Assessment of radioactivity level and associated radiological hazard in riverbed samples within industrial areas

Terrestrial gamma radiation is one of the major outdoor radiation exposures to the general public that varies substantially based on the type and geological properties of the soil. The objective of this study is to evaluate the naturally occurring radioactive materials (NORMs) distribution and assess the hazard parameters in the riverbank soil within various industrial zones in the densely populated Dhaka and Chattogram cities of Bangladesh. The mean activities of 226Ra (37 ± 3), 232Th (58 ± 4), and 40K (1129 ± 18) Bqkg-1 in the assessed soil samples were found to be slightly higher than the world average values 32, 35, and 420 Bqkg-1, respectively. The mean radium equivalent activity (207.49 Bqkg-1) and the external and internal hazard indices were within the recommended limits of 370 Bqkg-1 and <1, respectively. The mean absorbed dose rate (99.47 nGyhr-1), annual effective dose (0.12 mSva-1), ELCR (4.27 × 10-4), and gamma level index (1.58) exceeded the world average values 59 nGyhr-1, 0.07 mSva-1, 2.9 × 10-4, and 1 respectively. However, the studied areas are safe from a radiological viewpoint with no radiation health hazard to the people. The results of this study can be utilized to produce factual baseline data for future studies.

Complete genome sequence of the pandrug-resistant Vibrio cholerae strain KBR06 isolated from a cholera patient in Bangladesh

Vibrio cholerae poses a serious hazard to global health and causes cholera disease in humans. Here, we present the full-genome sequence of a pandrug-resistant V. cholerae strain KBR06 isolated from a cholera patient in Bangladesh that exhibited intermediate resistance to only two antibiotics out of 39 among 14 antibiotic categories.

Poor Respiratory Health is a Consequence of Dhaka's Polluted Air: A Bangladeshi Perspective

Dhaka, which is the capital and largest metropolis of Bangladesh, has seen an increase in the number of documented cases of respiratory disorders. Every day in Dhaka city, a remarkable number of patients are being diagnosed with poor respiratory conditions. The majority of these patients have no other severe disease history and mostly need to be exposed to outdoor air to meet their occupational requirements, indicating that the ailment may be associated with polluted air. As this is the most pressing issue that must be addressed in order to safeguard public health, we have made an effort to focus on the current situation surrounding the sources of air pollution in the city. Since this is a viewpoint article, we gathered data from various published articles, national dailies, and international reports generated by WHO, CDC, BBC, or other environmental news/report portals to highlight the public health issue related to respiratory health. Poor respiratory health is one of the main consequences of Dhaka's contaminated air, as determined by our analysis.

Association between depressive symptoms of mothers and eating behaviors of school-going children in Urban Bangladesh: A cross-sectional study

OBJECTIVE

This study aimed to investigate the association between depressive symptoms among mothers and the eating behaviors of their school-going children in Urban Bangladesh.

MATERIALS AND METHODS

This analytical cross-sectional study was conducted in the context of the urban area of Bangladesh. A multistage sampling technique was applied to select 324 children's mothers in Dhaka City. Data were collected from both city corporation settings in Dhaka, Bangladesh. Semi-structured questionnaires were used in this study. We estimated the depressive symptoms among mothers using the Zung Self-Rating Depression Scale. We examined the association of mothers of school-going children's socio-demographic variables and eating behaviors of school-going children with their mother's depression by using chi-square and evaluating the impact of these variables on mothers' depression through univariate and multivariate binary logistic regression.

RESULTS

In our study, 57.7% of the mothers of school-going children had depressive symptoms, and 42.3% had no depressive symptoms. The study explored that consuming fewer vegetables (AOR = 0.237, 95% CI: 0.099-0.569), taking fewer fruits (AOR = 0.177, 95% CI: 0.093-0.337), and interestingly, taking fast food less than 4 days per week (AOR = 3.024, 95% CI: 1.517-6.031) were significantly associated with mothers' depressive symptoms.

CONCLUSION

Mothers with depressive symptoms of school-going children in Dhaka city are alarmingly high as a grave concern. The eating behaviors of children are associated with their mothers' depressive symptoms. With an aim to build rigorous awareness on depression and child's healthy eating behaviors, it is imperative to arrange health education and awareness related programs.

Changing institutional landscape and transportation development in Dhaka, Bangladesh

Cities in the global south, constrained by limited resources, face challenges in delivering efficient transportation infrastructure and services to support their rapidly growing urban populations. Dhaka, serves as an example, as it grapples with the increasing demand driven by population growth, exacerbated by factors like land and resource scarcity, as well as intricate geopolitical dynamics. Despite the construction of a metro rail and other similar mass transit options, Dhaka continues to face difficulties in meeting the increasing transportation demand, posing a persistent challenge. Multiple institutions, including a coordination authority, are working to provide improved transportation services by implementing diverse strategic approaches focusing on infrastructure development, and formulating policies aimed at facilitating better mobility and accessibility. Over the past fifty years, the institutional arrangement and roles within the transportation system have changed. This study examines the institutional arrangements and how they have evolved, along with reviewing transportation development policies during this period. The findings indicate the involvement of multiple organizations in the city's transportation system performing distinct activities-- administrative, coordinating, legislative, regulatory, construction and management, and law enforcement. These authorities often encounter challenges fulfilling their responsibilities stemming from differences in vision, organizational structure, jurisdiction and most notably, lack of coordinatoon, resulting in ineffective infrastructure development and duplicated activities. To improve the transportation system, this study recommends better equipping the existing coordinating authority and expanding its jurisdiction to include other institutions. This approach aims to enhance coordination and address the challenges faced by Dhaka's transportation system, ultimately facilitating improved mobility and accessibility for the city's growing population.

Changes in the economic value of ecosystem services in rapidly growing urban areas: the case of Dhaka, Bangladesh

Assessing the effects of land use patterns on ecosystem services can provide a conceptual foundation and point of reference for spatial planning strategies. The benefits ecosystems bring to individuals' lives and general well-being are referred to as ecosystem services. Land use/land cover (LULC) could influence various ecosystems and have implications for natural habitats and the quality of life. LULC has changed dramatically in Bangladesh during the past few decades, notably in the Dhaka Metropolitan Area. However, no attempt has been made to examine the co-evolution of LULC variations and values of ecosystem services (ESV) in the Dhaka Metropolitan Area. The study's objective is to evaluate the impact of LULC changes and different socio-demographic factors on ESV. LULC data sets were extracted from Landsat OLI and TIRS images using maximum likelihood classification. Analyses were conducted on both ESV estimations and driving forces, and the influence of LULC dynamics on the ESV was assessed. Data from 1991, 2001, 2011, and 2021 were used to estimate ESVs. LULC in the major metropolitan area of Dhaka has seen considerable changes between 1991 and 2021, with the most important change being the declination of water bodies, vegetation, and agricultural land. Vegetation and agricultural land proportions dropped from 22.50% and 19.29%, respectively, to 6.45% and 10.60%. Overall, there was a US$25.11M drop in ESV during 1991-2021. The study emphasizes the value of integrated land use planning for tightly regulating and controlling the growth of built-up regions. This will be essential for maintaining ecological sustainability and contributing to ecosystem resilience.

