Emerging and Re-emerging Vector-Borne Infectious Diseases and the Challenges for Control: A Review

Teaching inequity in vector-borne diseases management through a socioscientific issue framework

The distribution and management of vector-borne diseases (VBD) are affected by a social and cultural environment, including forms of systemic oppression such as racism and classism. University classes that cover these diseases usually focus on teaching biological concepts while skimming over other social, economic, and cultural factors that influence them. With no current lesson plan widely available to implement, we present a lesson plan intended to be delivered at the end of courses related to disease ecology to emphasize inequity issues that impact VBD management while also serving as a capstone for the biological content taught in the class. The lesson is based on the demographic and disease risk data from local contexts to provide effective place-based and socioscientific issues instruction. The lesson is designed as a role-playing simulation where groups of students are given separate disease outbreaks to combat with specific budgets. Therefore, each group has unequal resources to manage the disease depending on their specific local context. The simulation is followed by a discussion about equity in disease management. To make this activity broadly applicable, the lesson plan has been written in four languages (English, Portuguese, Spanish, and Mandarin) according to a diversity of corresponding locations (Texas-USA, Brazil, Spain, and China), which are included in the supplementary materials. Incorporating this lesson into curricula across multiple disciplines is an important step for developing future entomologists, parasitologists, epidemiologists, and other One Health professionals to address disparities in VBD control and help drive the field forward equitably.

Incorporating adult age into mosquito population models: Implications for predicting abundances in changing climates

Mosquito-borne diseases (MBDs) pose increasing threats under future climate change scenarios and an understanding of mosquito population dynamics is pivotal to predicting future risk of MBDs. Most models that describe mosquito population dynamics often assume that adult life-history is independent of adult age and yet mosquito senescence is known to affect mosquito mortality, fecundity and other key biological traits. Despite this, little is known about the effects of adult age at the level of the mosquito population, especially under varying temperature scenarios. We develop a stage-structured delayed differential equations (DDEs) model incorporating the effects of the abiotic environment and adult age to shed light on the complex interactions between age, temperature, and mosquito population dynamics. Taking Culex pipiens, a major vector of West Nile Virus, as our study species our results show that failing to consider mosquito senescence can lead to underestimates of future mosquito abundances predicted under climate change scenarios. We also find that the age-dependent mechanisms combined with the effects of density-dependent mortality on the immature stages can result in mosquito abundances decreasing at extreme temperatures. With our work, we underscore the need for more studies to consider the effects of mosquito age. Not accounting for senescence can compromise the accuracy of abundance estimates and has implications for predicting the risk of future MBD outbreaks.

Collaborative engagement with vector control stakeholders is key to enhance the utility of vector-borne disease models

BACKGROUND

Despite the growing complexity, computational power, and mapping capacity incorporated into vector-borne disease models, they still do not fully elucidate the role of environmental, demographic, socioeconomic, or other drivers, and rarely directly inform vector control efforts. To understand how we can improve the utility of vector-borne disease models for vector control activities, we interviewed vector control agents from the United States (USA) and the European Union.

METHODS

Between July and December 2023, in-depth interviews were held using a geographically targeted convenience sample with 26 individuals from organizations involved in vector control operations: 12 in the USA and 14 in the EU. We used both deductive and inductive coding of transcribed interviews to identify themes with the goal of understanding barriers to model use and uptake.

RESULTS

Despite the recognition that models could be useful, few interviewees reported that models informed surveillance and control activities, citing a mismatch in spatial and temporal scale between model outputs and operational decisions or a general lack of accessibility. Interviewees reported relying on experienced field experts and legacy protocols. Despite these critiques, there is belief that models can support operational decision-making.

CONCLUSIONS

The disconnect between models and users can be improved by allowing time and resources to build collaborative relationships, by acknowledging the knowledge all members bring, and by ensuring clear communication and mutual respect. Modelers must shift their focus by aligning vector-borne disease models with operational needs.

Quantifying national burdens of foodborne disease-Four imperatives for global impact

Estimates of national burdens of the foodborne disease (FBD) inform country-level food safety policies, ranking infectious and non-infectious FBD hazards in terms of health and socioeconomic impact to mitigate FBD burdens. Using relevant publications on FBD burdens from scientific literature, this review contends that four major imperatives (health, economic, planetary boundaries, governance) argue for a sustainable programme to quantify national FBD burdens. FBD disproportionately affects children under five years of age, and low- and middle-income countries. The economic costs are significant and include medical care, child development, lost productivity and international trade losses. Climatic changes and environmental contamination cause socio-ecological disruptions, increasing risk factors for FBD. Good governance promotes food safety initiatives, addressing in part under-diagnosis and underreporting. Strengthening national policies on FBD surveillance and burden estimation can promote food safety policies and address the global and national imperatives for FBD control. Evidence-based educational and regulatory interventions for FBD can promote improvements in the health and socioeconomic circumstances of the most vulnerable.

Spatial and seasonal dynamics of mosquito species in Harris County, Texas, highlight risk of arbovirus introduction and transmission

Mosquito-borne diseases pose a significant public health threat, particularly in densely populated urban areas. Climate change, urbanization, and global connectivity have fueled the expansion of mosquitoes and their associated pathogens, increasing the disease burden. Harris County, Texas, is among the most vulnerable regions in the United States for mosquito-borne disease outbreaks, underscoring the critical need for localized insights into mosquito population dynamics to inform vector surveillance and control strategies. This study provides a comprehensive analysis of the population dynamics of mosquito species in Harris County by exploring their species composition, spatial distribution, and seasonal patterns. Our findings reveal the extensive distribution of Culex quinquefasciatus and Aedes albopictus, with Aedes aegypti concentrated in highly urbanized areas. Notably, three of the five most abundant species are primary vectors of human pathogens, highlighting the urgent need for targeted interventions. By leveraging high-resolution surveillance data, this research deepens our understanding of mosquito dynamics and lays the groundwork for future studies investigating the effects of climate change, urbanization, and other environmental drivers on vector populations.

Diseases Transmitted by Arthropods: Module to Train Medical Providers in English and Spanish

Introduction

Arthropod-borne diseases like Chagas, dengue, and West Nile virus are common among migrants and immigrants from Spanish-speaking countries and U.S. travelers. The U.S. Census Bureau predicts that by 2060, 28% of the total U.S. population and 39% of the foreign-born population will be Hispanic. Health care practitioners need a thorough understanding of these diseases to provide proper care and improve patient compliance for the ever-changing U.S. population.

Methods

We used Kern's model to develop an hour-long interactive module consisting of a presentation, a video for large-group discussion, six case studies for small-group discussions, and pre- and postsession evaluations. All materials are available in English and Spanish; the module is tailored to health care providers communicating with Spanish-speaking patients. We used statistical tests to compare confidence levels and assess improvements in knowledge before and after the module.

Results

The module was implemented three times in Spanish and two times in English to a total of 49 participants, which included prehealth students, medical students, graduate students, and faculty/staff. The Wilcoxon rank sum test demonstrated significant improvement from pre- to postsession evaluations for all educational objectives. Based on a 5-point Likert scale, the median confidence level increased from 2 (slightly confident) to 4 (fairly confident), with p < .01.

Discussion

This module can be of particular importance to health care providers localized in or focused on Hispanic communities. It can be easily integrated into microbiology, epidemiology, and medical Spanish courses. Further research is needed to assess its effectiveness among faculty and staff.

Drug repositioning as a promising approach for the eradication of emerging and re-emerging viral agents

The global impact of emerging and re-emerging viral agents during epidemics and pandemics leads to serious health and economic burdens. Among the major emerging or re-emerging viruses include SARS-CoV-2, Ebola virus (EBOV), Monkeypox virus (Mpox), Hepatitis viruses, Zika virus, Avian flu, Influenza virus, Chikungunya virus (CHIKV), Dengue fever virus (DENV), West Nile virus, Rhabdovirus, Sandfly fever virus, Crimean-Congo hemorrhagic fever (CCHF) virus, and Rift Valley fever virus (RVFV). A comprehensive literature search was performed to identify existing studies, clinical trials, and reviews that discuss drug repositioning strategies for the treatment of emerging and re-emerging viral infections using databases, such as PubMed, Scholar Google, Scopus, and Web of Science. By utilizing drug repositioning, pharmaceutical companies can take advantage of a cost-effective, accelerated, and effective strategy, which in turn leads to the discovery of innovative treatment options for patients. In light of antiviral drug resistance and the high costs of developing novel antivirals, drug repositioning holds great promise for more rapid substitution of approved drugs. Main repositioned drugs have included chloroquine, ivermectin, dexamethasone, Baricitinib, tocilizumab, Mab114 (Ebanga™), ZMapp (pharming), Artesunate, imiquimod, saquinavir, capmatinib, naldemedine, Trametinib, statins, celecoxib, naproxen, metformin, ruxolitinib, nitazoxanide, gemcitabine, Dorzolamide, Midodrine, Diltiazem, zinc acetate, suramin, 5-fluorouracil, quinine, minocycline, trifluoperazine, paracetamol, berbamine, Nifedipine, and chlorpromazine. This succinct review will delve into the topic of repositioned drugs that have been utilized to combat emerging and re-emerging viral pathogens.

