks, also vary considerably between countries.

“In some Central and Eastern European countries increases in the incidence of STIs (particularly syphilis) occurred among the general population during the 1990s. Data on the prevalence and incidence of bacterial STIs among MSM in many Eastern European countries are sparse, largely due to high stigmatization of homosexual behaviour.”


Gonorrhoea and chlamydia 

“From very low levels in the mid-1990s, incidence of gonorrhoea and chlamydia increased among MSM in Western Europe in the late 1990s and early 2000s. This may have been partly due to improved sensitivity of diagnostic tests and the expanded use of combination diagnostic tests, in addition to behavioural changes such as increases in partner numbers and declines in condom use.

“Many studies conducted in the last decade have convincingly demonstrated that the usual standard testing of urogenital sites for gonorrhoea and chlamydia misses most infections in MSM, which occur at extra-genital sites in the pharynx and rectum, and are mostly asymptomatic. While pharyngeal infections are self-limiting and usually clear within two to three weeks even without treatment, rectal infections can persist over longer periods, often without severe symptoms. 

“Few European countries provide an infrastructure for routine screening of MSM in dedicated low-threshold testing sites, thus many MSM rely on general practitioners (GPs) for sexual healthcare, where they do not disclose their sexual preference and will therefore not be offered comprehensive three-site screening, even if this is recommended by guidelines. Even if sexual preference is disclosed, comprehensive screening is less frequently initiated by GPs compared to at dedicated STI clinics, for various reasons. This results in very high levels of undiagnosed asymptomatic extra-genital infections among MSM. 

“As a result, data on trends in gonorrhoea and chlamydia diagnoses are difficult to interpret without additional information on testing frequency, as well as on testing policies and practices, such as the anatomical sites tested, and whether testing was part of routine screening or was symptom-driven.”

Estimates of prevalence of gonorrhoea among MSM

“Studies conducted in Western European countries have reported the following pharyngeal prevalences of gonorrhoea: 4.2% among MSM attending an STI clinic in the Hague, 5.5% among MSM attending sentinel STI sites (local health offices, STI clinics, private practitioners) in 16 German cities, and 9.5% among HIV-positive MSM attending a university hospital outpatient clinic in Madrid. The studies in the Hague and Germany reported rectal prevalence of gonorrhoea to be 6% and 4.6% respectively, while the study in the Hague reported urethral prevalence to be 2.8%. One study among MSM attending a genitourinary medicine (GUM) clinic in inner London between 1999 and 2001 reported urethral, pharyngeal and rectal prevalence of gonorrhoea to be similar at 7.2%, 7.3% and 7.3% respectively.”

Gonorrhoea: epidemiology across all populations – 2017 figures

“In 2017, 89 239 confirmed gonorrhoea cases were reported in 27 countries, an increase of 17% compared with 2016. One country less (Greece) reported data for 2017 compared with 2016. The United Kingdom reported 55% of all cases reported in 2017. The crude notification rate in 2017 was 22.2 per 100 000 population for countries with comprehensive surveillance systems, an increase of 22% compared with 2016. The highest rates in 2017 (>25/100 000 population) were observed in the United Kingdom (75 per 100 000), Ireland (47 per 100 000), Denmark (33 per 100 000), Iceland (29 per 100 000), Norway (27 per 100 000) and Sweden (25 per 100 000). The lowest notification rates (<1 per 100 000) were observed in Bulgaria, Croatia, Cyprus, Poland and Romania.”

For more information and the latest figures around Gonorrhoea epidemiology.

For the facts around gonorrhoea.

Chlamydia: epidemiology across all populations – 2017 figures

“In 2017, 26 countries reported 409 646 chlamydia infections. The crude notification rate for the 22 EU/EEA countries with comprehensive surveillance systems was 146 per 100 000 population. The United Kingdom accounted for 56% of all reported cases in 2017, while the combined case numbers of Denmark, Norway and Sweden, and the United Kingdom amount to 79% of all cases reported in 2017. The disproportionate contribution of the United Kingdom is due to its inclusion of data from a successful screening programme targeted at 15–24-year-olds in England that has been in operation since 2008. This programme offers community-based testing services outside of sexually transmitted infection (STI) clinics and resulted in a large increase of chlamydia diagnoses from 2008 onwards.

