Vector-borne Disease Research Research Articles

Artificial Feeding Systems for Vector-Borne Disease Studies.

This review examines the advancements and methodologies of artificial feeding systems for the study of vector-borne diseases, offering a critical assessment of their development, advantages, and limitations relative to traditional live host models. It underscores the ethical considerations and practical benefits of such systems, including minimizing the use of live animals and enhancing experimental consistency. Various artificial feeding techniques are detailed, including membrane feeding, capillary feeding, and the utilization of engineered biocompatible materials, with their respective applications, efficacy, and the challenges encountered with their use also being outlined. This review also forecasts the integration of cutting-edge technologies like biomimicry, microfluidics, nanotechnology, and artificial intelligence to refine and expand the capabilities of artificial feeding systems. These innovations aim to more accurately simulate natural feeding conditions, thereby improving the reliability of studies on the transmission dynamics of vector-borne diseases. This comprehensive review serves as a foundational reference for researchers in the field, proposing a forward-looking perspective on the potential of artificial feeding systems to revolutionize vector-borne disease research.

A Qualitative Analysis of the Perceptions of Stakeholders Involved in Vector Control and Vector-Borne Disease Research and Surveillance in Orinoquia, Colombia.

Colombia has a tropical climate and environmental conditions that favour the circulation of most of the known vector-borne diseases (VBDs). Protocols have been established and implemented to address the threats of these diseases, but they are for country-wide use and do not take into consideration the nuances of the different environments of the country. Almost the entire population is vulnerable to infection with one or more VBD. This study aims to characterise the perceptions and experiences of stakeholders involved in vector control and VBDs in the Orinoquia region in Colombia. Two panel discussions, and 12 semi-structured interviews, were conducted. Experts from the Colombian National Health Institute (INS), health secretaries from Meta, Guaviare and Vichada Departments, academic researchers, and individuals from private vector control companies participated. All sessions were recorded, transcribed, and translated, and then subject to thematic analysis. Three major themes emerged: involvement, limitations, and recommendations. Results showed that participants are engaged in vector surveillance activities, education, and vector control research. Participants focused on problems of disjointed efforts towards VBD control between health secretaries and the health ministry, as well as societal issues, such as socioeconomic, cultural, and political issues, which became the rationale for the lack of vector control resources. Responses in the panel discussions and interviews overlapped in opinions, and suggested that vector control could be improved through better communication between vector control bodies, strengthened engagement with vulnerable communities, more collaborative actions, and a more balanced distribution of resources.

Factors affecting African postdoctoral researcher capacity development within ‘learn-by-doing’ international research partnerships: findings from the ‘Partnership for Increasing the Impact of Vector Control (PIIVeC)’

IntroductionThe Partnership to Increase the Impact of Vector Control sought to develop the research and leadership capacity of 10 African postdoctoral vectorborne disease scientists via a ‘learn-by-doing’ approach. We identified...

2021 AMCA Presidential Address.

2021 AMCA Presidential Address.

Impact of COVID-19 on the Vector-Borne Disease Research and Applied Public Health Workforce in the United States.

ABSTRACT.The coronavirus pandemic has imposed extraordinary demands on the public and environmental health workforce, including those who work on vector-borne disease (VBD) prevention and control. In late 2021, we surveyed more than 100 applied public health professionals, academic researchers, and others working on VBDs in the United States. They reported that the supply chain disruptions and limited access to facilities that impeded laboratory work in the early months of the COVID-19 pandemic in 2020 have largely resolved. However, many public health personnel across job types and career stages are still working fewer hours on VBDs than they did before the pandemic. Many reported that they expect it to take several years for VBD specialists to fully reengage with clinicians and the public, reinvigorate their partnerships and professional networks, and recover from interruptions to work productivity and professional development. Despite these challenges, most applied and academic VBD workers remain enthusiastic about their work and eager to advance this important area of infectious disease research and practice.

Unleashing the literature: a scoping review of canine zoonotic and vectorborne disease research in Canis familiaris in North America.

