Vectorial Diseases Research Articles

The Effect of Climate Change on Vectorial Diseases and Crimean-Congo Hemorrhagic Fever

Dünya nüfusunun yarıdan fazlası vektör kaynaklı hastalık riski altındadır. Vektörle bulaşan hastalıklar yüksek ölüm oranı ve yüksek düzeyde engelliliğe neden olmaları nedeniyle halk sağlığını tehdit eden ve ayrıntılı irdelemeyi gerektiren sorunlardır. Küresel sıcaklığın 2100 yılına gelindiğinde ortalama 1 ila 3,5 C⸰ artacağı; ilişkili olarak vektör kaynaklı hastalıkların da daha geniş bir coğrafyada yayılacağı ve prevalansının artacağı öngörülmektedir. Ekolojik değişim Kırım Kongo Kanamalı Ateşinin (KKKA) örüntüsünü etkilemekte ve böylece bulaşma riskini değiştirebilmektedir. İnsandan insana bulaşma potansiyeli düşük olduğu için sadece küçük salgınlar oluşturabilir ancak yüksek ölüm oranları nedeniyle halk sağlığı yönünden üstünde durulması gereken bir hastalıktır. Önleme çalışmalarında ribavirinin yararı kanıtlanmıştır. Tedavide ribavirin etkililiği ise tartışmalıdır. Ayrıca sağlık hizmeti sunumu uygulamaları sürecinde hastalığın bulaş riski yüksektir ve yüksek viral yük nedeniyle büyük olasılıkla ölümle sonuçlanır. Dünya genelinde insan ve hayvan sağlığı ile ilgilenen kuruluşların bu hastalığa karşı koruma ve tedavi yöntemleri geliştirmesi bir halk sağlığı gereksinimidir.

Health Impact Assessment in protected areas: a proposal for urban contexts in Brazil.

The use of Health Impact Assessment (HIA) in the establishment of an urban protected area can enhance the positive impacts and mitigate the negative impacts resulting from its implementation. Brazil hosts some of the most important biodiversity hotspots in the world and the HIA may benefit biodiversity and human health. These areas are commonly created without any preceding survey to assess their impacts on health. Protected areas located in urban zones are essential to maintain environmental balance and quality of life in cities. It promotes positive impacts on health, providing ecosystem services and salutogenic benefits. However, they can generate negative impacts such as the violation of human rights, property speculation, spread of vectorial diseases, and psychosocial stress. Based on the identification of the potential impacts of urban protected areas on health and best practices, this qualitative and exploratory study justifies the use of HIA in urban protected areas, especially in the Brazil, and indicates the main elements for the construction of a methodological approach to contribute to the Sustainable Development Goals and one of its alternatives, the Buen Vivir approach.

The Multi-Dimensional Impacts of Extreme Weather Events on Human Health in a Changing Climate and the Evaluation of Climate Risks Specific to Vectoral Diseases

