View clinical trials related to Typhoid Fever.
Filter by:Enteric fever, an infection characterised by diarrhoea and rash, is most often caused by a bacteria called Salmonella enterica. After ingesting contaminated food or drink, the Salmonellae travel first to the gut, then the bloodstream, from where they can infect other parts of the body. Antibiotics are used to kill the bacteria, but with increasing rates of antibiotic resistance, this treatment is becoming less effective. Two Salmonella variants, Typhi and Paratyphi, cause over 30 million cases of enteric fever and more than 200,000 deaths per year, mostly in developing countries. While improved hygiene and sanitation should eventually eliminate enteric fever, reduction of the disease burden in the medium term is achievable through effective vaccination. Vaccines likely to be available for mass vaccination are effective only against those Salmonella strains that bear the Vi polysaccharide capsule protein. Strains that do not have these capsule proteins, or have no capsule, will not be affected by vaccination and could 'fill' the space vacated by the capsulated strains. Indeed, enteric fever caused by S. Paratyphi A which does not carry the Vi protein, has risen during the past decade and accounts for more than half of all cases in some areas. Thus it is important that effective vaccines are available to protect against infection by both capsulated and noncapsulated Salmonella enterica. To develop such vaccines, we need a complete understanding of the human immune response to both types, including the contribution of immunity in the gut and the bloodstream, immune response to bacterial surface proteins, and the role of antibodies. How much cross-protection there is between the types of typhoidal Salmonellae after natural infection or vaccination is not known, but this is critical to vaccine development. This project aims to fill in the knowledge gaps highlighted, by fully characterising the infection process and immune response in enteric fever.
Enteric fever is responsible for over 20 million illnesses and 200,000 deaths each year. S. Paratyphi A accounts for a substantial and increasing proportion of these cases, as high as 90% in some regions of Asia. There are currently no vaccines directed against S. Paratyphi A, although there some candidates in preclinical and phase 1 trials. This study is funded by the European Vaccine Initiative and the Bill and Melinda Gates Foundation. Paratyphoid is a human-restricted infection, for which there are currently no small animal models available. In order to further our understanding of the host-pathogen interactions, this study will develop a novel human challenge model in which to investigate this infection, using a recent successful typhoid challenge model as its template. Healthy subjects to ingest a dose of Salmonella enterica serovar Paratyphi A, strain NVGH308, after drinking a bicarbonate buffer. Intensive follow up over 14 days will establish whether each participant meets clearly defined criteria for diagnosis of paratyphoid infection. Statistical analysis will be performed on this outcome will determine if it consistently gives an attack rate of 60 to 75%. If this is not reached with the first cohort of 20 participants, the dose will be escalated and the process repeated. A maximum of 80 participants will be enrolled. Total follow up will be over the course of one year. Descriptive clinical and laboratory data collected from participant observations, samples of blood, faeces, urine and saliva will allow insights into the disease and the host response. These insights will forward our knowledge of paratyphoid disease and may help discover or develop diagnostic methods. This study is funded by the European Vaccine Initiative and the Bill and Melinda Gates Foundation. Paratyphoid is a human-restricted infection, for which there are currently no small animal models available. In order to further our understanding of the host-pathogen interactions, this study will develop a novel human challenge model in which to investigate this infection, using a recent successful typhoid challenge model as its template. Healthy subjects will ingest a dose of Salmonella enterica serovar Paratyphi A, strain NVGH308, after drinking a bicarbonate buffer. Intensive follow up over 14 days will establish whether each participant meets clearly defined criteria for diagnosis of paratyphoid infection. Statistical analysis will be performed on this outcome will determine if it consistently gives an attack rate of 60 to 75%. If this is not reached with the first cohort of 20 participants, the dose will be escalated and the process repeated. A maximum of 80 participants will be enrolled. Total follow up will be over the course of one year. Descriptive clinical and laboratory data collected from participant observations, samples of blood, faeces, urine and saliva will allow insights into the disease and the host response. These insights will forward our knowledge of paratyphoid disease and may help discover or develop diagnostic methods. Anticipating the development of a successful live challenge model through this study, there will be the possibility of evaluating novel paratyphoid vaccines that are currently in early clinical phase testing. This serves an important function because field trials in endemic areas are expensive and time consuming. Speeding up this process using our model will be of great benefit to endemic areas.
