Megacity Dhaka Research Articles

Particulate Matter Emissions at Different Microenvironments Using Low-Cost Sensors in Megacity Dhaka, Bangladesh

Particulate Matter Emissions at Different Microenvironments Using Low-Cost Sensors in Megacity Dhaka, Bangladesh

Climate-resilient urban drainage planning: An approach using a GIS-based SCS-CN model

ABSTRACT Inexorable urbanization continues apace across the world and urban flooding in megacities is now frequently evidenced due to extreme rainfall events due to climate change (CC). Climate-resilient urban drainage planning is critical towards making sustainable cities or any new urbanization. This paper presents an approach through an insightful assessment of climate resilient urban drainage applying GIS-based Soil Conservation Service-Curve Number (SCS-CN) model of a new urban growth of megacity Dhaka, Bangladesh. A precise DEM (Digital Elevation Model) of the study area has been used for catchment delineation using ArcSWAT. Localized climate anomalies of rainfall of around 11% have been identified during monsoon from statistical downscaling and included in the cumulative rainfall event of 5 days. The effect of historical and CC-induced rainfall have been used to identify and map the peak discharges of sub-catchments considering the return period of 5-day cumulative rainfall for 10, 25, and 100 years of the urban catchment for both existing and future land-use scenarios accounting for the change in CN. The varying results of the peak discharges of the sub-catchments for resilient drainage planning is not only dependent on the increase in rainfall but also the combined response of the land-use and soil profile.

Exposure of polychlorinated biphenyls via indoor dust particles and their health risks in Dhaka City, Bangladesh

This study is a pioneer evaluation of Polychlorinated Biphenyls (PCBs) within the indoor environment of the megacity Dhaka, Bangladesh. It assessed the occurrence, distribution and associated human health risks of selected 6 PCB congeners in four types of buildings (commercial, industrial, institutional, and residential). Dust samples were collected from the air conditioner filters and subsequently analyzed by Gas Chromatography- Electron Capture Detector (GC-ECD). ∑6 PCB concentrations in commercial, industrial, institutional, and residential buildings ranged from 168 ± 59.42 to 3419 ± 1307, 590 ± 217 to 4669 ± 1731, 244 ± 89.08 to 2538 ± 779, and 161 ± 60.54 to 5413 ± 2136 ng/g, respectively. Considering the total PCB loads from each building type, the industrial category revealed the maximum concentration (19176 ± 1141 ng/g), followed by commercial, residential, and institutional, meaning industrial buildings are more susceptible to PCBs exposure. The heavy PCBs (hexa- and hepta-CBs) were dominant over the light PCBs (di-, tri-, and tetra-CBs). All hazard index (HI) values, except PCB-180, were below 1, suggesting a lower risk of non-carcinogenic effect. The incremental lifetime cancer risk (CR) values were below 10−03, indicating no high carcinogenic risk of the human population from PCB-contaminated dust through the exposure routes.

Development at the cost of unsustainable degradation of wetlands: Unraveling the dynamics (historic and future) of wetlands in the megacity Dhaka

Despite the recognized role of wetlands in providing ecological benefits for human wellbeing, ∼70% of global wetland ecosystems have been destroyed since the 1990s. Further intensive studies revealed that 3.4 million km2 of natural wetland has declined since 1700. In particular, wetland habitats in the world's megacities have been replaced unsustainably by faster economic, urban, and population growth, and have received less attention in research and policy. However, wetlands degradation in the megacities of developing countries is not quantified and the trends of Land Surface Temperature (LST) are not well understood. Therefore, we are making our first attempt to unravel the historical and future spatiotemporal dynamics of wetlands and the trends of LST in the megacity of Dhaka. The results show that Dhaka lost ∼69% of wetlands and LST has increased between 3.44°C and 9.35°C from 1990 to 2020. An environmental Kuznets curve analysis implies that the point has not yet been reached for wetlands when economic development feeds back to the sustainability of the environment. This assumption coincides with our model-based prediction, as respectively ∼74% and ∼90% of wetlands area of Dhaka city will be decreased by 2050 in Business as Usual (BAU) and development scenarios, whereas, ∼66% of wetlands area will be decreased under conservation scenario over the time period of next 30 (2020 to 2050) years. Our findings suggest that it will be incredibly challenging to restore wetlands to their 1990s condition. Efforts to preserve them should be made, as they potentially provide a nature-based alternative for coping with wetland sustainability and climate change.

