Sirajul Islam

International Centre for Diarrhoeal Disease Research, Bangladesh | ICDDR,B

The environmental reservoir of Vibrio cholerae, the causative agent of cholera, has been a topic of scientific investigation ever since the discovery of the bacterium itself. While the bacteria can be isolated from both clinical and environmental sources during epidemics, it evades isolation by conventional culture techniques during the period betw...

Introduction: In Bangladesh, human sludge from dry pit latrines is commonly applied directly to agricultural lands as manure. This study was conducted to investigate the presence of antibiotic resistance, virulence factors and plasmid contents of E. coli strains isolated from sludge samples. Methodology: E. coli were isolated from human feces from...

DNA origami has emerged in recent years as a powerful technique for designing and building 2D and 3D nanostructures. While the breadth of structures that have been produced is impressive, one of the remaining challenges, especially for DNA origami structures intended to carry out useful biomedical tasks in vivo, is to endow them with the ability to...

DNA origami has emerged in recent years as a powerful technique for designing and building 2D and 3D nanostructures. While the breadth of structures that have been produced is impressive, one of the remaining challenges, especially for DNA origami structures intended to carry out useful biomedical tasks in vivo, is to endow them with the ability to...

We conducted a cross sectional study to assess 1) the association between access to basic sanitation and fecal contamination of sentinel toy balls and 2) if other sanitation factors such as shared use and cleanliness are associated with fecal contamination of sentinel toy balls. We assessed sanitation facilities in 454 households with a child aged...

Faecal contamination of groundwater from pit latrines is widely perceived as a major threat to the safety of drinking water for several billion people in rural and peri-urban areas worldwide. On the floodplains of the Ganges-Brahmaputra-Meghna delta in Bangladesh, we constructed latrines and monitored piezometer nests monthly for two years. We dete...

Faecal contamination of groundwater from pit latrines is widely perceived as a major threat to the safety of drinking water for several billion people in rural and peri-urban areas worldwide. On the floodplains of the Ganges-Brahmaputra-Meghna delta in Bangladesh, we constructed latrines and monitored piezometer nests monthly for two years. We dete...

This study was conducted to investigate the levels of heavy metals in twelve species of vegetables and assessment of health risk. Samples were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). The ranges of Cr, Ni, Cu, As, Cd and Pb in vegetables species were 0.37-5.4, 0.03-17, 0.35-45, 0.01-2.6, 0.001-2.2, and 0.04-8.8 [mg/kg,...

Background Groundwater drawn from shallow tubewells in Bangladesh is often polluted by nearby pit latrines, which are commonly used toilets in rural and sub-urban areas of the country. Methods To determine the minimum safe distance of a tubewell from a pit latrine in different hydrogeological conditions of Bangladesh, 20 monitoring wells were insta...

Point-of-use water treatment with chlorine is underutilized in low-income households. The Zimba, an automated batch chlorinator, requires no electricity or moving parts, and can be installed at shared water points with intermittent flow. We conducted a small-scale trial to assess the acceptability and quality of Zimba-treated municipal water. Field...

We used a prospective, longitudinal cohort enrolled as part of a program evaluation to assess the relationship between drinking water microbiological quality and child diarrhea. We included 50 villages across rural Bangladesh. Within each village field-workers enrolled a systematic random sample of 10 households with a child under the age of 3 year...

In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by cu...

Drinking raw date palm sap is the primary route of Nipah virus (NiV) transmission from bats to people in Bangladesh; subsequent person-to-person transmission is common. During December 2010 to March 2011, we investigated NiV epidemiology by interviewing cases using structured questionnaires, in-depth interviews, and group discussions to collect cli...

Rice false smut (RFSm) has lately been recognized as an emerging disease worldwide. Its alarming prevalence in Bangladesh in the transplant Aman rice in the last three years has been widely reported. However, there is no effective control measure against the disease in this country. We hypothesized that manipulation of flowering time in aman rice m...

Presence of Vibrio cholerae serogroups O1 and O139 in the waters of the rural area of Matlab, Bangladesh, was investigated with quantitative measurements carried out by using a portable flow cytometer. The relevance of this work relates to the testing of a field-adapted measurement protocol that might prove useful for cholera epidemic surveillance...

