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1.
The Korean Journal of Parasitology ; : 167-173, 2019.
Article in English | WPRIM | ID: wpr-761724

ABSTRACT

Rickettsial infections (Rickettsioses) are the causes of acute fever found in Thailand. It is classified as acute febrile illnesses transmitted by bloodsucking arthropod vectors (tick, flea, and chigger). This research investigated pathogens of scrub typhus in vectors from Bangkaew District, Phatthalung Province. A total of 303 pools of vector samples were ticks (Rhipicephalus sanguineus, R. microplus, and Haemaphysalis sp.), fleas (Ctenocephalides felis orientis, C. f. felis, and C. canis), and chiggers (Leptotrombidium deliense, Aschoschoengastia indica, Blankaartia acuscutellaris and Walchia disparunguis pingue) collected from reservoir hosts (dogs and rodents). The 17 and 56 kDa gene of Rickettsia causing scrub typhus were found in 29% of ticks and 98% of flea. DNA sequence analysis reveeled the detected strains were R. asembonensis and Rickettsia sp. cf1 and 5.The chiggers, 1%, were infected with Rickettsia strain TA763, a pathogen of scrub typhus.


Subject(s)
Animals , Cats , Arthropod Vectors , Felis , Fever , Orientia tsutsugamushi , Rickettsia , Scrub Typhus , Sequence Analysis, DNA , Siphonaptera , Thailand , Ticks , Trombiculidae
2.
Biomédica (Bogotá) ; 38(4): 534-544, oct.-dic. 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-983964

ABSTRACT

Resumen Introducción. Las especies del complejo Amblyomma cajennense, potenciales vectores implicados en la transmisión de Rickettsia rickettsii en Centroamérica y Suramérica, presentan una amplia distribución geográfica en el neotrópico. En Colombia, todavía es incipiente el conocimiento sobre las especies de este complejo, su distribución y su ecología. Objetivo. Explorar la ecología del complejo A. cajennense en Colombia a partir del estudio de su selección de hábitat y la generación de modelos potenciales de distribución geográfica y climática. Materiales y métodos. Se utilizaron registros únicos de la presencia de estas garrapatas en el estudio de sus patrones de selección del hábitat, mediante el análisis factorial del nicho ecológico (Ecological Niche Factor Analysis, ENFA), y se construyeron modelos de distribución potencial con las metodologías MaxEnt y GARP. Resultados. El complejo A. cajennense se encontró en las cinco regiones naturales de Colombia, con 64,71 % de los registros procedentes de los departamentos de Antioquia, Cundinamarca y Huila. La selección del hábitat evidenció que estas garrapatas escogen preferentemente las áreas geográficas (ENFA: 96,03 %) según sus condiciones de índice de estabilidad térmica y de precipitación en el trimestre más seco del año. Los modelos de distribución potencial indicaron la idoneidad del hábitat en 31 a 51 % del área del país dependiendo del algoritmo empleado. Conclusiones. En Colombia, el complejo A. cajennense presenta una distribución muy influenciada por el comportamiento en la selección del hábitat climático, característica que facilitó la creación de modelos de distribución. En futuros estudios de campo, se podrían validar los modelos presentados; se requieren, además, otros estudios genéticos para la identificación de especies del complejo y el manejo de sus potenciales zonas de hibridación en el país.


Abstract Introduction: The species of the Amblyoma cajennense complex, potential vectors involved in the transmission of Rickettsia rickettsii in Central and South America, have a wide geographical distribution in the Neotropics. In Colombia, the knowledge about these species, their distribution, and many aspects of their ecology is still limited. Objective: To explore the ecology of A. cajennense complex in Colombia based on the study of its habitat selection, as well as the generation of potential geographic and climatic distribution models. Materials and methods: We used unique records of these ticks to study the selection patterns of the climatic habitat using the Ecological Niche Factor Analysis (ENFA), and we built distribution models using the MaxEnt and GARP algorithms. Results: The record of distributions showed that A. cajennense complex is present in all five natural regions of Colombia with 64.71% of the records found in the departments of Antioquia, Cundinamarca, and Huila. The analysis of their habitat selection showed that these ticks preferably select geographical areas (ENFA: 96.03%) according to the isothermality conditions and the precipitation of the driest quarter of the year. The potential distribution models indicated habitat suitability in 31 to 51% of the area of the country depending on the algorithm. Conclusions: The distribution of A. cajennense complex in Colombia is highly influenced by a climatebased habitat selection, a characteristic that favored the creation of distribution models. Field studies will allow the validation of the potential distribution models and further genetic studies will be required in the country to identify species within the complex and study their potential hybridization areas.