The differential impacts of the spatiotemporal vertical and horizontal expansion of megacity Dhaka on ecosystem services

The relationship between ecosystem services (ES) and urbanization is crucial for sustainable development. Rapid urbanization threatens the natural capital of Dhaka city, affecting the delivery of ES through changes in land use and land cover. We used vertical growth (VG), nighttime light data (NTL), and population density (PD) as standard urbanization indicators alongside technomass, a three-dimensional indicator, to evaluate the degree of urbanization as a continuous spatial process. We modeled the spatiotemporal relationships between urbanization degrees and ES using the ecosystem service value (ESV) dataset applied in Dhaka, with regional modified value coefficients. Results from the geographically weighted regression (GWR) model showed that technomass emerged as a more appropriate indicator to analyze urbanization for ESV analysis (r > 0.61), followed by NTL (r > 0.56), and PD (r > 0.54) across all zones from 2000 to 2021. We observed a 68.34% decrease in net ESV, equivalent to $245.88 million (in 2021 USD), from 2000 to 2021. This decline was driven by the conversion of water bodies (−70.93%), agricultural land (−60.08%), forest and vegetation (−70.18%) into urban built-up areas and other uses. In contrast, net technomass increased by 243.11% due to the city's vertical growth. The digital building height (DBH) model revealed that the built-up area had expanded by 94.94% over the study period, with an average annual growth rate of 4.52%. Significant correlations (p < 0.05) were observed between ES and urbanization. The rural-urban fringe area exhibited the most significant increase in urbanization (r > 0.90), along with a 440.47% growth in technomass. Our results provide insights into the impact of urbanization on ES, particularly at the regional scale, and have highlighted the importance of integrating VG and technomass for urbanization analysis. These findings could be useful for environmental management, policymaking, spatial planning, and coordinating future ES protection and urban development.

Mothers’ dietary diversity and associated factors in megacity Dhaka, Bangladesh

Mothers in developing countries are nutritionally vulnerable due to an undiversified diet. Dietary diversity and healthy dietary patterns of mothers are necessary for the health and nutrition of both the mother and the child. Keeping these in mind, the study was designed to investigate the determinants of mothers' dietary diversity in the capital city (Dhaka) of Bangladesh. A total 613 mothers who had at least one child aged 6–59 months were surveyed in 2020. Dietary diversity (DD) was measured by 24 h recall period following the established guidelines. To explore the determinants of dietary diversity, a log linear regression model was employed. The findings revealed that the overall DD of mothers was low, with less than 15% of respondents consuming more than 5 of the 9 food groups. The study found that if a mother receives one more year of formal education, her DD, on average, would increase by 0.70%. Receiving antenatal care (ANC) for four or more times during pregnancy increases DD by 5.13% compared to mothers who receive ANC less than four times. The findings also showed that mothers with access to assets have 10.18% higher DD than mothers without access to assets. On the other hand, mothers' employment status was negatively associated with DD. Redistributing the household workload between mother and other household members can play a critical role in increasing mothers’ DD. Providing care facilities and counseling to mothers about the nutritional value of consuming different food groups can substantially improve the situation.

A study on measuring the 222Rn in the Buriganga River and tap water of the megacity Dhaka.

Radon (222Rn), an inert gas, is considered a silent killer due to its carcinogenic characteristics. Dhaka city is situated on the banks of the Buriganga River, which is regarded as the lifeline of Dhaka city because it serves as a significant source of the city's water supply for domestic and industrial purposes. Thirty water samples (10 tap water from Dhaka city and 20 surface samples from the Buriganga River) were collected and analyzed using a RAD H2O accessory for 222Rn concentration. The average 222Rn concentration in tap and river water was 1.54 ± 0.38 Bq/L and 0.68 ± 0.29 Bq/L, respectively. All the values were found below the maximum contamination limit (MCL) of 11.1 Bq/L set by the USEPA, the WHO-recommended safe limit of 100 Bq/L, and the UNSCEAR suggested range of 4-40 Bq/L. The mean values of the total annual effective doses due to inhalation and ingestion were calculated to be 9.77 μSv/y and 4.29 μSv/y for tap water and river water, respectively. Although all these values were well below the permissible limit of 100 μSv/y proposed by WHO, they cannot be neglected because of the hazardous nature of 222Rn, especially considering their entry to the human body via inhalation and ingestion pathways. The obtained data may serve as a reference for future 222Rn-related works.

