Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: an emerging tool for studying the vectors of human infectious diseases.

Arthropod vectors have historically been identified morphologically, and more recently using molecular biology methods. However, both of these methods are time-consuming and require specific expertise and equipment. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, which has revolutionized the routine identification of microorganisms in clinical microbiology laboratories, was recently successfully applied to the identification of arthropod vectors. Since then, the robustness of this identification technique has been confirmed, extended to a large panel of arthropod vectors, and assessed for detecting blood feeding behavior and identifying the infection status in regard to certain pathogenic agents. In this study, we summarize the state-of-the-art of matrix-assisted laser desorption ionization time-of-flight mass spectrometry applied to the identification of arthropod vectors (ticks, mosquitoes, phlebotomine sand-flies, fleas, triatomines, lice and Culicoides), their trophic preferences and their ability to discriminate between infection statuses.

Artrópodos vectores en España y sus enfermedades transmisibles / Arthropods as vectors of transmisible diseases in Spain

Diferentes aspectos relacionados con la globalización junto a la gran capacidad de los artrópodos vectores para adaptarse a un mundo cambiante propician la emergencia y reemergencia de numerosos procesos infecciosos transmitidos por los mismos. Dípteros (culícidos y flebótomos), garrapatas, pulgas y piojos, entre otros, provocan un variado espectro de enfermedades con gran importancia en Salud Pública. En esta revisión se repasan las diferentes afecciones transmitidas por artrópodos vectores, haciendo un especial hincapié en el riesgo existente para contraerlas en España en función de diferentes parámetros, como la presencia del artrópodo y la circulación o posible circulación de los agentes causales

Different aspects related to globalization together with the great capacity of the arthropod vectors to adapt to a changing world favour the emergence and reemergence of numerous infectious diseases transmitted by them. Diptera (mosquitoes and sandflies), ticks, fleas and lice, among others, cause a wide spectrum of diseases with relevance in public health. Herein, arthropod-borne disease are reviewed, with special emphasis on the existing risk to contract them in Spain according to different parameters, such as the presence of arthropod and the circulation or the possible circulation of the causative agents

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine.

INTRODUCTION: Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS: Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS: Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine

Abstract INTRODUCTION: Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS: Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS: Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Transmission Risk from Imported Plasmodium vivax Malaria in the China-Myanmar Border Region.

Malaria importation and local vector susceptibility to imported Plasmodium vivax infection are a continuing risk along the China-Myanmar border. Malaria transmission has been prevented in 3 border villages in Tengchong County, Yunnan Province, China, by use of active fever surveillance, integrated vector control measures, and intensified surveillance and response.

Arbovirosis y operación ATALANTA: riesgo para viajeros y medidas de prevención y control / Arbovirosis and Operation Atalanta: risk for travelers and prevention and control measures

El término arbovirosis se utiliza para definir a un grupo de enfermedades producidas por virus, que tiene en común la utilización de artrópodos como vectores para su transmisión. Se han reconocido más de 500 arbovirus pertenecientes en su mayoría a 5 familias: Flaviviridae, Togaviridae, Bunyaviridae, Reoviridae y Rhabdoviridae. Pese a su naturaleza mayoritariamente zoonótica, al menos un 25% de ellas afectan al hombre, siendo responsables de enfermedades como la fiebre amarilla, dengue o la fiebre de Chikungunya. Desde enero de 2009 un contingente militar se encuentra desplegado en el Golfo de Adén y en el Océano Indico integrado en la operación EU NAVFOR-ATALANTA de lucha contra la piratería y protección del tráfico mercante del Programa mundial de alimentos para Somalia. Las enfermedades transmitidas por vectores, en especial la malaria y diversas arbovirosis (dengue, Chikungunya, fiebre del Valle del Rift, fiebre del Nilo occidental) se consideran un importante problema de salud pública en el area de operaciones (sobre todo en zonas rurales y/o costeras). Los vectores de estas enfermedades se encuentran ampliamente distribuidos por toda esta región, con tasas de infestación muy altas y que se incrementa de año en año. Por todo ello nos planteamos este trabajo cuyos objetivos son: conocer las características epidemiológicas de las principales arbovirosis que pueden afectar a las tropas españolas desplegadas en la operación Atalanta: fiebre del Valle del Rift, fiebre de O´nyong Nyong, fiebre del Nilo occidental, fiebre hemorrágica del Congo, fiebre amarilla, enfermedad de Sindbis, fiebre de Chikungunya y Dengue. Así mismo se pretende analizar las principales medidas para la prevención de estas enfermedades realizadas por el contingente español allí desplegado: educación sanitaria, control ambiental, protección frente a mosquitos

