Evaluation of the usefulness of Aedes aegypti rapid larval surveys to anticipate seasonal dengue transmission between 2012-2015 in Fortaleza, Brazil

Solid waste management and Aedes aegypti infestation interconnections: A regression tree application

Public health is at the core of all environmental and anthropic impacts. Urban and territorial planners should include public health concerns in their plans. Basic sanitation infrastructure is essential to maintaining public health and social and economic development. This infrastructure deficiency causes diseases, death and economic losses in developing countries. Framing interconnections among health, sanitation, urbanization and circular economy will assist sustainable development goal achievements. This study aims to identify the relationships between solid waste management indicators in Brazil and the Aedes aegypti mosquito infestation index. Regression trees were employed for modelling due to the complexity and characteristics of the data. The analyses were performed separately from data collected from 3501 municipalities and 42 indicators from the country's five regions. Results show that expenses and personnel indicators were the most critical indicators (in the mid-western, southeastern and southern regions), operational (northeastern (NE) region) and management (northern region). The mean absolute errors ranged from 0.803 (southern region) to 2.507 (NE region). Regional analyses indicate that the municipalities with better SWM results display lower infestation rates in buildings and residences. This research is innovative as it analyses infestation rates rather than dengue prevalence, using a machine learning method, in a multidisciplinary research field that needs further study.

A systematic review of published literature on mosquito control action thresholds across the world

BACKGROUND

Despite the use of numerous methods of control measures, mosquito populations and mosquito-borne diseases are still increasing globally. Evidence-based action thresholds to initiate or intensify control activities have been identified as essential in reducing mosquito populations to required levels at the correct/optimal time. This systematic review was conducted to identify different mosquito control action thresholds existing across the world and associated surveillance and implementation characteristics.

METHODOLOGY/PRINCIPAL FINDINGS

Searches for literature published from 2010 up to 2021 were performed using two search engines, Google Scholar and PubMed Central, according to PRISMA guidelines. A set of inclusion/exclusion criteria were identified and of the 1,485 initial selections, only 87 were included in the final review. Thirty inclusions reported originally generated thresholds. Thirteen inclusions were with statistical models that seemed intended to be continuously utilized to test the exceedance of thresholds in a specific region. There was another set of 44 inclusions that solely mentioned previously generated thresholds. The inclusions with "epidemiological thresholds" outnumbered those with "entomological thresholds". Most of the inclusions came from Asia and those thresholds were targeted toward Aedes and dengue control. Overall, mosquito counts (adult and larval) and climatic variables (temperature and rainfall) were the most used parameters in thresholds. The associated surveillance and implementation characteristics of the identified thresholds are discussed here.

CONCLUSIONS/SIGNIFICANCE

The review identified 87 publications with different mosquito control thresholds developed across the world and published during the last decade. Associated surveillance and implementation characteristics will help organize surveillance systems targeting the development and implementation of action thresholds, as well as direct awareness towards already existing thresholds for those with programs lacking available resources for comprehensive surveillance systems. The findings of the review highlight data gaps and areas of focus to fill in the action threshold compartment of the IVM toolbox.

Aedes aegypti in Southern Brazil: Spatiotemporal Distribution Dynamics and Association with Climate and Environmental Factors

In Brazil, the mosquito Aedes (Stegomyia) aegypti is considered the main vector of the dengue, chikungunya, and Zika arbovirus transmission. Recent epidemiological studies in southern Brazil have shown an increase in the incidence of dengue, raising concerns over epidemiological control, monitoring, and surveys. Therefore, this study aimed at performing a historical spatiotemporal analysis of the Ae. aegypti house indices (HI) in southern Brazil over the last 19 years. As vector infestation was associated with climatic and environmental variables, HI data from the Brazilian Ministry of Health, climate data from the Giovanni web-based application, and environmental data from the Mapbiomas project were used in this study. Our results showed an expressive increase in the number of HI surveys in the municipalities confirming the vector presence, as compared to those in 2017. Environmental variables, such as urban infrastructure, precipitation, temperature, and humidity, were positively correlated with the Ae. aegypti HI. This was the first study to analyze Ae. aegypti HI surveys in municipalities of southern Brazil, and our findings could help in developing and planning disease control strategies to improve public health.

Awareness and perception of malaria and dengue at school and college level in the district of Multan

The purpose of this study is to examine the awareness and perception of malaria and dengue fever in Multan Punjab, Pakistan while taking into account the important role of government policies and other variables. The goal of this study is to examine the awareness of students in Multan, Pakistan on malaria and dengue. This study is based on a quantitative approach of secondary evidence from scientific journals and questionnaire surveys. It is also based on observational evidence gathered in Multan Punjab Pakistan, in a field study. The survey with school children, teachers and healthcare professionals were both formal and semi-structuralize. Studies have found that malaria and dengue mainly affect children’s schooling through their absence, but can also induce brain loss and cognitive disability. In questionnaires, students were seen to have different understanding of the illness, but also to be able to serve as agents of health reform only through teachers. A sample size of 500 respondents has been selected from different colleges of district Multan Punjab, Pakistan. Correlation technique is used for the data analysis. According to our results it is concluded that the students at college level are aware of malaria and dengue diseases, but they are not capable of engaging and serving as agents for health reform. On the basis of results it is recommended that students must teach about epidemics diseases regarding how to handle these diseases.

