Natsal Panel: Vaginal sample information leaflet

Thank you for taking part in the interview. We would also like your help with the next part of the study that involves you collecting vaginal samples.

We very much hope you will agree to give these samples, as they are an important part of the study. However, you don’t have to give a sample if you prefer not to.

Why give vaginal samples?

We would be very grateful if you would agree to provide the Natsal research team with vaginal samples using small cotton swabs. The samples will be tested for some infections that can be transmitted through sexual activity, as well as other microbes that are harmless and live in the genital tract.

It is important to know how many people have different sexually transmitted infections (STIs) in Britain to help plan for sexual health services. To do this, we need to get a true picture of the levels of infections by asking all participants of the Natsal study if they would be willing to provide a sample for testing.

Who is being asked to take part?

We are asking everyone taking part in Natsal to provide samples, even if they are not sexually active or think they are at no risk of STIs. It is important that as many people take part as possible, as this will help us understand the true overall picture of STIs in Britain.

What if I have never had sex?

We are still interested in samples from you if you have not had sex. Your samples help us understand what is happening in the general population. There is no risk to self-collecting samples. The swabs used to collect the samples are small and smooth.

What do I have to do?

You will be sent in the post a kit that contains instructions and containers to collect vaginal samples. This part of the study involves you inserting a small cotton swab approximately 2 inches (5 cm) into the vaginal opening and gently swirling it around, before placing it into a collection tube. This should be repeated two more times, for a total of three swabs. This should be done in a bathroom or somewhere else private and will only take a few minutes.

You will be provided with a pre-paid envelope and instructions about how to pack and post your samples yourself in a Royal Mail post box. You will be able to ask the interviewer any questions you may have. If you have further questions, please contact Freephone 0800 652 4569 or email To thank you for your co-operation, a £10 gift card will be given to everyone who provides these samples.

What will my samples be tested for?

The samples will be sent to certified laboratories and will be tested for the following:

Chlamydia and Gonorrhoea: These are infections that can be passed on through sexual contact. They can be treated with antibiotics, but if not treated can lead to problems such as infertility and can be passed on to sexual partners.

Human papillomavirus (HPV): This is an infection that can be passed on through sexual contact. HPV can cause genital warts or, in rare cases, can lead to cervical or other types of cancer. A vaccine to protect against common types of HPV is available.

Trichomonas: This is an infection that can be passed through sexual contact. It may be more common in women but can also be found in men and can be treated with antibiotics.

Mycoplasma genitalium (MGen): This is an infection that can be passed through sexual contact. However, we need more information about how common it is. At present, only people who have symptoms are tested and treated with antibiotics for this infection.

Microbiome: This is the term used for all microbes that live in the human genital tract. We want to know how the microbiome varies by age, gender and sexual behaviour.

The tests above will never involve analysis of human DNA or human genetics. Sample collection and storage is controlled by the Human Tissue Act (2004). The samples may be sent to Natsal  investigators and collaborators, including at the World Health Organization STI Reference Centre in Sweden and the Wellcome Sanger Institute in the UK.

What happens to the rest of my samples?

We will ask you separately for consent to store what is left of your samples after the tests listed above have been done. If you agree, any remaining samples may be used for future studies investigating infections in the population, for example, when new tests become available. Stored samples will only be used in future studies if all necessary approvals and permissions have been obtained in advance. As before, any new studies will not involve analysis of human DNA or human genetics. The samples will not be labelled with your identifying information and researchers who want to use the stored samples will have to apply for permission. If you do not agree to the rest of your samples being stored for future studies, NatCen will inform the laboratory and they will be destroyed. You may still give the samples even if you do not wish any remaining samples to be stored for future use.

What happens to the results of these tests?

The test results will be linked to the answers given in your interview and the information will be used for research purposes only. The laboratory will not know your name or address. The data will be kept strictly confidential, and no results will ever be traced to you or given to you. All data will be dealt with according to the Data Protection Act 2018 and the UK General Data Protection Regulation (GDPR). For more information on how the information you provide will be used, please see the privacy information at

Why will my test results not be returned?

We will not return individual results to you because: (1) the tests are good enough to help us understand what is happening with these infections at a population level, but they may not be as accurate as the ones used by the NHS to make a diagnosis.

Testing through the NHS is the best way to find out if you have an infection that needs treatment; (2) we are testing for some infections and harmless microbes that do not need treatment; (3) not returning results means that we do not need to link your sample to your name and address.

What if I am on my period or menstruating?

We are still interested in samples from you and the tests will not be affected. However, if you prefer, you can collect a sample a few days later when your period has stopped.

What if I am pregnant?

We are still interested in samples from you and there is no risk to self-collecting samples if you are pregnant. The swabs used to collect the samples are small and smooth.

What should I do if I am worried about having a sexually transmitted infection (STI) or about my sexual health?

If you have concerns that you may have been infected with an STI, we suggest you seek professional advice. Free testing for STIs, as well as free confidential advice about sexual health, cervical  screening, family planning and contraception, can be obtained online or from your local sexual health or Genitourinary Medicine (GUM) clinic, your GP, family planning clinics, as well as some pharmacies and youth centres. The following website will allow you to find your nearest sexual health service:

The interviewer will provide you with more information about organisations near you and their telephone numbers; you can also visit their websites for further information. The UK Health Security Agency (UKHSA - previously part of Public Health England) recommends sexual health check-ups for sexually active people every time they change partner. This is because STIs may be present without a person knowing or having symptoms.

What if I change my mind?

You can withdraw your consent to participate in this part of the study at any point in time by contacting the National Centre for Social Research (NatCen) using the details below. NatCen will inform the laboratory and the samples will be destroyed.

Your co-operation is very much appreciated If you have any questions, you can contact NatCen by writing to 35 Northampton Square, London, EC1V 0AX calling freephone 0800 652 4569 or emailing

The Natsal research team is from the National Centre for Social Research (NatCen), University College London (UCL), the London School of Hygiene and Tropical Medicine (LSHTM) and the University of Glasgow.