Pyrethroid Susceptibility in Culex quinquefasciatus Say. (Diptera: Culicidae) Populations from Delta State, Niger-Delta Region, Nigeria

The development of insecticide resistance in different species of mosquitoes to Pyrethroids is a major challenge for vector-borne diseases transmitted by mosquitoes. Failure of Pyrethroids in control of mosquitoes would impact negatively on the gains recorded in control of mosquito-borne diseases in previous years. In anticipation of a country-wide deployment of Pyrethroid-treated nets for control of mosquito-borne diseases in Nigeria, this study assessed susceptibility of Culex quinquefasciatus Say. (Diptera: Culicidae) to Pyrethroids in Owhelogbo, Ejeme and Oria-Abraka communities in Delta State, Niger-Delta, Nigeria. Three to five day old Cx. quinquefasciatus were exposed to Deltamethrin (0.05%), Permethrin (0.75%), and Alphacypermethrin (0.05%) using World Health Organization bioassay method. Polymerase chain reaction (PCR) was employed in characterization of species and knockdown mutation. Results revealed that Cx. quinquefasciatus were generally susceptible (98-100%) to Deltamethrin, Permethrin, and Alphacypermethrin in the three communities with the exception of Owhelogbo where resistance to Deltamethrin (97%) was suspected. Knockdown time to Deltamethrin (11.51, 11.23, and 12.68 min), Permethrin (28.75, 13.26, and 14.49 min), and Alphacypermethrin (15.07, 12.50, and 13.03 min) were considerably low for Owhelogbo, Ejeme, and Oria-Abraka Cx. quinquefasciatus populations, respectively. Species identification result showed that all amplified samples were Cx. quinquefasciatus; however, no kdr allele was found in the three populations. Deployment of pyrethroid-treated nets for control of mosquito-borne diseases in Niger-Delta region of Nigeria is capable of reducing burden of diseases transmitted by Cx. quinquefasciatus as well as addressing nuisance value of the vector; however, caution must be entertained so as not to increase selection pressure thereby aiding resistance development.

Synthesis and antiplasmodial activity of regioisomers and epimers of second-generation dual acting ivermectin hybrids

With its strong effect on vector-borne diseases, and insecticidal effect on mosquito vectors of malaria, inhibition of sporogonic and blood-stage development of Plasmodium falciparum, as well as in vitro and in vivo impairment of the P. berghei development inside hepatocytes, ivermectin (IVM) continues to represent an antimalarial therapeutic worthy of investigation. The in vitro activity of the first-generation IVM hybrids synthesized by appending the IVM macrolide with heterocyclic and organometallic antimalarial pharmacophores, against the blood-stage and liver-stage infections by Plasmodium parasites prompted us to design second-generation molecular hybrids of IVM. Here, a structural modification of IVM to produce novel molecular hybrids by using sub-structures of 4- and 8-aminoquinolines, the time-tested antiplasmodial agents used for treating the blood and hepatic stage of Plasmodium infections, respectively, is presented. Successful isolation of regioisomers and epimers has been demonstrated, and the evaluation of their in vitro antiplasmodial activity against both the blood stages of P. falciparum and the hepatic stages of P. berghei have been undertaken. These compounds displayed structure-dependent antiplasmodial activity, in the nM range, which was more potent than that of IVM, its aglycon or primaquine, highlighting the superiority of this hybridization strategy in designing new antiplasmodial agents.