Imported fever in returning travellers and migrants in Spain, 2009-2021. Analysis by the +REDIVI network

BACKGROUND

Travellers and migrants commonly present to health services with febrile syndrome, which can have different causes, including some that are life-threatening. A better understanding of these causes may help guide management and determine appropriate empirical treatments.

OBJECTIVES

The aim was to identify the leading causes of fever and to assess their association with the region of travel and type of travellers.

METHODS

This prospective, multicentre study was conducted within the +REDIVI network. Data were collected on febrile syndrome cases among migrants, travellers, and people visiting friends and relatives (VFRs) from 2009 to 2021. Comparative analyses were performed according to patient categories and regions of travel/origin.

RESULTS

Of the 4186 patients with febrile syndrome, the most frequent diagnosis was malaria (31.0 %), followed by dengue fever (12.0 %) and nonspecific fever of less than three weeks' duration (11.6 %). Malaria predominated in people coming from sub-Saharan Africa (58.4 %), while dengue fever was more common in the rest of the regions (19.0 % in South America, 25.0 % in Central America and the Caribbean, 34.2 % in Southeast Asia, and 18.1 % in South-Central Asia). By type of traveller, tuberculosis was more frequent in migrants, malaria in VFRs, and dengue and other arboviral infections in travellers and VFRs.

CONCLUSIONS

Geographical area of travel and type of traveller are the main determinants of imported fever aetiology. Malaria remains the most common cause of febrile syndrome, especially in VFRs from sub-Saharan Africa, while dengue fever prevails in the other tropical regions.

Seroprevalence and Risk Factors of Crimean-Congo Hemorrhagic Fever Exposure in Wild and Domestic Animals in Benin

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic viral disease prevalent in Africa. While infection is asymptomatic in animals, it can cause severe illness with hemorrhagic manifestations and high mortality rates in humans. This study aimed to determine the seroprevalence and potential risk factors of CCHF in wild (rodents, birds) and domestic (cattle, horses) animals in Benin. A cross-sectional study was carried out from 2022 to 2024 with the assistance of cattle breeders, hunters, farmers and bushmeat sellers in 15 districts found in three agroecological zones in the country. A total of 366 serum samples were analyzed, comprising 254 collected from wild animals and 112 from domestic animals. Among the wild animals tested, 1.18% (95% CI: 0.31-3.70; n = 3) were seropositive for antibodies against CCHF virus (CCHFV). The seroprevalence rates were 3.7% (95% CI: 0.19-20.89) in squirrels, 5.88% (95% CI: 0.31-30.76) in hares and 1.19% (95% CI: 0.06-7.38) in giant rats. In domestic animals, anti-CCHFV antibodies were detected in 38 of the 112 samples, resulting in an overall seroprevalence of 33.93% (95% CI: 25.42-43.56). Specifically, antibodies were identified in 34 out of 81 cattle (41.98%, 95% CI: 31.26-53.46) and 4 out of 24 horses (16.67%, 95% CI: 5.48-38.19). No positive samples were reported in pigeons. This study provides the first seroprevalence data on CCHF in wild and domestic animals in Benin. It highlights the risk and epidemiological dynamics of the disease and underscores the need for further investigations into tick vectors and human populations.

Viral metagenomics of hematophagous insects collected in the Carajas mining complex, Pará State, Brazil

Hematophagous insects are vectors of viruses that cause diseases in humans and animals worldwide. Mosquitoes (Culicidae), biting midges (Ceratopogonidae), and sandflies (Psychodidae) were collected in three municipalities (Marabá, Canaã dos Carajás, and Curionópolis) in the state of Pará, Brazil, in 2019. Morphological keys were used for the taxonomic identification of insect species. High-throughput sequencing and metagenomic analysis were employed to characterize the viromes of the hematophagous insects. We characterized the virome of 839 insects grouped into 14 pools. A total of 729 million paired reads were generated, with 12 million viral sequences (3 % of the reads). The families Reoviridae, Myoviridae, Retroviridae, and Poxviridae were found in all samples of this study. Phylogenies of RNA-dependent RNA polymerase (RdRp) from viruses of the families Chuviridae, Dicistroviridae, Flaviviridae, Iflaviridae, Mesoniviridae, Phenuiviridae, and Rhabdoviridae were performed. In this study, the first isolation of the Guaico Culex Virus (GCXV) in the northern region of Brazil was obtained from a pool of Culex (Melanoconion) spp. mosquitoes collected in Curionópolis. The data obtained in this study demonstrate that the Carajás region has an ecosystem rich in viruses. Additional studies are needed to understand the dynamics of viruses in vectors, vertebrates, and the human population in the region.

HL-IR mediates cinnamaldehyde repellency behavior in parthenogenetic Haemaphysalis longicornis

Chemical repellents against arthropods have limitations in terms of toxicity and resistance. Natural plant compounds can be utilized as alternatives for developing environmentally friendly repellents for humans and animals. A variety of plant essential oils exhibit strong repellent effects against ticks; however, the mechanisms of action against ticks remain unknown. Here, we investigated the repellency of cinnamaldehyde, a primary compound found in cinnamon oil, and demonstrated that it affected the electrophysiological responses on Haller's organs of parthenogenetic Haemaphysalis longicornis. Transcriptome data indicated that the cinnamaldehyde response was linked to ionotropic receptor (HL-IR) at various tick developmental stages. HL-IR was widely expressed in a variety of tissues and developmental stages of ticks according to RT-qPCR. In situ hybridization results showed that HL-IR was highly expressed on Haller's organs of the ticks. Microinjection of HL-IR double-stranded RNA (dsRNA) showed that reduced transcript levels led to significant decreases in the tick repellency rate from cinnamaldehyde and the EAG response of Haller's organ. Experiments using competitive fluorescence binding and mutation sites showed that 218ASN was the critical binding site for cinnamaldehyde and HL-IR. We conclude that Haller's organ of ticks expresses HL-IR, and that this interaction mediates tick-repellent behavior by binding to cinnamaldehyde.

High seroprevalence of selected vector-borne pathogens in dogs from Saipan, Northern Mariana Islands

BACKGROUND

Canine vector-borne diseases (CVBDs) are illnesses caused by pathogens transmitted by blood-feeding arthropods such as ticks and mosquitoes. Many CVBDs, including dirofilariosis, anaplasmosis, and ehrlichiosis, are globally distributed and may cause a variety of clinical signs in dogs. Several CVBD agents are zoonotic, making epidemiological surveillance a joint veterinary and public health effort. In this study, we determined the seropositivity of four pathogens from dogs on Saipan, Northern Mariana Islands, a US Commonwealth located in the western Pacific Ocean.

METHODS

Blood samples (n = 443) were collected from client-owned, owner surrendered, and shelter dogs that participated in an island-wide spay-and-neuter event in 2023. All samples were assessed using a commercial, point-of-care enzyme-linked immunosorbent assay (ELISA) test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) to detect the Dirofilaria immitis antigen and antibodies against Ehrlichia spp., Anaplasma spp., and Borrelia burgdorferi sensu lato. Risk factors were assessed for each pathogen through a univariate analysis, followed by a multivariable logistic regression.

