Age-related Risk Factors and Severity of SARS-CoV-2 Infection: a systematic review and meta-analysis

Objectives: We aimed to estimate the reported symptoms and comorbidities and assess the correlation between a series of symptoms and comorbidities and age of the patients’ positive in COVID-19. Methods: We performed a systematic review and meta-analysis [PROSPERO registration: CRD42020182677]. Databases [PubMed, SCOPUS, EMBASE, WHO, Semantic Scholar, and COVID-19 Primer] were searched for clinical studies published from January to April 2020. The pooled prevalence of symptoms and comorbidities were identified using the random effect model, and the multivariable factor analysis was performed to show the correlation between a group of symptoms and comorbidities and age of the COVID-19 patients. Results: Twenty-nine articles, with 4,884 COVID-19 patients were included in this study.  Altogether, we found 33 symptoms and 44 comorbidities where the most frequent 19 symptoms and 11 comorbidities were included in the meta-analysis. The fever [84%], cough/dry cough [61%], and fatigue/weakness [42%] were found more prevalent. On the other hand, acute respiratory distress syndrome, hypertension and diabetes were the most prevalent comorbid condition. The multivariable factor analysis showed positive association between a group of symptoms and comorbidities, and with the patients' age. The symptoms comprising fever, dyspnea/shortness of breath, nausea, vomiting, abdominal pain, dizziness, anorexia and pharyngalgia; and the comorbidities including diabetes, hypertension, coronary heart disease, COPD/lung disease and ARDS were positively correlated with the COVID-19 patient’s age. Conclusion: As a unique effort, this study found a group of symptoms and comorbidities, correlated with age of the COVID-19 patients that may help to implement patient-centred interventions

<i>Campylobacter</i> in an urban estuary:public health insights from occurrence, hela cytotoxicity, and Caco-2 attachment cum invasion

Aquatic recreation in urban estuaries worldwide is often restricted by fecal pollution. Variability in the occurrence of fecal pathogens and their differential virulence potentials within these estuaries may result in variable public health risks. To address this hypothesis, Campylobacter were isolated from the Yarra River estuary, Australia and then characterized via HeLa cell cytotoxicity and attachment to and the invasion of Caco-2 monolayers. Overall, 54% (n=216) of estuarine samples (water and sediment combined) yielded biochemically confirmed culturable Campylobacter; higher detection was recorded in water (92%, n=90) than in the bank and bed sediments combined (27%, n=126). The seasonality of occurrence was not significant. HeLa cell cytotoxicity revealed that estuarine Campylobacter had low cytotoxin titers; the 95% confidence interval (CI) ranged between 61 and 85, which was markedly lower than the mean value (~386) for the C. jejuni 11168 reference pathogenic strain. The Caco-2 attachment of estuarine Campylobacter isolates (n=189) revealed that the 95%CI for the attachment efficiency of the test strains ranged between 0.09 and 0.1%, with only 3.7% having a higher efficiency than the 5th percentile value for C. jejuni 11168. None of the estuarine strains exhibited Caco-2 invasion capabilities. In contrast to the common assumption during quantitative microbial/risk assessments (QMRAs) that all environmental strains are pathogenic, the present results revealed that Campylobacter within the Yarra River estuary had very low virulence potential. Since this is the first study to use human epithelial cell lines to characterize estuary-borne pathogens, these results generate valuable insights for a better understanding of the public health risks in urban estuaries that will underpin more robust QMRAs.</p

Dengue in a crowded megacity:Lessons learnt from 2019 outbreak in Dhaka, Bangladesh

Dengue is a mosquito-borne viral disease commonly reported in the tropical regions of the world. The presence of two mosquito vectors (Aedes aegypti is highly urban, while A. albopictus is less urban) throughout the year makes dengue fever an endemic disease in a number of countries. Among the predicting variables, a rise of temperature and rainfall have shown to be associated with the number of dengue cases [1]. While relatively less emphasized compared to the climatic factors, mass movement is particularly important during large-scale outbreaks. This article presents a case based on the available data from the 2019 outbreak in Bangladesh, where the dengue fever was initially concentrated in Dhaka, the capital city