Disgust can be considered a psychological arm of the immune system that acts to prevent exposure to infectious agents. High disgust sensitivity is associated with greater behavioral avoidance of disease vectors and thus may reduce infection risk. A cross-sectional survey in rural Bangladesh provided no strong support for this hypothesis. In many sp...

We conducted a randomized, non-inferiority field trial in urban Dhaka, Bangladesh among mothers to compare microbial efficacy of soapy water (30 g powdered detergent in 1.5 L water) with bar soap and water alone. Fieldworkers collected hand rinse samples before and after the following washing regimens: scrubbing with soapy water for 15 and 30 secon...

People in rural Bangladesh have a poor understanding of the link between use of contaminated surface water and disease. An inexpensive point-of-use water treatment agent was developed to purify surface water. Surface water was collected from various sources in Bangladesh from February 2007 to January 2008. Microbiological and physicochemical parame...

Objective To evaluate household faecal contamination using children's toys among 100 rural Bangladeshi households categorised as ‘cleaner’ (toilet that reliably separates faeces from the environment and no human faeces in/around living space) or ‘less clean’ (no toilet or toilet that does not reliably separate faeces from the environment and human...

During 2012, Sierra Leone experienced a cholera epidemic with 22,815 reported cases and 296 deaths. We conducted a matched case-control study to assess risk factors, enrolling 49 cases and 98 controls. Stool specimens were analyzed by culture, polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE). Conditional logistic regress...

An experiment was conducted at Sher-e-Bangla Agricultural University farm to study the efficacy of some insecticides against major insect pests of French bean (Phaseolus vulgaris L.). The treatments of the experiment were T 1 : Bamper 20SL (Imidacloprid) @ 0.5 ml L-1 , T 2 : Shobicron4 25EC @ 2 ml L-1 , T 3 : Actara 25WG (Thiamethoxam) @ 0.3 g L-1...

In 2010, an acute illness outbreak was reported in school students eating high-energy biscuits supplied by the school feeding programme in northwest Bangladesh. We investigated this outbreak to describe the illness in terms of person, place and time, develop the timeline of events, and determine the cause and community perceptions regarding the out...

The apodization function plays an important role in the behavior of the mean dispersion, group delay and significant reduction of sidelobe level in reflection spectrum. On the other hand, the grating length represents as one of the critical parameters in contributing to a high performance fiber Bragg grating compensator. In this paper, we have inve...

Parasitic infection is a global health problem especially in developing countries. Municipal wastewaters always contain cysts of parasitic protozoans at some level. The present study was conducted to detect protozoan parasites in different stages of the treatment plant to check its efficacy. Wastewaters were collected from 3 points of the Pagla Sew...

The high cost of bar soap relative to household income is an important barrier to handwashing in low-income communities. Soapy water made from powdered detergent is a low-cost alternative that could overcome these barriers. Among low-income households in Dhaka, Bangladesh, we compared the efficacy of handwashing with soapy water to washing with bar...

Cholera epidemics are thought to be influenced by changes in populations of estuarine Vibrio cholerae. We investigated the abundance and distribution of this bacterium, as “free-living” (<20 μm fraction) and associated with microphytoplankton (>20 μm) or zooplankton (>60 μm), in the Karnaphuli estuary of Bangladesh during pre- and post-monsoon seas...

Vibrio vulnificus, a common human pathogen, is autochthonous to warm estuarine and coastal waters. Present study was carried out to investigate the occurrence of V. vulnificus in Nile tilapia of gher, pond and markets. V. vulnificus was detected in all three organs namely muscle, gill and intestine of netted and market Nile tilapia and in all water...

We utilize a portable flow cytometer, which allows for absolute counts of particle concentration, along with specific staining to analyze the waters of the rural area of Matlab, Bangladesh, where cholera is endemic, in the month of January 2012. Such period is interepidemic, as conditions for V. cholerae survival are less apt, because of low temper...