Domestic dogs (Canis familiaris) provide important benefits to human beings but can also transmit pathogens. Information on the breadth of canine zoonoses and vectorborne research in North America is scarce. A scoping review was conducted to examine (1) the number and type of canine zoonoses and vectorborne studies in domestic dogs conducted in North America since the start of the 21st century; (2) the main research methods reported; (3) the Inequality-adjusted Human Development Index (IHDI) countries in which research was conducted; and (4) whether collaborative integrated terminology was reported in objectives or methods sections. Title/abstract screening, full-text screening, and data-charting were completed by two reviewers. We identified 507 publications evaluating 43 zoonotic or vectorborne pathogens in domestic dogs. Most studies (n = 391 of 512 (76.37%)) were conducted in the USA. The five most frequently researched pathogens were Ehrlichia spp. (n = 81 of 507 (15.98%)), Borrelia burgdorferi (n = 64 of 507 (12.62%)), Leptospira spp. (n = 54 of 507 (10.65%)), Rabies virus (n = 42 of 507 (8.28%)), and Influenza viruses (n = 41 of 507 (8.09%)). These pathogens can cause moderate to severe health outcomes in human beings and in dogs irrespective of IHDI ranking; our review highlights important counts of research conduct among North American countries.

Worldwide Presence and Features of Flea-Borne Rickettsia asembonensis.

Rickettsia asembonensis, the most well-characterized rickettsia of the Rickettsia felis-like organisms (RFLO), is relatively unknown within the vector-borne diseases research community. The agent was initially identified in peri-domestic fleas from Asembo, Kenya in an area in which R. felis was associated with fever patients. Local fleas collected from domestic animals and within homes were predominately infected with R. asembonensis with < 10% infected with R. felis. Since the identification of R. asembonensis in Kenya, it has been reported in other locations within Africa, Asia, the Middle East, Europe, North America, and South America. With the description of R. asembonensis-like genotypes across the globe, a need exists to isolate these R. asembonensis genotypes in cell culture, conduct microscopic, and biological analysis, as well as whole genome sequencing to ascertain whether they are the same species. Additionally, interest has been building on the potential of R. asembonensis in infecting vertebrate hosts including humans, non-human primates, dogs, and other animals. The current knowledge of the presence, prevalence, and distribution of R. asembonensis worldwide, as well as its arthropod hosts and potential as a pathogen are discussed in this manuscript.

Biosafety Aspects of Arthropod-Borne Disease Vectors Laboratory

With increased research efforts on vector-borne diseases such as malaria, dengue, and recently Zika, there has been a need to maintain in captivity arthropods that are known or believed to be involved in the transmission of pathogens to humans in a well-controlled laboratory environment. Therefore, it is pivotal to establish safe yet practical procedures inside an insectary to minimize the associated biosafety risks and prevent the potential escape of the arthropods used into the environment. This article provides a detailed overview of an arthropod disease vectors facility features with a focus on arthropod containment level 2 (ACL-2) laboratory and aims to support health safety and environment (HSE) and biosafety professionals as well as scientists who work on vector-borne diseases by detailing safety procedures inside an ACL-2 environment. In particular, I detail here the associated safety procedures of an ACL-2 and the insectary-specific equipment required for this type of facility. Research on mosquitoes was used here as an example of a disease vector and presents procedures relevant to usage of this vector in the context of Zika virus. The work presented here shows that risks associated with working on infected arthropod vectors can be minimized to an acceptable level and in turn facilitate the research on the diseases they help spread. Similar principles can be applied to other vector-borne diseases research as well, although the work may have a distinct nature.

