STI Cities

Where in England are you most and least at risk of catching an STI?

STI cities

The thought of getting intimate with someone in the early stages of a meeting can often be really exciting, and the adrenaline rush can sometimes turn that temptation into a reality. 

We know that one-night stands are fairly common amongst young people, but it is important to stay safe as having sex with multiple partners can increase your chances of catching an STI. 

There were 317,901 new STI diagnoses during the year 2020, and that was a year riddled with lockdowns. As things are getting back to normality, here at FROM MARS, we used our expertise in STIs to figure out which places in England have the highest number of STI cases. 

We looked at the sexual and reproductive health profiles of every local authority in England, and looked at the diagnostic rates per 100,000 for chlamydia, gonorrhoea, syphilis, genital warts, and genital herpes, and revealed the places most at risk from contracting an STI.

The riskiest place to have casual sex in England

Top 3 riskiest places to have casual sex

To find out the riskiest places to have casual sex in England, we looked at each local authority and their diagnostic rates per 100,000 for chlamydia, gonorrhoea, syphilis, genital warts and genital herpes. We then created a normalized score out of 10 to uncover which places are most at risk of catching an STI, with a score closer to 10 having the highest risk. 

  1. Lambeth, London – 9.99 STI score

The riskiest place to live if you’re worried about catching an STI is South London’s Lambeth. Lambeth had the highest rates per 100,000 for every STI other than genital warts where it ranked second. Lambeth is also 0.01 points off of max points, highlighting just how risky it could be. Condoms would be a worthy investment in Lambeth if you want to reduce your chances of contracting an STI.

  1. Southwark, London – 9.94 STI Score

The second riskiest place to live in England is Southwark, located in South London with the second-highest diagnoses per 100,000 for chlamydia, syphilis and gonorrhoea. Southwark is also in the top five for genital herpes and genital warts. A very risky place to have casual sex. 

  1. Hammersmith and Fulham, London – 9.88 STI Score

Completing a top three of London local authorities is Hammersmith and Fulham in West London. Hammersmith ranks high for all of the STIs, and tops the list for genital warts, with the highest diagnostic rate per 100,000. Genital herpes is also very prominent in Hammersmith and Fulham and has the second-highest diagnostic rate per 100,000 in England.

The safest place to have casual sex in England

Although these places are the safest in England for casual sex, that doesn’t mean you don’t have to practice safe sex measures in these areas. It is incredibly important to use protection such as condoms to reduce your chances of transmitting or catching an STI. The safest areas listed below are the best examples of why you should take safe sex measures, wherever you are.

Safest places to have sex in England
  1. Craven, Yorkshire and the Humber – 0.29 STI Score

If you want to have casual sex without the risk then Yorkshire’s Craven looks like the place to be. With 0 cases of syphilis per 100,000 and low diagnostic rates per 100,000, Craven ranks as the place with the lowest risk of catching an STI. However, It doesn’t mean you shouldn’t take the necessary precautions before engaging in casual sex in Craven! 

  1. Ryedale, Yorkshire and the Humber – 0.69 STI Score

Staying in Yorkshire and the Humber Region is Ryedale. Although the STI risk isn’t as low as Craven, Ryedale has the lowest diagnostic rate per 100,000 for gonorrhoea and is the third-lowest for Chlamydia. 

  1. Vale of White Horse, South East – 0.72 STI Score

This place in Oxfordshire has the third-lowest risk of catching an STI. Although Vale of White Horse hasn’t got the lowest diagnostic rate per 100,000 for any of the STIs, it consistently ranks lower down the list for each infection. 

Highest Cases of Chlamydia

Lambeth, London – 1,171 cases per 100,000

Chlamydia is the most common STI in England. Of the 317,901 cases of STIs in England in 2020, 161,672 were chlamydia, which is just over 50% of the total cases. 

Riskiest place to catch chlamydia

Least Cases of Chlamydia

Mid Sussex, South East – 67 cases per 100,000

Mid Sussex contributed the least to the 160,000 total cases of chlamydia during 2020. Cleary the practices of safe sex have been working well in this area in the South East.

Least risk of catching Chlamydia

Highest Cases of Gonorrhoea

Lambeth, London – 1,024 cases per 100,000

Once again, Lambeth tops our list with the most gonorrhoea cases per 100,000. There were over 1,000 cases during 2020, which was almost 300 cases more than Southwark in second place. Gonorrhoea is the second most common STI in England, with 57,084 cases recorded in 2020.

Riskiest place to catch Gonorrhoea

Least Cases of Gonorrhoea

Ryedale, Yorkshire and the Humber – 5 cases per 100,000

Ryedale has the lowest risk of catching gonorrhoea, with just five cases per 100,000. This is half as many as second place, East of Lindsey and Isle of Wight, which recorded 10 per 100,000.

Least at risk of catching Gonorrhoea

Highest Cases of Syphilis 

Lambeth, London – 149.7 cases per 100,000

Syphilis is the least common STI in England with just 6,926 cases in 2020. To put Lambeth’s total into perspective, the average syphilis rate per 100,000 is just 12.2, which is 12 times lower than Lambeth’s rate.

Riskiest place to catch Syphilis

Least Cases of Syphilis 

Craven (Yorkshire and the Humber), Maldon (East of England), Mid Devon (South West), Rutland (East Midlands) – 0 cases per 100,000

These four local authorities didn’t record a single case of syphilis during 2020 and were four of nine local authorities that recorded less than 1 case per 100,000.

Least risk of catching Syphilis

Highest Cases of Genital Warts

Hammersmith and Fulham, London – 160.2 cases per 100,000

The only list that Lambeth doesn’t top is for genital warts. It still has the second-most cases, however, with 149.2. There were 27,473 cases of genital warts overall in 2020, which equalled 48.8 cases per 100,000 – over three times less than this London region. As well as using a condom, getting an HPV vaccine is a good way of preventing genital warts.

Riskiest place to catch Genital Warts

Least Cases of Genital Warts

Sheffield, Yorkshire and the Humber – 16.5 cases per 100,000

This South Yorkshire city is where you would be least likely to catch genital warts. Only just, however, with Solihull’s rate of 16.6 cases per 100,000.

Least at risk of catching Genital Warts

Highest Cases of Genital Herpes

Lambeth, London – 129.6 cases per 100,000

Once again, it is Lambeth which recorded the most cases of genital herpes. Hammersmith and Fulham is a close second with 128 cases per 100,000. Both of these London boroughs are almost three times higher than the national average of 36.6 cases per 100,000. 

Riskiest places to catch genital herpes

Least Cases of Genital Herpes

Mendip, South West – 6.9 cases per 100,000

Finally, it is Mendip which concludes our lists of most and least at risk of catching STIs. Mendip recorded just 6.9 cases of genital herpes per 100,000 – around five times lower than the national average. 

List riskiest places to catch genital herpes


We used Public Health England’s Sexual and Reproductive Health Profiles to find out the diagnostic rates per 100,000 of chlamydia, gonorrhoea, syphilis, genital warts, and genital herpes during 2020.

These diagnostic rates are based only on reported cases for each health authority. Not all health authorities may be catching every case, and distortions may occur depending on how cases are reported. 

Finally, we gave each authority a normalized score out of ten for each STI, before taking an average of these scores to create an overall score out of 10, with 10 registering the highest risk of contracting an STI.