Embassy in Dhaka, Bangladesh using observations and the CMAQ modeling system

We analyze hourly PM2.5 (particles with an aerodynamic diameter of ≤ 2.5 μm) concentrations measured at the U.S. Embassy in Dhaka over the 2016 - 2021 time period and find that concentrations are seasonally dependent with the highest occurring in winter and the lowest in monsoon seasons. Mean winter PM2.5 concentrations reached ~165-175 μg/m3 while monsoon concentrations remained ~30-35 μg/m3. Annual mean PM2.5 concentration reached ~5-6 times greater than the Bangladesh annual PM2.5 standard of 15 μg/m3. The number of days exceeding the daily PM2.5 standard of 65 μg/m3 in a year approached nearly 50%. Daily-mean PM2.5 concentrations remained elevated (>65 μg/m3) for more than 80 consecutive days. Night-time concentrations were greater than daytime concentrations. The comparison of results obtained from the Community Multiscale Air Quality (CMAQ) model simulations over the Northern Hemisphere using 108-km horizontal grids with observed data suggests that the model can reproduce the seasonal variation of observed data but underpredicts observed PM2.5 in winter months with a normalized mean bias of 13-32%. In the model, organic aerosol is the largest component of PM2.5, of which secondary organic aerosol plays a dominant role. Transboundary pollution has a large impact on the PM2.5 concentration in Dhaka, with an annual mean contribution of ~40 μg/m3.

Source identification, contamination status and health risk assessment of heavy metals from road dusts in Dhaka, Bangladesh

In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90, BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7 (municipal waste dumping) and 8 (medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5 (Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9 (urban), 10 (sub-urban), 11 (rural) while sites-7 and 8 (urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites-7 and 8. Values of incremental lifetime cancer risk were from 10^-9 to 10^-11 showed no carcinogenic health risk by road dusts contaminated with the heavy metals.

Is there tea complemented with the appealing flavor of microplastics? A pioneering study on plastic pollution in commercially available tea bags in Bangladesh

Microplastic pollution is a global concern, mainly due to its adverse effects on organisms and ecosystems. However, our knowledge of its impact on humans, in particular, is still very limited. Thus, while we have not gathered definitive information on their consequences, studies that aim to identify the MP's sources constitute subsidies to better understand the various exposure pathways to these pollutants. Thus, we investigated the possible presence of MP-like particles in teabag samples (of different brands) obtained in Dhaka, Bangladesh. Surprisingly, all analyzed samples (five brands) were contaminated with MPs. Fragments and fibers were identified in a higher percentage, and a wide variety of colors was identified, with a predominance of brown, blue, and red colors. Scanning electron microscope images of teabags exhibited net-like structures of fiber particles with a smooth surface. Furthermore, we observed irregularly shaped MPs and rougher surfaces and fragments in the process of detachment from the main fiber, oxidation flakes, and fracture-like. The average size of these pollutants was between 200.6 and 220.7 μm, and the polymer types identified via Fourier-transform infrared spectroscopy (FT-IR) were polytetrafluoroethylene, high-density polyethylene, polycarbonate, nylon, polyvinyl chloride, polytetrafluoroethylene, ethylene-vinyl acetate, cellulose acetate, and acrylonitrile butadiene styrene, the last three being the most frequent in the analyzed samples. Finally, we noticed that MPs from tea bags in Dhaka could cause an average emission of 10.9 million grams of MPs/year. Although the teabags analyzed in our study are not "complemented with the appealing flavor of MPs", it is very likely that tea ingestion in Dhaka is accompanied by the concomitant ingestion of plastic particles making teabags an important route of human exposure to these micropollutants.

Psychological status of mass people in the capital city of Bangladesh during COVID-19: Do home quarantine challenges matter?

This study aimed to identify the impact of home quarantine challenges on the psychological status of mass people during Coronavirus Disease (COVID-19) in the capital city (Dhaka) of Bangladesh. A highly organized questionnaire was created in "Google Form" and given to respondents at random via multiple social media sites, including WhatsApp, LinkedIn, and Messenger. However, a sample size of 208 people was taken and analysis was carried out using Statistical Package for the Social Sciences and Analysis of a Moment Structures software. Analysis showed that home quarantine challenges are positively related to the psychological status and home quarantine challenges have a significant impact on psychological status during COVID-19. In Bangladesh, the major challenges to home quarantine are lack of consciousness, lack of medical support, and the possibility of losing their current jobs. This study provides insight into the challenges of home quarantine and the psychological status of Bangladeshi people. The findings may be helpful for policymakers in identifying necessary measures to overcome these challenges. Only Dhaka division was taken out of seven divisions in Bangladesh to conduct this study, which might be difficult to generalize the findings of this study. Thus, in the future, it is suggested that more respondents from other divisions need to be covered.

Temperature variability associations with cardiovascular and respiratory emergency department visits in Dhaka, Bangladesh

BACKGROUND

Greenhouse gas emissions are changing the Earth's climate, most directly by modifying temperatures and temperature variability (TV). Residents of low- and middle-income countries (LMICs) are likely more adversely affected, due to lack of air conditioning to compensate. To date, there is no local epidemiological evidence documenting the cardio-respiratory health effects of TV in Dhaka, Bangladesh, one of the most climate change vulnerable cities in the world.

OBJECTIVES

We assessed short-term TV associations with daily cardiovascular disease (CVD) and respiratory emergency department (ED) visits, as well as effect modification by age and season.

METHODS

TV was calculated from the standard deviations of the daily minimum and maximum temperatures over exposure days. Time-series regression modeling was applied to daily ED visits for respiratory and CVD from January 2014 through December 2017. TV effect sizes were estimated after controlling for long-term trends and seasonality, day-of-week, holidays, and daily mean relative humidity and ambient temperature.

RESULTS

A 1 °C increase in TV was associated with a 1.00% (95 %CI: 0.05%, 1.96%) increase in CVD ED visits at lag 0-1 days (TV_0-1) and a 2.77% (95 %CI: 0.24%, 5.20%) increase in respiratory ED visits at lag 0-7 days (TV_0-7). TV-CVD associations were larger in the monsoon and cold seasons. Respiratory ED visit associations varied by age, with older adults more affected by the TV across all seasons. A 1 °C increase in TV at lag 0-7 days (TV_0-7) was associated with a 7.45% (95 %CI: 2.33%, 12.57%) increase in respiratory ED visits among patients above 50 years of age.

CONCLUSION

This study provided novel and important evidence that cardio-pulmonary health in Dhaka is adversely affected year-round by day-to-day increases in TV, especially among older adults. TV is a key factor that should be considered in evaluating the potential human health impacts of climate change induced temperature changes.