Salmonella from a Microtidal Estuary Are Capable of Invading Human Intestinal Cell Lines

Faecal contamination poses health risks for the recreational users of urban estuaries. However, our understanding of the potential pathogenicity of faecal microbes in these environments is limited. To this end, a study was conducted to understand the spatial and seasonal distribution of Salmonella in water and sediments of the Yarra River estuary, Melbourne, Australia. Among 210 samples in total, culturable Salmonella were recovered from 27%, 17%, and 19% of water, bank, and bed sediment samples, respectively. The combined detection increased from 15% in winter to 32% in summer (p < 0.05) indicating seasonal variation as potential part of public health risk assessments. Further, pathogenic potential of the Salmonella isolates was characterised via the quantification of attachment and invasion capacity using human epithelial colorectal cell line Caco-2 on a subset of isolates (n = 62). While all of these isolates could attach and invade Caco-2 cells, 52% and 13% of these showed greater attachment and invasiveness, respectively, than the corresponding mean values for S. Typhimurium ATCC14028 control. Isolates from winter were on average more invasive (seven out of eight isolates with the highest invasiveness recovered from the colder sampling period) than the isolates from summer, and Salmonella collected during summer showed lower invasion (p < 0.05) compared with the control. Similar low invasion compared with the same control was observed for isolates recovered from bank sediment (p < 0.05). While the higher prevalence in summer may imply higher risks during these peak recreational periods, it is essential that this information is used in combination with quantitative microbial risk assessments to fully understand the health risks posed by Salmonella in microtidal estuaries.</p

Evaluation of lettuce growth, yield, and economic viability grown vertically on unutilized building wall in Dhaka City

Production of safe food in the densely populated areas of the developing countries is the most challenging issue due to the speedy urbanization, fragile food transportation facilities, and reduced farmlands. Given this background, a study was conducted to evaluate the agronomic properties and economic viability of lettuce grown vertically in the wall of building in Dhaka city, Bangladesh. Two lettuce cultivars (V1: Green wave and V2: New red fire) and three organic growing media (P1: 40% soil + 40% vermicompost + 20% coir; P2: 50% soil + 50% vermicompost; P3: 20% soil + 40% vermicompost + 40% spent mushroom compost) along with control (P0:100% soil) were used. The results revealed that plant height, leaf area, fresh weight, dry weight, and total yield of leaf lettuce were significantly increased when the green-leafed cultivar (VI) was grown in the P1 compared to all other treatments, but V2 got maximum sensory attribute scores when grown in the P1. Lettuce leaves grown in the formulated growing media (P1, P2, and P3) had higher microbial infestation whereas, a lower content occurred in the P0. The higher economic return was observed in V1P1. These results provided baseline information for further study on urban commercial vertical farming on the building walls. These demonstrate the agronomic and economic potential for vertical farming in densely populated areas but emphasize the need for optimized food safety strategies

<i>Salmonella enterica</i> Serovar Typhimurium and <i>Escherichia coli</i> Survival in Estuarine Bank Sediments

Estuarine bank sediments have the potential to support the survival and growth of fecal indicator organisms, including Escherichia coli. However, survival of fecal pathogens in estuarine sediments is not well researched and therefore remains a significant knowledge gap regarding public health risks in estuaries. In this study, simultaneous survival of Escherichia coli and a fecal pathogen, Salmonella enterica serovar Typhimurium, was studied for 21 days in estuarine bank sediment microcosms. Observed growth patterns for both organisms were comparable under four simulated scenarios; for continuous-desiccation, extended-desiccation, periodic-inundation, and continuous-inundation systems, logarithmic decay coefficients were 1.54/day, 1.51/day, 0.14/day, and 0.20/day, respectively, for E. coli, and 1.72/day, 1.64/day, 0.21/day, and 0.24/day for S. Typhimurium. Re-wetting of continuous-desiccated systems resulted in potential re-growth, suggesting survival under moisture-limited conditions. Key findings from this study include: (i) Bank sediments can potentially support human pathogens (S. Typhimurium), (ii) inundation levels influence the survival of fecal bacteria in estuarine bank sediments, and (iii) comparable survival rates of S. Typhimurium and E. coli implies the latter could be a reliable fecal indicator in urban estuaries. The results from this study will help select suitable monitoring and management strategies for safer recreational activities in urban estuaries