RESULTS

Overall, 66.1% (n = 300/443) of the dogs tested positive for at least one pathogen, with the highest prevalence observed for Ehrlichia spp. (58.0%; n = 246/443), followed by Anaplasma spp. (43.1%; n = 184/443) and D. immitis (14.8%; n = 63/443). Among the dogs with a single pathogen detected (30.9%; n = 137/443), Ehrlichia spp. was most prevalent (64.9%; n = 89/137), followed by Anaplasma spp. (23.3%; n = 32/137) and D. immitis (11.6%; n = 16/137). For co-detection of two or more pathogens (36.7%; n = 163/443), Ehrlichia spp. + Anaplasma spp. presented the highest frequency (70.5%; n = 115/163), followed by Ehrlichia spp. + D. immitis (6.7%; n = 11/163), Anaplasma spp. + D. immitis (3.6%; n = 6/163), and Ehrlichia spp. + Anaplasma spp. + D. immitis (19.0%; n = 31/163). Age (P = < 0.001), residing district (P = 0.001), and ownership status (P = < 0.001) were significantly associated with D. immitis positive status in a univariable analysis. Age (P = < 0.001), residing district (P = 0.177), and ownership status (P = 0.014) were significant in a univariable analysis with Ehrlichia spp. as an outcome. Finally, Anaplasma spp. had a significant association with ownership status (P = < 0.001) as a risk factor in a univariable analysis.

CONCLUSIONS

This study shows high seropositivity for CVBPs in a dog population living in a poorly studied area. The results of this study suggest that strategies for the prevention and control of these CVBDs should be reinforced on the Island of Saipan.

Dengue: epidemiology, diagnosis methods, treatment options, and prevention strategies

Dengue is an arboviral disease caused by dengue virus, which is mostly found in tropical regions, and the number of human cases has increased dramatically since 2000, with 5.2 million cases reported in 2019, according to WHO reports, 70% of which were in Southeast Asia, the Western Pacific, and Asia. Dengue infection can result in a wide range of clinical manifestations, ranging from fever to severe dengue shock syndrome, which can be fatal, particularly in those with secondary dengue. This review of the aetiology of dengue fever examines the complex interactions between the virus and the immune system and the interaction between viral and host factors and also covers outbreaks, the severity of disease caused by different serotypes, and methods for diagnosis of dengue, such as serological tests, nucleic acid amplification tests, and ELISA assays for detecting the NS1 antigen. Current treatment options and prevention strategies, including vector control measures, environmental interventions, and insect repellents are also discussed. This review highlights the challenges involved in developing a dengue vaccine, which is complicated by the need for an efficient and balanced immune response against all genotypes of the four serotypes.

A One Health Perspective on the Resurgence of Flea-Borne Typhus in Texas in the 21st Century: Part 1: The Bacteria, the Cat Flea, Urbanization, and Climate Change

Flea-borne typhus (FBT), due to Rickettsia typhi and R. felis, is an infection typically causing fever, headache, rash, hepatitis, and thrombocytopenia. About one quarter of patients suffer pulmonary, neurologic, hematologic, renal, hepatic, cardiac, ocular or other complications. In the 21st century, the incidence of FBT has increased in both Texas and California compared to the 1990s. In this paper, county-level epidemiological data for the number of cases of FBT occurring in Texas for two decades, 1990-1999 and 2010-2019, were compared with respect to county of residence, urbanization, and climatic region. Human population growth in Texas has promoted FBT by increased urbanization and the abundance of pet dogs and cats, stray/feral dogs and cats, and opossums. Increasing temperatures in Texas in the new millennium have increased the flea-borne transmission of FBT by promoting host infestation and flea feeding and defecation, accelerating the flea life cycle, and increasing rickettsial replication within the flea. Increased numbers of opossums and stray cats and dogs in the urban/suburban landscape have increased the risk of flea transfer to humans and their pets.

Vector borne disease control interventions in agricultural and irrigation areas in sub-Saharan Africa: A systematic review

Irrigation farming has raised concerns about the steady transmission and introduction of new vector-borne infectious diseases (VBD) in the areas involved. This systematic review aimed to determine interventions that are effective for the management and control of VBDs in irrigation areas in sub-Saharan Africa (SSA). We searched the literature on VBD interventions in SSA from published and grey literature without specifying the publication year. A search strategy identified 7768 records from various databases, and after screening, 16 were included in the final analysis. Results showed various VBD control interventions were effective, including indoor residue spray (IRS), insect-treated nets (ITN), larva source management (LSM), mass drug administration (MDA), integrated vector management (IVM), and mollusciciding. IVM was commonly practiced, and its success was because of the complementarity of the various interventions involved. Successful VBD control interventions led to improved health amongst irrigation communities and consequently improved agricultural productivity. However, some challenges to these interventions were identified, which include seasonal changes and climate variability, insecticide and drug resistance, and farmers' attitudes toward accepting the interventions. Regardless, results showed that VBD control and management can be integrated into irrigation farming before or after the establishment of the irrigation scheme.

Zoonotic Host Richness in the Global Wildland-Urban Interface

Where human settlements abut or intermix with wildlands, people may encounter animals that host zoonotic pathogens which can spillover to cause human disease. Known as the wildland-urban interface (WUI), this zone occupies around 5% of the Earth's surface and is home to 3.5 billion people. The rapid spread of SARS-CoV-2 has demonstrated the importance of understanding risk factors for disease among an increasingly urbanized population. However, the contribution of the WUI to zoonotic disease risk is poorly understood. Here, we show that low-level host richness occurs throughout most of the global WUI, and 20% of the human WUI population live in zones of particularly high zoonotic potential, where more than 20 host species could occur. Zones of high zoonotic potential are concentrated in low-middle-income countries (LMICs) across equatorial Africa, Brazil, Central America, and Southeast Asia where vulnerability is further elevated by widespread poverty, inadequate housing, and lack of easily accessible healthcare. Three of four people living in WUIs with high host richness (520 million people) are in LMICs. Of this population, 35% (183 million) live in and around cities in West, East, and South Africa. This means that WUI-based populations of LMICs may face the double threat of high zoonotic potential and vulnerability to disease. Our results identify global priorities for monitoring exposure to zoonotic diseases in the rapidly expanding WUI.

Deep learning in disease vector image identification

Vector-borne diseases (VBDs) represent a critical global public health concern, with approximately 80% of the world's population at risk of one or more VBD. Manual disease vector identification is time-consuming and expert-dependent, hindering disease control efforts. Deep learning (DL), widely used in image, text, and audio tasks, offers automation potential for disease vector identification. This paper explores the substantial potential of combining DL with disease vector identification. Our aim is to comprehensively summarize the current status of DL in disease vector identification, covering data collection, data preprocessing, model construction, evaluation methods, and applications in identification spanning from species classification to object detection and breeding site identification. We also discuss the challenges and possible prospects for DL in disease vector identification for further research. © 2024 Society of Chemical Industry.

Dose and strain dependent lethality of Usutu virus in an Ifnar-/- mouse model

Usutu virus (USUV) is a mosquito-borne zoonotic flavivirus with a geographic range that has expanded over recent years. Maintained in a transmission cycle between mosquito vectors and avian reservoirs the virus can cause large seasonal outbreaks in bird populations, but spillover into mammalian hosts has also been reported. While usually mild or asymptomatic in humans, neurological disorders are increasingly observed, which has boosted interest and the need for better understanding of the pathogenesis of various USUV lineages. In this study we inoculated interferon α/β receptor knockout (Ifnar-/-) mice with decreasing doses of USUV, monitoring symptoms and survival to determine a less lethal dose, and we directly compared isolates from three different viral lineages. We found that a Dutch isolate of USUV Africa-3 lineage is lethal at a dose of 20 pfu per mouse, which is considerably lower than what was anticipated based upon the literature. A Europe-2 strain showed an even higher virulence in this mouse model, compared to strains from Africa-3 and Europe-3 lineages-though this was not reflected in in vitro studies. These results enhance our understanding of the pathogenicity of different USUV strains and provide guidance for the use of low doses for inoculation in an Ifnar-/- animal model.