Transmission of SARS-CoV-2 in the Population Living in High- and Low-Density Gradient Areas in Dhaka, Bangladesh

Community transmission of SARS-CoV-2 in densely populated countries has been a topic of concern from the beginning of the pandemic. Evidence of community transmission of SARS-CoV-2 according to population density gradient and socio-economic status (SES) is limited. In June−September 2020, we conducted a descriptive longitudinal study to determine the community transmission of SARS-CoV-2 in high- and low-density areas in Dhaka city. The Secondary Attack Rate (SAR) was 10% in high-density areas compared to 20% in low-density areas. People with high SES had a significantly higher level of SARS-CoV-2-specific Immunoglobulin G (IgG) antibodies on study days 1 (p = 0.01) and 28 (p = 0.03) compared to those with low SES in high-density areas. In contrast, the levels of seropositivity of SARS-CoV-2-specific Immunoglobulin M (IgM) were comparable (p > 0.05) in people with high and low SES on both study days 1 and 28 in both high- and low-density areas. Due to the similar household size, no differences in the seropositivity rates depending on the population gradient were observed. However, people with high SES showed higher seroconversion rates compared to people with low SES. As no difference was observed based on population density, the SES might play a role in SARS-CoV-2 transmission, an issue that calls for further in-depth studies to better understand the community transmission of SARS-CoV-2.

Poly- and Perfluorinated Alkyl Substances in Air and Water from Dhaka, Bangladesh

Bangladesh hosts extensive textile manufacturing, for some of which per- and polyfluorinated alkyl substances (PFAS) have been used to impart water and dirt repellency, among other things. Textile waste emissions to the atmosphere and discharge into rivers and other bodies of water could present a significant concern for human and ecosystem health, but there is little information on PFAS in Bangladesh. To assess the presence of ionic PFAS and their precursors in air and water from Dhaka, Bangladesh, polyethylene sheets were deployed for 28 days as passive samplers for neutral PFAS in outdoor air and water, while ionic PFAS were measured from discrete water grabs. Fluorotelomer alcohols (FTOHs) were detected at almost all sites in air and water; the most frequently detected compound was 6:2 FTOH, ranging from below instrumental detection limits (<IDL) to 70 ng m^-3 in air and from <IDL to -19 ng L^-1 in water. Of the ionic PFAS, perfluorobutanoic acid (PFBA), perfluorohexanoic acid, perfluorooctanoic acid, perfluorohexane sulfonic acid, and perfluorooctane sulfonic acid dominated in frequency of detection and magnitude, with concentrations ranging from 1.8 to 19.0 ng L^-1 in surface waters. The prevalence of 6:2 FTOH and PFBA across sites probably reflects their use in textile manufacturing and could indicate the industry's switch to shorter-chain PFAS alternatives. Environ Toxicol Chem 2022;41:334-342. © 2021 SETAC.

Nurses' knowledge, skills and preparedness for disaster management of a Megapolis: Implications for nursing disaster education

As frontline health caregivers, nurses must be adequately prepared to respond effectively to disasters. Therefore, it is necessary to assess nurses' disaster management capacity to know their preparedness levels, especially for a densely populated Megapolis like Dhaka, which is at high risk of disasters. Thus, the study aimed to examine Dhaka city nurses' knowledge, skills, preparedness (KSP) for disasters and explore the factors influencing the KSP levels. A self-explanatory descriptive survey questionnaire was developed adopting the Disaster Preparedness Evaluation Tool (DPET) in Bangla language for quantitative data collection. Following multistage sampling, 410 nurses' data were collected from eight hospitals in Dhaka city. The nurses in Dhaka city had moderate levels of knowledge, skills, and preparedness for disaster management, reflecting that they need more development to deal with disasters effectively. Moreover, multiple linear regression analyses indicate that nurses' disaster knowledge, skills, and preparedness scores were significantly positively associated with training on disaster management (p < 0.001) and disaster response experience (p < 0.001). In addition, one-half of the respondents demanded more drills and exercises on disaster management in their workplaces to enhance their disaster skills and preparedness. Furthermore, disaster education should be incorporated into the nursing curriculum, which would play a seminal role in preparing them for future disaster management.

Clinical spectrum and predictors of severity of dengue among children in 2019 outbreak: a multicenter hospital-based study in Bangladesh

BACKGROUND

The mosquito-borne arboviral disease dengue has become a global public health concern. However, very few studies have reported atypical clinical features of dengue among children. Because an understanding of various spectrums of presentation of dengue is necessary for timely diagnosis and management, we aimed to document the typical and atypical clinical features along with predictors of severity among children with dengue during the largest outbreak in Bangladesh in 2019.

METHODS

We conducted a cross-sectional study between August 15 and September 30, 2019. in eight tertiary level hospitals in Dhaka city. Children (aged < 15 years) with serologically confirmed dengue were conveniently selected for data collection through a structured questionnaire. Descriptive, inferential statistics, and multivariable logistic regression were used to analyze data.

RESULTS

Among the 190 children (mean age 8.8 years, and male-female ratio 1.22:1) included in the analysis, respectively 71.1 and 28.9% children had non-severe and severe dengue. All children had fever with an average temperature of 103.3 ± 1.2 F (SD). Gastrointestinal symptoms were the most common associated feature, including mostly vomiting (80.4%), decreased appetite (79.5%), constipation (72.7%), and abdominal pain (64.9%). Mouth sore, a less reported feature besides constipation, was present in 28.3% of children. Atypical clinical features were mostly neurological, with confusion (21.3%) being the predominant symptom. Frequent laboratory abnormalities were thrombocytopenia (87.2%), leucopenia (40.4%), and increased hematocrit (13.4%). Age (AOR 0.86, 95%CI 0.75-0.98, p = 0.023), mouth sore (AOR 2.69, 95%CI 1.06-6.96, p = 0.038) and a decreased platelet count (< 50,000/mm3) with increased hematocrit (> 20%) (AOR 4.94, 95%CI 1.48-17.31, p = 0.01) were significant predictors of severity.

CONCLUSIONS

Dengue in children was characterized by a high severity, predominance of gastrointestinal symptoms, and atypical neurological presentations. Younger age, mouth sores, and a decreased platelet with increased hematocrit were significant predictors of severity. Our findings would contribute to the clinical management of dengue in children.

Risk Areas for Influenza A(H5) Environmental Contamination in Live Bird Markets, Dhaka, Bangladesh

We evaluated the presence of influenza A(H5) virus environmental contamination in live bird markets (LBMs) in Dhaka, Bangladesh. By using Bernoulli generalized linear models and multinomial logistic regression models, we quantified LBM-level factors associated with market work zone–specific influenza A(H5) virus contamination patterns. Results showed higher environmental contamination in LBMs that have wholesale and retail operations compared with retail-only markets (relative risk 0.69, 95% 0.51–0.93; p = 0.012) and in March compared with January (relative risk 2.07, 95% CI 1.44–2.96; p<0.001). Influenza A(H5) environmental contamination remains a public health problem in most LBMs in Dhaka, which underscores the need to implement enhanced biosecurity interventions in LBMs in Bangladesh.