Engaging healthcare providers and patients on climate action through physical, emotional and social wellness

According to the World Health Organization, the health challenges from climate change are many and varied including: Malnutrition due to lack of quality food access. Mental health challenges in addition to severe socioeconomic challenges, through the loss of homes, jobs and needed social connections due to extreme events. Acute illness and the risk of water-borne diseases associated with lack of access to clean water. The increased risk of vector-borne diseases with warmer temperatures. Chronic illnesses associated with heat stress and pollution. Death from cardiovascular and respiratory disease, particularly among vulnerable people as temperatures rise to extreme levels. Both healthcare providers and patients must be engaged on climate change and action. While several medical training institutions are exploring opportunities to embed climate change and health education into their curricula, of importance are the holistic strategies to engage patients on climate action. The challenges are complex, and the data is overwhelming. Patients may not fully comprehend the personal implications of climate change and as citizens, may not understand their role in climate action. We suggest through the creation of a sustainable living mindset based on wellness, it is possible for healthcare providers to create a personal and emotional connection to climate action. The results from workshops with older adults are shared in this paper, demonstrating how the link to physical, emotional and social wellness, can encourage behavior change with respect to dietary and consumption practices as well as increased connection to and protection of greenspaces for health and well-being.

When The Last Tree Dies, The Last Man Dies: Do Forests Hold The Key To Survival In Ghana? A Critical Analysis Using The Bootstrapped Rolling Window Granger Causality Test Approach

This paper investigates the role of forests in the life expectancy of people in Ghana. We test whether the extinction of forests will inevitably lead to extinction of people in Ghana. We first examined the causal relationship between life expectancy and deforestation using the full sample bootstrap Granger causality test approach and find causality to run from deforestation to life expectancy with no feedback from life expectancy to deforestation. Testing for parameter stability, we found the short run and long run parameters of the estimated Vector Auto Regressive models to be unstable. A time-varying approach, the rolling window bootstrapped Granger causality test was then employed to investigate the causal relationship between life expectancy and deforestation. The results showed that deforestation has a negative effect on life expectancy, confirming the widely accepted saying that the health of forests is inextricably linked to the health of mankind. The empirical results further show that, on trend higher life expectancy increases the rate of deforestation in Ghana. Highlighting the importance of the role of forests in influencing life expectancy in Ghana, we recommend awareness creation on the role of forests in supporting human life and also extensive afforestation programs to reduce the rate of deforestation in Ghana. This, we believe, will reduce the spread of vector borne diseases such as malaria and reduce the surge in respiratory diseases which shorten the life span of Ghanaians.JEL codesQ23, Q50, Q53, Q58, Q58

A look at photodynamic inactivation as a tool for pests and vector-borne diseases control

The control of pests and vector-borne diseases (VDBs) are considered public health issues Worldwide. Among the control techniques and pesticides used so far, photodynamic inactivation (PDI) has been shown as an eco-friendly, low cost, and efficient approach to eliminate pests and VDBs. PDI is characterized using a photosensitizing molecule, light and molecular oxygen (O2) resulting in production of reactive oxidative species which can promote the oxidation of biomolecules on pests and vectors. Herein, we review the past 51 years (1970–2021) regarding the use of photo pesticides, reporting the most important parameters for the protocol applied, the results obtained, and limitations. Moreover, we described the mechanism of action of the PDI, main classes of photopesticides used so far as well as the cell death mechanism resulting from the photodynamic action.

Phlebotomine sand flies (Diptera: Psychodidae) of the Maghreb region: A systematic review of distribution, morphology, and role in the transmission of the pathogens