Modeling the Impact of Seasonality on Mosquito Population Dynamics: Insights for Vector Control Strategies

Mosquitoes are important vectors for the transmission of some major infectious diseases of humans, i.e., malaria, dengue, West Nile Virus and Zika virus. The burden of these diseases is different for different regions, being highest in tropical and subtropical areas, which have high annual rainfall, warm temperatures, and less pronounced seasonality. The life cycle of mosquitoes consists of four distinct stages: eggs, larvae, pupae, and adults. These life stages have different mortality rates and only adults can reproduce. Seasonal weather may affect the population dynamics of mosquitoes, and the relative abundance of different mosquito stages. We developed a stage-structured model that considers laboratory experiments describing how temperature and rainfall affects the reproduction, maturation and survival of different Anopheles mosquito stages, the species that transmits the parasite that causes malaria. We consider seasonal temperature and rainfall patterns and describe the stage-structured population dynamics of the Anopheles mosquito in Ain Mahbel, Algeria, Cape Town, South Africa, Nairobi, Kenya and Kumasi, Ghana. We find that neglecting seasonality leads to significant overestimation or underestimation of mosquito abundance. We find that depending on the region, mosquito abundance: peaks one, two or four times a year, periods of low abundance are predicted to occur for durations ranging from six months (Ain Mahbel) to not at all (Nairobi); and seasonal patterns of relative abundance of stages are substantially different. The region with warmer temperatures and higher rainfall across the year, Kumasi, Ghana, is predicted to have higher mosquito abundance, which is broadly consistent with reported malaria deaths relative to the other countries considered by our study. Our analysis reveals distinct patterns in mosquito abundance across different months and regions. Control strategies often target one specific life stage, for example, applying larvicides to kill mosquito larvae, or spraying insecticides to kill adult mosquitoes. Our findings suggest that differences in seasonal weather affect mosquito stage structure, and that the best approaches to vector control may differ between regions in timing, duration, and efficacy.

Essential oil and furanosesquiterpenes from myrrh oleo-gum resin: a breakthrough in mosquito vector management

Mosquitoes (Diptera: Culicidae) are vectors of various pathogens of public health concern and replacing conventional insecticides remains a challenge. In this regard, natural products represent valuable sources of potential insecticidal compounds, thus increasingly attracting research interest. Commiphora myrrha (T.Nees) Engl. (Burseraceae) is a medicinal plant whose oleo-gum resin is used in food, cosmetics, fragrances, and pharmaceuticals. Herein, the larvicidal potential of its essential oil (EO) was assessed on four mosquito species (Aedes albopictus Skuse, Aedes aegypti L., Anopheles gambiae Giles and Anopheles stephensi Liston), with LC50 values ranging from 4.42 to 16.80 μg/mL. The bio-guided EO fractionation identified furanosesquiterpenes as the main larvicidal compounds. A GC-MS-driven untargeted metabolomic analysis revealed 32 affected metabolic pathways in treated larvae. The EO non-target toxicity on Daphnia magna Straus (LC50 = 4.51 μL/L) and its cytotoxicity on a human kidney cell line (HEK293) (IC50 of 14.38 μg/mL) were also assessed. This study shows the potential of plant products as innovative insecticidal agents and lays the groundwork for the possible exploitation of C. myrrha EO in sustainable approaches for mosquito management.

Use of ProMED as a Surveillance System for Emerging and Re-Emerging Infectious Diseases in Brazil from 2015 to 2020

Emerging and re-emerging infectious diseases have been frequently reported in Brazil. The Program for Monitoring Emerging Diseases (ProMED) is a virtual system with expert curation for monitoring health events, including those occurring in Brazil. This study aimed to describe the ProMED as a complementary surveillance system for emerging infectious diseases in Brazil. It has a retrospective and descriptive design, and was conducted using ProMED-PORT reports that cited Brazil and were published from 1 January 2015, to 31 December 2020. In total, 220 new reports were identified during the study period. Most of these were published between January and June. Reports on humans were predominant (n = 177), and comprised 78 kinds of events, most of which were related to arboviruses. Reports on animals were the second most prevalent (n = 35), and encompassed 18 kinds of events, particularly yellow fever in non-human primates, rabies in different mammals, and sporotrichosis in felines. Six (2.7%) reports were related to humans and animals, while two (0.9%) were related to plants or the environment. Most reports were from Southeast and Northeast regions. ProMED identified leading emerging and reemerging infectious diseases in Brazil, serving as an information source for local and international health authorities.

SFG and TG seropositivity in Humans suspected of TBD in Yucatan, Mexico

Since 1996, the incidence of rickettsiosis has been increasing in Yucatán, Mexico, but recent prevalence data are lacking. This study aimed to determine exposure to the Spotted Fever Group (SFG) and Typhus Group (TG) in human serum samples suspected of tick-borne diseases (TBD) between 2015 and 2022. A total of 620 samples were analysed using indirect immunofluorescence assay (IFA) to detect IgG antibodies against SFG (Rickettsia rickettsii) and TG (Rickettsia typhi), considering a titer of ≥64 as positive. Results showed that 103 samples (17%) were positive for R. rickettsii and 145 (24%) for R. typhi, while 256 (41%) and 229 (37%) were negative, respectively. There was a cross-reaction in 244 samples (39%). Individuals with contact with vectors, such as ticks, showed significant exposure to fleas (p = 0.0010). The study suggests a high prevalence of rickettsiosis and recommends prospective studies to assess the disease burden and strengthen surveillance and prevention in Yucatán, considering factors like temperature and ecological changes.

Repellency of Essential Oils and Plant-Derived Compounds Against Aedes aegypti Mosquitoes

Plant-based oils have a long history of use as insect repellents. In an earlier study, we showed that in a 10% concentration, geraniol, 2-phenylethl propionate, and the plant-based essential oils clove and cinnamon effectively protected from mosquito bites for over 60 min. To expand on this study, we reanalyzed our GC-MS data to identify the short organic constituents of these oils. We then used an arm-in-cage assay to test the repellency of different concentrations and combinations of these oils and pure compounds. We found a sigmoidal relationship between the complete protection time from mosquito bites and the concentration of these oils. The complete protection times we recorded for combinations of these oils suggest an absence of additive effects. The results of this study can inform the development of novel, effective, and plant-based insect repellents.

Reconciling heterogeneous dengue virus infection risk estimates from different study designs

Uncovering rates at which susceptible individuals become infected with a pathogen, i.e., the force of infection (FOI), is essential for assessing transmission risk and reconstructing distribution of immunity in a population. For dengue, reconstructing exposure and susceptibility statuses from the measured FOI is of particular significance as prior exposure is a strong risk factor for severe disease. FOI can be measured via many study designs. Longitudinal serology is considered gold standard measurements, as they directly track the transition of seronegative individuals to seropositive due to incident infections (seroincidence). Cross-sectional serology can provide estimates of FOI by contrasting seroprevalence across ages. Age of reported cases can also be used to infer FOI. Agreement of these measurements, however, has not been assessed. Using 26 y of data from cohort studies and hospital-attended cases from Kamphaeng Phet province, Thailand, we found FOI estimates from the three sources to be highly inconsistent. Annual FOI estimates from seroincidence were 1.75 to 4.05 times higher than case-derived FOI. Seroprevalence-derived was moderately correlated with case-derived FOI (correlation coefficient = 0.47) with slightly lower estimates. Through extensive simulations and theoretical analysis, we show that incongruences between methods can result from failing to account for dengue antibody kinetics, assay noise, and heterogeneity in FOI across ages. Extending standard inference models to include these processes reconciled the FOI and susceptibility estimates. Our results highlight the importance of comparing inferences across multiple data types to uncover additional insights not attainable through a single data type/analysis.

Insect-specific RNA viruses detection in Field-Caught Aedes aegypti mosquitoes from Argentina using NGS technology

Mosquitoes are the primary vectors of arthropod-borne pathogens. Aedes aegypti is one of the most widespread mosquito species worldwide, responsible for transmitting diseases such as Dengue, Zika, and Chikungunya, among other medically significant viruses. Characterizing the array of viruses circulating in mosquitoes, particularly in Aedes aegypti, is a crucial tool for detecting and developing novel strategies to prevent arbovirus outbreaks. In this study, we address the implementation of a sequencing and analysis pipeline based on the Oxford Nanopore Technologies MinION Mk1b system, for arboviral detection in field-caught mosquitoes from Argentina. Full genome of Humaita Tubiacanga Virus (HTV), Phasi Charoen-like Phasivirus (PCLV), Aedes aegypti totivirus (AaeTV) has been sequenced in three distinct regions of Argentina comprising Buenos Aires province, Santa Fe province and the northern province of Salta. Viral sequences enriched by SISPA and coupled with Nanopore sequencing can be a useful tool for viral surveillance, not only for detecting viruses that have a high impact on human and animal health, but also for detecting insect-specific viruses that could promote the transmission of arboviruses.