Dhaka landfill waste practices: addressing urban pollution and health hazards

Two Dhaka, Bangladesh, landfills are explored to understand how management practices impact environmental quality and public health in the surrounding areas. A combination of research methods is used, such as geospatial buffer zone analysis, semi-structured observation checklist and qualitative interviews, to gain an understanding of the waste transportation, leachate percolation, and adverse health and environmental effects. A multi-ring buffer zone and ground truth method were applied through ArcMap for the spatial distribution of landfill-adjacent environmental features. Qualitative interviews were conducted with landfill officials and nearby residents. Findings reveal that landfills are situated very close to residential areas, water bodies and agricultural lands, exposing them to various health and environmental hazards. Improper solid waste management practices of the landfills cause adverse environmental effects by leachate percolation, waste incineration and vector breeding. Adjacent dwellers suffer from bronchial diseases, pneumonia, diarrhoea, itching problems, headache and appetite loss. The existing solid waste management system requires managerial and technical modifications to reduce the associated environmental pollution and health hazards.

Insights into the first seven-months of COVID-19 pandemic in Bangladesh: lessons learned from a high-risk country

South Asian countries have been struggling to control the COVID-19 pandemic despite imposing months of lockdown and other public health measures. This review aims to describe the epidemiological features and shortcomings in public health preparedness to tackle COVID-19 as well as derive lessons from these events in the context of Bangladesh. We have shown that an increase in human mobility was evident throughout the lockdown period. Over 20,000 frontline health workers were affected, and more than 2100 unofficial deaths possibly linked with COVID-19 diagnosis were reported. Males were disproportionately affected in terms of infection (71%) and death (77%) than females. Over 50% of infected cases were reported among young adults (20-40-year age group). After seven months into the pandemic, a downward trend in laboratory test positive percentage was seen, although the number of new deaths per day remained largely unchanged. We believe our findings, observations and recommendations will remain as a valuable resource to facilitate better public health practice and policy for managing current and future infectious disease like COVID-19 in resource-poor developing countries.

Spatiotemporal patterns and trends of community transmission of the pandemic COVID-19 in South Asia: Bangladesh as a case study

South Asian (SA) countries have been fighting with the pandemic novel coronavirus disease 2019 (COVID-19) since January 2020. Earlier, the country-specific descriptive study has been done. Nevertheless, as transboundary infection, the border sharing, shared cultural and behavioral practice, effects on the temporal and spatial distribution of COVID-19 in SA is still unveiled. Therefore, this study has been revealed the spatial hotspot along with descriptive output on different parameters of COVID-19 infection. We extracted data from the WHO and the worldometer database from the onset of the outbreak up to 15 May, 2020. Europe has the highest case fatality rate (CFR, 9.22%), whereas Oceania has the highest (91.15%) recovery rate from COVID-19. Among SA countries, India has the highest number of cases (85,790), followed by Pakistan (38,799) and Bangladesh (20,065). However, the number of tests conducted was minimum in this region in comparison with other areas. The highest CFR was recorded in India (3.21%) among SA countries, whereas Nepal and Bhutan had no death record due to COVID-19 so far. The recovery rate varies from 4.75% in the Maldives to 51.02% in Sri Lanka. In Bangladesh, community transmission has been recorded, and the highest number of cases were detected in Dhaka, followed by Narayanganj and Chattogram. We detected Dhaka and its surrounding six districts, namely Gazipur, Narsingdi, Narayanganj, Munshiganj, Manikganj, and Shariatpur, as the 99% confidence-based hotspot where Faridpur and Madaripur district as the 95% confidence-based spatial hotspots of COVID-19 in Bangladesh. However, we did not find any cold spots in Bangladesh. We identified three hotspots and three cold spots at different confidence levels in India. Findings from this study suggested the "Test, Trace, and Isolation" approach for earlier detection of infection to prevent further community transmission of COVID-19.

Identification of factors influencing severity of motorcycle crashes in Dhaka, Bangladesh using binary logistic regression model

Dhaka, the capital and megacity of the developing country Bangladesh, has experienced a sharp rise in motorcycle users in the last decade, especially after the introduction of ridesharing services. Therefore, the morbidity and mortality rates of motorcycle crash injuries have also increased and become one of the major safety concerns. However, there is scant empirical evidence on motorcycle crash severity in the context of developing countries. Hence, this study was conducted to identify the factors that influenced the severity of motorcycle crashes in Dhaka. A binary logistic regression model was developed using motorcycle crash data of Dhaka over the period of 2006-2015 to identify the contributing factors of motorcycle crash severity. The model output showed that eleven factors significantly increased the probability of fatal motorcycle crashes. These factors were crashes occurring on weekends, during the rainy season, during dawn and night period, at non-intersections, on straight and flat roads, on highways, hit pedestrian type crashes, crashes involving motorcycles with no defect, crashes with heavier vehicles, crashes involving motorcyclists not wearing helmets, and drivers with alcohol suspicion. These findings would help to formulate prevention strategies to reduce the injury severity of motorcycle crashes in the developing countries.

Strategies to Connect Low-Income Communities with the Proposed Sewerage Network of the Dhaka Sanitation Improvement Project, Bangladesh: A Qualitative Assessment of the Perspectives of Stakeholders

In Bangladesh, approximately 31% of urban residents are living without safely managed sanitation, the majority of whom are slum residents. To improve the situation, Dhaka Water Supply and Sewerage Authority (DWASA) is implementing the Dhaka Sanitation Improvement Project (DSIP), mostly funded by the World Bank. This study assessed the challenges and opportunities of bringing low-income communities (LICs) under a sewerage connection within the proposed sewerage network plan by 2025. We conducted nine key-informant interviews from DWASA and City Corporation, and 23 focus-group discussions with landlords, tenants, and Community Based Organisations (CBOs) from 16 LICs near the proposed catchment area. To achieve connections, LICs would require improved toilet infrastructures and have to be connected to main roads. Construction of large communal septic tanks is also required where individual toilet connections are difficult. To encourage connection in LICs, income-based or area-based subsidies were recommended. For financing maintenance, respondents suggested monthly fee collection for management of the infrastructure by dividing bills equally among sharing households, or by users per household. Participants also suggested the government’s cooperation with development-partners/NGOs to ensure sewerage connection construction, operation, and maintenance and prerequisite policy changes such as assuring land tenure.