Hubungan Kandungan Hara Tanah dengan Produksi Senyawa Metabolit Sekunder pada Tanaman Duku (Lansium domesticum Corr var Duku) dan Potensinya sebagai Larvasida

Duku is a plant that grows in the tropics and has bioactivity as pesticide. Compounds that have the potential as a pesticide on duku is secondary metabolites. This study aimed to determine the correlation between the soil nutrient and secondary metabolites on duku also their larvacidal potency. The research was done by comparing the measurement of physical and chemical soil, phytochemical test and larvacial test against the sample. This study was conducted from February to November 2014, in the Village Simpang Agung South Sumatra province and village Rengas Bandung Jambi Province. The extraction and characterization of secondary metabolites was conducted at the Laboratory of Pharmacy Center, Biomedical and Health Basic Technology, National Institute of Health and Research Development. Larvicidal potency test was conducted in Vector Borne Disease Research and Development Unit Baturaja. The results showed that soil nutrient content of Rengas Bandung Villagewas higher than the Simpang Agung due to the regularly maintaining and fertilizing.The larvicidal test showed extracts from Simpang Agung Village more potent than extracts from the village Rengas Bandung, possibly due to the more secondary metabolites produced in samples from Simpang Agung.

‘Where the Wind Comes Sweeping Down the Plain’: Using a Bibliometric Study to Identify Trends and Knowledge Gaps of Vector-borne Disease Research in Oklahoma

Abstract. Research on vector-borne diseases on the Great Plains has a rich and dynamic publication history. The aim of this study was to assess the publication trends in Oklahoma between 1965 and 2015 with a view to identifying knowledge gaps on which to focus future research initiatives. Using Web of Science (Thompson Reuters) and Pubmed (National Center for Biotechnology Information) in EndNote, a total of 747 publications was identified that involved Oklahoma-based researchers, samples, or data obtained since 1965. Eighty-two percent (n = 615) of the published studies focused on ticks and tick-borne diseases. Most of the studies involving specific tick species (n = 282) focused on the lone star tick, Amblyomma americanum (L.), (51.1%), with anaplasmosis the primary disease system studied. Until 1989, most vector-borne disease research focused on ecology and control. The trend shifted almost complementarily since the 1990s with as much as 80% of research focused on clinical- or laboratory-based studies....

REVIEW OF THE EXISTING POLICIES PERTAINING TO DENGUE IN CONSTRUCTION PROJECTS AND IDENTIFICATION OF GAP IN RESEARCH

World Health Organization (WHO) identifies that more than half of the world’s population are at risk for vector-borne diseases. Vectors are living organisms that transmit infectious diseases and mosquitoes are the best-known carrier of vector-borne diseases. Among the vector-borne diseases, dengue has become a widespread health problem faced by Malaysians. There has been various research studies in curbing dengue issues; however, the Malaysian government is still having a hard time in reducing the number of dengue issues. Existing guidelines and legislation seem insufficient in controlling and reducing the number of dengue cases. It has been reported from January 2015 to October 2015, that there were 96,222 of dengue cases and 263 deaths cases in Malaysia. Construction projects have been identified as one of the reasons for the high incidences of dengue menace. The construction activities and uncleanliness of the construction sites have caused a spate of dengue cases. This paper seeks to review the existing policies pertaining to dengue in construction projects and to identify the gap in vector-borne disease research. The findings may act as a catalyst for conducting further researches in this field of study.

Pengujian Ekstrak Biji Jarak Merah (Jatropha Gossypiifolia L) terhadap Keong Perantara Schistosomiasis, Oncomelania hupensis lindoensis di Napu, Kabupaten Poso, Sulawesi Tengah

Schistosomiasis is still a health problem in endemic areas of Napu highland, Poso, Central Sulawesi. Oncomelania hupensis lindoensis, an host of intermediate schistosomiasis is widespread in the region Napu. Snail control was done by spraying molluscicides. However, due to high potential of chemical molluscicides resistance, study for natural ingredients as an alternative molluscicides Bayluscide is needed. One of the potential botanical molluscicides is environmental friendly of Jatropha gossypifolia extract. The aim of this study was to identify effect of J.gossypifolia extract against O.h.lindoensis.The research was conducted in Schistosomiasis Laboratory Napu, in period of March – November 2012. For field test: Animal Histology and Embryology, Facultas of Biology, Gadjah Mada University for histological analysis; and Laboratory of Parasitology, Vector Borne Diseases Research Unit (VBDRU) for tissue damage observation. The result showed severe damage of gill tissues and muscular foot organ particularly in the gill epithellial form, gill lamella, epithellial cell in the epidermis of muscular foots.By the histological analyis, the mode of J.gossypifolia toxic action can be identified through contact and respiration.Test with LC50 (10.4 ml / L) seed extract showed the snails mortality of 56.8%. The test results with Lc95 (18.6 ml / L) seed extract showed the snails mortality by 72%.The most severe snail tissue damage caused by J.gossypifolia extract found in gills and muscular foot in the period of 24 hours observation.