Tropical fevers have been a diagnostic challenge from the antiquity. Nowadays, despite the availability of good diagnostic capacities, undifferentiated febrile illnesses continue to be a thorny problem for travel physicians. In developing countries, the scarcity of skilled personnel and adequate laboratory facilities makes the differential diagnosis of fevers even more complex. Health care workers must often rely on syndrome-oriented empirical approaches to treatment and might overestimate or underestimate the likelihood of certain diseases. For instance Neglected Tropical Diseases (NTD) contribute substantially to the burden of persistent (more than 1 week) fevers in the Tropics, causing considerable mortality and major disability. These diseases are however rarely diagnosed at primary health care (PHC) level. The difficulty in establishing the cause of febrile illnesses has resulted in omission or delays in treatment, irrational prescriptions with polytherapy, increasing cost and development of drug resistance. In resource-limited settings, clinical algorithms constitute a valuable aid to health workers, as they facilitate the therapeutic decision in the absence of good laboratory capacities. There is a critical lack of appropriate diagnostic tools to guide treatment of NTDs. While clinical algorithms have been developed for some NTDs, in most cases they remain empirical. Besides, they rarely take into account local prevalence data, do not adequately represent the spectrum of patients and differential diagnosis at the primary care level and often have not been properly validated. The purpose of the study is to develop evidence-based Rapid Diagnostic Test (RDT)-supported diagnostic guidelines for patients with persistent fever (≥ 1 week) in the Democratic Republic of the Congo (DRC), Sudan, Cambodia and Nepal.
This study is designed to assess the immunogenicity and safety of typhoid Vi polysaccharide vaccine in Japanese participants to support registration of the product in Japan. Primary Objective: To describe the seroconversion rate (percentage of subjects with at least a 4-fold increase of their Vi antibody titer) between Day 0 before vaccination and Day 28 after vaccination with typhoid Vi polysaccharide (SP093) vaccine in subjects aged 2 years and above. Secondary Objectives: - To describe the safety profile of a single dose of typhoid Vi polysaccharide vaccine up to 28 days after vaccination, in subjects aged 2 years and above. - To describe the immune response following a single dose of typhoid Vi polysaccharide vaccine in subjects aged 2 years and above.
This study compares the safety and immunogenicity profile of several travel vaccines given alone or concomitantly with MenACWY-CRM to healthy adults.
The purpose of this study is to evaluate the immunogenicity and the kinetics of the anti-Vi antibody response following secondary vaccination with the Novartis Vaccines Institute for Global Health (NVGH) Vi-CRM197 vaccine in healthy adults previously vaccinated with either the NVGH Vi-CRM197 or Vi-polysaccharide (Typherix) in the H01_04TP study (NCT01193907) and the immunogenicity and the kinetics of the anti-Vi antibody response following primary vaccination with the NVGH Vi-CRM197 vaccine in naïve healthy adults.
This phase 2 trial is aimed to obtain information on the safety and immunogenicity of the Vi-CRM197 in children and infants from various age groups in the Philippines where Typhoid Fever is highly endemic and an efficacious vaccine against this disease is very much needed.
The investigators aim to compare two antibiotic treatments for enteric (typhoid) fever. Three hundred patients at Patan Hospital will be enrolled in the study. Patients will be assigned to one of the two treatments by chance and followed for 6 months. The two treatment groups will be compared to see which treatment is more likely to make the patient better.
Using an established model of human typhoid infection, whereby healthy adults are deliberately infected with typhoid-causing bacteria, the investigators will determine how effective a new oral typhoid vaccine (M01ZH09) is in preventing infection. A previously licensed oral typhoid vaccine (Ty21a) will be used to make sure the challenge model used works properly.
This phase 2 trial is aimed to obtain information on the safety and immunogenicity of the Vi-CRM197 in subjects from various age groups in India and Pakistan where Typhoid Fever is highly endemic and an efficacious vaccine against this disease is very much needed.