A systematic review on malaria and dengue vaccines for the effective management of these mosquito borne diseases: Improving public health

Insect vector-borne diseases (VBDs) pose significant global health challenges, particularly in tropical and subtropical regions. The WHO has launched the "Global Vector Control Response (GVCR) 2017-2030" to address these diseases, emphasizing a comprehensive approach to vector control. This systematic review investigates the potential of malaria and dengue vaccines in controlling mosquito-borne VBDs, aiming to alleviate disease burdens and enhance public health. Following PRISMA 2020 guidelines, the review incorporated 39 new studies out of 934 identified records. It encompasses various studies assessing malaria and dengue vaccines, emphasizing the significance of vaccination as a preventive measure. The findings indicate variations in vaccine efficacy, duration of protection, and safety considerations for each disease, influencing public health strategies. The review underscores the urgent need for vaccines to combat the increasing burden of VBDs like malaria and dengue, advocating for ongoing research and investment in vaccine development.

Microbiome of Hyalomma dromedarii (Ixodida: Ixodidae) Ticks: Variation in Community Structure with Regard to Sex and Host Habitat

Hyalomma dromedarii ticks are the main hematophagous ectoparasites of camels, harboring a variety of microbes that can affect tick vector competence and pathogen transmission. To better understand the tick microbiome influenced by sex and host habitat, we analyzed the bacterial community of H. dromedarii male and female ticks collected from camel farms, livestock markets, and slaughterhouses, representing the range of major habitats in the UAE, by sequencing the 16S rRNA gene. Tick samples were collected during 2022 and 2023. A total of 40 ticks (male (15), female (15), and nymph (10)) were selected from tick samples collected from camels and processed for genomic DNA and next-generation sequencing using the Illumina MiSeq platform. We obtained 151,168 read counts, and these formed 237 operational taxonomic units representing 11 phyla, 22 classes, 77 families, and 164 genera. The phyla Actinomycetota, Bacillota, Bacteroidota, Pseudomonadota, and Fusobacteriota were the most abundant. The bacterial genus Corynebacterium dominated the microbiomes of farm-collected female H. dromedarii ticks, while Proteus dominated the microbiomes of farm-collected male H. dromedarii ticks. In comparison, the microbiomes of H. dromedarii ticks collected from slaughterhouse samples were dominated by genus Francisella in both males and females. Our results confirm that the bacterial microbiomes of H. dromedarii ticks vary by sex and habitat settings. Furthermore, recent findings could deliver insight into the differences in the ability of camel ticks to acquire, maintain, and transmit pathogens in various habitats that may impact the tick vector competence of medically and agriculturally important species in the Middle East and North Africa (MENA) region and Asia.

Climate change and the emergence and exacerbation of infectious diseases: A review

Experts expressed severe concerns over the possibility of increasing burden of infectious diseases as the planet's climate began to change years ago. There have been increased rates of climate-related catastrophes and as global temperatures rise, emergence of certain viruses has become a serious concern. Vectors are susceptible to changing temperatures as they exhibit innate responses to thermal stress to increase survivability. Climate change impacts virus reservoirs, increasing transmission rates of vectors. Vector-borne diseases have already witnessed increasing numbers compared to before. Certain non-endemic areas are encountering their first-ever infectious disease cases due to increasing temperatures. Tick-borne diseases are undergoing transformations provoking a heightened prevalence. Food-borne illnesses are expected to increase owing to warmer temperatures. It is important to recognize that climate change has a multivariable impact on the transmission of viruses. With climate change comes the potential of increasing interspecies interactions promoting jumps. These factors must be considered, and an informed strategy must be formulated. Adaptation and mitigation strategies are required to curb these diseases from spreading. Despite significant evidence that climate change affects infectious diseases, gaps in research exist. We conducted this review to identify the potential role climate change plays in the emergence of new viruses.

Research progress toward arthropod salivary protein vaccine development for vector-borne infectious diseases

Hematophagous arthropods, including mosquitoes, ticks, and flies, are responsible for the transmission of several pathogens to vertebrates on whom they blood feed. The diseases caused by these pathogens, collectively known as vector-borne diseases (VBDs), threaten the health of humans and animals. In general, attempts to develop vaccines for pathogens transmitted by arthropods have met with moderate success, with few vaccine candidates currently developed. Nowadays, there are vaccine candidates under clinical trials, including different platforms, like mRNA, DNA, recombinant viral vector-based, virus-like particles (VLPs), inactivated-virus, live-attenuated virus, peptide and protein-based vaccines, all of them based on the presentation of pathogen antigens to the host immune system. A new approach to prevent VBDs has arose during the last decades, based on the design of vaccines that target vector-derived antigens. The salivary secretions of arthropods, in addition of causing allergic reactions and harbor pathogens, are also involved in the transmission and infection establishment in the host, altering its immune responses. In this review, we summarize the achievements in the arthropod salivary-based vaccine development for different vector-borne infectious diseases. This provides a rationale for creating vaccines against different types of arthropod salivary proteins, such as mosquitoes, ticks, and sand flies. Using salivary proteins of clinically important vectors might contribute to achieve protection against and control multiple arthropod-borne infection diseases.

COMPARATIVE LABORATORY ACTIVITY AND SEMI-FIELD EFFICACY OF OMNIPRENE® G AND ALTOSID® PELLETS AGAINST AEDES AEGYPTI

Mosquito larval control by biorational larvicides plays a crucial role in mosquito and mosquito-borne disease management. However, the availability of larvicides that meet the criteria of efficacy, safety, and quality is limited and conventional pesticides are no longer preferred for larval control. Although efforts are made to research new active ingredients (AIs), it is equally important to innovate new formulations based on currently available AIs such as microbial agents and insect growth regulators. Studies were therefore conducted to compare the laboratory activity and semi-field efficacy of OmniPrene® G and Altosid® Pellets with DR-tech, both containing 4.25% S-methoprene, at 2.8 kg/ha and 11.2 kg/ha against the yellow fever mosquito Aedes aegypti (L.) in outdoor microcosms. Both products performed equally in bioassays against the test species with comparable inhibition of emergence activities. In the semi-field study, the lower dose of Altosid Pellets at 2.8 kg/ha, showed lower efficacy than OmniPrene G during the initial 6 weeks; this difference became negligible on week 7, followed by higher efficacy in Altosid Pellets on weeks 8 and 9. More uniform efficacy was observed at the higher dose of 11.2 kg/ha. Equal performance was revealed during weeks 2 to 6, with the OmniPrene G outperforming the Altosid Pellets in week 1, but the opposite during weeks 7 to 9. Mortality patterns were similar in both products, i.e., majority of mortality occurred before emergence, although more incomplete emergence was noted in lower doses, particularly in Altosid Pellets. Overall, newly available OmniPrene G provided comparable activity and efficacy with Altosid Pellets against the test species, with the advantages of fast initial AI release and even coverage, particularly when applied at low doses.

The Wildlife Malaria Research network (WIMANET): Meeting report on the 1st WIMANET workshop

The Wildlife Malaria Network (WIMANET) is a groundbreaking multinational collaboration focused on studying vector-borne haemosporidian parasites in wildlife. Unlike human malaria, wildlife malaria is found on all continents except Antarctica, with parasites being transmitted by a range of vectors. The complexity and diversity of these parasites makes it necessary to have an interdisciplinary approach to understand and mitigate their impacts. Established in 2023 within the framework of COST-Action (European Cooperation in Science and Technology), WIMANET unites researchers from diverse scientific backgrounds to tackle critical questions about wildlife malaria on a global scale. This meeting report summarises the activities and plans resulting from the 1st meeting of WIMANET's six working groups, spanning the genetic and morphological identification of parasites to understanding the drivers of host-parasite-vector associations from individual to community levels. WIMANET's collaborative efforts aim to fill the knowledge gaps and foster large-scale research initiatives transcending local and regional boundaries.

