Nadia Ali Rimi

Live bird markets are known foci for avian influenza zoonoses, with market workers at high risk of spillover infections. In Bangladesh, 95% of poultry are sold in live poultry markets. To assess how building structure, ventilation, and work activities affect concentrations of airborne influenza within live poultry markets, we collected data from 40 poultry shops in ten markets of Dhaka and Gazipur, Bangladesh. We also collected size-selective bioaerosol samples in a subset of 28 shops from the seven markets. Within these 28 shops, there was a 100% prevalence of airborne avian influenza, with the virus found most often in particles >1 μm. The average ventilation rate was high (mean: 26.8 air changes per hour (ACH) [95% confidence interval (CI): 20.5, 33.0]), exceeding the World Health Organization minimum of 12 ACH in 70% of locations when the fans were off and 81% of locations when fans were on (p=0.28). However, indoor air pollution was also high, with mean indoor particulate matter (PM2.5) concentrations averaging 55.2 μg/m3 and outdoor concentrations averaging 32.3 ug/m3. Indoor PM2.5 concentrations were 24.7 ug/m³ [95% CI: 11.9, 37.6] higher than in air directly outside the market. High indoor air pollution despite observed high ventilation rates suggests that the observed air exchange occurs primarily through the (re)circulation of contaminated indoor air instead of through the replacement with outdoor air. We suggest market-wide interventions in poultry markets that improve ventilation.

In Bangladesh, influenza A(H5N1) viruses are endemic in poultry. Processing infected chickens can aerosolize viruses, increasing the risk for human infections. We evaluated particulate matter (PM_2.5) mass concentration during slaughtering and defeathering methods used in live bird markets in Bangladesh to identify solutions to reduce aerosol exposure. We slaughtered 675 chickens using cones and barrels with 3 lid types and defeathered 45 chickens using a defeathering machine with 5 lid types. We interviewed 3 slaughterers to understand method preference. For slaughtering, barrels with a solid or star-cut lid reduced PM_2.5 mass concentrations by 65%-73% compared with uncovered barrels. For defeathering, machines fully covered by a solid lid or lid with a hole and pivot door reduced PM_2.5 mass concentrations by 50% compared with machines with no lid. Slaughterers preferred barrels covered with solid lids and defeathering machines covered with solid or hinged lids. Those methods might reduce aerosol exposure during poultry processing.

We aimed to explore coronavirus disease 2019 (COVID-19) risk perception and prevention practices among people living in high- and low-population density areas in Dhaka, Bangladesh. A total of 623 patients with confirmed COVID-19 agreed to participate in the survey. Additionally, we purposively selected 14 participants from diverse economic and occupational groups and conducted qualitative interviews for them accordingly. Approximately 70% of the respondents had low socioeconomic status. Among the 623 respondents, 146 were from low-density areas, and 477 were from high-density areas. The findings showed that study participants perceived COVID-19 as a punishment from the Almighty, especially for non-Muslims, and were not concerned about its severity. They also believed that coronavirus would not survive in hot temperatures or negatively impact Bangladeshis. This study revealed that people were reluctant to undergo COVID-19 testing. Family members hid if anyone tested positive for COVID-19 or did not adhere to institutional isolation. The findings showed that participants were not concerned about COVID-19 and believed that coronavirus would not have a devastating impact on Bangladeshis; thus, they were reluctant to follow prevention measures and undergo testing. Tailored interventions for specific targeted groups would be relevant in mitigating the prevailing misconceptions.

There is a paucity of recent research on direct water quantity measurement for personal and domestic hygiene. We aimed to measure the water quantity used for personal and domestic hygiene and to explore the reasons and determinants for variation of water usage. We conducted this study from September 2014 to June 2016 in a low-income urban community in Dhaka. In 12 households, the team conducted a day-long bimonthly ethnographic observation for one year to measure the volume of water used per activity per person. They conducted 28 in-depth interviews to explore the reasons for changes of water usage. Participants used a median of 75 L (61–100) of water per capita per day (LCPD) and of this 75 LCPD they used a median of 39 LCPD (26–58) for personal hygiene. Women used less water than men. Individual and social norms, beliefs, and weather determinants determined personal hygiene. Water availability determined domestic hygiene (e.g., washing dishes, toilets and bathrooms). This study helps to elucidate a range of determinants of water usage of the participants from the participants’ perspective. The quantity of water used for domestic and personal hygiene and its relationship to fecal-oral transmitted disease can be explored in future research.

Improving hygiene practices is considered to be the single most cost-effective means of reducing the global health burden of infectious diseases. Hygiene promotion and disease prevention interventions often portray and promote “hygiene” from a biomedical perspective, which may not be optimally effective for achieving their goal of changing people’s behaviors. This study aimed to educe the meaning of hygiene for the residents of a low-income community in Bangladesh and how that meaning shapes their personal hygiene practices. We conducted this study in the Tongi township in Dhaka, Bangladesh, from September 2014 to June 2016. The research team purposively selected 24 households. The team conducted day-long observations using the participant observation approach and in-depth interviews with specific members of the 24 households. The concept of “hygiene” had two separate meanings to the study participants: cleanliness and holiness. The participants reported that cleanliness was required to remove odors, grease, hot spices and dirt. The motivation for cleanliness was to feel fresh, avoid heavy feelings, feel light and feel comfortable. To maintain the holiness of the body, bathing and ablution needed to be performed following particular religious rules/rituals. The motivation of holiness was derived from their accountability to God. The participants also reported that the cleansing processes and methods for the body and the home for cleanliness reasons were also different from those for holiness reasons. The notion of “hygiene” was multidimensional for the residents of the low-income urban community in Bangladesh. Our study participants did not explicitly conceptualize a notion of hygiene that was based on the germ theory of diseases but rather a notion that was based on individual physical comfort and cultural belief systems. Future studies on the prevention of hygiene-related diseases should combine and link the biomedical aspect to religious and cultural rituals to promote improved hygiene practices.