Abundance, distribution and composition of microplastics in sediment and fish species from an Urban River of Bangladesh

Microplastics (MPs) are a growing concern due to its ubiquitous presence and exceptional stability. We examined the abundance, dispersion, and attributes of MPs in the sediment and fish species of the Turag River in Bangladesh, which separated the industrial city Gazipur from the Mega-city Dhaka. Collected samples were digested and the chemical structure was identified using ATR-FTIR spectroscopy. The concentration of MPs in the sediment ranged from 10 to 35 particles kg−1, with a mean abundance of 19.2 ± 2.44 particles kg−1and MPs of the fragment type account for 34 % of all. The majority of MPs were discovered in the 3-5 mm size range. MPs concentrations in freshwater fish gut from the Turag River ranged from 0.63 ± 0.18 to 7.0 ± 1.1 microplastics individual−1. Fiber was found to be the most commonly ingested MPs type (43 %), followed by fragments (41 %), film (12 %), and foam (4 %). The most common type of MPs was transparent (34 %) followed by red (28 %), white (20 %), green (9 %) and black (8 %). The results showed that demersal (1.87 ± 0.39 items individual−1) and benthopelagic (1.5 ± 0.26 items individual−1) fish species had more MPs than pelagic fish (0.63 ± 0.18 items individual−1) species. Polypropylene (PP) was found to be the most dominant polymer type in the sediment sample, and PS (39 %) in the fish sample. Polyethylene (PE) was discovered to be 30 % and PP 25 % in sediment and fish samples, respectively. Other commonly detected polymer types include polyamide (PA), polystyrene (PS), cellulose acetate (CA), and polyethylene terephthalate (PET). In different sampling sites along the Turag River, the pollution load index (PLI) of MPs contamination was found to be in the risk level category I. The PLI values reflected the city's anthropogenic influence. The findings of the study could be used to establish a baseline for MPs pollution in Bangladesh's vast freshwater ecosystem.

Risk assessment of naturally occurring radioactivity in soil adjacent to a coal-fired brick kiln

Being aware of the potential health effects brought on by exposure to radionuclides, besides chemical and air pollution, produced by coal-fired brick kilns, first-ever measurements of terrestrial radionuclides were performed in the topsoil sampled from the surrounding of a randomly chosen coal-fired brick kiln operating at the outskirts of megacity Dhaka, Bangladesh. By employing the HPGe gamma-ray spectroscopy, the activity concentrations of 226Ra, 232Th, and 4 K was found to be in the range of (19.2 ± 2.7–54 ± 7.0) Bq/kg, (33 ± 5.3–68 ± 9.5) Bq/kg, and (360 ± 43–540 ± 65) Bq/kg respectively, where almost all the values of 40 K, 232Th; and some of the values of 226Ra exceeded the corresponding world average values. Possible causes of the elevated level of radionuclides include the deposition of bottom ash in lowlands, the accumulation of fly ash in soils, and the fallout of fine particles that absorb the minerals released from the coal burning process. 137Cs was also found in two samples that might indicate contamination of the feed coal. Most of the outdoor absorbed dose rates, some internal absorbed dose rates, annual effective dose, gamma level index and excess lifetime cancer risk surpass the worldwide average. According to these hazard parameters, there are health risks to the brick kiln workers and the populace who consumes food crops produced in the studied agricultural soils. The present quantitative measurements urge the municipal authorities to manage and monitor the discharge of fly ash from the brick kilns and take precautionary actions to reduce unwanted health hazards. It also demands to monitor of the human health of workers and residents near the brick kilns.