Structural elucidation of andrographolide from Andrographis paniculata and its ovicidal, larvicidal and pupicidal activities against Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae)

Both human beings and animals around the globe are vulnerable to the transmission of infectious diseases carried by mosquitoes. They have the ability to transmit a diverse array of pathogenic agents, such as viruses and parasites, while feeding on blood. The objective of this research is to investigate andrographolide isolation, characterization, and structure elucidation from Andrographis paniculata. Furthermore, it aims to evaluate the activity of andrographolide against the immature stages of Aedes aegypti and Culex quinquefasciatus. The fractions obtained from A. paniculata extracts underwent further purification and analysis to identify the most active ones. To confirm the structure of andrographolide, spectroscopic methods including IR, 1H-NMR, 13C-NMR, and GC-MS were used. Biological assays were conducted to assess its ovicidal, larvicidal, and pupicidal activities. Importantly, andrographolide demonstrated moderate ovicidal activity, resulting in mortality rates of 36% and 32% in Ae. aegypti and Cx. quinquefasciatus eggs, respectively, at a concentration of 2 ppm. Additionally, it exhibited strong larvicidal and pupicidal efficacy, with LC50 values of 2.02 ppm and 3.19 ppm against Ae. aegypti larvae and pupae, and 2.14 ppm and 2.73 ppm against Cx. quinquefasciatus larvae and pupae. These findings highlight the potential of andrographolide as a powerful natural compound in mosquito control efforts. Furthermore, this study underscores the importance of natural products as viable alternatives to synthetic insecticides in managing vector-borne diseases.

Spatial examination of social and environmental drivers of Middle East respiratory syndrome coronavirus (MERS-CoV) across Kenya

Climate and agricultural land-use change has increased the likelihood of infectious disease emergence and transmissions, but these drivers are often examined separately as combined effects are ignored. Further, seldom are the influence of climate and agricultural land use on emerging infectious diseases examined in a spatially explicit way at regional scales. Our objective in this study was to spatially examine the climate, agriculture, and socio-demographic factors related to agro-pastoralism, and especially the combined effects of these variables that can influence the prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels across northern Kenya. Our research questions focused on: (1) How MERS-CoV in dromedary camels has varied across geographic regions of northern Kenya, and (2) what climate, agriculture, and socio-demographic factors of agro-pastoralism were spatially related to the geographic variation of MERS-CoV cases in dromedary camels. To answer our questions, we analyzed the spatial distribution of historical cases based on serological evidence of MERS-CoV at the county level and applied spatial statistical analysis to examine the spatial relationships of the MERS-CoV cases between 2016 and 2018 to climate, agriculture, and socio-demographic factors of agro-pastoralism. Regional differences in MERS-CoV cases were spatially correlated with both social and environmental factors, and particularly ethno-religious camel practices, which highlight the complexity in the distribution of MERS-CoV in dromedary camels across Kenya.

Development of flame retardant slow release insecticides paint and testing its efficacy for four years against dengue and malaria vectors

Insecticide based paint formulations have been available since years, however the concept of using such paint products at household level did not get attention due to various reasons. The advancement in insecticidal paint technology has steered toward the development and evaluation of such formulations for use against arthropod vectors. The improved insecticidal paint formulations may contain two or more active agents, hence could display different type of activity against the target vectors. In the present study, optimum concentrations of deltamethrin (1%), chlorpyriphos (0.5%) and pyriproxyfen (0.075%) were used as active ingredients (AIs) to develop flame retardant slow-release insecticides paint (FRSRIP) formulation. The developed formulation was tested for physico-chemical properties, toxicity and efficacy against two important mosquito vectors. The formulation was glossy, smooth, uniform and scratch proof. Furthermore, the formulation was flame retardant and conformed to class-A according to the guidelines. Acute oral, dermal and inhalation toxicity suggested that the formulation is safe for use in human dwellings. The formulation was evaluated against Ae. aegypti and An. stephensi mosquitoes in laboratory upto four years. It was found that KDT50 after 24 months (T24) was 14.8 ± 0.8 min and 17.1 ± 1.0 min, while after 48 month (T48) was 21.3 ± 2.0 min and 22.4 ± 1.4 min in both Ae. aegypti and An. stephensi respectively. KDT50 was found varying during the different time intervals (T6 to T48) in both Ae. aegypti (p = 0.01) and An. stephensi (p = 0.0003). Furthermore the corrected mortality (CM) also found statistically declined during the period of evaluation (T6 to T48) in both the test species (F ≥ 42. 4; p ≤ 0.0001). Ae. aegypti mosquitoes that survived FRSRIP exposure exhibited overall decline in total eggs laid, eggs hatched, pupae formed and adult emerged at different time intervals upto T21. Behavioural experiments showed that both the tested species elicited negative response to the test formulation. The concentrations of all the three active agents were estimated by HPLC after different time intervals, however only deltamethrin (0.24%) was found after T48. The developed formulation was stable, safe and effective against mosquito vectors for a considerably longer time. In the pretext of continuous toll of vector borne diseases and trans-boundary expansion of mosquito vectors into new geographical areas, the idea of using insecticidal paint could be a game changer.

Deafness due to loss of a TRPV channel eliminates mating behavior in Aedes aegypti males

Attraction and mating between male and female animals depend on effective communication between conspecifics. However, in mosquitoes, we have only a rudimentary understanding of the sensory cues and receptors critical for the communication that is essential for reproductive behavior. While it is known that male Aedes aegypti use sound to help them identify females, it is not unclear whether sound detection is absolutely required since other cues such as vision may also participate in mating behavior. To determine the effect of eliminating hearing on mating success, we knocked out the Ae. aegypti TRPVa channel, which is a protein expressed in chordotonal neurons in the Johnston's organ (JO) that respond to sound-induced movements in the antenna. Loss of trpVa eradicated sound-induced responses from the JO, thereby abolishing hearing. Strikingly, mutation of trpVa eliminated mating behavior in males. In contrast, trpVa-null females mated, although this behavior was slightly delayed relative to wild-type females. Males and females produce sounds as they beat their wings at distinct frequencies during flight. Sound mimicking the female wingbeat induced flight, attraction, and copulatory-like behavior in wild-type males without females present, but not in trpVa-null males. Males are known to modulate their wingbeat frequencies before mating in the air, which is a phenomenon referred to as rapid frequency modulation (RFM). We found that RFM was absent in mosquitoes lacking TRPVa. We conclude that the requirement for trpVa and hearing for male reproductive behavior in Aedes is absolute, as mating in the deaf males is eliminated.

Global stability for a mosquito-borne disease model with continuous-time age structure in the susceptible and relapsed host classes

Mosquito-borne infectious diseases represent a significant public health issue. Age has been identified as a key risk factor for these diseases, and another phenomenon reported is relapse, which involves the reappearance of symptoms after a symptom-free period. Recent research indicates that susceptibility to and relapse of mosquito-borne diseases are frequently age-dependent. This paper proposes a new model to better capture the dynamics of mosquito-borne diseases by integrating two age-dependent factors: chronological age and asymptomatic-infection age. Chronological age refers to the time elapsed from the date of birth of the host to the present time. On the other hand, asymptomatic infection age denotes the time elapsed since the host became asymptomatic after the primary infection. The system of integro-differential equations uses flexible, unspecified functions to represent these dependencies, assuming they are integrable. We analyzed the global stability of both the disease-free and endemic equilibrium states using the direct Lyapunov method with Volterra-type Lyapunov functionals. Additionally, the paper explores several special cases involving well-known host-vector models.

Psychometric Properties of the Anxiety Measure: Stress and Anxiety to Viral Epidemics-6 (SAVE-6) for Spanish Medical Students

Backgroud and Objective: The aim of this study was to evaluate the psychometric properties of SAVE-6 in the medical student population and assess its gender invariance. Subjects and Methods: The sample consisted of 320 medical students aged 18-23 years (153 men and 167 women) who completed an anonymous online questionnaire. Data collection took place in June 2024. To assess the scale structure, a descriptive analysis of the items was carried out, followed by a confirmatory factor analysis (CFA). To analyze whether there were differences in the invariance of the measure by gender, a multigroup CFA was performed. Results: SAVE-6 showed high internal consistency, α = 0.89 and ω = 0.92, a minimum score of 12, a maximum score of 22, an unifactorial structure, and adequate convergent validity. Specifically, the following were found: the positive and significant relationship with HADS was 0.98 for the full scale, 0.76 for depression, and 0.91 for anxiety, and there was a negative and significant convergent validity with resilience (-0.82) and resilience to suicide attempts (-0.88). Regarding the gender invariance, relevant data is that the factor loadings between each item and the SAVE-6 factor were not the same, so women present a higher level of anxiety than men (Δχ 2 (6) = 42.53). Discussion: The results showed good internal reliability of SAVE-6 and good suitability. Data also revealed that they were not equal in relation to gender. Specifically, the scalar invariance revealed significant differences by items between men and women in anxiety. Conclusions: This scale can be applied to medical students as a reliable and valid instrument to assess the anxiety response to disease contagion in future health professionals.

