Can screening for Clostridioides difficile carriage help prevent disease?
| ISRCTN | ISRCTN13663361 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN13663361 |
| Integrated Research Application System (IRAS) | 354961 |
| Central Portfolio Management System (CPMS) | 74202 |
| Sponsor | Public Health Wales |
| Funders | Cepheid, National Institute for Health and Care Research |
- Submission date
- 02/07/2026
- Registration date
- 24/07/2026
- Last edited
- 24/07/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
Plain English summary of protocol
Background and study aims
Clostridioides difficile (often called C. difficile or C. diff) is a bacterium that can cause diarrhoea, particularly in people who are in hospital or who have recently taken antibiotics. While some people become unwell from C. diff, others carry the bacterium in their gut without having any symptoms. This is known as asymptomatic carriage.
People who carry C. diff may have a higher chance of developing an infection if they need antibiotics. This is because antibiotics can upset the normal balance of bacteria in the gut, allowing C. diff to grow and cause illness.
This study will look at whether testing patients to find out if they are carrying C. diff can help doctors make better decisions about antibiotic treatment. If a patient is found to be carrying C. diff, this information may encourage the healthcare team to choose antibiotics that are less likely to increase the risk of C. diff infection, where it is safe and appropriate to do so. The aim is to see whether this approach can reduce the number of people who go on to develop C. diff infection.
The main purpose of this study is to find out whether testing patients for C. diff and using the results to help doctors choose antibiotics can work as part of everyday care in a busy hospital.
The study will also help us to:
• Find out how many patients carry C. diff without having symptoms.
• Understand whether people who carry C. diff are more likely to develop an infection.
• See whether knowing a patient's C. diff status changes the antibiotics that are prescribed.
• Assess whether this type of screening could become a practical part of routine hospital care in the future.
It is hoped that the results of this study will help improve the prevention of C. diff infection and support safer use of antibiotics for future patients.
Who can participate?
Any adult (aged 18 years or over) who is admitted to the Medical Assessment Unit and is able to understand the study and give their consent to take part may be invited to participate.
What does the study involve?
Participants will be asked to provide a stool sample so that it can be tested for C. diff. If preferred, a rectal swab can be taken instead. A rectal swab involves gently inserting a small cotton swab just inside the back passage to collect a sample. It is a quick procedure and may be slightly uncomfortable, but should not be painful. Participants and the doctors looking after them will be told the result of your test.
If the test shows that the participant is carrying C. diff, some additional infection prevention measures may be put in place to reduce the chance of the bacteria spreading to other patients (washing hands with soap and water and using an apron and gloves as appropriate). The medical team may also use this information when making decisions about participants' antibiotic treatment, where appropriate, to help reduce their risk of developing a C. diff infection.
Taking part in the study will not affect any other aspect of participants' care, and all treatment decisions will continue to be made by the healthcare team looking after them.
What are the possible benefits and risks of participating?
What are the possible benefits?
The healthcare team will know whether the participant is carrying C. diff. This information may help them make decisions about their antibiotic treatment. Where it is safe and appropriate, they may choose antibiotics that are less likely to increase the risk of developing a C. diff infection.
It is also hoped that this study will help us learn how best to care for people who carry C. diff without symptoms. The results may help improve antibiotic prescribing and the prevention of C. diff infection for future patients.
However, there is no promise that taking part will provide a direct benefit to participants.
What are the possible risks?
There are very few risks associated with taking part. Providing a stool sample has no physical risks. If participants choose to have a rectal swab instead, the procedure may be briefly uncomfortable but should not be painful.
There is a small risk that knowing participants are carrying C. diff could influence treatment decisions in a way that is not helpful. To reduce this risk, healthcare staff involved in the study will receive guidance on how to use the test results, and all treatment decisions will continue to be made by the doctors responsible for their care. Doctors in the hospital are experienced in caring for patients who are known to carry C. diff, so this is not expected to be a significant risk.
If their test shows that they are carrying C. diff, additional infection prevention measures may be put in place to help reduce the chance of the bacteria spreading to other patients.
Where is the study run from?
Public Health Wales in collaboration with Swansea Bay University Health Board.
When is the study starting and how long is it expected to run for?
August 2026 to December 2026.
Who is funding the study?
The Swansea Bay University Health Board, UK. Cepheid is supplying the test cartridges but is not responsible for the day-to-day running of the study or the care of participants.
Who is the main contact?