İklim değişikliği insan sağlığını doğrudan ve dolaylı olarak kısa veya uzun süreli etkileyebilir. Aşırı hava sıcakları kalp-damar hastalıklarına, solunum rahatsızlıklarına ve ruhsal problemlere neden olabildiği gibi doğrudan ölümlere de yol açabilmektedir. Kuraklık insan sağlığını dolaylı olarak gıda ve su güvenliğinin bozulması açısından etkilerken, sel ve kasırga gibi ani gelişen aşırı hava olayları önemli ölçüde can kaybına sebep olmakta, yakınlarını kaybeden bireyler için çeşitli ruhsal problemlerin kaynağı hâline gelmektedir. Sellerin doğrudan fiziksel etkilerinin yanında, dolaylı olarak güvenli suya erişimi etkilediği ve su yoluyla bulaşan hastalıklara neden olduğu bilinmektedir. Diğer taraftan sıcaklık ve yağış rejimindeki değişimler birçok canlının göç etmesi yoluyla vektör kaynaklı hastalıkların alansal genişlemesine ve enfekte olan kişi sayısının artmasına yol açmaktadır. Bu gelişmeler dikkate alınarak çalışmada iklim değişikliği kaynaklı hastalıklar genel boyutuyla araştırılmış ve spesifik olarak vektörel hastalıklar detaylıca incelenerek, bu hastalıkların ortaya çıkmasına neden olan iklimsel riskler değerlendirilmiştir. Çalışmada ayrıca mevcut iklimsel değişimlere bağlı ortaya çıkan hastalıklar ile yakın ve orta vade projeksiyonları kapsamında iklim değişikliğinin Türkiye’de sağlık etkileri boyutu araştırılmıştır. Ayrıca iklim değişikliği kapsamında ulusların sağlık etkilenebilirliği ve sağlık sistemi uyumu değerlendirmelerine de yer verilmiştir. Araştırma sonucunda, aşırı hava olaylarının yaşanma süresi, sıklığı ve şiddetinin giderek artmasıyla insan sağlığı için risk teşkil eden hastalıklarda ve buna bağlı etki boyutlarında artış olacağı bulgusuna ulaşılmıştır. İklim değişikliği ve aşırı hava olayları ile yaşam alanları genişleyen ve göç eden vektörlerin insan sağlığı açısından büyük risk oluşturacağı elde edilen bir diğer bulgudur. Araştırmada uzun vadede aşırı hava olaylarının su ve gıda güvenliği açısından oluşturabileceği risklerin, hâlihazırda açlık, yetersiz beslenme ve yetersiz sanitasyon sonucu ortaya çıkan hastalıkların görüldüğü bölge ve insan popülasyonunu arttırabileceği sonucuna varılmıştır. Bu kapsamda aşırı hava olaylarından etkilenme düzeyi ve potansiyel riskleri ele alan çalışmalardan hareketle, Türkiye’de gelecekte birçok vektörün yaşayabileceği ideal iklim koşullarının oluşması ve vektörel hastalıklarda artış görülmesi beklenebilir.

The possible route of introduction of bluetongue virus serotype 3 into Sicily by windborne transportation of infected Culicoides spp.

SummaryIn October 2017, the first outbreak of bluetongue virus serotype 3 (BTV‐3) began in Italy, specifically in western Sicily. The route of entrance remains unclear, although since 2016 the same strain had been circulating only 150 km away, on the Tunisian peninsula of Cape Bon. The present analysis assessed the feasibility that wind could have carried BTV‐3‐infected Culicoides spp. from Tunisia to Sicily. An advection‐deposition‐survival (ADS) model was used to estimate when and where Culicoides spp. were likely to be introduced prior to the first BTV‐3 report in Italy. Additionally, the Hybrid Single‐Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to support ADS outputs. The modelling suggests that during September 2017, strong wind currents and suitable climatic conditions could have allowed the transportation of Culicoides spp. from BTV‐3‐infected areas in Tunisia into Sicily. ADS simulations suggest that particles could have reached the province of Trapani in western Sicily on 2 and 12 September. These simulations suggest the feasibility of aerial transportation of infected Culicoides spp. from Tunisia into Sicily. They demonstrate the suitability of the ADS model for retrospective studies of long‐range transportation of insects across large water bodies, which may enhance the early detection of vectorial disease introduction in a region.

Evolution of research in health geographics through the International Journal of Health Geographics (2002-2015).

Health geographics is a fast-developing research area. Subjects broached in scientific literature are most varied, ranging from vectorial diseases to access to healthcare, with a recent revival of themes such as the implication of health in the Smart City, or a predominantly individual-centered approach. Far beyond standard meta-analyses, the present study deliberately adopts the standpoint of questioning space in its foundations, through various authors of the International Journal of Health Geographics, a highly influential journal in that field. The idea is to find space as the common denominator in this specialized literature, as well as its relation to spatial analysis, without for all that trying to tend towards exhaustive approaches. 660 articles have being published in the journal since launch, but 359 articles were selected based on the presence of the word “Space” in either the title, or the abstract or the text over 13 years of the journal’s existence. From that database, a lexical analysis (tag cloud) reveals the perception of space in literature, and shows how approaches are evolving, thus underlining that the scope of health geographics is far from narrowing.

