Dengue Fever andAedes aegyptiin indigenous Brazilians: seroprevalence, risk factors, knowledge and practices

A scoping literature review of global dengue age-stratified seroprevalence data: estimating dengue force of infection in endemic countries

BACKGROUND

Dengue poses a significant burden worldwide, and a more comprehensive understanding of the heterogeneity in the intensity of dengue transmission within endemic countries is necessary to evaluate the potential impact of public health interventions.

METHODS

This scoping literature review aimed to update a previous study of dengue transmission intensity by collating global age-stratified dengue seroprevalence data published in the Medline, Embase and Web of Science databases from 2014 to 2023. These data were then utilised to calibrate catalytic models and estimate the force of infection (FOI), which is the yearly per-capita risk of infection for a typical susceptible individual.

FINDINGS

We found a total of 66 new publications containing 219 age-stratified seroprevalence datasets across 30 endemic countries. Together with the previously available average FOI estimates, there are now more than 250 dengue average FOI estimates obtained from seroprevalence studies from across the world.

INTERPRETATION

The results show large heterogeneities in average dengue FOI both across and within countries. These new estimates can be used to inform ongoing modelling efforts to improve our understanding of the drivers of the heterogeneity in dengue transmission globally, which in turn can help inform the optimal implementation of public health interventions.

FUNDING

UK Medical Research Council, Wellcome Trust, Community Jameel, Drugs for Neglected Disease initiative (DNDi) funded by the French Development Agency, Médecins Sans Frontières International; Swiss Agency for Development and Cooperation and UK aid.

Determining reference ranges for immunological cells of healthy indigenous individuals from a region in Brazil

Morais et al. conducted a pioneering study with Brazilian indigenous populations to determine reference values for immunologic cells from healthy adult individuals. The main findings included a higher relative median for T lymphocyte subsets in females than males, and T CD3+, T CD4+, and T CD8+ relative values were statistically different when compared with Brazilian populations from other Brazilian regions. The relative medians of CD3+, CD4+, and CD8+ T cells were significantly higher in women than in men in a healthy indigenous population. Demographic and ethnic diversity of the Brazilian population can be associated with quantitative modifications in the immunologic cells of healthy individuals.

OBJECTIVE

The establishment of reference values for a subset of leukocytes is common in clinical practice, and ethnic variations are strongly associated with disease development. In Brazil, indigenous people are vulnerable to infections, and few studies have described the health and disease conditions of this population. This study aimed to provide reference values for immunological cell subsets in indigenous Brazilians living in the state of Mato Grosso do Sul.

METHODS

Flow cytometry and 4-color combinations of monoclonal antibodies were used to characterize cells. A total of 115 healthy adults, mostly females (72%), were included in the study. The results are presented as mean and median (2.5%-97.5% percentiles) for T and B lymphocytes, CD4+ T cells, CD8+ T cells, Natural Killer cells, monocytes, and dendritic cells, providing an average immunological profile for the population in question.

RESULTS

The relative medians of CD3+, CD4+, and CD8+ T cells were significantly higher in women than in men in a healthy indigenous population.

CONCLUSION

To our knowledge, cell reference data from indigenous Brazilians are unknown in the literature. The immune cell results presented in this pioneering study will contribute to the clinical and laboratory evaluation of the Brazilian indigenous population, especially given the important differences when compared with other Brazilian ethnic groups.

Knowledge, Attitudes, and Practices of the Population in Jazan Region, Saudi Arabia Regarding Dengue Fever and Its Prevention Measures: A Community-Based Cross-Sectional Study

In previous studies, there was an apparent lack of health education about dengue fever (DF) among the Saudi population. Therefore, we conducted this study to assess the knowledge, attitude, and practices (KAP) about dengue fever among the Jazan region population, which is one of the most prevalent diseases in the region in Saudi Arabia (KSA). This was a cross-sectional and community-based study. The adult population was divided into governorates according to the regions that were close to each other, and then a convenient stratum was selected from each region. Next, random sampling was applied. Data were collected using a self-administered questionnaire. Exclusion criteria were young people (<18 years old) and health workers. Data analysis was performed using descriptive statistics, the Pearson's correlation coefficient, and multiple linear regression. Of the 392 participants in this cross-sectional study, 59.18% were male, 76.28% were aged 18-35 years, 72.96% had a university degree, and 63% had a monthly income of less than SAR 5000 (USD1 = 3.76). The scores (mean ± SD) for KAP regarding DF among the responders were 22.77 ± 7.9, 22.68 ± 7.24, and 25.62 ± 9.4, respectively. KAP constructs were positively correlated according to the Pearson's coefficient. In multiple linear regression analysis, males were favorably and substantially linked with attitude score (β = 2.76, p = 0.001) and negatively associated with practice score (β = -2.45, p = 0.023). No-degree participants scored lower on knowledge (β = -2.78, p = 0.003). There is potential for more research in Saudi Arabia to increase the generalizability to reduce the impact of dengue epidemics.