“In 2017, notification rates higher than 200 cases per 100 000 were observed in Iceland (650 per 100 000), Denmark (573), Norway (478), the United Kingdom (350), Sweden (337) and Finland (263). All countries reporting rates above 200 per 100 000 had chlamydia control strategies recommending either active screening (UK–England) or widespread opportunistic testing (Denmark, Finland, Iceland, Norway, Sweden and the rest of the United Kingdom). Rates below 10 per 100 000 were reported by eight countries (Bulgaria, Croatia, Cyprus, Hungary, Luxembourg, Poland, Portugal and Romania).”

For more information and the latest figures around chlamydia epidemiology.

For the facts around chlamydia.

Syphilis incidence among MSM

“Syphilis transmission is most effective in the presence of primary syphilitic ulcers and secondary mucocutaneous lesions. Early diagnosis is facilitated by the visibility of lesions in the genital area. While oral and perioral lesions can be relatively easily recognized (but also easily mis-diagnosed), typically painless intra-rectal lesions usually remain unnoticed. Thus, infections transmitted to insertive partners during oral and anal intercourse may be diagnosed as penile ulcers earlier than infections transmitted to receptive partners, particularly to anal receptive partners. Condomless anal intercourse is therefore associated with an increased risk for syphilis transmission, particularly within sexual networks where condomless anal sex with multiple partners is common.

“On the other hand, new infections can be detected by regular serological screening if people are in medical care, such as for HIV treatment, even if they cause no characteristic symptoms. Onward transmission of syphilis to new partners can be effectively reduced if screening frequency is adapted to risk behaviour and partner numbers.

“By sharing common modes of transmission, the prevalence and incidence of syphilis and HIV among MSM are highly associated. This association is further strengthened by immunological and biological factors. A recent history of syphilis is a strong independent risk factor for acquiring HIV infection, just as being diagnosed with HIV is a strong independent risk factor for syphilis infection.

“Syphilis incidence among MSM declined to an all-time low in Western Europe in the mid-1990s, although localized outbreaks still occurred in larger cities in the late 1990s (such as in Hamburg in 1997), and the proportion of HIV-positive men among syphilis patients was very high.

“More generalized spread of syphilis among MSM started from about 2000 onwards, fuelled by increases in partner numbers, and larger sexual networks facilitated by online social and sexual networking websites. After a four-to-five-year period of increasing syphilis incidence, this levelled off in many countries in the mid-2000s, as increasing awareness and improved testing strategies helped to control further spread.

“Increases in syphilis incidence among MSM in the UK and Germany from about 2010 onwards appear to be fuelled by increasing diversification of HIV risk reduction strategies, such as HIV serosorting, and declining rates of consistent condom use. These behavioural changes have been mitigated, although not fully matched, by expansions and intensifications of testing policies. While syphilis screening rates among MSM treated for HIV infection have increased in recent years, several modelling studies suggest that screening intervals would need to be shortened to six or even three months among groups with high partner numbers to have an impact on the epidemic.”

Syphilis prevalence

“Among an HIV-negative cohort of MSM recruited in Lisbon between 2011 and 2014, self-reported lifetime prevalence of syphilis infection was 7%.

“In the Sialon II study, syphilis markers were investigated in four European cities; the prevalence of active syphilis was 9.7% in Bucharest, 5.1% in Verona, 1.4% in Bratislava and 0.1% in Vilnius. In the same study, markers of prior syphilis infection were highest in Vilnius (10.5%) and lowest in Bratislava (3.3%).

“A study in Germany among 1 052 MSM seroconverting for HIV between 1996 and 2007 reported an overall syphilis prevalence of 26%, increasing from 10% between 1996-1999 to 35% in 2005. Co-incident syphilis infection at HIV diagnosis increased significantly (p<0.001) from 2.3% in 2000 to 16.9% in 2003, declining thereafter to 4.3% in 2007. Another cohort study among HIV-positive MSM in Germany which collected data between 1996 and 2012 reported that syphilis prevalence at HIV-seroconversion was 27.1%.”

