View clinical trials related to Cholera.
Filter by:The purpose of this study is to conduct and evaluate the feasibility and effectiveness of a mass cholera vaccination program to reduce diarrhea due to Vibrio cholerae in a high incidence urban area. This study will also evaluate the feasibility of adding a household hand washing and safe drinking water promotion intervention to a cholera vaccine program and the overall impact of this combination on decreasing the incidence of diarrhea due to Vibrio cholerae.
The absence of a boosting response after a 14 day interval with the two-dose regimen of the modified killed oral cholera vaccine raises the possibility that a longer dosing interval may be required to observe a boost in the immune response. This study will compare the immune responses following 14-day and 28-day dosing intervals.
Background: Severe dehydrating cholera due to V. cholerae O1 is an important public health problem in Bangladesh and many other developing countries. V. cholerae O1 is a major bacterial pathogen causing around 5 million cases and at least 200,000 deaths in adults and children each year. It can be assumed that there are at least 300,000 severe cases and 1.2 million infections in people in Bangladesh alone. The rate of cholera varies from around 1 to 8 per 1000 population and the highest attack rate is in children 2- to 9-year years of age . Cholera is now also being documented in very young children. Currently enteric vaccine approaches are regarded as the most accessible short term and practical means to prevent and control such illnesses to prevent disease and epidemics in resource poor settings with limited public health and sanitary facilities. An effective inactivated whole cell bivalent cholera vaccine against Vibrio cholerae O1 and O139 was produced and implemented for public health purposes in Vietnam since the 1990s. This bivalent vaccine has been found to be safe and to confer significant protection against El Tor cholera in both children and adults and has over the last decade being used in the Vietnam to protect against cholera. This vaccine has further been reformulated by the IVI to meet WHO requirements and is now being produced in WHO prequalified vaccine company in India. The reformulated vaccine has been shown to be safe and immunogenic in Indian children as well as adults. A large Phase III study of the vaccine, has recently been carried out in Kolkata, India in over 120,000 participants aged from one year and above. Results of the study are encouraging and the vaccine gives over 60% protection against cholera. The vibriocidal antibody response rate was 80% in children and 53% in adults. Following this study, the vaccine, designated as ShanChol has been licensed in India in April 2009. The vaccine is now being marketed in India and is available at a cost affordable for developing country settings. Objective: The aim of the proposed study is to assess if the orally administered, killed, bivalent whole-cell cholera vaccine, ShanChol will be safe and immunogenic in different age groups in Bangladesh in children and adults. Study design: This will be a randomized, double blind, placebo-controlled study on a total of 330 subjects, 165 vaccine and 165 placebo recipients. The specific aims will be to determine: i) safety and determine adverse events if any (ii) determine immune responses. Relevance: The study of ShanChol on Bangladeshi children and adults will be able to give information regarding the safety and immunogenicity of the vaccine in Bangladeshi subjects. This information will be important for proceeding with larger studies in Bangladesh and if proven useful for introduction the cholera vaccine in the country in the future.
The efficacy and immunogenicity of enteric vaccines have generally been found to be lower in children in the developed than in the developing countries. This has been observed with vaccines against cholera rotavirus, ETEC and typhoid vaccines. There are a number of factors that may contribute to such differences in vaccine "take rates" in children, e.g. breast feeding and nutritional status of the children might influence their immunogenicity and efficacy. Thus, breast feeding of newborn and young infants may adversely influence the immune response to vaccination, which might have more pronounced effect in developing than in developed countries. Breastfeeding has also been shown to interfere with the serum immune responses to rotavirus vaccine although this effect could be overcome by administering three rather than one dose of the oral rotavirus vaccine. Our recent study of Dukoral in Bangladeshi children aged 18 months or younger has shown that the response rates and the magnitude of responses improved when breast milk was temporarily withheld . Thus, administration of vaccines may have to be adjusted when given to breast fed children. Another factor that may affect the immunogenicity is the effect of zinc. Previous studies have shown that zinc enhances the immune response to cholera vaccine in participants > 2 years of age , a recent study also observed a similar effect in infants. In this research project, we plan to study a number of different factors that might influence the immunogenicity of the two licensed oral model vaccines, specifically the inactivated killed oral cholera vaccine, Dukoral, and the live oral typhoid vaccine, Ty21a. We will also identify strategies that might improve the immunogenicity of the vaccines. The main objective of our study is to identify immunization regimens that may improve the immunogenicity of the vaccines in young children, which could be subsequently in field trials in Bangladesh and other developing countries. Specifically, we will determine if: (i) interventions identified to enhance immune responses to Dukoral, including zinc supplementation, could also enhance the immune responses to Ty21a; (ii) these two vaccines are able to induce both acute and memory B and T cell responses, (iii) treatment with antiparasitic drugs prior to immunization could modulate the immune responses to cholera and typhoid vaccines; and (iv) examine if arsenic exerts a suppressive effect on the immunogenicity of these vaccines.