The term arbovirosis is used to define a group of diseases produced by virus transmitted by arthropod vectors. More than 500 arbovirus have been recognized most of them belonging to 5 families: Flaviviridae, Togaviridae, Bunyaviridae, Reoviridae y Rhabdoviridae. Although they are mainly zoonotic, at least 25 % of them affect humans, being responsible for diseases like yellow fever, dengue or Chikungunya fever. Since January 2009 a military contingent is deployed in the Gulf of Aden and the Indian Ocean integrated in the operation EU NAVFOR-ATALANTA against piracy and protecting the merchant traffic of the World Food Programme Somalia. Vector borne diseases, especially malaria and different arbovirosis (dengue, Chikungunya, Rift Valley fever, West Nile fever) are considered an important public health issue in the Area of Operations (mainly in rural or coastal areas). The vectors of these diseases are widely distributed throughout the region with high infestation rates and increasing every year. This is the reason for this paper with the objectives of: to determine the epidemiological characteristics of the main arbovirosis that might affect the Spanish forces deployed in Operation Atalanta: Rift Valley fever, O'nyong'nyong fever, West Nile fever, Congo hemorrhagic fever, yellow fever, Sindbis virus disease, Chikungunya fever and dengue. It also aims to evaluate the main preventive measures against these diseases used by the deployed Spanish contingent: health education, environmental control and protection against mosquitoes

Model analysis for plant disease dynamics co-mediated by herbivory and herbivore-borne phytopathogens.

Plants are subject to diseases caused by pathogens, many of which are transmitted by herbivorous arthropod vectors. To understand plant disease dynamics, we studied a minimum hybrid model combining consumer-resource (herbivore-plant) and susceptible-infected models, in which the disease is transmitted bi-directionally between the consumer and the resource from the infected to susceptible classes. Model analysis showed that: (i) the disease is more likely to persist when the herbivore feeds on the susceptible plants rather than the infected plants, and (ii) alternative stable states can exist in which the system converges to either a disease-free or an endemic state, depending on the initial conditions. The second finding is particularly important because it suggests that the disease may persist once established, even though the initial prevalence is low (i.e. the R(0) rule does not always hold). This situation is likely to occur when the infection improves the plant nutritive quality, and the herbivore preferentially feeds on the infected resource (i.e. indirect vector-pathogen mutualism). Our results highlight the importance of the eco-epidemiological perspective that integration of tripartite interactions among host plant, plant pathogen and herbivore vector is crucial for the successful control of plant diseases.

La fiebre/encefalitis por virus West Nile: reemergencia en Europa y situación en España / West Nile fever/encephalitis: re-emergence in Europe and the situation in Spain

En los últimos años se ha producido un incremento en la incidencia y rango geográfico de algunas arbovirosis, de las cuales quizá la más destacable sea la fiebre/encefalitis por virus West Nile. Esta enfermedad no recibió demasiada atención hasta los graves brotes ocurridos entre 1996 y 1999 en Rumanía, Rusia e Israel. Pero el acontecimiento que provocó una atención sin precedentes fue su aparición en Nueva York en 1999. Desde entonces su incidencia no ha dejado de crecer, y su rango geográfico de ampliarse. En América se ha extendido de costa a costa y desde Canadá hasta Argentina. En Europa ha aumentado su incidencia allí donde ya había ocurrido, y, recientemente, afectado zonas donde nunca antes había sido observada. El presente artículo es una revisión sobre el virus, la enfermedad, y su situación en Europa, con especial referencia a España, donde en 2010 se produjeron casos clínicos humanos y veterinarios (AU)