Epidemiology across all populations – 2017 figures

“In 2017, 33 189 confirmed syphilis cases were reported in 28 countries, giving a crude notification rate of 7.1 cases per 100 000 population for countries with comprehensive surveillance systems. The highest rate was observed in Iceland (15.4 cases per 100 000 population), followed by Malta (13.5 per 100 000), the United Kingdom (11.8 per 100 000) and Spain (10.3 per 100 000). Low rates below 3 cases per 100 000 population were observed in Croatia, Cyprus, Estonia, Italy, Portugal and Slovenia.”

For more information and the latest figures around syphilis epidemiology.

For the facts around syphilis.

STI antibiotic resistance – World Health Organisation recommendations

“New guidelines for the treatment of 3 common sexually transmitted infections (STIs) have been issued by WHO in response to the growing threat of antibiotic resistance.

“Chlamydia, gonorrhoea and syphilis are all caused by bacteria and are generally curable with antibiotics. However, these STIs often go undiagnosed and are becoming more difficult to treat, with some antibiotics now failing as a result of misuse and overuse. It is estimated that, each year, 131 million people are infected with chlamydia, 78 million with gonorrhoea, and 5.6 million with syphilis.

“Resistance of these STIs to the effect of antibiotics has increased rapidly in recent years and has reduced treatment options. Of the 3 STIs, gonorrhoea has developed the strongest resistance to antibiotics. Strains of multidrug-resistant gonorrhoea that do not respond to any available antibiotics have already been detected. Antibiotic resistance in chlamydia and syphilis, though less common, also exists, making prevention and prompt treatment critical.

“When left undiagnosed and untreated, these STIs can result in serious complications and untreated gonorrhoea and chlamydia can cause infertility in both men and women. Infection with chlamydia, gonorrhoea and syphilis can also increase a person’s risk of being infected with HIV two- to three-fold.

“Chlamydia, gonorrhoea and syphilis are major public health problems worldwide, affecting millions of peoples’ quality of life, causing serious illness and sometimes death. The new WHO guidelines reinforce the need to treat these STIs with the right antibiotic, at the right dose, and the right time to reduce their spread and improve sexual and reproductive health. To do that, national health services need to monitor the patterns of antibiotic resistance in these infections within their countries.

“The new recommendations are based on the latest available evidence on the most effective treatments for these 3 sexually transmitted infections.”


“Gonorrhoea is a common STI that can cause infection in the genitals, rectum, and throat. Antimicrobial resistance has appeared and expanded with every release of new classes of antibiotics for the treatment of gonorrhoea. Because of widespread resistance, older and cheaper antibiotics have lost their effectiveness in treatment of the infection.”

WHO guidelines for the treatment of neisseria gonorrhoeae

“WHO urges countries to update their national gonorrhoea treatment guidelines in response to the growing threat of antibiotic resistance. National health authorities should track the prevalence of resistance to different antibiotics in the strains of gonorrhoea circulating among their population. The new guideline calls on health authorities to advise doctors to prescribe whichever antibiotic would be most effective, based on local resistance patterns. The new WHO guidelines do not recommend quinolones (a class of antibiotic) for the treatment of gonorrhoea due to widespread high levels of resistance.”


“Syphilis is spread by contact with a sore on the genitals, anus, rectum, lips or mouth.”

WHO guidelines for the treatment of treponema pallidum (syphilis)

“To cure syphilis, the new WHO guidelines strongly recommend a single dose of benzathine penicillin – a form of the antibiotic that is injected by a doctor or nurse into the infected patient’s buttock or thigh muscle. This is the most effective treatment for syphilis, as it is more effective and cheaper than oral antibiotics.
Benzathine penicillin was recognized by the Sixty-ninth World Health Assembly in May 2016 as an essential medicine which has been in short supply for several years. Reports of stock outs have been received by WHO from antenatal care representatives and providers in countries with high burdens of syphilis from 3 WHO Regions. WHO is working with partners to identify countries with shortages and help monitor global availability of benzathine penicillin to close the gap between national needs and supply of the antibiotic.”


