Investigating Enteric Fever

You are invited to take part in a study to test the human response to Salmonella Typhi and Paratyphi.  The study is being run by the Oxford Vaccine Group, part of the University of Oxford.

Salmonella Typhi and Salmonella Paratyphi cause infections known as enteric fever, which is becoming an increasing problem in developing countries, particularly in Asia.  Although rare in the UK it can be picked up by travelers to these countries. Enteric fever is responsible for over 30 million infections each year, mostly affecting children.  Although the disease can be treated with antibiotics and is preventable with access to clean water and sanitation facilities, there are still many deaths each year. A vaccine for Salmonella Typhi does exist but provides limited protection against infection. There is no licensed vaccine to protect against Salmonella Paratyphi.

Our study is a part of a new effort to find better ways of preventing and diagnosing enteric fever. We are aiming to advance the scientific knowledge of enteric fever and the effect this illness has on the human immune system. We hope that this knowledge will help us better understand enteric fever, develop new diagnostic tests, and help develop new vaccines against S. Typhi and S. Paratyphi in the future. It is thought that people who have repeated enteric fever, do develop some level of immunity to further infection.

We are looking for up to 60 healthy volunteers to swallow a drink containing either Salmonella Typhi or Salmonella Paratyphi. An additional small number of volunteers are needed to act as ‘negative controls’ – this group will not be given bacteria but will have the same procedures and tests as those receiving S. Typhi or S. Paratyphi. After drinking the bacteria (the ‘challenge’), blood, stool (faeces), saliva and urine will be taken regularly for two weeks with a clinic visit every day. Some people will develop enteric fever and they will be treated immediately with effective antibiotics. Those who do not develop enteric fever two weeks after swallowing the bacteria will still receive a full course of antibiotics, even if they develop no symptoms.

For this study we ask volunteers to have two endoscopies (a camera looking down into the stomach and small intestine) and have biopsies of the gut lining taken. This is to answer questions on how the bacteria cause illness and why some people are protected and others become unwell. Participants will then have a further five or six follow up appointments over the next year.  Volunteers in the control group finish three months after the challenge visit.

Volunteers may also be asked to participate in optional additional tests such as a video capsule endoscopy (swallowing a camera the size of a vitamin pill until it is passed in the stool) or a ‘string test’  (swallowing a capsule attached to a long string, then later withdrawing the string and collecting the gut liquid).

Volunteers would need to be available for an intensive period of four weeks where the participants would need to attend daily visits with study doctors and nurses for two weeks, take a two week course of antibiotics, and remain in contact with the study team. They would also need to be available for an endoscopy (a day procedure) about a month before and after they ingest the drink containing the bacteria. Visits will occur either at the Centre for Clinical Vaccinology and Tropical Medicine (at the Churchill Hospital site) or at the Endoscopy Unit, John Radcliffe Hospital.

Before you decide whether you would like to take part, it is important for you to understand exactly what the study is about and what participation would involve.  The study has been funded by the Medical Research Council.

  • If you are aged 18 to 60 years old, in good health and have never previously received a typhoid vaccine you may be eligible to take part in the study.
  • We will provide reimbursement for your time, inconvenience and travel
  • The maximum study participation time is 15 months

If you are interested in finding out more, please read the Study Information Booklet

If you would like any further information regarding the study please contact us on:

Email info@ovg.ox.ac.uk, Tel: 01865 611400

Many thanks,

The Oxford Vaccine Group

Study reference: 2014/01

Ethics reference: 14/SC/1204

(i.e. have no active medical problems and do not take regular medications)
(Typhoid vaccines are often given as travel vaccines, please check with your GP if you are uncertain of your vaccination history)
(Typhoid is prevalent in the following regions: South Asia – e.g. India, Pakistan, Southeast Asia – e.g. Vietnam, Thailand, and certain areas of Africa and Central/South America)