• Plan aims to cut UK's rate of infection among young • Many with symptoms 'too embarrassed to go to GP'

Mobile phones and computers will soon be able to diagnose sexually transmitted diseases under innovative plans to cut the UK's rising rate of herpes, chlamydia and gonorrhoea among young people.

Doctors and technology experts are developing small devices, similar to pregnancy testing kits, that will tell someone quickly and privately if they have caught an infection through sexual contact.

People who suspect they have been infected will be able to put urine or saliva on to a computer chip about the size of a USB chip, plug it into their phone or computer and receive a diagnosis within minutes, telling them which, if any, sexually transmitted infection (STI) they have. Seven funders, including the Medical Research Council, have put £4m into developing the technology via a forum called the UK Clinical Research Collaboration.

Sexual health experts hope it will help reduce the growing number of STIs, which have increased for the last decade and reached a record 482,696 last year. Two-thirds of women reporting a new STI were under 25, as were more than half of men.

The self-testing devices are aimed at technology-savvy young people. Public health experts are concerned that, although most STIs occur among that age group, many are too embarrassed to visit a GP or a genito-urinary medicine clinic to get tested and therefore continue to suffer and potentially pass the disease on. Doctors hope that the ability to obtain a private, confidential diagnosis will overcome their widespread reluctance to take a test.

The developers of the rapid testing devices expect them to be sold for as little as 50p or £1 each in vending machines in nightclubs, pharmacies and in supermarkets, as condoms are. They are drawing on nanotechnology and microfluidics, the creation of miniaturised laboratories.

"Your mobile phone can be your mobile doctor. It diagnoses whether you've got one of a range of STIs, such as chlamydia or gonorrhea and tells you where to go next to get treatment," said Dr Tariq Sadiq, a senior lecturer and consultant physician in sexual health and HIV at St George's, University of London, who is leading the project. "We need to tackle the rising epidemic of STIs, which have been going up and up and up. Britain is one of the worst [countries] in western Europe for teenage pregnancy and STIs. That there's a major embarrassment factor here, especially among young people, makes the situation worse." Some people do not get tested because they choose to do nothing about their symptoms, such as an itch or discharge, or dislike clinics' waiting lists or opening times. With some STIs people can remain infectious, even when the initial symptoms have disappeared.

Self-testing could lead to quicker diagnosis, fewer STIs and patients gaining greater control of their sexual health, as well as the ability to alert recent sexual partners, he added.

Sadiq is head of the Electronic Self-testing Instruments for Sexually Transmitted Infections consortium, which includes experts in microbiology, public health, telecommunications and micro-engineering from medical research institutions, the NHS and industry. The NHS's technology adoption centre, the National Institute of Health and Clinical Excellence and mobile phone operators, including 02, are also involved.

Doctors said the devices could help by removing the need to meet a health professional. "Some people may find going into a doctor's surgery to be tested an intimidating experience, so it's crucial that we find new ways to engage with people," said Dr Marion Henderson, from the MRC's social and public health sciences unit. Some STIs do not always display symptoms, she added. "This is important, particularly for women, as it can lead to future painful pelvic inflammatory disease and even infertility, both of which could be avoided with testing and appropriate treatment."

Prof Noel Gill, head of HIV and STIs at the Health Protection Agency, the government agency that monitors infections and advises on containment strategies, said: "HPA surveillance has shown that the impact of STIs is greatest among young people and we hope that the application of new technology will help to reduce transmission of infection in this age group.

"This is an exciting research and development consortium which will develop new technologies that both improve and expand testing for STIs. As innovations become available, the HPA will co-ordinate large-scale evaluations within a network of collaborating STI clinics," Gill added.