Serosurveillance among urban slum and non-slum populations immunized with COVID-19 vaccines in Bangladesh.

Using two rounds of serosurveillance, we aimed to observe the COVID-19 vaccination status and the dynamics of antibody responses to different vaccines among urban slum and non-slum populations of Bangladesh. Adults (>18 years) and children (10-17 years) were enrolled in March and October 2022. Data including COVID-19 vaccine types and dosage uptake were collected. SARS-CoV-2 spike (S)-specific antibodies were measured in blood. The proportion of vaccinated children was significantly lower among slum than non-slum populations. Two doses of vaccines showed an increase in the level of anti-S-antibodies up to 2 months, followed by reduced levels at 2-6 months and a resurgence at 6-12 months. Children showed significantly higher anti-S-antibodies after two doses of the Pfizer-BioNTech vaccine than adults; however, after 6 months, the level of antibodies declined in younger children (10 - < 12 years). In a mixed vaccine approach, mRNA vaccines contributed to the highest antibody response whether given as the first two doses or as the third dose. Our findings emphasized the need for increasing the coverage of COVID-19 vaccination among slum children and booster dosing among all children. The use of mRNA vaccines in the mixed vaccination approach was found to be useful in boosting the antibody response to SARS-CoV-2.

Seroprevalence of SARS-CoV-2 infection and associated factors among Bangladeshi slum and non-slum dwellers in pre-COVID-19 vaccination era: October 2020 to February 2021.

BACKGROUND: Seroprevalence studies have been carried out in many developed and developing countries to evaluate ongoing and past infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Data on this infection in marginalized populations in urban slums are limited, which may offer crucial information to update prevention and mitigation policies and strategies. We aimed to determine the seroprevalence of SARS-CoV-2 infection and factors associated with seropositivity in slum and non-slum communities in two large cities in Bangladesh. METHODS: A cross-sectional study was carried out among the target population in Dhaka and Chattogram cities between October 2020 and February 2021. Questionnaire-based data, anthropometric and blood pressure measurements and blood were obtained. SARS-CoV-2 serology was assessed by Roche Elecsys® Anti-SARS-CoV-2 immunoassay. RESULTS: Among the 3220 participants (2444 adults, ≥18 years; 776 children, 10-17 years), the overall weighted seroprevalence was 67.3% (95% confidence intervals (CI) = 65.2, 69.3) with 71.0% in slum (95% CI = 68.7, 72.2) and 62.2% in non-slum (95% CI = 58.5, 65.8). The weighted seroprevalence was 72.9% in Dhaka and 54.2% in Chattogram. Seroprevalence was positively associated with limited years of formal education (adjusted odds ratio [aOR] = 1.61; 95% CI = 1.43, 1.82), lower income (aOR = 1.23; 95% CI = 1.03, 1.46), overweight (aOR = 1.2835; 95% CI = 1.26, 1.97), diabetes (aOR = 1.67; 95% CI = 1.21, 2.32) and heart disease (aOR = 1.38; 95% CI = 1.03, 1.86). Contrarily, negative associations were found between seropositivity and regular wearing of masks and washing hands, and prior BCG vaccination. About 63% of the population had asymptomatic infection; only 33% slum and 49% non-slum population showed symptomatic infection. CONCLUSION: The estimated seroprevalence of SARS-CoV-2 was more prominent in impoverished informal settlements than in the adjacent middle-income non-slum areas. Additional factors associated with seropositivity included limited education, low income, overweight and pre-existing chronic conditions. Behavioral factors such as regular wearing of masks and washing hands were associated with lower probability of seropositivity.

Health-Related Quality of Life among Rural-Urban Migrants Living in Dhaka Slums: A Cross-Sectional Survey in Bangladesh.

BACKGROUND: The study aimed to assess the health-related quality of life (HRQoL) and its associated factors among urban slum dwellers who migrated from different rural parts of Bangladesh. METHODS: The present study analyzed data from a Migration and Mobility Determinants on Health survey and was conducted in 2017 among 935 migrant slum dwellers of Dhaka city (North & South) and Gazipur City Corporations, as a part of the icddr,b's Urban Health and Demographic Surveillance System (UHDSS). The face-to-face interviews were conducted with the adult population by using a semi-structured questionnaire that included variables related to socio-demographics, migration, occupation, and HRQoL (SF-12). Bivariate and multiple linear regression analyses were performed to determine the factors associated with HRQoL. RESULTS: The mean (±SD) scores of physical component summary (PCS), and mental component summary (MCS) were 57.40 ± 22.73 and 60.77 ± 22.51, respectively. As per multiple regression analysis, lower PCS scores were associated with having older age, being female, and not having any job. Mean MCS scores were significantly lower among participants who reported having older age, not having any job, not working/ less working hours (≤8 h/day), as well as increased work-related stress in the current urban slum. CONCLUSIONS: The findings suggest that available urban social protection programs should include a comprehensive social safety net for the improvement of the slum infrastructure as well as proper health care and risk mitigation plans at workplaces.

Socio-demographic, health and institutional determinants of caesarean section among the poorest segment of the urban population: Evidence from selected slums in Dhaka, Bangladesh.

Caesarean sections (CS) is the most common lifesaving surgeries for obstructed labour and other emergency obstetrical conditions. The WHO had recommended ideal rate for CS to be between 5% and 15%. The rate higher than 15% indicates overused other than lifesaving. Bangladesh has experienced a dramatic increase in CS delivery from 4% in 2004 to 23% in 2014. This increase is elevated by the several factors including maternal education, maternal request or elective CS, and by the urban richest population. However, little is known about the use CS by the urban poorest population. Therefore, the study aimed to examine and identify the factors associated with CS among the urban disadvantaged section of the population. A total of 1063 randomly chosen women aged 15-49 years from the population of 121,912 residing five-different slums were interviewed during November-December 2016. CS delivery was considered as outcome variable. Both bivariate and multivariable statistical analyses were carried-out. We performed logistic regression analyses to examine the net-effect of independent variables on outcome variable. Over 25% of total deliveries and 50% of facility-based deliveries were CS. The odds of CS delivery was 3.4-fold greater among better-off women than poorest. Women who had 4 + ANC checks-up during pregnancy had a 2-fold higher odds of CS delivery than women of ANC check-up. In private facilities, 76% of births were delivered as CS, followed by 51% in public facilities and 24% in NGO facilities. The likelihood of CS delivery in private facilities was 9.2-fold greater than NGO facilities after controlling for women socio-demographic, pregnancy and delivery characteristics. Thus, the high use of CS is largely associated with private facility, ANC visits and household wealth. Therefore, the Government of Bangladesh should take immediate actions by designing new policies and regulations to ensure CS for the lifesaving condition, not for financial gain.