A review of Environmental risks and vulnerability factors of indigenous populations from Latin America and the Caribbean in the face of the COVID-19

Latin America and the Caribbean (LAC) was declared a new epicentre of the coronavirus pandemic by the World Health Organization (WHO) on 22 May 2020. As of 13 January 2021, the numbers of deaths and cases caused by COVID-19 in LAC reported are 552,000 and 17'485,000 respectively. LAC concentrates the largest percentage of indigenous populations throughout the world. In this region, poverty is persistent and particularly rural indigenous peoples hold the steepest barriers to health services and experience profound discrimination based on ethnicity, poverty, and language, compared to their non-indigenous counterparts. The information regarding the health of indigenous populations, in general, is scarce, and this problem is aggravated in the face of the COVID-19 pandemic. Therefore, the main objective of this work is to address the overall scenario of indigenous peoples in the Latin American and Caribbean region from March 2020 to January 2021, in this manner gathering information regarding health problems, economic, social, cultural and environmental factors that make indigenous populations in LAC particularly vulnerable to serious health effects from the COVID-19 pandemic, as well as compiling the mitigation strategies implemented in indigenous communities.

Mapping China's time-series anthropogenic heat flux with inventory method and multi-source remotely sensed data

Mapping time-series anthropogenic heat flux (AHF) is of great significance for understanding the process of urbanization and its impact on urban environment and climate. By collecting energy consumption data and socioeconomic statistics, combined with multi-source remotely sensed data, this study mapped the surface AHF in China with a high spatial resolution of 500 m × 500 m from 2000 to 2016 with 4 years of interval through constructing AHF estimation scheme. The main conclusions are: (1) There is a strong correlation between the vegetation adjusted nighttime light urban index (VANUI) and AHF. The highest coefficient of determination (R²) of VANUI and AHF is 0.97 in partition of northwest region (NWR). The average R² value in partitions is 0.76, which shows that VANUI can well reflect the spatial differentiation characteristics of anthropogenic heat emissions. In addition, the fitting R² value of the AHF estimation result and the AHF calculated by the inventory method is between 0.7 and 0.9, which indicates that the AHF estimation model constructed by VANUI can obtain reliable AHF estimation results. (2) In 2000-2016, the composition of AHF value changed a lot. The most obvious change is the AHF of 2-5 W·m^-2, with a total increase of 21.53%. The area ratio of the low-value AHF of 0-2 W·m^-2 showed a decreasing trend, from 91.93% in 2000 to 50.45% in 2016. Due to the increase of AHF, the reduced area has evolved to a high anthropogenic heat emission area. By constructing the AHF estimation model, this study acquired the time-series AHF with good accuracy and time-variation consistency in China from 2000 to 2016, which can effectively serve the research on urban environment and climate.

Assessing the relationship between anthropogenic heat release warming and building characteristics in Guangzhou: A sustainable development perspective

We assessed the spatial heterogeneity of warming due to total anthropogenic heat release (AHR) and building anthropogenic heat release under different heat release scenarios and its relationship with building properties in the highly urbanized portion of Guangzhou using the Weather Research and Forecasting (WRF) model. The simulation results show that different AHR scenarios result in different temperature rise outcomes. A rise of 0.40 °C and 0.23 °C results from a normal total AHR scenario and normal building AHR scenario, while a rise of 0.71 °C and 0.41 °C arises when total AHR and building AHR is doubled. This indicates that more anthropogenic heat results in a more serious warming effect. Moreover, the spatial heterogeneity of the AHR-caused temperature rise is affected by the building area. The AHR-derived warming effect is most serious in high-height-medium-density (H-M) and high-height-high-density (H-H) building areas, where temperature rose by 0.36 °C and 0.34 °C due to building AHR under two AHR scenarios, while it was least serious in low-height-high-density (L-H) and high-height-low-density (H-L) areas, where temperature rose by 16 °C and 0.25 °C under two building AHR scenarios. When AHR is doubled, the hot spot of AHR-derived warming tends to become more concentrated. The quantitative relationship between building AHR-derived warming and building property data was assessed using a multiple linear regression model. The model shows that the combination of building height and building density provides better predictor of building AHR warming than either property alone; and the relationship is best predicted in L-H and H-L areas, with R² values of 0.68 and 0.79, respectively. Warming due to AHR should be considered as one of the most serious urban warming forces and the land surface properties are the key factors that influence AHR-derived warming. This study provides evidence for the significance of AHR in the urban environment and offers suggestions for mitigating urban thermal heating.