La vaccination dans la gestion des maladies vectorielles : rôles et réponses de l’industrie du médicament vétérinaire

Vaccination in the management of vector-borne diseases : roles and answers of veterinary medicine industry. Vaccination is an option among the different tools against animal vector-borne diseases. The animal health care industry is often involved in manufacturing vaccines to prevent enzootic diseases (as leishmaniosis) or emerging diseases (as Blue Tongue and Schmallenberg diseases). Cooperation with scientific experts or institutes and governmental organizations is quite essential to coordinate management of such vectorial diseases : examples of networks in terms of research and field application are mentioned. The development of vaccines by the healthcare companies generally takes 7 to 10 years, sometimes more, but, in case of emerging diseases, could be achieved within a few months, with fast availability of such vaccines on the field due to special authorization. Then issues for the pharmaceutical companies are discussed, either on a scientific (R and D) basis or on an economical point of view (Return On Investment). Finally, numerous initiatives are taken by the pharmaceutical industry to favor collaborations in a spirit of open innovation for tomorrow’s innovations.

Modeling the spatial distribution of Chagas disease vectors using environmental variables and people´s knowledge

BackgroundChagas disease is caused by the protozoan Trypanosoma cruzi, which is transmitted to mammal hosts by triatomine insect vectors. The goal of this study was to model the spatial distribution of triatomine species in an endemic area.MethodsVector’s locations were obtained with a rural householders’ survey. This information was combined with environmental data obtained from remote sensors, land use maps and topographic SRTM data, using the machine learning algorithm Random Forests to model species distribution. We analysed the combination of variables on three scales: 10 km, 5 km and 2.5 km cell size grids.ResultsThe best estimation, explaining 46.2% of the triatomines spatial distribution, was obtained for 5 km of spatial resolution. Presence probability distribution increases from central Chile towards the north, tending to cover the central-coastal region and avoiding areas of the Andes range.ConclusionsThe methodology presented here was useful to model the distribution of triatomines in an endemic area; it is best explained using 5 km of spatial resolution, and their presence increases in the northern part of the study area. This study’s methodology can be replicated in other countries with Chagas disease or other vectorial transmitted diseases, and be used to locate high risk areas and to optimize resource allocation, for prevention and control of vectorial diseases.

Actualités sur les leishmanioses viscérales

During the last decade, visceral leishmaniasis has been reconsidered in its epidemiology and strategies for diagnosis, treatment and prevention. This vectorial disease, responsible for more than 50,000 deaths each year across India, East Africa, South America, the Mediterranean area, Central Asia and China, is currently spreading over new territories. This formerly rural disease has even reached cities in South America. This spreading is caused by environmental changes due to global warming or human activity, and by the movement of workers and refugees. As a consequence, the burden of HIV/Leishmania coinfection is increasing in many developing countries even though effective antiretroviral therapy has led to a marked decrease in its incidence in Europe. The disease is now handled differently than it was 10 years ago: PCR has become the most accurate tool for diagnosis and follow-up in developed countries, and field diagnostic tools have been developed (antigenuria, rK39 dipstick). While resistance to antimoniate has appeared in India and Europe, new therapies have been evaluated such as miltefosine, the first oral therapy, or short treatment with liposomal amphotericin B. In France, liposomal amphotericin B has supplanted antimoniate meglumine because of better tolerance and shorter hospitalization duration. Protecting dogs through immunization or collars impregnated with deltamethrin proved effective to prevent zoonotic leishmaniasis due to Leishmania infantum.

Artrópodos con interés vectorial en la salud pública en España

Fifteen of the thirty-one Obligatory Communicable Diseases in Spain, exempting those of congenital or neonatal types, can be transmitted by several species of arthropods that are present in our country. Several arthropod orders are the suitable transmitters of tens of bacteria, fungi, virus and protozoa. This fact demands a through of the biology knowledge of these vectors in order to adopt efficient control measures that allow us to reduce the incidence levels of these diseases. Nevertheless, the epidemiological studies shouldn't remain only restricted to the diseases with active transmission cycles in our country. It is necessary to acquire a global vision because of allochton diseases that are perfectly extensible to our territory in the globalization context in which we are situated. All this information is important to know which factors are preventing the disease presence. The aim is to provide the National Epidemiological Surveillance Network with a valuable predictive capacity that allows it to predict the potential arrival of diseases and the consequent strengthening of the spanish Public Health. The goal of this work is to carry out a review of the spanish arthropod fauna with any vectorial interest. The current situation of some of the more important vectorial diseases in our country and the factors related to a resurgence reappearance and/or intensification of those ones are also discussed. Therefore, the study of these inappealable protagonists in our Public Health as an articulatory element in the complex network that any vectorial disease entails is absolutely necessary.