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.

The illness cost borne by households, known as out-of-pocket expenditure, was 74% of the total health expenditure in Bangladesh in 2017. Calculating economic burden of diarrhea of low-income urban community is important to identify potential cost savings strategies and prioritize policy decision to improve the quality of life of this population. This study aimed to estimate cost of illness and monthly percent expenditure borne by households due diarrhea in a low-income urban settlement of Dhaka, Bangladesh. We conducted this study in East Arichpur area of Tongi township in Dhaka, Bangladesh from September 17, 2015 to July 26, 2016. We used the World Health Organization (WHO) definition of three or more loose stool in 24 hours to enroll patients and enrolled 106 severe patients and 158 non-severe patients from Tongi General Hospital, local pharmacy and study community. The team enrolled patients between the first to third day of the illness (≤ 72 hours) and continued daily follow-up by phone until recovery. We considered direct and indirect costs to calculate cost-per-episode. We applied the published incidence rate to estimate the annual cost of diarrhea. The estimated average cost of illness for patient with severe diarrhea was US$ 27.39 [95% CI: 24.55, 30.23] (2,147 BDT), 17% of the average monthly income of the households. The average cost of illness for patient with non-severe diarrhea was US$ 6.36 [95% CI: 5.19, 7.55] (499 BDT), 4% of the average monthly income of households. A single diarrheal episode substantially affects financial condition of low-income urban community residents: a severe episode can cost almost equivalent to 4.35 days (17%) and a non-severe episode can cost almost equivalent to 1 day (4%) of household’s income. Preventing diarrhea preserves health and supports financial livelihoods. The illness cost borne by households, known as out-of-pocket expenditure was 74% of the total health expenditure in Bangladesh in 2017. Most of the studies in Bangladesh that estimated the cost of diarrheal illness collected data from hospital patients and mostly targeted under-five children. Information on economic burden of diarrhea borne by households of low-income urban communities who commonly had ≤ 2 US$ dollar income per capita per day still remained unknown. We conducted this study in East Arichpur area of Tongi township in Dhaka, Bangladesh from September 2015 to July 2016 to estimate cost of illness and monthly percent expenditure borne by households due diarrhea in a low-income urban settlement of Dhaka, Bangladesh. The estimated average cost of illness for patient with severe diarrhea was US$ 27.39 (2,147 BDT) and non-severe diarrhea was US$ 6.36 (499 BDT). A single diarrheal episode substantially affects financial capability of the low-income urban community: a severe episode can cost 4.35 days (17%) and a non-severe episode can cost 1 day (4%) of income of a households. Preventing diarrhea preserves health and supports financial livelihoods.

To date, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected over 80 million people globally. We report a case series of five clinically and laboratory confirmed COVID-19 patients from Bangladesh who suffered a second episode of COVID-19 illness after 70 symptom-free days. The International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), is a leading public health research institution in South Asia. icddr, b staff were actively tested, treated and followed-up for COVID-19 by an experienced team of clinicians, epidemiologists, and virologists. From 21 March to 30 September 2020, 1370 icddr,b employees working at either the Dhaka (urban) or Matlab (rural) clinical sites were tested for COVID-19. In total, 522 (38%) were positive; 38% from urban Dhaka (483/1261) and 36% from the rural clinical site Matlab (39/109). Five patients (60% male with a mean age of 41 years) had real-time reverse transcription-polymerase chain reaction (rRT-PCR) diagnosed recurrence (reinfection) of SARS-CoV-2. All had mild symptoms except for one who was hospitalized. Though all cases reported fair risk perceptions towards COVID-19, all had potential exposure sources for reinfection. After a second course of treatment and home isolation, all patients fully recovered. Our findings suggest the need for COVID-19 vaccination and continuing other preventive measures to further mitigate the pandemic. An optimal post-recovery follow-up strategy to allow the safe return of COVID-19 patients to the workforce may be considered.

Bats are important wildlife to their ecologic system, but they are also a zoonotic disease reservoir. Close bat–human interaction can lead to pathogen spillover. We conducted a qualitative study in two districts of Bangladesh and interviewed 30 bat hunters who hunt bats primarily for consumption, to understand the process and their reasons for hunting bats and their perceptions about bats and bat-borne disease. Most hunters catch bats during winter nights, using a net. Bat meat is used for household consumption, and the surplus is sold to cover household expenditures. They prepare the bat meat at home to sell it in their own and in neighboring communities. They also sell live bats to traditional healers. They report that the bat population has declined compared with 5 or 10 years ago, a decline they attribute to hunting and deforestation. Many have heard of a disease from bat-contaminated date palm sap but do not believe that bats can spread such disease to humans. Close bat–human interaction reported in this study pose a risk of pathogen spillover. Conservation initiatives have the potential to reduce such interaction and so both reduce disease risk and support the ecology.