The present study was designed for the qualitative and quantitative detection of Giardia in the Pagla Sewage Treatment Plant (PSTP) in Dhaka. The physico-chemical parameters of the sewage water were also recorded. Total 72 raw and treated samples were collected from PSTP throughout the year 2008 and these were processed with the Formol-Ether Concen...

This chapter treats two main topics: the relationship between human health, aquatic ecosystems, and water use; and the necessity of interdisciplinary approaches for the development of water management policies and disease control.

Measuring hand contamination at critical times, such as eating, can be challenging. We examined whether hand contamination measured at random, such as on arrival (initial), predicts contamination at critical times. Mothers of young children in Bangladesh rinsed both hands in 200 mL of ringer’s solution. We compared results of serial samples with...

Study site location, Mirpur, Dhaka, Bangladesh. (DOC)

Test of randomization by predicting treatment status as a function of baseline characteristics. Dependent variable = 1 if household is assigned to intervention (vs. control) group at baseline. Standard errors in parentheses. (DOC)

Predicting dropout as a function of treatment assignments. Probit regression with dependent variable = 1 if a baseline household dropped out before end of study. Standard errors in parentheses. (DOC)

Instrumental variables (IV) regressions for endogenous self-reports on usage. Column 1 contains first stage results for both IV regressions. Columns 2−3 contain results for “no detectable” E. coli (E. coli <1 CFU/100 mL) and compares OLS results in column 2 with IV results in column 3. Columns 4−5 make similar comparison for Log10(E. coli) outcome....

(DOC)

There is evidence that household point-of-use (POU) water treatment products can reduce the enormous burden of water-borne illness. Nevertheless, adoption among the global poor is very low, and little evidence exists on why. We gave 600 households in poor communities in Dhaka, Bangladesh randomly-ordered two-month free trials of four water treatmen...

In Bangladesh, one of the main causes of waterborne diseases is related to the use of contaminated surface water. This pilot study was conducted to determine the acceptability and effectiveness of a recently developed surface water purifying mixture to prevent diarrhoeal diseases in a rural community in Bangladesh. The mixture, using a combination...

Structured observation is often used to evaluate handwashing behavior. We assessed reactivity to structured observation in rural Bangladesh by distributing soap containing acceleration sensors and performing structured observation 4 days later. Sensors recorded the number of times soap was moved. In 45 participating households, the median number of...

To pilot two intensive hand hygiene promotion interventions, one using soap and one using a waterless hand sanitizer, in low-income housing compounds in Dhaka, Bangladesh and assess subsequent changes in handwashing behaviour and hand microbiology. Fieldworkers randomized 30 housing compounds: 10 received handwashing promotion with free soap, 10 re...

A total of 24 water samples were collected from March 2005 to February 2006 from a permanent station of Gulshan lake. The eggs and larva of four types of helminth parasites were identified; two were helminth eggs of Ascaris lumbricoides and Trichuris trichiura and two were helminth larva (rhabditiform larvae) of Strongyloides stercoralis and hookwo...

Vibrio cholerae, the etiological agent of cholera is an autochthonous bacterium of aquatic environment, often found attached to crustacean zooplankton. Chitin is the main component of crustacean exoskeleton, an insoluble polysaccharide. V. cholerae can secrete chitinase enzymes, which can facilitate the bacterium's association with chitinous aquati...

Homogenized samples of skin, gill and gut of twelve freshwater fishes of four feeding habits were used for bacteriological test. Total bacterial count (TBC), total coliform (TC), faecal coliform (FC), faecal streptococci (FS) and total Vibrio? like colonies were enumerated using serial dilution and spread plate techniques. Variation of bacterial lo...

Author Contributions: Dr Islam had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Midzi, Cravioto, Endtz. Acquisition of data: Midzi, Charimari. Analysis and interpretation of data: Islam, Cravioto. Drafting of the manuscript: Midzi,...

Analysis of the CTX prophage and RS1 element in hybrid and altered Vibrio cholera O1 strains showed two classifiable groups. Group I strains contain a tandem repeat of classical CTX prophage on the small chromosome. Strains in this group either contain no element(s) or an additional CTX prophage or RS1 element(s) on the large chromosome. Group II s...

