Frequently Asked Questions (FAQs)

The aim of this research is to investigate why some people carry the bacterium Staphylococcus aureus (S. aureus) in their nose while others never do. The research will provide a better understanding of the biological, genetic and environmental determinants of S. aureus carriage

S. aureus is a common bacterium with about one person in every three carrying it in their nose, or elsewhere on the skin. Some people carry it all the time, some only now and then, and others never carry it. Currently, we can’t explain why. For most people, carriage of S. aureus is harmless. However, a small number of people are susceptible to S. aureus infections due to a weakened immune system and, in some cases, these infections may be serious and resistant to antibiotic treatment. Understanding why only some people are carriers while others aren’t will help design new ways to prevent and treat such infections.

We propose to conduct a large study of ~20,000 blood donors to understand what determines the carriage of S. aureus in humans. We will ask participants to take nasal swabs, which will be returned by freepost and to fill in online questionnaires. We see INTERVAL and COMPARE participants, who are willing to take part, as an ideal group for this research because we have already collected some essential data from them (e.g. blood sample measurements, genetic results, lifestyle factors etc.). Also there is some evidence that S. aureus carriage could be linked to the body’s iron levels.

We are aiming to recruit approximately 20,000 blood donors to take part in the CARRIAGE study. We are inviting blood donors, like you, who have taken part in the INTERVAL or COMPARE studies for whom there is data available on biological, genetic and environmental factors, because we suspect such factors may be important in determining S. aureus carriage.

No. It is entirely up to you to decide whether or not to take part. If you do decide to take part, you will be asked to complete a brief online screening questionnaire and consent form. You are free to withdraw at any time and without giving a reason.

You are eligible to take part if you:

• Have an email address and internet access for study participation
• Reside in mainland England
• Have a good understanding of the English language, both written and oral (as study materials are not tailored to support non-English language speakers).

You are not eligible to take part if you:

• Have any abnormalities or on-going medical conditions that affect the nose (e.g. recurrent nosebleeds, nasal polyps, rhinitis, etc.)
• Have undergone nasal surgery in the last year
• Have had a broken nose in the last year
• Are not going to available to take part in the study during the next two months.

You will be asked to provide your contact details so a researcher is able to post a CARRIAGE study ‘participant pack’ to you. Before sending this we will ask you to complete a short (no more than 10 minute) online questionnaire which will ask for health and lifestyle information about you, your family and the people who live in your household. Once you have completed this you will receive your ‘participant pack’ which will contain:

• Three sample tubes with nasal swabs
• Pre-prepared barcode stickers each with an unique anonymous study identification number, one for each tube
• Step-by-step instructions (including a video-link on this website) to show you how to take your swabs
• Postage-paid FREEPOST envelopes to return your nasal swabs.

Once you have returned your swabs, we will ask you to complete a further short (5-minute) questionnaire asking for feedback on your experiences of taking part in the study.

Periodically, and only when necessary, we will send you email and text reminders to take swabs and to fill out questionnaires.

The following steps will be taken to ensure the confidentiality of your samples and data during the CARRIAGE study:

• Your samples and data will not include any person identifiable details. Therefore, researchers working with your samples and data will never know your identity. Your data are stored using a unique, anonymous study identification number.
• In order to retrieve relevant health information we will use your NHS number. A single table linking your anonymous study identification number to your NHS number is stored on a separate password-protected location, which may be accessed only by the study data manager.
• The link table is used to retrieve only relevant health information from your medical and other health-related records. The retrieved information is anonymous.
• All study data is stored in a restricted-access, study database on secure computers at the University of Cambridge. The study data is linked to your study identification number, but your personal details (surname, first name, address) never appear in this database. Access to the study database is password-protected and used only by named researchers working on this study under the direct supervision of the senior scientific investigators
• Your personal details provided during the study will be stored in a secure location, separately from the study database and used for the purpose of study communication and retrieval of your NHS number.

Information that will be stored on the database will be anonymised and will include:

• Data from the online questionnaires (described above).
• Relevant data collected during your participation in the INTERVAL or COMPARE study including email address and results from blood samples (including genetic information)
• Results from all laboratory measurements using your nasal samples
• Information on health outcomes collected from routine medical and other health-related records at the time of joining the study and from time to time thereafter.

Your anonymised data will be used by the study investigators to look at characteristics that influence nasal carriage of S. aureus. Stored anonymised data will be used for future medical and health-related studies, which have relevant scientific and ethics approval.

They will not be labeled with your name or contact details, but only with a unique study number. Once returned to the processing laboratory we will try to grow S. aureus from them. We will also extract bacterial DNA from the swab material so we can identify other bacterial species. A small amount of the nasal swab material will be stored in the freezer for future health-related research purposes.

Your samples and all the information collected about you during the course of this study will be kept strictly confidential. Any information you have provided will be anonymised, therefore researchers working with your data will never know your identity. Your anonymous information and samples are available only to researchers who have relevant scientific and ethics approvals for their planned research. This could include researchers who are working in other countries and in commercial companies who are looking for new treatments or laboratory tests. Insurance companies and employers will not be given any individual’s information, samples or test results, and we will not allow access to the police, security services, relatives or lawyers, unless forced to do so by the courts. All data will be stored securely by the CARRIAGE research team and will be encrypted where necessary.