Resurgence Of Vector-borne Diseases Research Articles

Impact of Climate Change on Vector-borne Diseases: Exploring Hotspots, Recent Trends and Future Outlooks in Bangladesh

Climate change is a significant risk multiplier and profoundly influences the transmission dynamics, geographical distribution, and resurgence of vector-borne diseases (VBDs). Bangladesh has a noticeable rise in VBDs attributed to climate change. Despite the severity of this issue, the interconnections between climate change and VBDs in Bangladesh have yet to be thoroughly explored. To address this research gap, our review meticulously examined existing literature on the relationship between climate change and VBDs in Bangladesh. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach, we identified 3849 records from SCOPUS, Web of Science, and Google Scholar databases. Ultimately, 22 research articles meeting specific criteria were included. We identified that the literature on the subject matter of this study is non-contemporaneous, with 68% of studies investing datasets before 2014, despite studies on climate change and dengue nexus having increased recently. We pinpointed Dhaka and Chittagong Hill Tracts as the dengue and malaria research hotspots, respectively. We highlighted that the 2023 dengue outbreak illustrates a possible shift in dengue-endemic areas in Bangladesh. Moreover, dengue cases surged by 317% in 2023 compared to 2019 records, with a corresponding 607% increase in mortality compared to 2022. A weak connection was observed between dengue incidents and climate drivers, including the El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). However, no compelling evidence supported an association between malaria cases, and Sea Surface Temperature (SST) in the Bay of Bengal, along with the NINO3 phenomenon. We observed minimal microclimatic and non-climatic data inclusion in selected studies. Our review holds implications for policymakers, urging the prioritization of mitigation measures such as year-round surveillance and early warning systems. Ultimately, it calls for resource allocation to empower researchers in advancing the understanding of VBD dynamics amidst changing climates.

Indirect impact of COVID-19 on the incidence rates of vector-borne diseases in Mexico.

SARS-CoV-2 infection spatial and temporal distribution overlaps with endemic areas of vector-borne diseases (VBD), whose surveillance in Mexico has substantially changed since the first COVID-19 confirmed case. To estimate and compare the incidence rates of VBDs before and after the introduction of SARS-CoV-2 in Mexico. Retrospective study of VBD cases from 2014 to 2021. The incidence rates of each VBD in the period before (2014-2019) and after (2020-2021) the introduction of SARS-CoV-2 in Mexico were calculated and compared. Before the introduction of SARS-CoV-2, the incidence rates of VBDs were high and after the introduction of coronavirus there was a decrease in epidemiological indices; however, there was only statistically significant difference in the incidence rate of malaria (p ≤ 0.05) and other rickettsiae (p ≤ 0.05). Some measures to reduce COVID-19 cases, such as social distancing, home confinement, reductions in public transport and working at home (home office), probably temporarily decreased the number of VBD cases; however, there may be a resurgence of VBDs in the near future.

Worldwide impacts of landscape anthropization on mosquito abundance and diversity: A meta-analysis.

In recent decades, the emergence and resurgence of vector-borne diseases have been well documented worldwide, especially in tropical regions where protection and defense tools for human populations are still very limited. In this context, the dynamics of pathogens are influenced by landscape anthropization (i.e., urbanization, deforestation, and agricultural development), and one of the mechanisms through which this occurs is a change in the abundance and/or diversity of the vectors. An increasing number of empirical studies have described heterogeneous effects of landscape anthropization on vector communities; therefore, it is difficult to have an overall picture of these effects on a global scale. Here, we performed a meta-analysis to quantify the impacts of landscape anthropization on a global scale on the presence/abundance and diversity of mosquitoes, the most important arthropods affecting human health. We obtained 338 effect sizes on 132 mosquito species, compiled from 107 studies in 52 countries that covered almost every part of the world. The results of the meta-analysis showed an overall decline of mosquito presence/abundance and diversity in response to urbanization, deforestation, and agricultural development, except for a few mosquito species that have been able to exploit landscape anthropization well. Our results highlighted that these few favored mosquito species are those of global concern. They, thus, provide a better understanding of the overall effect of landscape anthropization on vector communities and, more importantly, suggest a greater risk of emergence and transmission of vector-borne diseases in human-modified landscapes.

Models of spatial analysis for vector-borne diseases studies: A systematic review.