Evaluation of the efficacy of a topically administered combination of imidacloprid and permethrin against Phlebotomus perniciosus in dog

The phlebotomine sand fly Phlebotomus perniciosus is one of the main vectors of Leishmania infantum, responsible for human and canine leishmaniasis in the Mediterranean Basin. The objective of this study was to evaluate the repellent and insecticidal efficacy of imidacloprid 10% (w/v)/permethrin 50% (w/v) spot-on against sand flies ( P. perniciosus) on dogs. The dogs used in this trial were laboratory-bred beagles: eight were impregnated with the solution (treated group), while the other eight were left untreated (control group). On day 0 the animals in the treatment group received 0.1 ml/kg body weight of the combination imidacloprid/permethrin spot-on. Dogs were exposed for 1 h to about 100 female sand flies at weekly intervals for a period of 4 weeks, on day 1, 7, 14, 21, and 28 after applying the product. The repellency criterion was based on the feeding rate of sand flies in the treated compared to the untreated group. The insecticidal efficacy criterion was based on comparison of the survival rate of sand flies between the two groups. The product had an insecticidal efficacy on female sand flies of 53.2% (day 1), 49.4% (day 7), 15.1% (day 14), 13.2% (day 22), and 2.9% (day 29). The product showed a repellent effect of 97.7% (day 1), 96.3% (day 7), 96.5% (day 14), 92.7% (day 22), and 74.0% (day 29). Within the first week of application the insecticidal effect was significant; however it did not surpass 50%. On the other hand, the product showed a potent anti-feeding effect of over 90% during the first 3 weeks of this trial. Therefore, the application of this product every 3 weeks would be a good tool to significantly reduce sand fly bites over the period of transmission of vectorial diseases such as leishmaniasis and several arbovirosis such as Toscana virus.

Vectorial role of some dermanyssoid mites (Acari, Mesostigmata, Dermanyssoidea)

Among transmissible diseases, vectorial diseases represent a major problem for public health. In the group of acarina, while ticks are the most commonly implicated vectors, other arthropods and notably Dermanyssoidea are also involved in the transmission of pathogenic agents. Since the role of this superfamily is at present largely unknown, we have reviewed the vectorial role of these mites in the appearance, survival and propagation of pathogens. Various authors have shown that Dermanyssoidea are implicated in the transmission of both bacteria (Salmonella, Spirocheta, Rickettsia or Pasteurella) and viruses (equine encephalitis viruses, West Nile virus, Fowl pox virus, the virus causing Newcastle disease and tick borne encephalitis viruses or hantaviruses). Finally, some authors have also shown their role in the transmission of some protozoa and filaria. As the vectorial character of such mites has been more clearly demonstrated (Dermanyssus gallinae, Omithonyssus bacoti and Allodermanyssus sanguineus), it would be interesting to continue studies to better understand the role of this superfamily in the epidemiology of certain zoonoses.

Prevention of Lyme borreliosis infection after tick bites

Lyme borreliosis is one of the zoonotic and vectorial diseases in the world. Female of Taiga tick, Ixodes persulcatus play an important role being the main vector of the agents, Borrelia burgdorferi sensu lato, of the disease in the Far East including Japan. The number of patients who contacted Lyme borreliosis have been estimated to be around 100 cases in all of Japan. We also detected the spirochetes from the skin tissues of 27 cases involving erythema and 3 cases without erythema after tick bites in Hokkaido. We noticed that in those cases when the victims removed ticks by themselves using their fingers within several days later, almost all of them developed erythema. On the other hand, an infected tick from 8 cases which were removed by surgical procedure, the spirochetes were not transmitted in these cases (No. 31-38). Therefore, we supposed that the transmission of agents takes place by regurgitation of the spirochestes from the midgut diverticula due to the pressure by fingers (calling Syringe phenomenon). Then, the authors recommended that fine tweezers has a firm grip around the mouth part of infested tick and pull out within 24 hours and/or trials to surgical operation for tick removal on passing over 24 hours after infestation.