Sexually transmitted infections (STIs) are spreading due to avoidable delays in treating men and women, new research shows.
A study of more than 3,000 new patients at several clinics found that many suffer with symptoms for a week before receiving treatment.
But in that time, 44.8% of men and 58% of women continued to have sex, 7% of patients had sex with more than one partner, and 4.2% had unprotected sex with a new partner.
Because of these delays, more people could be being exposed to chlamydia, herpes, gonorrhoea, and genital warts, the survey published in STI Online added.
The researchers said one way to resolve the issue could be to introduce more "walk-in" clinics that can provide same-day treatment.
Dr Jackie Cassell, senior lecturer in clinical epidemiology at Brighton and Sussex Medical School, said: "We found that the availability of walk-in slots, slots you could attend by seeking care on the day, was the most important factor in enabling quick access to care.
"Minimising the delay in curative treatment that happens when patients in large numbers go first to their GP surgery, and maximising the availability of walk-in slots, would be expected to have a major impact on the control of STIs in the UK.
"There's also a need to educate young people into seeking care quickly and avoiding sexual contact when they think they have an STI."