Assessing the PM2.5 impact of biomass combustion in megacity Dhaka, Bangladesh

In Dhaka, Bangladesh, fine particulate matter (PM_2.5) air pollution shows strong seasonal trends, with significantly higher mean concentrations during winter than during the monsoon (winter = 178.1 μg/m³ vs. monsoon = 30.2 μg/m³). Large-scale open burning of post-harvest agricultural waste across the Indo-Gangetic Plain is a major source of PM_2.5 air pollution in northern India during the non-monsoon period. This study evaluates the extent to which the seasonal differences in PM_2.5 pollution concentrations in Dhaka are accounted for by biomass-burning vs. fossil-fuel combustion sources. To assess this, an index was developed based on elemental potassium (K) as a marker for biomass particulate matter, after adjusting for soil-associated K contributions. Alternatively, particulate sulfur was employed as a tracer index for fossil-fuel combustion PM_2.5. By simultaneously regressing total PM_2.5 on S and adjusted K, the PM_2.5 mass for each day was apportioned into: 1) fossil-fuels combustion associated PM_2.5; 2) biomass-burning associated PM_2.5; and, 3) all other PM_2.5. The results indicated that fossil-fuel combustion contributed 21.6% (19.5 μg/m³), while biomass contributed 40.2% (36.3 μg/m³) of overall average PM_2.5 from September 2013 to December 2017. However, the mean source contributions varied by season: PM_2.5 in Dhaka during the monsoon season was dominated by fossil-fuels sources (44.3%), whereas PM_2.5 mass was dominated by biomass-burning (41.4%) during the remainder of the year. The contribution to PM_2.5 and each of its source components by transport of pollution into Dhaka during non-monsoon time was also evaluated by: 1) Conditional bivariate (CBPF) and pollution rose plots; 2) Concentration weighted trajectories (CWT), and; 3) NASA satellite photos to identify aerosol loading and fire locations on high pollution days. The collective evidence indicates that, while the air pollution in Dhaka is contributed to by both local and transboundary sources, the highest pollution days were dominated by biomass-related PM_2.5, during periods of crop-burning in the Indo-Gangetic Plain.

Factors influencing pedestrians' decision to cross the road by risky rolling gap crossing strategy at intersections in Dhaka, Bangladesh

Pedestrian road-crossing strategy is one of the most important pedestrian road-crossing behaviors. The safety of the pedestrians often depends on it. Among the road-crossing strategies, rolling gap crossing strategy is the riskiest one. The objective of this research was to explore the factors that influenced pedestrians' decision to cross the road by rolling gap crossing at intersection. Data regarding road-crossing strategy of the pedestrians, their characteristics, their road-crossing behavior, intersection geometry, and traffic environmental condition were collected through videography survey method, on-site observation, and secondary source from six intersections of Dhaka, Bangladesh. A binary logistic regression model was developed in this study by using the collected data. Results of the developed model showed that seven statistically significant factors strongly influenced pedestrians' decision to cross the road by rolling gap crossing at intersections. These factors were intersection control type, median width, vehicle flow, available gap on the road, age group of the pedestrians, their crossing group size, and their behavior of crosswalk usage. The results of this study would help the policymakers to take proper interventions to alleviate pedestrian safety problems.

Exploring the factors influencing pedestrian-vehicle crash severity in Dhaka, Bangladesh

Although the rate of road crashes and their severity is relatively higher in developing countries, there is still a lack of research on pedestrian-vehicle crash severity in these contexts, particularly in Bangladesh. Therefore, this study aimed to identify the contributing environmental, road, and vehicular factors that influenced pedestrian-single-vehicle crash severity in Dhaka, a megacity and the capital of Bangladesh. A binary logistic regression model was developed in this study by analyzing a data set of pedestrian-single-vehicle crashes involving casualties in Dhaka from 2010 to 2015. The model identified seven significant factors influencing pedestrian-vehicle crash severity. Significant factors increasing the likelihood of fatal crashes included crashes during adverse weather, dawn/dusk period, night period (where street light was absent), off-peak period, crashes where road divider was unavailable, road geometry was straight and flat, and crashes those were occurred by heavier vehicles. Besides, crashes at three-legged intersections were less likely to be fatal. Both similarities and differences were found among the significant factors influencing pedestrian-vehicle crash severity in Dhaka from the findings of the developed countries. The findings of this study would help transport engineers and planners to design safer roadways for both pedestrians and vehicles.

Association of Time since Migration from Rural to Urban Slums and Maternal and Child Outcomes: Dhaka (North and South) and Gazipur City Corporations

This study analyzes data from a new Urban Health and Demographic Surveillance (UHDSS) in five slums in Dhaka (North and South) and Gazipur City Corporations to examine the relationship between migration status and maternal and child health service utilization. Migration status was determined by duration in urban slums (<= 9.99 years, 10-19.99 years, 20+ years, and urban-born). Compared to those born in the city, migrants were characterized by significant disadvantages in every maternal, neonatal, and child health (MNCH) indicator under study, including antenatal care, facility-based delivery, doctor-assisted delivery, child immunization, caesarean-section delivery, and use of modern contraceptives. We found that the level of service coverage among migrants gradually converged-but did not fully converge-to that of the urban-born with increasing duration in the city. We observed a strong positive association between wealth and total MNCH coverage, with a more modest association with higher levels of schooling attainment. Women who were engaged in market employment were less likely to receive adequate coverage, suggesting a tradeoff between livelihood attainment and mother-and-child health. After controlling for these socioeconomic and neighborhood variations in coverage, the duration gradient was diminished but still significant. In line with existing studies of healthcare access, this study highlights the persistent and widespread burden of unequal access to maternal and child health care facing migrants to slum areas, even relative to the overall disadvantages experienced in informal settlements.

Tube Well Use as Protection Against Rotavirus Infection During the Monsoons in an Urban Setting

Rotavirus, a diarrheal pathogen spread via fecal-oral transmission, is typically characterized by a winter incidence peak in most countries. Unlike for cholera and other waterborne infections, the role of sanitation and socioeconomic factors on the spatial variation of rotavirus seasonality remains unclear. In the current study, we analyzed their association with rotavirus seasonality, specifically the odds of monsoon cases, across 46 locations from 2001 to 2012 in Dhaka. Drinking water from tube wells, compared to other sources, has a clear protective effect against cases during the monsoon, when flooding and water contamination are more likely. This finding supports a significant environmental component of transmission.

Co-circulation of dengue virus type 3-genotype I and type 2-Cosmopolitan genotype in 2018 outbreak in Dhaka, Bangladesh

Dengue virus (DENV) that caused an outbreak in Dhaka, Bangladesh during 2018 was analysed phylogenetically. DENV samples were classified into type 2-Cosmopolitan genotype (54%) and type 3-genotype I (46%), indicating co-circulation of two DENV types and resurgence of type 3 associated with genotype replacement.

East/Central/South African Genotype in a Chikungunya Outbreak, Dhaka, Bangladesh, 2017

In 2017, an unprecedented increase in febrile illness was observed in Dhaka, Bangladesh. Real-time reverse transcription PCR confirmed that 603 (40.2%) of 1,500 cases were chikungunya fever. Phylogenetic analysis revealed circulation of the non-A226V East/Central/South African genotype of chikungunya virus in Bangladesh.

