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Showing 1-20 of 20 trials
NCT05500482
This cluster randomised trial will examine the impact of introducing TyphiBEV, a typhoid conjugate vaccine licensed in India, on the incidence of typhoid fever in a high burden urban setting in South India.
NCT04349826
Typhoid and paratyphoid (enteric) fever affects more than 11 million children and adults globally each year including 7 million in South Asia. Up to 1% of patients who get typhoid may die of the disease and, in those that survive, a prolonged period of ill health and catastrophic financial cost to the family may follow. In the last 20 years, treatment of typhoid fever with a 7-day course of a single oral antimicrobial, such as ciprofloxacin, cefixime or azithromycin, given in an out-patient setting has led to patient recovery in 4 to 6 days without the need for expensive hospitalization. Increasing antimicrobial resistance in Asia and sub-Saharan Africa, threatens the effectiveness of these treatments and increases the risk of prolonged illness and severe disease. The recent emergence of a particularly resistant typhoid strain in Pakistan, and subsequent international spread, adds urgency to this problem and Salmonella is now listed as a high (Priority 2) pathogen by world health organisation. Treatment with combinations of antimicrobials may be more effective for treating typhoid fever and mitigate the problems of resistance. This suggestion is based on expert opinion but not backed up by good quality evidence. The ACT-South Asia study aims to compare a combination of azithromycin and cefixime with azithromycin alone in the outpatient treatment of clinically suspected and confirmed uncomplicated typhoid fever. The total recruitment will be 1500 patients across sites in Bangladesh, India, Nepal and Pakistan. A placebo (sugar pill) will be used instead of cefixime in the single drug arm so that neither the patient nor the study team know which patient is receiving which treatment.Investigators will assess whether treatment outcomes are better with the combination after one week of treatment and at one and three month follow-up. Both antimicrobials are widely used and have excellent safety profiles. If the combination treatment is better than the single antibiotic treatment, this will be an important result for patients across South Asia and other typhoid endemic areas. This study will additionally investigate the financial implications for families and health system.
NCT06546982
The goal of this project is to adapt the gold nanoparticle-based surface-enhanced Raman spectroscopy (SERS) technology to clinical application. In this exploratory study a measurement protocol will be established to subsequently investigate whether SERS allows to diagnose patients infected with typhoid fever as well as to stage the disease.
NCT05579821
Fever management is a major problem in Low and Middle Income Countries (LMICs) where access to good quality diagnostic test is often unavailable. Fever due to typhoid is similar to other undifferentiated febrile illnesses and typhoid can be mistaken with other vector borne febrile illnesses such as scrub typhus. Currently available diagnostic tests, blood and bone marrow culture, and RDTs have several limitations including a low sensitivity and specificity . Recently, several antigens of Salmonella Typhi useful for serodiagnosis of typhoid has been identified. Salmonella Typhi lipopolysaccharide (LPS) and hemolysin E (HlyE) have been identified as top candidate antigens by several studies to differentiate acute typhoid patients from healthy individuals. DPP® Typhoid Assay is a multiplex rapid test that detects IgA antibodies to LPS and HlyE antigen. It is considered to have high sensitivity and specificity and its results were found to be highly correlated with ELISA results. However, very few studies have been conducted to evaluate this test and limited information about the accuracy of this test is present. Hence, this study will evaluate the sensitivity and specificity of this test in archived serum sample of well characterized blood culture positives and negatives in support of new innovation on typhoid diagnostics.
NCT01405521
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.
NCT05119426
This is a prospective cohort evaluation of vaccine effectiveness of a single dose of Typbar-TCV® against symptomatic blood culture-confirmed typhoid fever when administered through a mass vaccination campaign to children 9 months to \<16 years of age in Kisantu, DRC.
NCT02324751
Using an established model of human typhoid infection, whereby healthy adults are deliberately exposed to typhoid-causing bacteria, the investigators will determine how effective a new typhoid conjugate vaccine (Vi-TCV) is in preventing infection. The new typhoid vaccine will be compared with a control vaccine (meningococcal ACWY). The protective effect of a currently used typhoid polysaccharide vaccine (Vi-PS) will also be studied and compared with the control vaccine using this model of typhoid infection. A second component of this study will involve vaccinating 15-20 participants with Vi-PS. Serum will be obtained prior to vaccination and 4-6 weeks after vaccination. The post-vaccination serum will be pooled and used to create an anti-Vi IgG serum standard.
NCT02192008
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.
NCT03554213
The purpose of this study is to evaluate the impact of a government-led typhoid conjugate vaccine introduction program on typhoid disease burden in Navi Mumbai, India.
NCT03600025
Typhoid fever caused by Salmonella Typhi and Paratyphi causes over 21 million cases of febrile illness and 200,000 deaths are attributed to enteric fever each year. Typhoid fever is an enteric infection that results in febrile illness. Typhoid fever causes significant morbidity in the developing world especially young children.S. Typhi specific antibody responses are elicited in typhoid fever and following typhoid vaccination. Cross-reactive multifunctional CD+4 T cell mediated IL-17 responses have been shown in typhoid fever. As S. Typhi as an intracellular pathogen, cellular immune responses might be central to protection. S. Typhi peptide subunit vaccine elicits CD+4 T cell responses that correlate with protection in mice. The role of mucosal associated invariant T cell (MAIT) and natural killer (NK) cell responses in typhoid fever or following vaccination remain poorly understood. Transcriptome profiling of human immune responses to S. Typhi infection is not clearly understood. Establishing successful infection by S. Typhi evasion of T cell and neutrophil responses need to be investigated to better understand the correlates of protection.