Background Phlebotomine sand flies (Diptera: Psychodidae) are important vectors of various human and animal pathogens such as Bartonella bacilliformis, Phlebovirus, and parasitic protozoa of the genus Leishmania, causative agent of leishmaniases that account among most significant vector-borne diseases. The Maghreb countries Mauritania, Morocco, Algeria, Tunisia, and Libya occupy a vast area of North Africa and belong to most affected regions by these diseases. Locally varying climatic and ecological conditions support diverse sand fly fauna that includes many proven or suspected vectors. The aim of this review is to summarize often fragmented information and to provide an updated list of sand fly species of the Maghreb region with illustration of species-specific morphological features and maps of their reported distribution. Materials and methods The literature search focused on scholar databases to review information on the sand fly species distribution and their role in the disease transmissions in Mauritania, Morocco, Algeria, Tunisia, and Libya, surveying sources from the period between 1900 and 2020. Reported distribution of each species was collated using Google Earth, and distribution maps were drawn using ArcGIS software. Morphological illustrations were compiled from various published sources. Results and conclusions In total, 32 species of the genera Phlebotomus (Ph.) and Sergentomyia (Se.) were reported in the Maghreb region (15 from Libya, 18 from Tunisia, 23 from Morocco, 24 from Algeria, and 9 from Mauritania). Phlebotomus mariae and Se. africana subsp. asiatica were recorded only in Morocco, Ph. mascitti, Se. hirtus, and Se. tiberiadis only in Algeria, whereas Ph. duboscqi, Se. dubia, Se. africana africana, Se. lesleyae, Se. magna, and Se. freetownensis were reported only from Mauritania. Our review has updated and summarized the geographic distribution of 26 species reported so far in Morocco, Algeria, Tunisia, and Libya, excluding Mauritania from a detailed analysis due to the unavailability of accurate distribution data. In addition, morphological differences important for species identification are summarized with particular attention to closely related species such as Ph. papatasi and Ph. bergeroti, Ph. chabaudi, and Ph. riouxi, and Se. christophersi and Se. clydei.

Charting the evidence for climate change impacts on the global spread of malaria and dengue and adaptive responses: a scoping review of reviews

Background Climate change is expected to alter the global footprint of many infectious diseases, particularly vector-borne diseases such as malaria and dengue. Knowledge of the range and geographical context of expected climate change impacts on disease transmission and spread, combined with knowledge of effective adaptation strategies and responses, can help to identify gaps and best practices to mitigate future health impacts. To investigate the types of evidence for impacts of climate change on two major mosquito-borne diseases of global health importance, malaria and dengue, and to identify the range of relevant policy responses and adaptation strategies that have been devised, we performed a scoping review of published review literature. Three electronic databases (PubMed, Scopus and Epistemonikos) were systematically searched for relevant published reviews. Inclusion criteria were: reviews with a systematic search, from 2007 to 2020, in English or French, that addressed climate change impacts and/or adaptation strategies related to malaria and/or dengue. Data extracted included: characteristics of the article, type of review, disease(s) of focus, geographic focus, and nature of the evidence. The evidence was summarized to identify and compare regional evidence for climate change impacts and adaptation measures. Results A total of 32 reviews met the inclusion criteria. Evidence for the impacts of climate change (including climate variability) on dengue was greatest in the Southeast Asian region, while evidence for the impacts of climate change on malaria was greatest in the African region, particularly in highland areas. Few reviews explicitly addressed the implementation of adaptation strategies to address climate change-driven disease transmission, however suggested strategies included enhanced surveillance, early warning systems, predictive models and enhanced vector control. Conclusions There is strong evidence for the impacts of climate change, including climate variability, on the transmission and future spread of malaria and dengue, two of the most globally important vector-borne diseases. Further efforts are needed to develop multi-sectoral climate change adaptation strategies to enhance the capacity and resilience of health systems and communities, especially in regions with predicted climatic suitability for future emergence and re-emergence of malaria and dengue. This scoping review may serve as a useful precursor to inform future systematic reviews of the primary literature.

Vector Borne Diseases and Climate Change

The incidence of emergence diseases including vector borne diseases, water diseases, and some physiologic impairment is considered sensitive to climate. Malaria, leishmaniasis, dengue, and viral encephalitis are among those diseases most influenced by climate. Variation in the incidence of vector borne diseases is associated with extreme weather events and annual changes in weather conditions. Africa in general and Morocco in particular are designated as an area of significant impact by numerous the Intergovernmental Panel on Climate Change (IPCC) reports and notably susceptible to such drastic climate-related health consequences. Climatic parameter change would directly affect disease transmission by acting on the vector's geographic range, activity, or reproduction and by reduction the period of pathogen incubation. This chapter will discuss the increasing risk of some vector-borne diseases in hazard-prone localities. It further identifies the severe challenges both of health adaptation to climate change by highlighting Moroccan adaptive capacity to such crises.