Alarming Situation of Spreading Enteric Viruses Through Sewage Water in Dhaka City: Molecular Epidemiological Evidences

Global burden of acute viral gastroenteritis remains high, particularly in developing countries including Bangladesh. Sewage water (SW) is an important node to monitor enteric pathogens both in the environment and among the population. Analysis of SW in Dhaka city deems crucially important because a large number of urban-city dwellers live in Dhaka city, the capital of Bangladesh, under a constant threat of precarious sewerage system. In this study, we collected raw SW from five locations of Dhaka city every month from June 2016 to May 2017. It was concentrated with polyethylene glycol (PEG) and investigated for three major enteric viruses, rotavirus A (RVA), norovirus GII (NoV GII) and adenovirus (AdV) using polymerase chain reaction (PCR). Most of these SW samples collected from both hospitals and non-hospital areas yielded enteric viruses: 76% samples were positive for AdV, followed by 53% NoV GII and 38% RVA. Viral load was determined as much as 1 × 10⁷ copies/ml for RVA and 3.5 × 10³ copies/ml for NoV GII. Importantly, NoV GII and AdV that can affect people of all ages were predominated during monsoon also when SW overflows and spreads over a wide and crowded area. Genotypes G1, G2, G3, G8, and G9 for RVA, GII.4 for NoV, and type 41 for AdV were detected representing the current profile of circulating genotypes in the population. This study provides the first evidence of distribution of major diarrheal viruses in SW in Dhaka city which is alarming showing grave risk of impending outbreaks through exposure.

Clostridioides difficile ribotypes isolated from domestic environment and from patients in Bangladesh

Clostridioides difficile infection (CDI) is an emerging but often understudied infectious disease in developing countries. This study was aimed to isolate and characterize C. difficile from shoe sole swabs and diarrheal patient's stool samples in Bangladesh. We collected 94 shoe sole swabs samples from urban communities in Dhaka and 208 diarrheal stool samples from hospitalized patients over a period of 4 months. Samples were incubated anaerobically for C. difficile growth, confirmed toxigenic, and PCR-ribotyped. Eleven of 94 (11.7%) shoe sole swabs and 4 of 208 (1.9%) stool samples were culture positive of which 9 shoe sole isolates were toxigenic. Six PCR ribotypes from the 9 toxigenic isolates were identified with ribotype F014-020 being the most common (n = 4; 44%). The recently identified ribotype 106 strain was also identified. To the best of our knowledge, this is the first report of C. difficile culture, isolation and characterization from environmental sources in Bangladesh.

Uncovering the barriers to exclusive breastfeeding for mothers living in Dhaka's slums: a mixed method study

Background

Despite the substantial impact on child and maternal health, breastfeeding practices for infants remain at the suboptimum level in Bangladesh. Yet the understanding of why these practices are suboptimal, especially surrounding urban slum dwelling mothers, is unclear. The purpose of this study was to assess early infant feeding practices, examine associations with maternal factors, and uncover the facilitators and barriers to early feeding practices in selected slums of Dhaka, Bangladesh.

Methods

A mixed method study was conducted from June to September 2016 using both quantitative and qualitative methods among mothers with children under the age of 6 months. The survey included 342 mother-infant pairs and 18 in-depth interviews were conducted. Univariate and multiple logistic regression was used to determine status of early infant feeding practices and factors associated with exclusive breastfeeding (EBF) within the previous 24 h. Transcripts were coded to uncover the facilitators and barriers surrounding early infant feeding practices.

Results

Sixty four percent (220/342) of mothers initiated breastfeeding within 1 h, 96.5% (330/342) reported feeding colostrum, and 36.3% (124/342) infants were EBF in the last 24 h. After adjusting for child gender, maternal age, education, diet and household income; infant’s age (adjusted odds ratio (AOR) for 61–120 days 6.42; 95% CI 3.42, 12.1; AOR for 121–180 days 45.6; 95% CI 18.33, 113.45), prelacteal feeding (AOR 2.53; 95% CI 1.14, 4.58), lack of planning for EBF during pregnancy (AOR 4.06; 95% CI 1.09, 15.12) and infants delivered by cesarean section (AOR 2.76; 95% CI 1.34, 5.67) were negatively associated with EBF. During the 18 interviews, eight mothers reported a cesarean delivery and none of these mothers initiated breastfeeding within 1 h or exclusively breastfed. Moreover, all eight mothers gave their infants prelacteal feeds.

Conclusions

The status of early infant feeding practices in Dhaka’s slums was poor. The negative impact of cesarean section on all early infant feeding practices was evident in both quantitative and qualitative analysis.

Molecular characterization of chikungunya virus causing the 2017 outbreak in Dhaka, Bangladesh

Chikungunya viruses from the 2017 outbreak in Dhaka, Bangladesh, were analysed phylogenetically. E1 sequences from 21 strains belonged to the Indian Ocean clade of the East/Central/South African (ECSA) genotype, forming a novel cluster with latest South Asian strains. They lacked the A226V substitution.

Clinical profile, antibiotic susceptibility pattern of bacterial isolates and factors associated with complications in culture-proven typhoid patients admitted to an urban hospital in Bangladesh

OBJECTIVES

Typhoid fever is one of the major causes of morbidity and mortality in typhoid endemic countries like Bangladesh. However, data on the clinical and microbiological profile as well as factors associated with complications of typhoid in Bangladesh are scarce. We intended to characterise the clinical and microbiological profile of culture-proven typhoid fever and to identify factors associated with complications.

METHODOLOGY

Retrospective analysis of clinical data from 431 patients with culture-confirmed typhoid fever admitted to Dhaka hospital of International Centre for Diarrhoeal Disease Research, Bangladesh, between January 2010 and December 2014. Clinical and microbiological profiles of the patients including age, sex, and duration of illness prior to hospital admission, haematological parameters and the antimicrobial resistance profile of the infecting isolate, duration of hospital stay and defervescence time were examined by logistic regression to identify the factors associated with complications.

RESULT

About one of three patients were children under 5 years, and 21.5% of them were severely malnourished. During hospitalisation, 17.4% patients developed complications; mainly encephalopathy (6.7%), ileus (6.5%) and pneumonia (3.5%). Among culture-positive cases, 28.3% isolates showed multidrug resistant (MDR) and more than 90% of isolates were resistant to nalidixic acid and had intermediate sensitivity to ciprofloxacin. Five isolates were resistant to azithromycin; all isolates were sensitive to cefixime and ceftriaxone. Complication was independently associated with duration of fever before admission (adjusted odds ratio: 0.85; 95% CI: 0.074-0.97; P < 0.05), thrombocytopenia on admission (AOR: 2.84; 95% CI: 01.06-7.57; P < 0.05), duration of hospital stay (AOR: 1.34; 95% CI: 1.15-1.57; P < 0.01) and defervescence time (AOR: 0.83; 95% CI: 0.70-0.99; P < 0.05).

