BACKGROUND: Drinking water quality affects directly human health. Assessment and prevention of water-borne diseases are crucial for primary prevention, especially for children. OBJECTIVE: The main ...aim of this study was to investigate the quality of drinking water from tap water in preschools and primary schools in a district area in Hanoi City, Vietnam. METHODS: A cross-sectional study was performed from August to October 2019. Water samples from tap water of 154 schools in a district area of Hanoi were collected to determine the quality of drinking water. From each school, at least 2 bottles of water samples were collected on the basis of a standard operating procedure (SOP). Each water sample was analyzed for microbial and physicochemical parameters, including Color, Taste and Odor, Turbidity, pH, Nitrite, Nitrate, Ammonium, Total Iron, Permanganate, Chloride, Hardness, Total Manganese, Sulfate, Arsenic, Coliform, and E.coli, by analytical methods. The obtained values of each parameter were compared with the standard values set by WHO and National Technical Regulation on Domestic Water Quality of Vietnam. RESULTS: All of the schools employed community water system as a main source for drinking water. The results showed that all tested samples were found to be within the standards for some physicochemical properties, including Color, Taste and Odor, Hardness, Chloride, Total Iron (Fe2+ và Fe3+), Total Manganese (Mn), Nitrate (NO3–), Sulfate (SO42–), and Total Arsenic (As). On the other hand, some samples did not meet the allowable limits of the national standard, due to pH (3.9%), Turbidity (0.6%), Nitrite (3.2%), Permanganate (6.5%), and Ammonium (5.8%). Furthermore, the microbial data revealed that the substandard water samples from municipal water systems were contaminated by Coliform (9.7%) and/or E.coli (7.8%). CONCLUSIONS AND RECOMMENDATIONS: Contaminants such as bacterial and chemical agents in to drinking water could be occurred during transport, storage and handling before using by the consumer without regular surveillance. A periodic treatment procedure and monitoring system to keep the level of microbial and chemical contamination of drinking water in schools under control should be performed.
Background
: Rotavirus (RoV) remains the leading cause of acute gastroenteritis in infants and children aged under five years in both high- and low-middle-income countries (LMICs). In LMICs, RoV ...infections are associated with substantial mortality. Two RoV vaccines (Rotarix and Rotateq) are widely available for use in infants, both of which have been shown to be highly efficacious in Europe and North America. However, for unknown reasons, these RoV vaccines have markedly lower efficacy in LMICs. We hypothesize that poor RoV vaccine efficacy across in certain regions may be associated with genetic heritability or gene expression in the human host.
Methods/design
:
We designed an open-label single-arm interventional trial with the Rotarix RoV vaccine to identify genetic and transcriptomic markers associated with generating a protective immune response against RoV. Overall, 1,000 infants will be recruited prior to Expanded Program on Immunization (EPI) vaccinations at two months of age and vaccinated with oral Rotarix vaccine at two and three months, after which the infants will be followed-up for diarrheal disease until 18 months of age. Blood sampling for genetics, transcriptomics, and immunological analysis will be conducted before each Rotarix vaccination, 2-3 days post-vaccination, and at each follow-up visit (i.e. 6, 12 and 18 months of age). Stool samples will be collected during each diarrheal episode to identify RoV infection. The primary outcome will be Rotarix vaccine failure events (i.e. symptomatic RoV infection despite vaccination), secondary outcomes will be antibody responses and genotypic characterization of the infection virus in Rotarix failure events.
Discussion
: This study will be the largest and best powered study of its kind to be conducted to date in infants, and will be critical for our understanding of RoV immunity, human genetics in the Vietnam population, and mechanisms determining RoV vaccine-mediated protection.
Registration:
ClinicalTrials.gov, ID:
NCT03587389
. Registered on 16 July 2018.
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