“Chlamydia is the most common bacterial STI and people with this infection are frequently co-infected with gonorrhoea. Symptoms of chlamydia include discharge and a burning feeling when urinating, but most people who are infected have no symptoms. Even when chlamydia is asymptomatic, it can damage the reproductive system.”

WHO guidelines for the treatment of chlamydia trachomatis

“WHO is calling on countries to start using the updated guidelines immediately, as recommended in the ‘Global Health Sector Strategy for Sexually Transmitted Infections (2016-2021)’ endorsed by governments at the World Health Assembly in May 2016. The new guidelines are also in-line with the ‘Global Action Plan on Antimicrobial Resistance’, adopted by governments at the World Health Assembly in May 2015.”

Other main STI’s that affect MSM: Hepatitis A, B and C; lymphogranuloma venereum (LGV) and human papillomavirus (HPV).

Hepatitis A: Epidemiology across all populations – 2016 figures

“In 2016, 29 EU/EEA countries reported 12 502 cases of hepatitis A, 12 429 (99.4%) of which were confirmed.

“2016 was the year with the lowest number of confirmed cases for the period 2012–2016.

“Eighteen countries reported fewer than 100 confirmed cases, while nine countries reported more than 500 cases. Romania reported 25.7% of all confirmed cases. Compared with the four-year average from 2012–2015, nine countries reported increases of over 50% in the number of confirmed cases (Austria, Croatia, the Czech Republic, Greece, Luxembourg, Malta, Portugal, Slovakia and Spain) in 2016, while three countries (Estonia, Finland and Lithuania) reported decreases of more than 50%.

“In the 25 countries reporting information on travel history for all or part of their cases, 813 of 5 968 cases (13.6%) with available information were travel-associated. France (n=307) and Germany (n=151) accounted for more than half (56.3%) of all travel-associated cases.

In 2016, the EU/EEA notification rate was 2.4 cases per 100 000 population, ranging from 0 in Iceland to 25.0 in Slovakia (Table 1). About two-thirds of the EU/EEA countries (18/29) had notification rates below one confirmed case per 100 000 population (Figure 1). In addition to Slovakia (25.0 cases per 100 000 population), high notification rates were reported in Bulgaria (22.7 cases) and Romania (16.1 cases).”

For more information and the latest figures around Hepatitis A epidemiology.

For the facts around Hepatitis A.

Hepatitis B: Epidemiology across all populations – 2017 figures

“For 2017, 30 EU/EEA Member States reported 26 907 cases of hepatitis B virus (HBV) infection. Excluding the five countries that only reported acute cases, the number of cases, 26 262, corresponds to a crude rate of 6.7 cases per 100 000 population. No data were reported from Liechtenstein. Of all cases, 2 486 (9%) were reported as acute, 15 472 (58%) as chronic, 8 607 (32%) as ‘unknown’ and 342 cases (1%) could not be classified due to an incompatible data format.

“Twenty-six countries were able to provide data on acute cases. The overall rate of acute cases was 0.6 per 100 000 population, ranging from no cases in Luxembourg to 2.2 cases per 100 000 population in Latvia. When restricting the analysis to the 19 countries that reported consistently from 2008–2017, the rate for acute cases showed a steady decline from 1.1 cases per 100 000 population in 2008 to 0.6 in 2017. Not all countries share in this trend, however: the rate of acute cases reported by Portugal has shown a steady increase since 2012, when the country started to report.

“Twenty countries submitted data on chronic infections. The overall notification rate was 7.2 cases per 100 000 population, ranging from <0.1 in Romania to 18.0 in Iceland. The United Kingdom reported 62% of all chronic cases reported in 2017. Among the 13 countries that reported consistently between 2008 and 2017, the rate of reported chronic cases increased from 6.7 cases per 100 000 population in 2008 to 10.2 in 2017.”

For more information and the latest figures around Hepatitis B epidemiology.

For the facts around Hepatitis B.

Hepatitis C: Epidemiology across all populations – 2017 figures

“For 2017, 29 EU/EEA Member States reported 31 273 cases of HCV infection.