NORMs distribution in the dust samples from the educational institutions of Megacity Dhaka, Bangladesh: Radiological risk assessment

This study demonstrates the specific radioactivities of primordial radionuclides in dust samples collected from educational institutions of the megacity Dhaka, Bangladesh. Elemental levels from neutron activation analysis were converted into the corresponding radioactivity. Meann=26 radioactivity abundances of 226Ra, 232Th, and 40K (NORMs: Naturally Occurring Radioactive Materials) in the dust sample were 28.6, 43.8, and 462 Bq.kg−1, respectively, where 232Th and 40K activities were relatively higher compared to the corresponding world mean values (232Th: 30 Bq.kg−1, and 40K: 400 Bq.kg−1). Alterations in NORMs abundances compared to the source materials (surface soil) were explained in terms of weathering followed by aerodynamic transportation. Calculation of usual radiological indices invokes human health hazards. Considering the higher vulnerability of school going children and juveniles towards ionizing radiations and the entrance of NOMRs-containing dust particles into the respiratory system, the estimated radiological indices only demonstrate the possible lowest risks. But in a real scenario, alpha particles from the decay series of 238U and 232Th can cause severe radiation damage to the human respiratory system.

Unpacking the environmental movement in megacity Dhaka: how does the resource mobilisation theory explain local urban complexity?

ABSTRACT In the Global South, urban policies are heavily influenced by colonial heritages, and people often experience citizens-detached urban development initiatives. The environmental movement is seen as a new addition that might contribute to society’s efforts to achieve equal urban environmental opportunities. The geographical focus of this article is the megacity Dhaka, which is the social, political, and economic capital of Bangladesh. Unfortunately, this hyper-urbanised megacity suffers from a large poverty-stricken population, leading to a gap in environmental services between the poor and rich. In recent years, Dhaka has experienced a growing momentum with the environmental movement, demanding environmental rights and justice. Based on long-term empirical research, this article shows that even though local marginalised people were the key agents of environmental protests and demonstrations, the movements are usually initiated by very small and relatively homogenous social and political elites, who share the common social, cultural, economic, and political identities.

Dhaka city drivers’ community knowledge, attitude and practice on water, sanitation and hygiene and associated factors: a descriptive cross-sectional study

Background: Water, sanitation and hygiene (WASH) is to consider the first step to improving the public health of urban people. Primary health-related risk factors are largely induced by urban people's daily WASH practice and this is the leading cause of mortality and disability-adjusted life-years (DALYs) globally. About 28% of Bangladeshi people are living in urban areas and the megacity Dhaka accounts for around 40% of the urban population. In this explanatory research, we explored the knowledge, attitude and practice on WASH and associated factors of drivers’ communities in Dhaka, Bangladesh.Methods: The study was an observational descriptive cross-sectional study and both quantitative and qualitative data were collected. The study was conducted between 03 September 2020, and 28 February 2021. A total of 109 drivers, 8 focus group discussions (FGDs) and 8 key informant interviews (KIIs) were also conducted.Results: The vast majority of drivers were middle age and a few were younger. The vast majority of drivers were experienced and the current job duration was about 7.94±8.33 years. The majority of drivers usually passed leisure time by playing ludo, chess, carrom, cards, chatting online on Facebook (FB), watching the drama on YouTube, watching television (TV), hearing radio programs and gossiping with colleagues. Two-third of the drivers disposing of food waste in the dustbin, and one-third kept inside the vehicle aiming to dispose of it dustbin although some of them throw it into the street.Conclusions: Study findings suggested that there is a need to create WASH facilities and intensive campaigns on hygiene and sanitation to create awareness among aged drivers to practice health and hygiene during duty hours.

IMPACT OF TRANSPORTATION NETWORK COMPANY (TNC) SERVICES ON OTHER MODES: THE CASE OF DHAKA, BANGLADESH

Widespread popularity of TNC services has significantly changed the realm of urban transportation. This study presents an empirical investigation of the impact of TNC services on the other conventional modes in megacity Dhaka, the capital of the developing country Bangladesh. For this study, multinomial logit models have been developed using data collected from household travel survey. The no TNC scenario information has been collected by asking the respondents about their preferred mode for a similar kind of trip in a no TNC scenario when a trip made by TNC has been found. This study has found that TNC services are drawing passengers mostly from the CNGs. The finding is actually similar to several other researchers who concluded that TNCs are actually competing with taxi services in the cities of the first world countries. Considering the nature of these CNG vehicles, they can be compared to the taxi services of the first world countries. This study has also found comparatively higher impact of TNCs on public transit than many other studies.

Road dust-driven elemental distribution in megacity Dhaka, Bangladesh: environmental, ecological, and human health risks assessment.