Background and Aim:Vector-borne diseases (VBDs) constitute a global problem for humans and animals. Knowledge related to the spatial distribution of various species of vectors and their relationship with the environment where they develop is essential to understand the current risk of VBDs and for planning surveillance and control strategies in the face of future threats. This study aimed to identify models, variables, and factors that may influence the emergence and resurgence of VBDs and how these factors can affect spatial local and global distribution patterns.Materials and Methods:A systematic review was designed based on identification, screening, selection, and inclusion described in the research protocols according to the preferred reporting items for systematic reviews and meta-analyses guide. A literature search was performed in PubMed, ScienceDirect, Scopus, and SciELO using the following search strategy: Article type Original research, Language: English, Publishing period: 2010–2020, Search terms: Spatial analysis, spatial models, VBDs, climate, ecologic, life cycle, climate variability, vector-borne, vector, zoonoses, species distribution model, and niche model used in different combinations with “AND” and “OR.”Results:The complexity of the interactions between climate, biotic/abiotic variables, and non-climate factors vary considerably depending on the type of disease and the particular location. VBDs are among the most studied types of illnesses related to climate and environmental aspects due to their high disease burden, extended presence in tropical and subtropical areas, and high susceptibility to climate and environment variations.Conclusion:It is difficult to generalize our knowledge of VBDs from a geospatial point of view, mainly because every case is inherently independent in variable selection, geographic coverage, and temporal extension. It can be inferred from predictions that as global temperatures increase, so will the potential trend toward extreme events. Consequently, it will become a public health priority to determine the role of climate and environmental variations in the incidence of infectious diseases. Our analysis of the information, as conducted in this work, extends the review beyond individual cases to generate a series of relevant observations applicable to different models.

Meteorological Parameters and Mosquito Abundance in Pashan Area of Pune, India during South West Monsoon and Post-Monsoon Seasons in 2016

The resurgence of vector borne diseases over the last decade has raised concerns about the role of climatic factors. Rapid urbanization due to expansion of Indian cities like Pune over the last decade has altered local land-use and environment. The present study was undertaken to investigate the composition and seasonal abundance of mosquito population in Pashan area of urban Pune, which was urbanized rapidly during 2001-2005. Mosquitoes were trapped and identified to determine the species composition and abundance. Association of meteorological parameters like temperature, humidity and rainfall with mosquito abundance was also analyzed from June to November 2016. Raw meteorological data was obtained and analyzed mathematically to determine derived parameters like diurnal temperatures and fortnightly averages of all parameters. A total of 21 species of mosquitoes were observed across four genera viz. Aedes , Anopheles , Culex and Armigerus . Mosquito abundance (M) peaked during South West (SW) Monsoon and correlated positively with maximum and minimum relative humidity and rainfall. In post-monsoon season mosquito abundance decreased alongwith relative humidity. Interestingly, the mosquito abundance is modulated by diurnal temperature range (DTR). During SW monsoon, low DTR corresponded to high mosquito abundance. The trend was reversed in the post-monsoon season as DTR increased by ~4 folds in comparison to SW monsoon and mosquito abundance decreased sharply. Mosquito population in the study area showed diversity and seasonal variability, influenced by meteorological parameters. DTR seemed to be the major factor affecting seasonal variability in mosquito abundance.

On the dynamics of a class of multi-group models for vector-borne diseases

The resurgence of vector-borne diseases is an increasing public health concern, and there is a need for a better understanding of their dynamics. For a number of diseases, e.g. dengue and chikungunya, this resurgence occurs mostly in urban environments, which are naturally very heterogeneous, particularly due to population circulation. In this scenario, there is an increasing interest in both multi-patch and multi-group models for such diseases. In this work, we study the dynamics of a vector borne disease within a class of multi-group models that extends the classical Bailey–Dietz model. This class includes many of the proposed models in the literature, and it can accommodate various functional forms of the infection force. For such models, the vector-host/host-vector contact network topology gives rise to a bipartite graph which has different properties from the ones usually found in directly transmitted diseases. Under the assumption that the contact network is strongly connected, we can define the basic reproductive number R0 and show that this system has only two equilibria: the so called disease free equilibrium (DFE); and a unique interior equilibrium—usually termed the endemic equilibrium (EE)—that exists if, and only if, R0>1. We also show that, if R0≤1, then the DFE equilibrium is globally asymptotically stable, while when R0>1, we have that the EE is globally asymptotically stable.

The ecological dimensions of vector-borne disease research and control

Alarming trends in the resurgence of vector-borne diseases are anticipated to continue unless more effective action is taken to address the variety of underlying causes. Social factors, anthropogenic environmental modifications and/or ecological changes appear to be the primary drivers. The ecological dimension of vector-borne disease research and management is a pervasive element because this issue is essentially an ecological problem with biophysical, social, and economic dimensions. However there is often a lack of clarity about the ecological dimension, the field of ecology (e.g. role, limitations), and related concepts pertinent to ecosystem approaches to health. An ecological perspective can provide foresight into the appropriateness of interventions, provide answers to unexpected vector control responses, and contribute to effective management solutions in an ever-changing environment. The aim of this paper is to explore the ecological dimension of vector-borne diseases and to provide further clarity about the role of 'ecological thinking' in the development and implementation of vector control activities (i.e. ecosystem approaches to vector-borne diseases).