Studi Keanekaragaman Spesies Nyamuk Anopheles sp. Di Kabupaten Donggala, Provinsi Sulawesi Tengah

The aim of this study is to determine the diversity of morphological and genetic variation of the Anopheles sp. This study was conducted in the periode of November 2013 - February 2014 in two (2) malaria endemic areas; Labuan Village, in North Donggala and Lalombi Village, in South Banawa of South Donggala Regency. Sample collection was done around cattle cage throughout the night between 18:00 to 6:00. The capture period was 15 minutes oh each, and it was done in every hour. The collection was done by using an aspirator and the sampel was stored in paper cup prior covered by gauze pads. Morphological identification of samples was performed at Entomology Laboratory, Vector Borne Disease Research and Development Unit Donggala. Identification was done based on O'connor and Soepanto (1981). Analysis of genetic was done by RAPD-PCR method. Morphological identification found that there were three (3) species of mosquitoes from the two (2) sites, namely An. tesselatus , An. subpictus , and An. vagus . The highest spesies diversity index obtained in the Lalombi village with H' = 1,07 and the lowest value in the Labuan village with a value of H' = 0,33. RAPD analysis showed that there were similarity on DNA amplification band patterns on An. t esselatus from the village of Labuan and it from Lalombi. But interestingly, there were different on DNA amplification pattern of An. vagus from these two sites. This results indicating that the there was genetic variation on An. vagus from these two different villages, even though its have similarity in morphological characters.

Role of the Vector in Arbovirus Transmission

Many arboviral diseases are uncontrolled, and the viruses that cause them are globally emerging or reemerging pathogens that produce significant disease throughout the world. The increased spread and prevalence of disease are occurring during a period of substantial scientific growth in the vector-borne disease research community. This growth has been supported by advances in genomics and proteomics, and by the ability to genetically alter disease vectors. For the first time, researchers are elucidating the molecular details of vector host-seeking behavior, the susceptibility of disease vectors to arboviruses, the immunological control of infection in disease vectors, and the determinants that facilitate transmission of arboviruses from a vector to a host. These discoveries are facilitating the development of novel strategies to combat arboviral disease, including the release of transgenic mosquitoes harboring dominant lethal genes, the introduction of arbovirus-blocking microbes into mosquito populations, and the development of acquisition- and transmission-blocking therapeutics. Understanding the role of the vector in arbovirus transmission has provided critical practical and theoretical tools to control arboviral disease.

Article Commentary: Contributions in the First 21st Century Decade to Environmental Health Vector Borne Disease Research

A selective review of recent concepts, events and major recent research methodologies, and educational approaches in the field of vector-borne disease are drawn together in this article. Since vector borne disease is a major contributor to world disease burdens, and also comprises list of neglected diseases, recent research in the field elucidates the uncertain and far-reaching consequences of these diseases to human health and well-being. Some of the specific findings included in this review are the following: Chickungunya virus disease range is changing as a result of global climate change; Tick-borne disease vaccinations are being pursued with the help of PCR techniques; the wide availability of remote sensing and ecology are providing habitat surveillance tools to improve predictability of risk areas; environmental health education approaches are incorporating community and cultural aspects to improve success and reduce risk.