Road dust, which reflects ambient air quality, receives various pollutants including toxic metal(oid)s from several natural and/or anthropogenic sources. This manuscript reports a comprehensive evaluation of the levels of seventeen metal(oid)s in road dust of a megacity (Dhaka, Bangladesh). Different evaluation approaches were implemented including statistical analysis and GIS mapping, besides environmental, ecological, and human health risk indices. From 30 sampling sites, representative samples were collected, which were analyzed by neutron activation analysis. The average concentrations (± SD) of Na, Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Rb, Sb, Cs, Ba, and W were 11,738 ± 560µgg-1, 12,410 ± 1249µgg-1, 62,127 ± 5937µgg-1, 8.89 ± 0.47µgg-1, 5224 ± 1244µgg-1, 66 ± 8µgg-1, 66.7 ± 6.9µgg-1, 547 ± 110µgg-1, 25,150 ± 1723µgg-1, 8.39 ± 0.65µgg-1, 125 ± 17µgg-1, 3.63 ± 0.56µgg-1, 87 ± 9µgg-1, 0.75 ± 0.28µgg-1, 4.40 ± 0.48µgg-1, 397 ± 87µgg-1, and 3.82 ± 1.77µgg-1, respectively. The distance-based redundancy analysis showed that the northern region was enriched with Na, Mn, Al, Fe, Zn, and Rb, while the southern region was enriched with Fe, Al, Ti, Cr, and Mg. The GIS mapping shows hot spots of Sc, Cr, Zn, and Cs were observed mostly in heavy traffic areas. Significant positive correlations of Fe-Sc, Al-Mg, V-Mg, V-Al, Cs-Rb, Cs-Sc, Rb-Sc, As-Na, and Cs-Rb invoked their inter-dependency and persistence in road dust. Depending on a set of environmental and ecological index-based calculation, the degree of metal(oid) pollution followed the descending order as W > Sb > Zn > Cr > As > Ti > Sc > V, while no pollution was recorded by Mn, Fe, Al, Rb, Cs, Co, and Ba. Importantly, the total hazard index values for adults and children were higher than unity, indicating potential non-carcinogenic health risks from exposure of road dust. Furthermore, the total carcinogenic risks from Cr and As through ingestion and dermal contact exceeded the standard guideline values. The implementation of different evaluation approaches strengthens the findings of metal(oid) source apportionment.

Environmental Exposure to Metals and Metalloids in Primary School-Aged Children Living in Industrialised Areas of Eastern South Asian Megacity Dhaka, Bangladesh

Environmental Exposure to Metals and Metalloids in Primary School-Aged Children Living in Industrialised Areas of Eastern South Asian Megacity Dhaka, Bangladesh

Wintertime Air Quality in Megacity Dhaka, Bangladesh Strongly Affected by Influx of Black Carbon Aerosols from Regional Biomass Burning.

Clean air is a key parameter for a sustainable society, and currently, megacity Dhaka has among the worst air qualities in the world. This results from poorly constrained contributions of a variety of sources from both local emissions and regional influx from the highly polluted Indo-Gangetic Plain, impacting the respiratory health of the 21 million inhabitants in the Greater Dhaka region. An important component of the fine particulate matter (PM2.5) is black carbon (BC) aerosols. In this study, we investigated the combustion sources of BC using a dual carbon isotope (δ13C and Δ14C) in Dhaka during the high-loading winter period of 2013/14 (regular and lockdown/hartal period) in order to guide mitigation policies. On average, BC (13 ± 6 μg m-3) contributed about 9% of the PM2.5 (145 ± 79 μg m-3) loadings. The relative contribution from biomass combustion under regular conditions was 44 ± 1% (with the rest from fossil combustion), while during periods of politically motivated large-scale lockdown of business and traffic, the biomass burning contribution increased to 63 ± 1%. To reduce the severe health impact of BC and other aerosol pollution in Dhaka, mitigation should therefore target regional-scale biomass/agricultural burning in addition to local traffic.