Some arbovirosis have increased their incidence and geographic range in the past few years. This phenomenon has been particularly noticeable in the case of West Nile fever/encephalitis. This disease did not receive much attention until serious outbreaks occurred in Romania, Russia and Israel between 1996 and 1999. But the event drawing an unprecedented attention to this disease was its occurrence in New York in 1999. Since then its incidence and geographic range has not ceased to grow. In America it has extended from coast to coast and from Canada to Argentina. In Europe, the disease incidence has increased in areas where it had already been reported, and, recently, affected other areas where it had never been observed before. The present article is a review on the virus, the disease, and its situation in Europe, with special reference to Spain, where in 2010 human and veterinary cases were reported (AU)

Diversity of Bartonella species detected in arthropod vectors from animals in Australia.

A variety of Bartonella species were detected in two species of ticks and three species of fleas collected from marsupial hosts; brush-tailed bettong or woylie (Bettongia penicillata) and western barred bandicoots (Perameles bougainville) and from a rodent host; Rattus fuscipes in Western Australia. Bartonella species were detected using nested-PCR of the gltA gene and the 16S-23S ribosomal internal transcribed spacer region (ITS), and species were characterized using DNA sequencing of the 16S rRNA, gltA, rpoB, ftsZ genes and the ITS region. Bartonella rattaustraliani and B. coopersplainsensis were detected in Ixodes spp. ticks and fleas (Stephanocircus pectinipes) respectively collected from rodents. Two novel Bartonella species were detected from marsupials; Candidatus Bartonella woyliei n. sp. was detected in both fleas (Pygiopsylla hilli) and ticks (Ixodes australiensis) collected from woylies and Candidatus Bartonella bandicootii n. sp. was detected in fleas (Pygiopsylla tunneyi) collected from western barred bandicoots. Concatenated phylogenetic analysis of all 5 loci clarified the marsupial cluster of Bartonella species in Australia and confirmed the species status of these two Bartonella species in ticks and fleas from woylies and western barred bandicoots, which are classified as threatened species and are vulnerable to extinction.

Antibodies against a tick protein, Salp15, protect mice from the Lyme disease agent.

Traditionally, vaccines directly target a pathogen or microbial toxin. Lyme disease, caused by Borrelia burgdorferi, is a tick-borne illness for which a human vaccine is not currently available. B. burgdorferi binds a tick salivary protein, Salp15, during transmission from the vector, and this interaction facilitates infection of mice. We now show that Salp15 antiserum significantly protected mice from B. burgdorferi infection. Salp15 antiserum also markedly enhanced the protective capacity of antibodies against B. burgdorferi antigens, such as OspA or OspC. Mice actively immunized with Salp15 were also significantly protected from tick-borne Borrelia. In vitro assays showed that Salp15 antiserum increased the clearance of Salp15-coated B. burgdorferi by phagocytes, suggesting a mechanism of action. Vaccination with a vector molecule that a microbe requires for infection of the mammalian host suggests a new strategy for the prevention of Lyme disease, and this paradigm may be applicable to numerous arthropod-borne pathogens of medical importance.

Coffee ringspot virus vectored by Brevipalpus phoenicis (Acari: Tenuipalpidae) in coffee.