Is Childhood Overweight/Obesity Perceived as a Health Problem by Mothers of Preschool Aged Children in Bangladesh? A Community Level Cross-Sectional Study

Childhood obesity is rapidly rising in many developing countries such as Bangladesh; however, the factors responsible for this increase are not well understood. Being the primary caregivers of children, particularly in developing countries, maternal perceptions and knowledge could be important factors influencing the weight status of children. This study aimed to assess maternal perceptions of childhood obesity and associated socio-demographic factors in Bangladesh. A cross-sectional study using stratified random sampling was conducted among 585 mothers whose children aged 4 to 7 years attended preschools in a district town. Body Mass Index of the children was calculated and weight status categorized according to the Centers for Disease Control (CDC) criteria. Maternal perceptions were assessed using a self- or interviewer-administered questionnaire. Multinomial logistic regression was used to obtain crude and adjusted odds ratios. Fourteen percent of children were overweight or obese and approximately 30% were underweight. Only 3.1% of children were perceived as overweight/obese by their mothers. Over one-third (35%) of mothers perceived that childhood overweight/obesity could be a health problem and over two-thirds (68.6%) were not aware of any health consequences of childhood obesity. Maternal perceptions were significantly associated with maternal education, family income, and weight status of the child but were not associated with the sex of the child. We have identified knowledge gaps regarding maternal perception of childhood obesity and its contributing factors in a developing country. These findings can be used to develop and test parent-focused educational interventions for preventing childhood obesity in Bangladesh

Risk perception of sun exposure and knowledge of vitamin D among the healthcare providers in a high-risk country: a cross-sectional study

Abstract Background High levels of vitamin D deficiency are commonly reported even in regions with abundant sunshine. This necessitates a comprehensive understanding of the determinants that influence sun exposure practices. As the primary source of health-related knowledge for the general public, the attitude of the healthcare professionals towards sunlight and their awareness related to vitamin D deficiency can be critical in this regard. Methods A cross-sectional survey was conducted among 2,242 physicians, intern doctors, and senior medical students in Bangladesh from October 2019 to February 2020. A pre-tested structured questionnaire (containing twelve close-ended questions) was used. The perceptions of health risks due to sun exposure, and basic knowledge of the physiological and epidemiological aspects of vitamin D deficiency were tested. Results An overall negative attitude towards sunlight in the context of Bangladesh was highlighted – 68% participants thought regular sun exposure would be harmful or very harmful; 26% thought the level of UV radiation was very high; 44% recommended using sunscreen always; skin burns, heat stroke, and cancer were selected as potential consequences of regular sun exposure by 45%, 21%, and 30% respondents respectively. Overall knowledge regarding vitamin D deficiency appeared to be biased towards bone health; other symptoms and associated illnesses not having obvious link to Calcium-metabolism were identified much lesser frequently. Furthermore, ‘sunrise to 10 am’ was identified as the best time to get vitamin D by 69% participants; 60% believed < 30 min of weekly sun exposure would be sufficient for the Bangladeshi population; an only 33% identified that prevalence of vitamin D insufficiency in Bangladesh would be 50% or more. Taking vitamin D-rich food was suggested by more respondents over regular sun exposure (43% vs. 33%) as more effective remedial strategy to curb vitamin D deficiency in Bangladesh. Conclusion In addition to highlighting some crucial knowledge gaps, results from this study provides a comprehensive baseline dataset for knowledge and attitude regarding the public health aspects of vitamin D deficiency among the healthcare providers in Bangladesh, which would be generalizable to other countries with similar socio-demographic context, and will facilitate taking more effective policies worldwide