It is a biomedical research without direct individual benefit, exploring and comparing the mucosal immune response after oral, nasal and sublingual administration of B-subunit of non-toxic cholera toxin (CTB) in healthy adult volunteers.
The purpose of this study is to determine whether the killed bivalent (O1 and O139)whole cell oral cholera vaccine(Shancholâ„¢) is safe and effective in the treatment of Vibrio cholerae.
The purpose of this study is to assess the safety and immunogenicity of Peru-15 (CholeraGarde®) vaccine in HIV seropositive adult population of Bangkok Thailand
Cholera is an important diarrhoeal disease and an important cause of death, particularly during epidemic outbreaks, in Bangladesh and many other developing countries. Used as an adjunct to management of dehydration, antimicrobial therapy using an appropriate agent reduces diarrhoea duration and stool volume in severe cholera by about half. The usefulness of antimicrobials has, however, been greatly eroded by the increasing prevalence of resistant strains of V. cholerae O1. From October 2004 at the Matlab Hospital and from December 2004 at the Dhaka Hospital of ICDDR, B, V. cholerae strains became increasingly resistant to tetracycline and erythromycin- two drugs used in the treatment of severe cholera in adults and children respectively. Because of this high prevalence of resistance we resorted in early 2005 to using ciprofloxacin for treatment against multi drug resistant V. cholerae. Although all isolates were susceptible to ciprofloxacin when standard thresholds for disc-diffusion or E-test were used, but majority of the strains demonstrated a MIC value of 0.250 µg/ml, over hundred-folds greater than the V. cholerae strains tested in earlier years, which generally had a MIC of <0.003 µg/ml. In this randomized, double blind, controlled trial we will assess clinical and bacteriological response to 12 hourly oral dose of ciprofloxacin for 3 days in which the first two doses will be 1 g each and the later 4 doses will be 500 mg each, and compare them with a single 1 g oral dose of azithromycin. We are using azithromycin as the comparator drug because current circulating V. cholerae isolates are susceptible (MIC ≤ 0.125 µg/ml) to this azithromycin, and single-dose azithromycin has been evaluated earlier to be effective in the treatment of cholera.
The purpose of this study is to conduct cholera vaccinations in high-risk populations in Zanzibar in order to estimate herd protection conferred by the vaccine,estimate effectiveness of the vaccine, and describe the interaction of vaccination and improved water supply on the burden of cholera and diarrhoeal diseases.
In cholera, the function of small intestine is affected resulting in increased secretion of electrolytes and water and their reduced absorption leading to profuse watery diarrhoea. The human colon has the capacity to absorb water and electrolytes. A number of recent studies have shown that short chain fatty acids (SCFAs) such as acetate, butyrate and propionate stimulates absorption of sodium in the colon, which is not affected by cyclic AMP. It has also been shown that SCFAs inhibits c-AMP mediated chloride secretion in the colon. Benefiber (partially hydrolyzed guar gum) is water soluble fibre, and when added to ORS it undergoes fermentation in the colon liberating SCFAs. SCFAs not only serves as metabolic fuel to the enterocytes but they also enhance colonic absorption of salts and water. Thus, they have potentials to reduce the severity of diarrhoea in patients with cholera. The aim of this study is to assess the efficacy of Benefiber-added WHO-ORS in the management of adults with cholera. In this randomized, controlled clinical trial, a total of 174 adult males with cholera would be studied. Study patients would be selected from those who attend the Dhaka Hospital of ICDDR,B with a history of diarrhoea of less than 24 hours and signs of severe dehydration. They would be rehydrated using intravenous fluid (cholera saline) over 4 hrs during which a stool specimen would be subjected for dark-field microscopy for identification of V. cholerae. Those identified to have cholera would be randomized in equal numbers to receive either: a) Benefiber (25 g/L) added WHO-ORS, b) Benefiber (50 g/L) added to the new formulation (Na+ 75, glucose 75, Cl- 65, K+ 20 mmol/L, citrate 10 mmol/L, osmolarity 245 mosmol/L) of WHO-ORS , or c) the same WHO-ORS but without Benefiber for maintenance of hydration until resolution of diarrhoea. All patients would be treated with a single, 300 mg dose of doxycycline capsules and would be provided with the standard hospital diets. Fluid intake (intravenous fluid, ORS, and plain water) and output (stool, urine, and vomit) will be measured for each 6-hourly periods of the study. Patients would be hospitalized until resolution of their diarrhoea. Stool output, intake of intravenous fluid and ORS, the duration of diarrhoea, and the proportion of patients requiring "unscheduled intravenous fluid therapy" would be compared between the treatment groups. If Benefiber is found effective, it would be possible to formulate improved ORS for better case management of cholera.