Integrating Systematic Surveys With Historical Data to Model the Distribution of Ornithodoros turicata americanus, a Vector of Epidemiological Concern in North America

Globally, vector-borne diseases are increasing in distribution and frequency, affecting humans, domestic animals, and wildlife. Science-based management and prevention of these diseases requires a sound understanding of the distribution and environmental requirements of the vectors and hosts involved in disease transmission. Integrated Species Distribution Models (ISDM) account for diverse data types through hierarchical modeling and represent a significant advancement in species distribution modeling. We assessed the distribution of the soft tick subspecies Ornithodoros turicata americanus. This tick species is a potential vector of African swine fever virus (ASFV), a pathogen responsible for an ongoing global epizootic that threatens agroindustry worldwide. Given the novelty of this method, we compared the results to a conventional Maxent SDM and validated the results through data partitioning. Our input for the model consisted of systematically collected detection data from 591 sampled field sites and 12 historical species records, as well as four variables describing climatic and soil characteristics. We found that a combination of climatic variables describing seasonality and temperature extremes, along with the amount of sand in the soil, determined the predicted intensity of occurrence of this tick species. When projected in geographic space, this distribution model predicted 62% of Florida as suitable habitat for this tick species. The ISDM presented a higher TSS and AUC than the Maxent conventional model, while sensitivity was similar between both models. Our case example shows the utility of ISDMs in disease ecology studies and highlights the broad range of geographic suitability for this important disease vector. These results provide important foundational information to inform future risk assessment work for tick-borne relapsing fever surveillance and potential ASF introduction and maintenance in the United States.

One Health prevention and preparedness to vector-borne diseases: how should we deal with a multisectoral, multilevel and multigroup governance?

INTRODUCTION

Multifactorial determinants of vector presence, distribution and ability of transmitting diseases, demand holistic approaches that consider eco-biosocial factors, such as One Health (OH), and engage institutions and communities to reduce vulnerability to vector-borne diseases (VBDs). Although the importance of multisectoral, multilevel and multigroup collaboration for prevention and preparedness to VBDs has been promoted by international guidance, evidence about practical experiences adopting a OH approach needs to be gathered and enabling factors for a successful governance highlighted.

METHODS

This study included a rapid literature review coupled with a stakeholder consultation process.

RESULTS

The peer-reviewed literature search identified 1674 articles and 13 articles were finally included in the review. The collaboration and coordination of different sectors and stakeholders allowed to focus resources, and share knowledge and perspectives. To support coordination and collaboration among the stakeholders synergistic interaction mechanisms were created, such as working groups and committees, and connection agents emerged as the main link between institution and communities. These synergies allowed to target the multidimensional drivers of VBDs, supported transversal capacity building and an holistic monitoring evaluation framework, and improved effectiveness and sustainability of the interventions.

CONCLUSION

A OH model highlighting enabling factors for multisectoral, multilevel and multigroup interventions for VBDs prevention and preparedness was developed to support decision-makers and key stakeholders to deal with a OH governance.

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.

Unveiling the Larvicidal Potential of Golpar (Heracleum persicum Desf. ex Fisch.) Essential Oil and Its Main Constituents on Aedes and Anopheles Mosquito Vectors

Natural products are thoroughly studied as valuable alternatives to synthetic insecticides. Heracleum persicum Desf. ex Fisch. (Apiaceae), commonly known as Golpar, is an Iranian medicinal plant largely employed as a spice, which has previously revealed insecticidal potential. The chemical composition of H. persicum essential oil (EO) was investigated by GC-MS and was mainly dominated by hexyl butyrate (36.1%) and octyl acetate (23.7%). The EO and its main esters were tested on three mosquito species. Aedes aegypti (L.) larvae were the most sensitive to all tested products. Lethal concentrations (LC50) of 59.09, 53.59, and 47.05 ppm were recorded for the EO, hexyl butyrate, and octyl acetate, respectively. Aedes albopictus (Skuse) and Anopheles gambiae Giles demonstrated comparable sensitivity to the EO, with LC50 values of 102.97 and 97.91 ppm, respectively, whereas the isolated constituents appeared more active on An. gambiae (LC50 of hexyl butyrate and octyl acetate of 70.97 and 60.71 ppm, respectively) with respect to Ae. albopictus (LC50 of hexyl butyrate and octyl acetate of 85.40 and 91.38 ppm, respectively). Low toxicity was registered for both EO and single components against human embryonic kidney (HEK293) cells. Overall, the H. persicum EO, hexyl butyrate, and octyl acetate could be further considered for larvicide development.

Climate change and human health in Alpine environments: an interdisciplinary impact chain approach understanding today's risks to address tomorrow's challenges

The European Alps, home to a blend of permanent residents and millions of annual tourists, are found to be particularly sensitive to climate change. This article employs the impact chain concept to explore the interplay between climate change and health in Alpine areas, offering an interdisciplinary assessment of current and future health consequences and potential adaptation strategies.Rising temperatures, shifting precipitation patterns and increasing extreme weather events have profound implications for the Alpine regions. Temperatures have risen significantly over the past century, with projections indicating further increases and more frequent heatwaves. These trends increase the risk of heat-related health issues especially for vulnerable groups, including the elderly, frail individuals, children and recreationists. Furthermore, changing precipitation patterns, glacier retreat and permafrost melting adversely impact slope stability increasing the risk of gravity-driven natural hazards like landslides, avalanches and rockfalls. This poses direct threats, elevates the risk of multi-casualty incidents and strains search and rescue teams.The environmental changes also impact Alpine flora and fauna, altering the distribution and transmission of vector-borne diseases. Such events directly impact healthcare administration and management programmes, which are already challenged by surges in tourism and ensuring access to care.In conclusion, Alpine regions must proactively address these climate change-related health risks through an interdisciplinary approach, considering both preventive and responsive adaptation strategies, which we describe in this article.

Reconciling heterogeneous dengue virus infection risk estimates from different study designs

Uncovering rates at which susceptible individuals become infected with a pathogen, i.e. the force of infection (FOI), is essential for assessing transmission risk and reconstructing distribution of immunity in a population. For dengue, reconstructing exposure and susceptibility statuses from the measured FOI is of particular significance as prior exposure is a strong risk factor for severe disease. FOI can be measured via many study designs. Longitudinal serology are considered gold standard measurements, as they directly track the transition of seronegative individuals to seropositive due to incident infections (seroincidence). Cross-sectional serology can provide estimates of FOI by contrasting seroprevalence across ages. Age of reported cases can also be used to infer FOI. Agreement of these measurements, however, have not been assessed. Using 26 years of data from cohort studies and hospital-attended cases from Kamphaeng Phet province, Thailand, we found FOI estimates from the three sources to be highly inconsistent. Annual FOI estimates from seroincidence was 2.46 to 4.33-times higher than case-derived FOI. Correlation between seroprevalence-derived and case-derived FOI was moderate (correlation coefficient=0.46) and no systematic bias. Through extensive simulations and theoretical analysis, we show that incongruences between methods can result from failing to account for dengue antibody kinetics, assay noise, and heterogeneity in FOI across ages. Extending standard inference models to include these processes reconciled the FOI and susceptibility estimates. Our results highlight the importance of comparing inferences across multiple data types to uncover additional insights not attainable through a single data type/analysis.

Pylore Krishnaier Rajagopalan: Pioneer in Kyasanur Forest Disease Research and His Contributions to Zoonotic Disease Studies

Pylore Krishnaier Rajagopalan was a distinguished public health expert who made significant breakthroughs in the research of Kyasanur forest disease (KFD), a prevalent tick-borne viral ailment in South India. His extensive research on KFD provided vital insights into the impact of the disease on public health and considerably advanced our knowledge of it. Rajagopalan's work also encompasses the study of zoonotic diseases, where he made substantial contributions to our understanding of their epidemiology and control. His research on KFD was instrumental in comprehending the disease transmission dynamics, clinical manifestations, and control strategies, resulting in improved management practices in regions where the disease is endemic. Rajagopalan's contributions have had a long-lasting impact on public health practices, as his work has influenced both scientific research and public health policies. The enduring effects of his work can be observed in the enhanced disease surveillance, outbreak response, and comprehension of zoonotic disease dynamics, which will continue to inform contemporary public health practices.

