Feasibility and effectiveness of oral cholera vaccine in an urban endemic setting in Bangladesh: a cluster randomised open-label trial.

BACKGROUND: Cholera is endemic in Bangladesh with epidemics occurring each year. The decision to use a cheap oral killed whole-cell cholera vaccine to control the disease depends on the feasibility and effectiveness of vaccination when delivered in a public health setting. We therefore assessed the feasibility and protective effect of delivering such a vaccine through routine government services in urban Bangladesh and evaluated the benefit of adding behavioural interventions to encourage safe drinking water and hand washing to vaccination in this setting. METHODS: We did this cluster-randomised open-label trial in Dhaka, Bangladesh. We randomly assigned 90 clusters (1:1:1) to vaccination only, vaccination and behavioural change, or no intervention. The primary outcome was overall protective effectiveness, assessed as the risk of severely dehydrating cholera during 2 years after vaccination for all individuals present at time of the second dose. This study is registered with ClinicalTrials.gov, number NCT01339845. FINDINGS: Of 268,896 people present at baseline, we analysed 267,270: 94,675 assigned to vaccination only, 92,539 assigned to vaccination and behavioural change, and 80,056 assigned to non-intervention. Vaccine coverage was 65% in the vaccination only group and 66% in the vaccination and behavioural change group. Overall protective effectiveness was 37% (95% CI lower bound 18%; p=0·002) in the vaccination group and 45% (95% CI lower bound 24%; p=0·001) in the vaccination and behavioural change group. We recorded no vaccine-related serious adverse events. INTERPRETATION: Our findings provide the first indication of the effect of delivering an oral killed whole-cell cholera vaccine to poor urban populations with endemic cholera using routine government services and will help policy makers to formulate vaccination strategies to reduce the burden of severely dehydrating cholera in such populations. FUNDING: Bill & Melinda Gates Foundation.

Knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among urban high-risk groups: findings of a cross-sectional study in Dhaka, Bangladesh.

BACKGROUND: In endemic countries such as Bangladesh, consequences of cholera place an enormous financial and social burden on patients and their families. Cholera vaccines not only provide health benefits to susceptible populations but also have effects on the earning capabilities and financial stability of the family. Community-based research and evaluations are necessary to understand perceptions about and practices of the community relating to cholera and oral cholera vaccines. This may help identify the ways in which such vaccines may be successfully introduced, and other preventive measures can be implemented. The present study assessed the knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among an urban population residing in a high cholera-prone setting in Dhaka, Bangladesh. METHODS: This cross-sectional study was conducted in an area of high cholera prevalence in 15 randomly-selected clusters in Mirpur, Dhaka city. A study team collected data through a survey and in-depth interviews during December 2010-February 2011. RESULTS: Of 2,830 families included in the final analysis, 23% could recognize cholera as acute watery diarrhea and 16% had ever heard of oral cholera vaccine. About 54% of the respondents had poor knowledge about cholera-related issues while 97% had a positive attitude toward cholera and oral cholera vaccine. One-third showed poor practice relating to the prevention of cholera.The findings showed a significant (p < 0.05) association between the respondents' knowledge and sex, education, occupation, monthly overall household expenditure, attitudes and practice. In the adjusted model, male sex, having a lower monthly overall household expenditure, and having a less positive attitude toward cholera were the significant predictors to having poor knowledge. CONCLUSIONS: The findings suggest the strengthening of health education activities to improve knowledge on cholera, its prevention and treatment and information on cholera vaccination among high-risk populations. The data also underscore the potential of mass cholera vaccination to prevent and control cholera.

Invasive pneumococcal disease among children in rural Bangladesh: results from a population-based surveillance.