1. Dr Brendan Healy, Principal Investigator, brendan.healy@wales.nhs.uk
2. Personal Assistant Team, SwanseaMicrobiologyPATeam@wales.nhs.uk
Contact information
Principal investigator, Scientific, Public
Consultant in Microbiology and Infectious Diseases, Public Health Wales Microbiology Swansea, Singleton Hospital, Sketty Lane, Sketty
Swansea
SA2 8QA
United Kingdom
 ORCID ID |
0000-0002-5698-856X |
|---|---|
| Phone | +44 01792 285053 |
| brendan.healy@wales.nhs.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | N/A: single arm study |
| Masking | Open (masking not used) |
| Control | Uncontrolled |
| Assignment | Single |
| Purpose | Diagnostic, Prevention |
| Scientific title | A pilot study to determining the feasibility of screening of hospital patients on admission for asymptomatic C. difficile in order to act to reduce subsequent disease incidence |
| Study objectives | Primary Objective: 1. To assess the feasibility of carrying out C. difficile screening of admissions to an acute medical admissions unit. Secondary Objectives: 1. To estimate the temporal carriage rate (prevalence) in patients admitted to the medical admission units of MH. 2. To estimate the rate of C. difficile disease development (incidence) among previously asymptomatic C. difficile carriers. 3. To assess whether results from carriage can be successfully communicated to the clinical teams and determine if it results in enhanced contact precautions for those individuals (use of appropriate PPE (apron and gloves), using soap for hand hygiene). 4. To assess whether identification of carriage has any impact on prescribing. The notes of carriers will be reviewed for evidence of any impact on prescribing decisions and rate of initiation of broad spectrum antibiotics (Clindamycin, ciprofloxacin (quinolones), cephalosporins, co-amoxiclav (4C’s), Tazocin and Meropenem) will be compared between carriers and non carriers. 5. To determine level of relatedness between the screening identified C. difficile isolates and current and historic cases using WGS data. |
| Ethics approval(s) |
Approved 30/01/2026, Wales Research Ethics Committee 3 (Health and Care Research Wales Floor 4, Crown Building Cathays Park, Cardiff, CF10 3NQ, United Kingdom; -; Wales.REC3@wales.nhs.uk), ref: 25/WA/0354 |
| Health condition(s) or problem(s) studied | Acceptability of screening for C. difficile |
| Intervention | Overview: The study will be undertaken in the Medical Admission Units in Morriston Hospital. Screening all consenting adults (aged ≥18 years) admitted to the acute admission units in Morriston Hospital who do not, at the time of admission, have diarrhoea (defined as Bristol stool chart >4). The bacteria (i.e. germ) we will be screening for is Clostridioides difficile (a.k.a C. difficile or C. diff). If a patient has been confirmed to be carrying C. difficile, a simple intervention flagging the carriage status to clinical teams caring for patients and triggering increased scrutiny of antibiotic prescribing will be piloted. This is a similar approach to that adopted in national policies regarding Carbapenemase-producing Enterobacteriaceae (i.e. CPE). Screening for C. difficile: A faecal sample or rectal swab will be collected from patients as soon as practically possible after admission to the ward. Only one screening sample per patient will be required. Patients will be able to opt out of the screening. Patients who lack the capacity to consent will be excluded from the study, and a sample will not be collected. Patients will be provided with patient information sheets prior to verbal consent. Verbal consent will be obtained from the patients on the admission units prior to sample collection. The clinical staff responsible for providing care to the patients will ask the patients if they are willing to provide a faecal sample to identify C. difficile carriage. Patients will be required to complete a section of the patient information sheet confirming their verbal consent. Sample collection will be carried out using standard clinical procedures (these are used for similar microbiological screening e.g. CPE). Where rectal samples are collected, this will be done by trained clinical health care staff employed on the wards. Samples will be processed via existing Public Health Wales microbiology testing procedures, and results will be entered into patients' notes and recorded within existing laboratory and patient data management systems (as per standard practice). Laboratory test results from screening will be uploaded to existing electronic patient records (ICNET/LIMS/Welsh Clinical Portal). These are routinely visible to clinicians caring for the patient; this will include the patient's GP. The GP will not directly be informed of study enrollment. However, they will be able to see the electronic test record. The samples will be labelled as screening swabs to identify these samples, and results will contain an automated response indicating the context in which the test was taken. A member of the site infection prevention and control team will have responsibility for alerting the ward staff of carriage and to trigger the subsequent response; this individual will have existing access to all microbiology tests carried out on these patients. When a positive asymptomatic carrier of C. difficile is identified, the ward will be made aware, thus facilitating a high level of infection prevention vigilance around the patient. This will involve a highlight sticker on the patient's notes and other patient documentation to allow nursing staff to ensure optimal infection prevention steps are taken throughout the patient's hospital stay. This may include, for example, the use of dedicated commodes or lavatories, strict adherence to hand hygiene and appropriate cleaning of the patient environment (in line with best standard practice)-measures designed to reduce the risk of progression from C. difficile carriage to disease. The alert will be continued for the full length of the patient hospital episode. C. difficile isolates will be stored for future epidemiological comparison with other UK isolated strains. This will use Whole Genome Sequencing (WGS). Outcomes: This is a feasibility pilot to determine the acceptability of the intervention to patients and to hospital staff and the feasibility of delivering the intervention in a clinical setting. The key outcome measures will be the proportion of admitted patients who are screened and the rate of C. difficile carriage. The study is not designed to detect an impact on C. difficile incidence (i.e. transmission in the hospital setting); however, data on symptomatic cases within the study sites will be collected to inform future study of the intervention, including future comparison of phylogenetic information obtained from whole-genome sequencing of symptomatic and asymptomatic isolates. |
| Intervention type | Other |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 03/12/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 100 Years |
| Sex | All |
| Target sample size at registration | 700 |
| Key inclusion criteria | 1. All patients aged ≥18 years admitted to the acute admission units in the study site who do not, at the time of admission, have diarrhoea (defined as Bristol stool chart >4) 2. Willing to provide a faecal sample or rectal swab on the basis of a verbal consent process. |
| Key exclusion criteria | 1. Patients who decline screening 2. Patients who have diarrhoea on admission to Morriston Hospital 3. Aged under 18 years old 4. Patients without the capacity to provide verbal consent 5. Other clinical emergency issues that require precedence over study inclusion |
| Date of first enrolment | 03/08/2026 |
| Date of final enrolment | 03/12/2026 |
Locations
Countries of recruitment
- United Kingdom
- Wales
Study participating centre
Cwmrhydyceirw
Swansea
SA6 6NL
Wales
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|
Editorial Notes
02/07/2026: Study's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).