Determination of Species Identity and Genetic Diversity of Aedes aegypti and Other Medically Important Mosquitoes of India Using DNA Barcoding

Aedes aegypti-borne viruses (i.e., dengue, chikungunya, and Zika) have become endemic to India, posing a severe threat to public health. Vector control remains the mainstay of disease management due to nonavailability of licensed vaccines/therapeutics. Conventional morpho-taxonomical methods cannot differentiate between closely related sibling species or species complexes, and hence we evaluated two molecular markers, mitochondrial cytochrome c oxidase subunit 1 (Cox1) and nuclear DNA internal transcribed spacer 2 (-2) gene sequences, to characterize seven populations of Ae. aegypti and four medically important mosquito species (Aedes albopictus, Anopheles stephensi, Culex tritaeniorhyncus, and Culex murrelli). DNA extracted from the 11 mosquito populations (two mosquitoes per population) was polymerase chain reaction amplified, sequenced, and analyzed. Molecular characterization was found to be congruent with morphological identification, suggesting no variants or cryptic species exist in Ae. aegypti and the other mosquitoes studied. Phylogenetic analysis with sequences obtained with Cox1 gene of Ae. aegypti and other Aedes and non-Aedes mosquito species showed clustering of sequences from different species representing different clades, distinctly separating one taxon from the other, whereas ITS-2 sequences of Aedes aegypti from across the world clustered tightly. Nucleotide divergence values revealed a low percentage of intraspecies variation and a higher percentage of interspecies variation. The present study authenticates the applicability of Cox1 and ITS-2 in the precise identification of Ae. aegypti mosquitoes against cryptic or sibling species. Cox1 appeared to be a more reliable marker because it showed distinct clustering of mosquito species, and some sequence variations to represent genetic diversity.

Review on the impacts of indoor vector control on domiciliary pests: good intentions challenged by harsh realities

Arthropod vectored diseases have been a major impediment to societal advancements globally. Strategies to mitigate transmission of these diseases include preventative care (e.g. vaccination), primary treatment and most notably, the suppression of vectors in both indoor and outdoor spaces. The outcomes of indoor vector control (IVC) strategies, such as long-lasting insecticide-treated nets (LLINs) and indoor residual sprays (IRSs), are heavily influenced by individual and community-level perceptions and acceptance. These perceptions, and therefore product acceptance, are largely influenced by the successful suppression of non-target nuisance pests such as bed bugs and cockroaches. Adoption and consistent use of LLINs and IRS is responsible for immense reductions in the prevalence and incidence of malaria. However, recent observations suggest that failed control of indoor pests, leading to product distrust and abandonment, may threaten vector control programme success and further derail already slowed progress towards malaria elimination. We review the evidence of the relationship between IVC and nuisance pests and discuss the dearth of research on this relationship. We make the case that the ancillary control of indoor nuisance and public health pests needs to be considered in the development and implementation of new technologies for malaria elimination.

Geospatial Analysis of Lumpy Skin Disease Outbreaks among Cattle in Uttar Pradesh, India, 2021-2022

The emergence of lumpy skin disease (LSD) among cattle in India is concerning. District-level data on LSD cases in Uttar Pradesh between 2021 and 2022 were analyzed. A stepwise spatial analytical approach was followed by first constructing yearly and monthly disease maps for LSD incidence rates (IRs), then spatially interpolating the LSD IRs, followed by evaluating the global and local clustering of LSD IRs and finally conducting spatial regression modeling. Overall, 5784 LSD cases from 6 districts and 112,226 cases from 33 districts were detected in 2021 and 2022, respectively. In the incremental spatial autocorrelation analysis, the highest global clustering of LSD IRs for the 2022 outbreak was detected at 196.49 km. For the 2021 LSD outbreak, one district with high-low and nine districts with low-high LSD IRs were identified in the eastern region of the state. For the 2022 LSD outbreak, 13 districts with high-high and 7 districts with low-high LSD IRs were identified in the western part of the state. A geographically weighted regression model identified the impact of climate (temperature and humidity) and land cover (pasture, fallow, and non-agricultural land) on LSD IRs. The study results can aid animal health authorities in developing LSD prevention and control programs.

Diversity and ecological niche model of malaria vector and non-vector mosquito species in Covè, Ouinhi, and Zangnanado, Southern Benin

The present study aimed to assess mosquito species diversity, distribution, and ecological preferences in the Covè, Ouinhi, and Zangnanado communes, Southern Benin. Such information is critical to understand mosquito bio-ecology and to focus control efforts in high-risk areas for vector-borne diseases. Mosquito collections occurred quarterly in 60 clusters between June 2020 and April 2021, using human landing catches. In addition to the seasonal mosquito abundance, Shannon's diversity, Simpson, and Pielou's equitability indices were also evaluated to assess mosquito diversity. Ecological niche models were developed with MaxEnt using environmental variables to assess species distribution. Overall, mosquito density was higher in the wet season than in the dry season in all communes. A significantly higher Shannon's diversity index was also observed in the wet season than in the dry seasons in all communes (p < 0.05). Habitat suitability of An. gambiae s.s., An. coluzzii, Cx. quinquefasciatus and Ma. africana was highly influenced by slope, isothermality, site aspect, elevation, and precipitation seasonality in both wet and dry seasons. Overall, depending on the season, the ecological preferences of the four main mosquito species were variable across study communes. This emphasizes the impact of environmental conditions on mosquito species distribution. Moreover, mosquito populations were found to be more diverse in the wet season compared to the dry season.

Gold nanoparticles-based biosensors: pioneering solutions for bacterial and viral pathogen detection-a comprehensive review

Gold Nanoparticles (AuNPs) have gained significant attention in biosensor development due to their unique physical, chemical, and optical properties. When incorporated into biosensors, AuNPs offer several advantages, including a high surface area-to-volume ratio, excellent biocompatibility, ease of functionalization, and tunable optical properties. These properties make them ideal for the detection of various biomolecules, including proteins, nucleic acids, and bacterial and viral biomarkers. Traditional methods for detecting bacteria and viruses, such as RT-PCR and ELISA, often suffer from complexities, time consumption, and labor intensiveness. Consequently, researchers are continuously exploring novel devices to address these limitations and effectively detect a diverse array of infectious pathogenic microorganisms. In light of these challenges, nanotechnology has been instrumental in refining the architecture and performance of biosensors. By leveraging advancements in nanomaterials and strategies of biosensor fabrication the sensitivity and specificity of biosensors can be enhanced, enabling more precise detection of pathogenic bacteria and viruses. This review explores the versatility of AuNPs in detecting a variety of biomolecules, including proteins, nucleic acids, and bacterial and viral biomarkers. Furthermore, it evaluates recent advancements in AuNPs-based biosensors for the detection of pathogens, utilizing techniques such as optical biosensors, lateral flow immunoassays, colorimetric immunosensors, electrochemical biosensors, and fluorescence nanobiosensors. Additionally, the study discusses the existing challenges in the field and proposes future directions to improve AuNPs-based biosensors, with a focus on enhancing sensitivity, selectivity, and their utility in clinical and diagnostic applications.

Culex-Transmitted Diseases: Mechanisms, Impact, and Future Control Strategies using Wolbachia

Mosquitoes of the Culex genus are responsible for a large burden of zoonotic virus transmission globally. Collectively, they play a significant role in the transmission of medically significant diseases such as Japanese encephalitis virus and West Nile virus. Climate change, global trade, habitat transformation and increased urbanisation are leading to the establishment of Culex mosquitoes in new geographical regions. These novel mosquito incursions are intensifying concerns about the emergence of Culex-transmitted diseases and outbreaks in previously unaffected areas. New mosquito control methods are currently being developed and deployed globally. Understanding the complex interaction between pathogens and mosquitoes is essential for developing new control strategies for Culex species mosquitoes. This article reviews the role of Culex mosquitos as vectors of zoonotic disease, discussing the transmission of viruses across different species, and the potential use of Wolbachia technologies to control disease spread. By leveraging the insights gained from recent successful field trials of Wolbachia against Aedes-borne diseases, we comprehensively discuss the feasibility of using this technique to control Culex mosquitoes and the potential for the development of next generational Wolbachia-based control methods.