The experiment was carried out at the Agroforestry Farm, to evaluate the performance of three winter vegetables grown under Hopea odorata at different distances. The vegetables were stem amaranth (Amaranthus lividus), red amaranth (Amaranthus gangeticus) and coriander (Coriandrum sativum). Each vegetable were laid out using the Randomized Complete...

Cholera is considered as a model for climate-related infectious diseases. In Bangladesh, cholera epidemics occur during summer and winter seasons, but it is not known how climate variability influences the seasonality of cholera. Therefore, the variability pattern of cholera events was studied in relation to the variation in local climate variables...

Background: Chromobacterium violaceum, a Gram-negative bacterium, usually occurs as a saprophyte in various tropical and subtropical ecosystems, primarily in water and soil. It is recognized as an opportunistic pathogen of extreme virulence and high mortality in humans. Both pigmented and non-pigmented colony types are ubiquitous in the environment...

Results: P. aeruginosa was detected in 59 (25%) of 238 samples tested. Among the P. aeruginosa-positive samples, approximately 50% were contaminated with TC and FC. HPC were found in all the sam-ples; however, 80% had >500 cfu per mL (maxi-mum 105 cfu/mL). All the isolates were resistant to 9 of 15 commonly-employed antibiotics, such as tetracyclin...

The experiment was carried out at the Agroforestry Farm, Department of Agroforestry, Bangladesh Agricultural University, Mymensingh, during November 2008 to March 2009 to evaluate the performance of three winter vegetables grown under Hopea odorata at different distances. The vegetables were stem amaranth (Amaranthus lividus), red amaranth (Amarant...

Vibrio cholerae, the etiological agent of cholera is an autochthonous bacterium of aquatic environment, often found attached to crustacean zooplankton. Chitin is the main component of crustacean exoskeleton, an insoluble polysaccharide. V. cholerae can secrete chitinase enzymes, which can facilitate the bacterium’s association with chitinous aquati...

To evaluate the effectiveness of the chulli water purifier, a new household water treatment strategy in Bangladesh that relies on passing water through a stove, we interviewed persons who had this water purifier. From households using it regularly, we tested untreated water, sand-filtered water without heat pasteurization, sand-filtered and heat pa...

Vibrio vulnificus is a ubiquitous toxigenic bacterium found in a coastal environment but little is known about its occurrence and seasonality among seaweeds, which are widely consumed as seafood in Japan. Therefore, we have observed the bacterium’s abundance in seawater and seaweed samples from three areas of the Kii Channel, Japan, during June 2003...

To measure enteric bacterial contamination of tubewells in three flood prone areas in Bangladesh and the relationship of bacteriological contamination with tubewell sanitary inspection scores. Microbiologists selected 207 tubewells in three flood prone districts, assessed physical characteristics of the tubewells and collected a single water sample...

Background The seasonality of cholera is described in various study areas throughout the world. However, no study examines how temporal cycles of the disease vary around the world or reviews its hypothesized causes. This paper reviews the literature on the seasonality of cholera and describes its temporal cycles by compiling and analyzing 32 years...

To evaluate the usefulness of the hydrogen sulfide (H(2)S) test for assessing water quality in Bangladesh. We tested 382 water samples from a variety of sources using locally produced H(2)S test kits and laboratory-based membrane filtration for the detection of Escherichia coli. Compared with membrane filtration, H(2)S tests, when incubated for 24...

Gastroenteritis caused by Vibrio parahaemolyticus has recently been associated with foods prepared with seaweeds, but little is known about the bacterium's abundance and diversity among seaweeds in coastal environment. Therefore, we determined its phenotypic and genotypic diversity in relation to its seasonal abundance in seawater and seaweed sampl...

To describe the extent of faecal pollution and point of use water treatment strategy during and after the 2004 flood in Dhaka. A total of 300 water samples were collected from 20 different drinking water sources in Kamalapur, Dhaka city from August 2004 to January 2005. The level of faecal contamination was estimated using measurements of faecal in...