NCT04673487
The study aims to perform a head to head comparison of 11 typhoid tests currently in the market and simultaneously develop a sample set that can be used in future evaluations of emerging technologies. The central objective is to evaluate different Typhoid Rapid Diagnostic Tests (RDTs) that are commercially available internationally for detecting antigens or antibodies to Salmonella Typhi and use Blood culture as standard for comparison. The end point will be to determine estimates of sensitivity and specificity for each test, with 95% confidence interval, using blood culture as reference.
NCT04235361
A mobile suitcase laboratory for EBOV point-of-care (POC) detection at Ebola treatment centers was successfully implemented in Guinea during the large Ebola virus disease (EVD) outbreak in West-Africa 2014-2015. It was shown that isothermal amplification (Recombinase Polymerase Amplification (RPA)) could be efficiently used to test suspect EVD cases and local teams were trained in and successfully deployed with this fast method. In the frame of this project we want to train teams in DRC and expand RPA testing capacity to the differentials recommended by the WHO. Existing RPA assays for all parameters will be included into a multistrip for simultaneous use. This will be integrated with a simple biosafe extraction method. Implementing this approach and testing in the ongoing EVD outbreak will provide teams in DRC with response capacity for future EVD outbreaks.
NCT00386789
Typhoid fever remains an important cause of morbidity and mortality in the developing world. It is estimated that more than 16 million cases and about 600,000 deaths occur annually, most of which occur in Southeast Asia and Africa. Ingestion of food or water contaminated by acutely infected persons or chronic carriers is the most common form of transmission. As a result, typhoid fever is prevalent where unsafe drinking water or contaminated food is common. Typhoid fever is highly endemic in Vietnam, especially in the southern provinces and is a significant disease in both preschool and school-aged children. Data from Dong Thap Provincial Hospital, Mekong delta region showed that among 3,934 hospitalized typhoid fever cases from 1990 to 1995, 4.2% had complications and 0.8% died. Typhoid fever has become difficult and expensive to treat. About 90% of Salmonella typhi isolates are of multidrug-resistant (resistant to chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole) and 76% of isolates showed reduced susceptibility to fluoroquinolones. Isolates with full fluoroquinolone or extended spectrum cephalosporin resistance have not yet reported in Vietnam but occur sporadically in the Indian subcontinent. If they become widespread, alternative treatment options will be limited. The improvement of sanitation, provision of safe water and elimination of chronic carriage is not expected to be achieved quickly. Accordingly, vaccination against typhoid fever is increasingly important national public health priority.
NCT00277147
This study will evaluate a new (conjugate) vaccine for typhoid fever, which remains a serious disease especially difficult to treat in developing countries. Salmonella typhi, the bacteria causing typhoid fever, have become resistant to several antibiotics increasing the difficulty of treating the disease. The disease may have serious complications effecting bones, brain, and intestines, with permanent injury or death. Methods to control typhoid fever, such as a sanitary water and food supply, along with effective sewage treatment, are not likely to be available soon in those countries. NIH scientists developed a vaccine called Vi, made of a polysaccharide (a chain of linked sugars) from the surface of Salmonella typhi, the bacteria that cause typhoid fever. It has been approved by the World Health Organization and is licensed in 94 countries. It is effective in adults but not in young children. Clinical trials have shown that chemically binding the Vi to a protein to form a "conjugate vaccine" has improved and extended its efficacy to children (conjugate vaccines to other bacteria, notably meningitis causing bacteria have been used extensively and successfully). Now NIH scientists have developed another vaccine for typhoid fever - using a polysaccharide from fruit, known as pectin. The pectin has been chemically treated so that it resembles Vi. The treated pectin, O-acetyl pectin, is bound to a protein; exoprotein A, (rEPA). The result is a conjugate, as was formed for Vi. Similarly to the Vi conjugate it induces antibodies against Salmonella typhi in laboratory animals. If the O-acetyl pectin conjugate proves successful, it will be evaluated in children ages 5 to 14 years old and in infants, toward using it with routine vaccines for infants. Volunteers ages 18 to 45 who do not have an allergy to fruit pectin and who have not been vaccinated against nor had typhoid fever within the last 5 years may be eligible for this study. Volunteers will undergo several tests at their first visit to the clinic for this study. A blood sample (about 2/3 of an ounce) will be taken to test for HIV, hepatitis B and C, complete blood count, liver functions, blood chemistry and pregnancy in women of childbearing age. The blood sample will also be tested for antibodies to Vi, rEPA (the protein of the conjugate), and pectin. There will also be a urine collection for testing. If the laboratory tests are acceptable, volunteers will be asked to return to the clinic on a...
NCT02224040
The current study goal is to examine the effect of Cephalosporins, Azithromycin and the combination of both on typhoid fever therapy in endemic population. The investigator's hypothesize that the combination of azithromycin and ceftriaxone may prove superior to each drug, ceftriaxone or azithromycin, alone.
NCT01608815
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.
NCT01229176
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.
NCT01438996
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.
NCT00498654
The purpose of this trial is to examine the safety and immunogenicity of Ty800 oral vaccine in healthy adult subjects.
NCT00131833
This study is part of International Vaccine Institute (IVI)'s typhoid Vi demonstration project that aims to accelerate the rational introduction of Vi vaccines in typhoid endemic countries. The purpose of this study is to determine the effectiveness of the Vi vaccine following a mass typhoid immunization campaign in an endemic area in Hechi City in the Guangxhi province of China. The cost-effectiveness and safety of Vi vaccination will also be evaluated.