Physarum-Inspired Bicycle Lane Network Design in a Congested Megacity

Improvement of mobility, especially environment-friendly green mobility, is challenging in existing megacities due to road network complexity and space constraints. Endorsing the bicycle lane network (BLN) in congested megacities is a promising option to foster green mobility. This research presents a novel bioinspired network design method that considers various constraints and preferences related to the megacity for designing an optimal BLN. The proposed method is inspired by natural Physarum polycephalum, a brainless, multi-headed single-celled organism, which is capable of developing a reticulated network of complex foraging behaviors in pursuit of food. The mathematical model of Physarum foraging behavior is adapted to maneuver various BLN constraints in megacity contexts in designing the optimal BLN. The Physarum-inspired BLN method is applied to two case studies on the megacity Dhaka for designing BLNs: the first one covers congested central city area, and the second one covers a broader area that includes major locations of the city. The obtained BLNs were evaluated comparing their available routes between different locations with the existing vehicle routes of the city in terms of distance and required travel times in different time periods, and the BLN routes were found to be suitable alternatives for avoiding congested main roads. The expected travel time using BLNs is shorter than other transport (e.g., car and public bus); additionally, at glance, the average travel speed on BLNs is almost double that of public buses in peak hours. Finally, the designed BLNs are promising for environment-friendly and healthy mobility.

Impact of COVID-19 on PM2.5 Pollution in Fastest-Growing Megacity Dhaka, Bangladesh.

The purpose of the research was to investigate and identify the impact of COVID-19 lockdown on fine particulate matter (PM2.5) pollution in Dhaka, Bangladesh by using ground-based observation data. The research assessed air quality during the COVID-19 pandemic for PM2.5 from January 1, 2017 to August 1, 2020. The research considered pollution in pre-COVID-19 (January 1 to March 23), during COVID-19 (March 24 to May 30), and post-COVID-19 (May 31 to August 1) lockdown periods with current (2020) and historical (2017-2019) data. PM2.5 pollution followed a similar yearly trend in year 2017-2020. The average concentration for PM2.5 was found 87.47 μg/m3 in the study period. Significant PM2.5 declines were observed in the current COVID-19 lockdown period compared with historical data: 11.31% reduction with an absolute decrease of 7.15 μg/m3. The findings of the research provide an overview of how the COVID-19 pandemic affects air pollution. The results will provide initial evidence regarding human behavioral changes and emission controls. This research will also suggest avenues for further study to link the findings with health outcomes.

Urban ecosystems and ecosystem services in megacity Dhaka: mapping and inventory analysis

Urban ecosystems and ecosystem services have received little research attention in South Asian countries where rapid urban development is currently problematic. We developed a typology of urban ecosystems and an inventory of current ecosystem services for Dhaka – the capital of Bangladesh. Our observations, surveys, analyses, and evaluation revealed a diversity of urban ecosystems including khal (canal), pond, wetland, cultivated land, park/rooftop garden, playground/field, open space/vacant plot, roadside trees, and graveyards. Important provisioning services included fruits, vegetables, fish, fodder, timber, fuelwood, and medicinal/ornamental plants. Regulating services included carbon sequestration and particulate matter removal by park and roadside trees, drainage service by khals and wetlands, and noise abatement by parks. Opportunities for recreation, fishing and sports, walk/exercise, inspirations for art and culture and religious values presented cultural services. Habitat services such as refugia for resident and migratory birds featured in parks, lakes, wetlands and trees on roadsides, playgrounds/fields, and graveyards. Evaluation of the states and values of urban ecosystems and ecosystem services are prerequisites to improving the wellbeing of urban communities particularly in Dhaka but more generally for other major cities in South Asia. Our findings will assist policy makers in sustainable urban ecosystem governance with possible implications for region-wide cooperation.

Challenges in medical waste management amid COVID-19 pandemic in a megacity Dhaka

The COVID-19 pandemic has altered global waste generation dynamics, which is a challenging task for poor countries having inefficient waste management system On an average, 6,180 tons of medical waste (MW) during this COVID-19 pandemic is generated per month in the Dhaka city This voluminous amount of MW generated in the Dhaka city is remained poorly managed, and thus, posing a serious threat to public health and environment To protect any risk of spread of SARS-CoV-2 through MW, a concerted and prompt effort from municipal authorities, hospital administration, and concerned non-government organization (NGOs) is needed to adopt new ways of state-of-the-art, safe and cost-effective MW management system for the Dhaka city Furthermore, research should be directed to find out other potential sources (e g , inanimate objects or aquatic bodies) of SARS-CoV-2 infections to track it’s spatial and temporal dynamics, and also to get early warning in case of future outbreaks © 2021, Bangladesh Society for Microbiology, Immunology and Advanced Biotechnology All rights reserved