BACKGROUND: Streptococcus pneumoniae infection is recognized as a global priority public health problem, and conjugate vaccines have been shown to prevent vaccine-type invasive pneumococcal disease (IPD) in children. However, better estimates of the disease burden and reliable population-based data on serotype composition are needed for vaccine development and implementation in developing countries. METHODS: We initiated a population-based surveillance in the rural Bangladesh community of Mirzapur, covering a population of approximately 144,000. Village health care workers made weekly visits to approximately 12,000 children 1-59 months of age in the study area. Children with reported fever, cough, or difficulty breathing were assessed by the village health care workers using a clinical algorithm and were referred to the hospital if required. Children from the study area who were seen in the hospital underwent clinical examination and laboratory testing if they met standardized case definitions. IPD was confirmed by blood and/or cerebrospinal fluid culture results. Isolates were identified, tested for susceptibility to antibiotics, and serotyped in accordance with standard laboratory methods. We present here the results from the first 3 years of the surveillance (July 2004-June 2007). RESULTS: Village health care workers identified 5020 cases of possible severe pneumonia and/or very severe disease (165 cases per 1000 child-years)and 9411 cases of possible pneumonia (310 cases per 1000 child-years) as well as 2029 cases of suspected meningitis and/or very severe disease (67 cases per 1000 child-years) and 8967 cases of high fever and/or possible bacteremia (295 cases per 1000 child-years). Pneumonia was the single most common form of illness observed among 2596 hospitalizations (found in 977 [38%] of cases). We recovered 26 S. pneumoniae isolates (25 isolates from 6925 blood cultures and 1 isolate from 41 cerebrospinal fluid cultures), which gave an overall IPD incidence of 86 cases per 100,000 child-years. Invasive pneumococcal infection was common during infancy (with infants accounting for 23 of the 26 cases), and 50% of the total isolates were obtained from nonhospitalized patients who received a diagnosis of upper respiratory tract infection and fever. The most prevalent pneumococcal serotypes were serotypes 1, 5, 14, 18C, 19A, and 38. Ten of the 26 isolates were completely resistant to trimethoprim-sulfamethoxazole, and another 10 isolates had intermediate resistance. CONCLUSIONS: IPD contributes substantially to childhood morbidity in rural Bangladesh. S. pneumoniae can cause invasive but nonsevere disease in children, and IPD incidence can be seriously under reported if such cases are overlooked. The emerging high resistance to trimethoprim-sulfamethoxazole should be addressed. Data on serotype distribution would help to guide appropriate pneumococcal conjugate vaccine formulation.

Post-vaccination campaign coverage evaluation of oral cholera vaccine, oral polio vaccine and measles-rubella vaccine among Forcibly Displaced Myanmar Nationals in Bangladesh.

Background: The new influx of Forcibly Displaced Myanmar Nationals (FDMNs) into Bangladesh started in August 2017 through different entry points of Bangladesh. Considering the imminent threat of infectious diseases outbreaks, the Government of Bangladesh (GoB) decided to vaccinate children against three deadly diseases (measles, rubella and poliomyelitis) and oral cholera vaccine (OCV) for all except <1 year children. After completion of the campaigns, post-vaccination campaign evaluation was carried out to assess the coverage of OCV, OPV and MR vaccines during campaigns.Methods: Post-vaccination campaign evaluation was conducted after completion of the 2nd dose of oral cholera vaccine (OCV2) and oral polio vaccine (OPV2) through a cross-sectional survey. The evaluation was conducted in the Balukhali camps under Ukhiya upazilla. Precision-based sample size was calculated to estimate the vaccine coverage. Ninety-two trained interviewers were involved to collect data from the target of approximately 40000 FDMNs between 18 and 25 November 2017.Results: Data were collected from 39,438 FDMNs during the survey period. The highest coverage was observed for OCVs (94% for OCV1 and 92% for OCV2). On the other hand, lower coverage was observed for the other vaccines; the coverage for OPV1, OPV2 and MR were 75%, 88% and 38%, respectively. Unawareness (30.7% did not know about the campaign) was the most notable cause of lowering down MR vaccine coverage.Conclusion: The experience in Bangladesh demonstrates that vaccine campaigns can be successfully implemented as part of a comprehensive response toward disease outbreak among high-risk populations in humanitarian crisis.