The ecological dimensions of vector-borne disease research and control

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

Epidemiological Situation of Japanese Encephalitis in Nepal

A human Japanese encephalitis (JE) case is considered to have elevated temperature (over 380 C) along with altered consciousness or unconsciousness and is generally confirmed serologically by finding of specific anti-JE IgM in the cerebro spinal fluid. No specific treatment for JE is available. Only supportive treatment like meticulous nursing care, introduction of Ryle's tube if the patient is unconscious, dextrose solution if dehydration is present, manitol injection in case of raised cranial temperature and diazepam in case of convulsion. Intra venous fluids, indwelling catheter in conscious patient and corticosteroids unless indicated should be avoided. Pigs, wading birds and ducks have been incriminated as important vertebrate amplifying hosts for JE virus due to viremia in them. Man along with bovines, ovines and caprines is involved in transmission cycle as accidental hosts and plays no role in perpetuating the virus due to the lack of viremia in them. The species Cx tritaeniorhyncus is suspected to be the principal vector of JE in Nepal as the species is abundantly found in the rice-field ecosystem of the endemic areas during the transmission season and JE virus isolates have been obtained from a pool of Cx tritaeniorhyncus females. Mosquito vector become infective 14 days after acquiring the JR virus from the viremic host. The disease was first recorded in Nepal in 1978 as an epidemic in Rupandehi district of the Western Development Region (WDR) and Morang of the Eastern Region (EDR). At present the disease is endemic in 24 districts. Although JE as found endemic mainly in tropical climate areas, existence and proliferation of encephalitis causing viruses in temperate and cold climates of hills and valleys are possible. Total of 26,667 cases and 5,381 deaths have been reported with average case fatality rate of 20.2% in an aggregate since 1978. More than 50% of morbidity and 60% mortality occur in the age group below 15 years. Upsurge of cases take place after the rainy season (monsoon). Cases start to appear in the month of April - May and reach its peak during late August to early September and start to decline from October. There are four designated referral laboratories, namely National Public Health Laboratory (Teku), Vector Borne Diseases Research and Training Center (Hetauda), B.P. Koirala Institute of Medical Sciences (Dharan) and JE Laboratory (Nepalgunj), for confirmatory diagnosis of JE. For prevention of JE infection; chemical and biological control of vectors including environmental management at breeding sites are necessary. Segregate pigs from humans habitation. Wear long sleeved clothes and trousers and use repellent and bed net to avoid exposure to mosquitos. For the prevention of the disease in humans, safe and efficacious vaccines are available. Therefore immunize population at risk against JE. Immunize pigs at the surroundings against JE. 225,000 doses of live attenuated SA-14-14.2 JE vaccine were received in donation from Boran Pharmaceuticals, South Korea for the first time in Nepal. Altogether 224,000 children aged between 1 to 15 years were vaccinated in Banke, Bardiya and Kailali districts during 1999. From China also, 2,000,000 doses of inactivated vaccine were received in 2000 and a total of 481,421 children aged between 6m to 10 yrs were protected from JE during 2001/2002. Ministry of Agriculture, Department of Livestock Services has vaccinated around 200,000 pigs against JE in terai zone during February 2001.

Differential modulation of murine cellular immune responses by salivary gland extract of Aedes aegypti.

The ability of salivary gland extract (SGE) of Aedes aegypti to modulate cellular immune responses was investigated in a mouse model. Cytokine production was induced in naive and antigen-primed murine (BALB/c) spleen cells in vitro by stimulation with the T cell mitogen concanavalin A or the T cell-dependent antigen ovalbumin (OVA), respectively. Inclusion of Ae. aegypti SGE in in vitro culture with naive cells caused significant suppression of the cytokines interleukin-2 (IL-2) and interferon gamma in culture supernatants, while levels of other cytokines (IL-4 and IL-5) were unaffected by SGE. In contrast, SGE did not affect cytokine production by antigen-activated cells derived from OVA-primed mice. To determine whether SGE could inhibit the responsiveness of cells to exogenous cytokine stimuli, optimized quantities of lymphocyte growth factor cytokines IL-2 and IL-4 were added to SGE-treated spleen cells and the degree of cellular proliferation was determined. Cellular proliferation in response to IL-2 was markedly suppressed by prior exposure of cells to SGE, while the proliferative response to IL-4 was also affected by SGE but to a lesser extent. These results confirm that mosquito SGE can modulate host immune responses, and suggest that in Ae. aegypti modulation is directed primarily against cytokines associated with type 1 lymphocyte responses. The mode of immunomodulation and the possible relevance of these results to vector-borne disease research are discussed.