CONCLUSION

The high prevalence of typhoid fever among under-five children and complications among hospitalised patients are matters of concern. Sensitivity of Salmonella Typhi to ceftriaxone and cefixime was better than to other conventional antibiotics. Shorter duration of fever and thrombocytopenia on admission can be considered as early signs of complications.

Detection of enteric- and non-enteric adenoviruses in gastroenteritis patients, Bangladesh, 2012-2015

Human adenoviruses (HAdVs) are common cause of nonbacterial acute gastroenteritis worldwide. Limited data exist on HAdVs molecular epidemiology associated with acute gastroenteritis in Bangladesh. We describe the genetic diversity and epidemiology of HAdVs among hospitalized diarrhea patients, including HAdV genotypes, clinical symptoms, and co-infecting enteric pathogens. Stool samples were collected from ongoing diarrhea surveillance during 2012-2015. HAdV was detected using PCR and genotyped by sequencing and phylogenetic analysis. Detailed socio-demographic and clinical information regarding each individual was recorded such as duration of diarrhea, dehydration status, vomiting, abdominal pain, fever, and severity. Of 871 fecal specimens, HAdV DNA was detected in 93 (10.7%). Among them 56% were co-infected with other known enteric viral and bacterial pathogens and 31.6% had severe gastroenteritis. The majority (55%) of HAdV positives were children <5 years of age. Two main clinical symptoms in HAdV infected patients were diarrhea and vomiting. HAdVs were detected throughout the year with low prevalence in winter (November-January). Five HAdV species (A, B, C, D, and F) including 17 different genotypes were identified during the study period, with enteric HAdV species F (HAdV-40/41) being the most dominant. However, non-enteric HAdV were also detected in substantial proportion of specimens (15% species C, 15% species D, 10.8% species A, and 4.3% species B). Our study demonstrates high genetic diversity of HAdVs including enteric and non-enteric HAdVs among diarrhea patients and provides a foundation for further clarification of the role of non-enteric HAdVs in diarrheal diseases.

Migration, health, and socioenvironmental safety net among children of Dhaka, Bangladesh

This study quantifies the diarrhea burden among migrant children under age 5 (who have migrated due to environmental degradation) in Dhaka. We used a multifactor socioepidemiological as well as environmental approach with pretested questionnaires and observations. It was found that 52% of the children were affected by diarrhea. Disability-adjusted life years (DALYs) lost was reduced manifold with the increase of mothers' behavioral determinants. Health losses were 1,718 fold with significant coefficient (β) in the migrant group. DALYs lost were significantly associated with socioenvironmental factors such as mother's illiteracy (β = .18; p < .001), no hand wash before eating (β = .08; p = .004), and no hand wash after defecation (β = .10; p < .001). This puts emphasis clearly on the awareness at household level, especially of mothers and children under age 5 in Dhaka, Bangladesh, in formulating migration-related policies.

Chikungunya: an emerging viral infection with varied clinical presentations in Bangladesh: Reports of seven cases

Background

Chikungunya is an emerging and rapidly spreading viral infection in many parts of the world including Bangladesh. It shares many epidemiological and clinical characteristics with dengue. So, a sound knowledge is required for its detection and differentiation from dengue, specially in endemic regions.

Case presentation

We present seven confirmed cases of chikungunya having different clinical presentations occurring among middle aged males and females from different socio-economic background in Dhaka city, the capital of Bangladesh. All patients had fever and aches and pains. Less common features were rash, diarrhea, vomiting and altered liver biochemistry. Dengue was excluded in six patients. Paracetamol remained the mainstay of treatment during febrile periods, but over 50% of the patients had prolonged joint symptoms requiring non-steroidal anti-inflammatory drugs.

Conclusions

In spite of being a self-limiting disease, chikungunya may have different presentations and a protracted clinical course. During the febrile episode, exclusion of dengue is equally important. Physicians should be aware of the condition and public health initiatives are necessary to break the disease transmission.

Treatment outcome of children with persistent Diarrhoea admitted to an Urban Hospital, Dhaka during 2012-2013

BACKGROUND

Despite availability of treatment guidelines, persistent diarrhoea (PD) has been a major contributor of diarrhoeal deaths in low and middle income countries. We evaluated the outcome of children under the age of 5 years who were treated for PD using management algorithm with locally available foods in a diarrhoeal disease hospital in Dhaka.

METHODS

We extracted retrospective data from electronic database for all the under-five children admitted for PD in the Longer Stay Ward and Intensive Care Unit of the Dhaka hospital at icddr,b between 2012 and 2013. Descriptive analysis was done to explore available baseline socio-demographic, nutritional, and co-morbid statuses, pathogens from stool isolates, duration of treatment, use of antibiotics, duration of hospital stay and treatment success rates. We sought to investigate above mentioned descriptive features in addition to associated factors with time to recover from PD using survival analysis with Cox proportional hazard model.

RESULTS

A total number of 426 children with a median age of 7.46 (inter-quartile range IQR; 5.39, 9.43) months were admitted for PD during the study period. Of these, 95% of children were recovered from PD and discharged from the hospital. The median duration of treatment response was 6 (IQR 4, 9) days. The case fatality rate was 1.17%. Multivariate analysis among the children of 6 months or less showed that the rate of recovery from PD was 57% lower in children with severe stunting compared to those without severe stunting (HR 0.43, 95% CI 0.22, 0.88, p < 0.05), 42% lower in children with severe wasting (HR 0.58, 95% CI 0.36, 0.95, p < 0.05), and 81% reduced in children who developed hospital acquired infection (HAI) compared to those without HAI (HR 0.19, 95% CI 0.06, 0.62, p < 0.05). Among the children who were more than 6 months old, age in months (HR 1.05, 95% CI 1.02, 1.09) and female gender (HR 1.41, 95% CI 1.09, 1.84) had better rates of recovery from PD (p < 0.05). Moreover, among children more than 6 months of age, HAI (HR 0.44, 95% CI 0.26, 0.75), and antibiotic use (HR 0.40, 95% CI 0.28, 0.56) were associated with impeded recovery rates from PD (p < 0.05).

CONCLUSION

The treatment guideline for persistent diarrhoea patients followed at icddr,b Dhaka hospital was found to be successful and can be used in other treatment facilities of Bangladesh and other developing countries where any treatment algorithm for PD is unavailable. More emphasis is required to be given for the prevention of hospital acquired infection that may help to limit the use of antibiotic in order to enhance the recovery rate from PD.

Socio-demographic characteristics and tobacco use among the adults in urban slums of Dhaka, Bangladesh

BACKGROUND

Use of tobacco has become one of the major causes of premature deaths in most developing countries, including Bangladesh. The poorest and most disadvantaged populations, such as those living in slums, are considered to be extremely vulnerable to non-communicable diseases and their risk factors, especially tobacco use. The objective of this study was to assess the current status of tobacco consumption among slum dwellers and its association with socio-demographic factors.