Integrating Spatial Modelling and Space-Time Pattern Mining Analytics for Vector Disease-Related Health Perspectives: A Case of Dengue Fever in Pakistan

The spatial–temporal assessment of vector diseases is imperative to design effective action plans and establish preventive strategies. Therefore, such assessments have potential public health planning-related implications. In this context, we here propose an integrated spatial disease evaluation (I-SpaDE) framework. The I-SpaDE integrates various techniques such as the Kernel Density Estimation, the Optimized Hot Spot Analysis, space–time assessment and prediction, and the Geographically Weighted Regression (GWR). It makes it possible to systematically assess the disease concentrations, patterns/trends, clustering, prediction dynamics, and spatially varying relationships between disease and different associated factors. To demonstrate the applicability and effectiveness of the I-SpaDE, we apply it in the second largest city of Pakistan, namely Lahore, using Dengue Fever (DF) during 2007–2016 as an example vector disease. The most significant clustering is evident during the years 2007–2008, 2010–2011, 2013, and 2016. Mostly, the clusters are found within the city’s central functional area. The prediction analysis shows an inclination of DF distribution from less to more urbanized areas. The results from the GWR show that among various socio-ecological factors, the temperature is the most significantly associated with the DF followed by vegetation and built-up area. While the results are important to understand the DF situation in the study area and have useful implications for public health planning, the proposed framework is flexible, replicable, and robust to be utilized in other similar regions, particularly in developing countries in the tropics and sub-tropics.

[Aedes aegypti larval indices and dengue incidence: an ecological study in the state of Rio de Janeiro, Brazil]

The simultaneous circulation of dengue, Zika, and chikungunya poses major challenges for Brazil. Due to climate changes and other associated factors, more than two billion people in the world may be exposed to these arbovirus infections, according to the World Health Organization. The principal strategy for Aedes aegypti control programs is based on the Infestation Index Rapid Survey for Ae. aegypti (LIRAa), a sample survey in which the Building Infestation Index (BII) is used to prioritize areas for intervention. This study analyzed the performance of LIRAa in terms of its sensitivity for predicting dengue epidemics in municipalities in the state of Rio de Janeiro in epidemic years. Incidence rates per municipality for the years 2011, 2012, 2013, 2015, and 2016, plus the BII in October of the previous years. Scatterplots were created, aimed at an exploratory analysis and graphic visualizations of the relationship between the above-mentioned variables, as well as analyses of the Spearman correlation between the BII and the Breteau Index for each year, aimed at estimating the quality of the LIRAa. Comparative analysis of the values for the BII and the respective incidence rates in the period only indicated significant correlation between these variables in 2011/2012 (rs = 0.479; p < 0.01). There was also a correlation between BII and Breteau Index. It is urgent to rethink the parameters established by the LIRAa methodology and invest in alternative methodologies in entomological and epidemiological surveillance that reliably measure transmission risk in the territory and thus design more effective strategies to control these arbovirus infections.

Proliferation of Aedes aegypti in urban environments mediated by the availability of key aquatic habitats

Aedes aegypti is the main vector of dengue, Zika, chikungunya, and yellow fever viruses. Controlling populations of vector mosquito species in urban environments is a major challenge and being able to determine what aquatic habitats should be prioritized for controlling Ae. aegypti populations is key to the development of more effective mosquito control strategies. Therefore, our objective was to leverage on the Miami-Dade County, Florida immature mosquito surveillance system based on requested by citizen complaints through 311 calls to determine what are the most important aquatic habitats in the proliferation of Ae. aegypti in Miami. We used a tobit model for Ae. aegypti larvae and pupae count data, type and count of aquatic habitats, and daily rainfall. Our results revealed that storm drains had 45% lower percentage of Ae. aegypti larvae over the total of larvae and pupae adjusted for daily rainfall when compared to tires, followed by bromeliads with 33% and garbage cans with 17%. These results are indicating that storm drains, bromeliads and garbage cans had significantly more pupae in relation to larvae when compared to tires, traditionally know as productive aquatic habitats for Ae. aegypti. Ultimately, the methodology and results from this study can be used by mosquito control agencies to identify habitats that should be prioritized in mosquito management and control actions, as well as to guide and improve policies and increase community awareness and engagement. Moreover, by targeting the most productive aquatic habitats this approach will allow the development of critical emergency outbreak responses by directing the control response efforts to the most productive aquatic habitats.

Efficacy of Residual Pesticide-Treated Plant Saucers Against Aedes albopictus Larvae Under Semi-Field and Field Conditions

Plant saucers are ubiquitous, outdoor water-holding receptacles and are one of the most productive domestic mosquito habitats in the urban environment. Two kinds of commonly used plant saucers, clay and plastic, were manually treated with 3 residual insecticides, bifenthrin (Talstar® Professional), lambda-cyhalothrin (Lambda 9.7 CS), and tau-fluvalinate (Mavrik® Perimeter), at their maximum rates to assess their residual efficacy against Aedes albopictus larvae under semi-field and field conditions. Both clay and plastic saucers treated with bifenthrin and lambda-cyhalothrin provided weeks of control of 3rd instars of Ae. albopictus, whereas tau-fluvalinate provided only 1 day of control. Results from this study show that bifenthrin and lambda-cyhalothrin can provide good control of Ae. albopictus larvae for a considerable period of time and have great potential with regard to container mosquito management in the future.