Coffee ringspot is characterized by conspicuous ringspot symptoms on leaves, berries, and less frequently on twigs. It is caused by coffee ringspot virus (CoRSV), a short, bacilliform virus (40 nm x 100-110 nm). The virus is not seed borne and is transmitted by Brevipalpus phoenicis (Geijskes). Transovarial transmission within the mite does not occur. CoRSV has been mechanically transmitted to Chenopodium amaranticolor Coste and Reynaud, C. quinoa Wildenow, Beta vulgaris L., and Alternanthera tenella Colla resulting in local lesions. Systemic infection within both C. amaranticolor and C. quinoa occurs. Virions are found in the nucleus or cytoplasm of infected cells, commonly associated with membranes. Occasionally, membrane bounded particles are found within the cisternae of the endoplasmic reticulum. A characteristic electron lucent, nuclear inclusion is commonly found in many infected cells. These cytopathic effects place CoRSV among the nuclear type of Brevipalpus-borne viruses. The disease has been reported in several Brazilian states (São Paulo, Paraná, Minas Gerais, and Federal District) and recently found in Costa Rica. A similar disease is known in the Philippines, but no information exists about its relationship to CoRSV. Coffee ringspot had no economical significance until recently when a large scale infection was reported in Minas Gerais that resulted in yield loss.

Pulícidos: aspectos adaptativos y biológicos / Pulicides: adaptative and biological aspects

Las pulgas son insectos hematófagos que se caracterizan por una baja especificidad parasitaria. Son ectoparásitos de distintos animales y del hombre. El cuerpo de estos insectos está comprimido lateralmente y las antenas pueden replegarse dentro de un surco a los costados de la cabeza, características óptimas para un mejor desplazamiento entre los pelos y las plumas de los hospedadores. Los tres pares de patas son fuertes y poderosas, armadas con robustas espinas y en sus extremos con un par de grandes uñas en forma de garfios. El tercer par es el que está adaptado para saltar. Las piezas bucales son sucsopicadoras y modificadas en forma de estiletes. Algunas especies tienen unas hileras de cerdas (ctenidios) en la zona genal y/o en el dorso del primer segmento toráxico que evitan los movimientos de retroceso y la caída del cuerpo del hospedador. Esta característica también dificulta la extracción de los parásitos. La importancia de los pulícidos radica entre otras, por ser transmisores de la peste y el tifus. Se muestran bajo SEM y con microfotografías las adaptaciones al parasitismo, la biología y las afecciones cutáneas que se producen (AU)

Pulícidos: aspectos adaptativos y biológicos / Pulicides: adaptative and biological aspects

Las pulgas son insectos hematófagos que se caracterizan por una baja especificidad parasitaria. Son ectoparásitos de distintos animales y del hombre. El cuerpo de estos insectos está comprimido lateralmente y las antenas pueden replegarse dentro de un surco a los costados de la cabeza, características óptimas para un mejor desplazamiento entre los pelos y las plumas de los hospedadores. Los tres pares de patas son fuertes y poderosas, armadas con robustas espinas y en sus extremos con un par de grandes uñas en forma de garfios. El tercer par es el que está adaptado para saltar. Las piezas bucales son sucsopicadoras y modificadas en forma de estiletes. Algunas especies tienen unas hileras de cerdas (ctenidios) en la zona genal y/o en el dorso del primer segmento toráxico que evitan los movimientos de retroceso y la caída del cuerpo del hospedador. Esta característica también dificulta la extracción de los parásitos. La importancia de los pulícidos radica entre otras, por ser transmisores de la peste y el tifus. Se muestran bajo SEM y con microfotografías las adaptaciones al parasitismo, la biología y las afecciones cutáneas que se producen

[The concept of medical entomology: the management of the influence of arthropods on human health]. / Kontseptsiia meditsinskoi éntomologii: upravlenie vliianiem chlenistonogikh na zdorov'e liudei.

The tasks of medical entomology are analyzed with special reference to the development of methods of protection against the harmful influence of arthropods on human health and the use of these animals in health sciences. Special attention is paid to the following problems: characterization of individual and group features of humans and their relationship with arthropods, elucidation of the properties of arthropods, determination of the state of their populations, estimation of the efficiency of controlling measures, their ecological consequences, etc.