METHODS

A cross-sectional study was conducted in three slums of Dhaka city. Information about tobacco use as well as socio-demographic characteristics was collected from adult slum dwellers via face to face interviews using WHO STEPS questionnaire.

RESULT

Overall proportion of smoking, smokeless tobacco consumption and dual use of tobacco was 35% [95% CI: 31.6-39.8], 40.6% [95% CI: 36.5-45.2] and 12% [95% CI: 9.3-15.0] respectively. Elderly people (55-64 years) were more likely to smoke (OR: 2.34, 95% CI: 1.21-4.49) than younger people (aged 25-34 years). On the other hand, those who had no schooling history (OR: 2.95, 95% CI: 1.66-5.25) were more likely to consume smokeless tobacco than those who had higher education (secondary or above). At the same time, manual workers were more likely to indulge in dual use of tobacco (OR: 5.17, 95% CI: 2.82-9.48) as compared to non-manual workers.

CONCLUSION

The urban slum population of Dhaka city has a high prevalence of tobacco use, which increases their likelihood of developing non-communicable diseases. Proper attention needs to be directed towards addressing the risk factors related to non-communicable diseases within this vulnerable population.

Bacterial etiology of bloodstream infections and antimicrobial resistance in Dhaka, Bangladesh, 2005-2014

Background

Bloodstream infections due to bacterial pathogens are a major cause of morbidity and mortality in Bangladesh and other developing countries. In these countries, most patients are treated empirically based on their clinical symptoms. Therefore, up to date etiological data for major pathogens causing bloodstream infections may play a positive role in better healthcare management. The aim of this study was to identify the bacterial pathogens causing major bloodstream infections in Dhaka, Bangladesh and determine their antibiotic susceptibility pattern.

Methods

From January 2005 to December 2014, a total of 103,679 single bottle blood samples were collected from both hospitalized and domiciliary patients attending Dhaka hospital, icddrb, Bangladesh All the blood samples were processed for culture using a BACT/Alert blood culture machine. Further identification of bacterial pathogens and their antimicrobial susceptibility test were performed using standard microbiological procedures.

Results

Overall, 13.6% of the cultured blood samples were positive and Gram-negative (72.1%) bacteria were predominant throughout the study period. Salmonella Typhi was the most frequently isolated organism (36.9% of samples) in this study and a high percentage of those strains were multidrug-resistant (MDR). However, a decreasing trend in the S. Typhi isolation rate was observed and, noticeably, the percentage of MDR S. Typhi isolated declined sharply over the study period. An overall increase in the presence of Gram-positive bacteria was observed, but most significantly we observed the percentage of MDR Gram-positive bacteria to double over the study period. Overall, Gram positive bacteria were more resistant to most of the commonly used antibiotics than Gram-negative bacteria, but the MDR level was high in both groups.

Conclusions

This study identified the major bacterial pathogens involved with BSI in Dhaka, Bangladesh and also revealed their antibiotic susceptibility patterns. We expect our findings to help healthcare professionals to make informed decisions and provide better care for their patients. Also, we hope this study will assist researchers and policy makers to prioritize their research options to face the future challenges of infectious diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13756-016-0162-z) contains supplementary material, which is available to authorized users.

Monitoring of metal pollution in waterways across Bangladesh and ecological and public health implications of pollution

Using innovative artificial mussels technology for the first time, this study detected eight heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, U, Zn) on a regular basis in waterways across Bangladesh (Chittagong, Dhaka and Khulna). Three heavy metals, viz. Co, Cr and Hg were always below the instrumental detection levels in all the sites during the study period. Through this study, seven metal pollution "hot spots" have been identified, of which, five "hot spots" (Cu, Fe, Mn, Ni, Pb) were located in the Buriganga River, close to the capital Dhaka. Based on this study, the Buriganga River can be classified as the most polluted waterway in Bangladesh compared to waterways monitored in Khulna and Chittagong. Direct effluents discharged from tanneries, textiles are, most likely, reasons for elevated concentrations of heavy metals in the Buriganga River. In other areas (Khulna), agriculture and fish farming effluents may have caused higher Cu, U and Zn in the Bhairab and Rupsa Rivers, whereas untreated industrial discharge and ship breaking activities can be linked to elevated Cd in the coastal sites (Chittagong). Metal pollution may cause significant impacts on water quality (irrigation, drinking), aquatic biodiversity (lethal and sub-lethal effects), food contamination/food security (bioaccumulation of metals in crops and seafood), human health (diseases) and livelihoods of people associated with wetlands.

Impacts of policy and market incentives for solid waste recycling in Dhaka, Bangladesh

Solid waste mismanagement in Dhaka, Bangladesh, illustrates a well-known market failure which can be summarized as: waste is a resource in the wrong place. Inorganic materials such as plastic or paper can be used to feed the demand for recycled materials in the industrial sector. Organic materials can be converted and used in the nutrient-starved agricultural sector which is currently heavily depending on chemical fertilizers. They are also a feedstock to generate renewable energy in the form of biogas for this energy-starved country relying on diminishing natural gas reserves and increasing import of coal. Reality however does not capitalize on this potential; instead the waste is a burden for municipal authorities who spend large portions of their budgets attempting to transport it out of the city for discharge into landfills. The major part of these materials still remains uncollected in the residential areas and is discarded indiscriminately in open spaces, polluting the residents' living environment including water, soil and air resources, in the city and beyond. Bangladeshi authorities have, to some extent, recognized this market failure and have developed policies to encourage the development of waste recycling activities. It is also important to note that this market failure is only partial: a large, mostly informal recycling sector has developed in Bangladesh, focusing on inorganic recyclables of market value. The fact that this sector remains largely informal means that these actors perceive significant barriers to formalization. Comparatively, the organic waste recycling sector is less driven by market mechanisms. Competition from chemical fertilizers and fossil fuels is fierce and hinders the development of market opportunities for compost and renewable energy. Nevertheless commercial production of compost and biogas from organic municipal waste is formalized and benefiting from policy incentives.

Projecting the impact of climate change on dengue transmission in Dhaka, Bangladesh

Weather variables, mainly temperature and humidity influence vectors, viruses, human biology, ecology and consequently the intensity and distribution of the vector-borne diseases. There is evidence that warmer temperature due to climate change will influence the dengue transmission. However, long term scenario-based projections are yet to be developed. Here, we assessed the impact of weather variability on dengue transmission in a megacity of Dhaka, Bangladesh and projected the future dengue risk attributable to climate change. Our results show that weather variables particularly temperature and humidity were positively associated with dengue transmission. The effects of weather variables were observed at a lag of four months. We projected that assuming a temperature increase of 3.3°C without any adaptation measure and changes in socio-economic condition, there will be a projected increase of 16,030 dengue cases in Dhaka by the end of this century. This information might be helpful for the public health authorities to prepare for the likely increase of dengue due to climate change. The modelling framework used in this study may be applicable to dengue projection in other cities.