International Centre for Diarrhoeal Disease Research, Bangladesh

About: International Centre for Diarrhoeal Disease Research, Bangladesh is a facility organization based out in Dhaka, Bangladesh. It is known for research contribution in the topics: Population & Vibrio cholerae. The organization has 3103 authors who have published 5238 publications receiving 226880 citations. The organization is also known as: SEATO Cholera Research Laboratory & Bangladesh International Centre for Diarrhoeal Disease Research.

Cluster-randomised controlled trials of individual and combined water, sanitation, hygiene and nutritional interventions in rural Bangladesh and Kenya: the WASH Benefits study design and rationale.

Abstract: Introduction: Enteric infections are common during the first years of life in low-income countries and contribute to growth faltering with long-term impairment of health and development. Water quality, sanitation, handwashing and nutritional interventions can independently reduce enteric infections and growth faltering. There is little evidence that directly compares the effects of these individual and combined interventions on diarrhoea and growth when delivered to infants and young children. The objective of the WASH Benefits study is to help fill this knowledge gap. Methods and analysis: WASH Benefits includes two cluster-randomised trials to assess improvements in water quality, sanitation, handwashing and child nutrition—alone and in combination—to rural households with pregnant women in Kenya and Bangladesh. Geographically matched clusters (groups of household compounds in Bangladesh and villages in Kenya) will be randomised to one of six intervention arms or control. Intervention arms include water quality, sanitation, handwashing, nutrition, combined water+sanitation+handwashing (WSH) and WSH +nutrition. The studies will enrol newborn children (N=5760 in Bangladesh and N=8000 in Kenya) and measure outcomes at 12 and 24 months after intervention delivery. Primary outcomes include child length-for-age Z-scores and caregiver-reported diarrhoea. Secondary outcomes include stunting prevalence, markers of environmental enteropathy and child development scores (verbal, motor and personal/ social). We will estimate unadjusted and adjusted intention-to-treat effects using semiparametric estimators and permutation tests.

Methodological Issues in Diarrhoeal Diseases Epidemiology: Definition of Diarrhoeal Episodes

Abstract: A review of the diarrhoeal disease literature reveals considerable variability in the definition of diarrhoeal episodes. The use of various definitions of diarrhoea and episodes leads to misclassification, affects the estimates of the disease burden in communities and reduces comparability of the findings from different studies. This study is an attempt to validate the definition of diarrhoeal episodes using prospectively collected community-based surveillance data. In comparative validation analyses, three or more loose stools or any number of loose stools containing blood in a 24-hour period seemed to be the best definition of diarrhoea. Three intervening diarrhoea-free days seemed to be the optimum to define a new episode. The implications of using differing definitions and the importance of using a validated definition are discussed.

Viable but nonculturable Vibrio cholerae O1 in biofilms in the aquatic environment and their role in cholera transmission

Abstract: Vibrio cholerae persists in aquatic environments predominantly in a nonculturable state. In this study coccoid, nonculturable V. cholerae O1 in biofilms maintained for 495 days in Mathbaria, Bangladesh, pond water became culturable upon animal passage. Culturability, biofilm formation, and the wbe, ctxA, and rstR2 genes were monitored by culture, direct fluorescent antibody (DFA), and multiplex PCR. DFA counts were not possible after formation of biofilm. Furthermore, wbe, but not ctxA, were amplifiable, even after incubation for 54 and 68 days at room temperature (≈25°C) and 4°C, respectively, when no growth was detectable. Slower biofilm formation and extended culturability were observed for cultures incubated at 4°C, compared with ≈25°C, suggesting biofilm production to be temperature dependent and linked to loss of culturability. Small colonies appearing after incubation in microcosms for 54 and 68 days at 25°C and 4°C, respectively, were wbe positive and ctxA and rstR2 negative, indicating loss of bacteriophage CTXΦ. The coccoid V. cholerae O1 observed as free cells in microcosms incubated for 495 days could not be cultured, but biofilms in the same microcosms yielded culturable cells. It is concluded that biofilms can act as a reservoir for V. cholerae O1 between epidemics because of its long-term viability in biofilms. In contrast to biofilms produced in Mathbaria pond water, V. cholerae O1 in biofilms present in cholera stools and incubated under identical conditions as the Mathbaria pond water biofilms could not be cultured after 2 months, indicating that those V. cholerae cells freshly discharged into the environment are significantly less robust than cells adapted to environmental conditions.