“Excluding the three countries that only report acute cases (Hungary, Lithuania and the Netherlands), the total number of cases (31 178) represents a decrease of 9.8% over the previous year. No data were reported from France or Liechtenstein. Of all cases reported, 861 (2.8%) were reported as acute, 6 805 (21.8%) as chronic, 23 311 (74.8%) as ‘unknown’ and 296 cases (0.9%) could not be classified due to an incompatible data format. Excluding countries that only reported acute cases, the crude rate of HCV infection was 7.3 per 100 000 population in 2017. From 2008–2017, the overall number of cases diagnosed and reported across the 22 EU/EEA Member States that reported data consistently over this time, excluding those who only reported acute cases, showed year-to-year fluctuations, increasing from 2010–2014 to a high of 9.8 cases per 100 000 population and decreasing again slightly since then.

“Country-specific rates ranged from 0.3 cases per 100 000 population in Italy to 71.5 cases per 100 000 population in Latvia. The United Kingdom accounted for 34% of all reported cases.

“Twenty countries were able to provide data on acute cases. The rate of reported acute cases was 0.3 per 100 000 population, ranging from <0.1 in Greece, Poland and the United Kingdom to 2.1 per 100 000 in Latvia. Nineteen countries submitted data on chronic infections. The notification rate of chronic cases was 2.8 cases per 100 000 population, ranging from <0.1 in Luxembourg and Romania to 69.4 in Latvia. The rate of cases classified as unknown ranged from <0.1 cases per 100 000 population in Cyprus and Denmark to 20.3 in Finland. Overall notification rates were mostly higher in northern and western European countries than in southern European countries.”

For more information and the latest figures around Hepatitis C epidemiology.

For the facts around Hepatitis C.

For more on epidemiology of Hepatitis B and C in selected populations (including MSM) in Europe.

Lymphogranuloma venereum (LGV): Epidemiology across all populations – 2017 figures

“In 2017, 24 countries provided LGV surveillance data. Fifteen countries reported a total of 1 989 cases, while the remaining nine reported no cases. Spain reported LGV surveillance data for the first time in the 2018 data collection and provided data for 2016 and 2017. Four countries (France, the Netherlands, Spain and the United Kingdom) accounted for 86% of all notified cases. Croatia reported the first two LGV cases in 2017.

“Compared with 2016, the number of cases reported in 2017 decreased by 13%. The largest decreases were reported by the two countries reporting the largest numbers of cases: the United Kingdom (-30%) and France (-23%), but Denmark, Finland, Ireland and Italy also reported fewer cases. On the other hand, increased numbers of cases were reported by eight countries, with increases of 50% or more in Hungary (57%), Norway (74%), Portugal (300%) and Slovenia (100%), although many of these countries reported small numbers of cases.

“Transmission category was reported for 1 377 cases in 2017 (69% of all reported cases). All but 12 cases were reported among men who have sex with men (MSM). Age was reported for 95% of cases, with the large majority of cases distributed evenly among 25–34-year-olds (31%), 35–44-year-olds (31%) and those aged 45 years or over (32%).”

For more information and the latest figures around LGV epidemiology.

For the facts around LGV.

Human papillomavirus (HPV)

There is no current epidemiological data available about HPV, for the facts about the infection.

STI treatment options – a simple approach


  • Bacterial infections can be quickly treated with antibiotics.


  • Generally, there are no treatments for viruses; they generally have to run their own course. However, we could loosely group them into three categories:
    • Can be cured (like Hepatitis C) but there is no vaccine as yet
    • There is a vaccine available (as with Hepatitis A & B), but there is no cure as yet.
    • Treatable but not curable, and no vaccine available as yet (HIV).


  • Parasitic skin infections can be relieved and treated with creams and lotions which can be purchased over the counter at the chemist. For parasitic gut infections, a doctor can prescribe specific antibiotic medications that can help.


  • Fungal infections can be relieved and treated with creams and lotions which can be purchased over the counter.

STIs that present symptoms within three days are normally bacterial infections. Viral infections have longer incubation periods. Sometimes they only manifest when the immune system is impaired or run down.

Next module: Chemsex: sexualised substance use

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