Subject(s)
Arthropod Vectors , Ticks , Climate , Ecosystem , Ecology
3.
MedUNAB ; 21(1): 10-15, 2018.
Article in Spanish | LILACS | ID: biblio-970190

ABSTRACT

El Aedes (Stegomyia) albopictus (Skuse, 1894) se denomina también "mosquito tigre" asiático (1) y, al igual que el Ae. aegypti (Linnaeus, 1762), se lo ha identificado en algunos países del continente asiático como importante vector de dengue (2), la más importante enfermedad viral de transmisión vectorial que presenta un fuerte impacto social debido a que se distribuye fundamentalmente en zonas urbanas; es altamente incapacitante y en algunos casos conduce a la muerte (3). Se ha reportado que el Ae. albopictus puede transmitir, experimental o naturalmente 22 tipos diferentes de arbovirus (4); entre estos, los cuatro serotipos de dengue y de los virus de la encefalitis equina del este (5) y la japonesa (6), así como también del virus chikungunya (7) y el del oeste del Nilo (8, 9). Además, se ha documentado que puede transmitir el virus de la fiebre amarilla, por lo cual se lo considera como vector puente entre los ciclos de transmisión selvática y urbana (5). Adicionalmente, en zonas endémicas para el dengue, en las cuales se presenten casos de fiebre amarilla, existe el riesgo potencial de que se urbanice esta enfermedad. Por este motivo resulta de interés compartir con los lectores de la revista MedUNAB la experiencia de la primera evidencia de Aedes albopictus en el departamento del Putumayo y mostrar cómo a través de la vigilancia entomológica liderada por el Laboratorio de Salud Pública y con el apoyo de auxiliares del Programa de Enfermedades Transmitidas por vectores (ETV), de la Secretaria de Salud del departamento del Putumayo y del Instituto Nacional de Salud (INS) se determinó la especie.


Subject(s)
Humans , Arthropod Vectors , Virus Diseases , Colombia , Aedes , Dengue , Dengue Virus
4.
Rev. bras. parasitol. vet ; 26(4): 525-531, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-1042453

ABSTRACT

Abstract The role of several feline vector-borne pathogens (FVBP) as a cause of disease in cats has not been clearly determined. In fact, with the exception of Bartonella spp. and hemoplasmas, FVBP in cats has not been clearly determined in Brazil yet. The present study aimed at identifying, by using molecular methods, the presence of FVBP in three cats showing non-specific clinical signs and inclusions suggestive of hemoparasites in blood smears. Cytauxzoon felis, 'Candidatus Mycoplasma haemominutum', Ehrlichia sp. closely related to Ehrlichia canis, and Anaplasma sp. closely related to Anaplasma phagocytophilum were detected in blood samples from two out of three sampled cats. Both cats positive for multiple FVBP did not show hematological and biochemical abnormalities. The present work emphasizes the need for molecular confirmation of co-infection by multiple FVBP in cats presenting non-specific clinical signs and inclusions resembling hemoparasites in blood smears.


Resumo O papel de diversos patógenos felinos transmitidos por vetores (PFTV) como causa de enfermidades em gatos não tem sido claramente determinado. De fato, com exceção de Bartonella spp. e hemoplasmas, PFTV têm sido bem menos estudados no Brasil. O presente estudo objetivou investigar, utilizando métodos moleculares, a presença de PFTV em três gatos apresentando sinais clínicos inespecíficos e inclusões sugestivas de hemoparasitas em esfregaços sanguíneos. Cytauxzoon felis, 'Candidatus Mycoplasma haemominutum', Ehrlichia sp. filogeneticamente relacionada a Ehrlichia canis, e Anaplasma sp. filogeneticamente relacionado a Anaplasma phagocytophilum foram detectados em amostras de sangue de dois dos três gatos amostrados. Os dois gatos positivos para múltiplos PFTV não apresentaram alterações hematológicas e bioquímicas. O presente trabalho enfatiza a necessidade de confirmação molecular da infecção por múltiplos PFTV em gatos apresentando sinais clínicos inespecíficos e inclusões sugestivas de hemoparasitas em esfregaços sanguíneos.


Subject(s)
Animals , Male , Female , Cats , Arthropod Vectors/parasitology , Cat Diseases/parasitology , Coinfection
6.
Rev. Soc. Bras. Med. Trop ; 50(5): 629-637, Sept.-Oct. 2017. tab, graf
Article in English | LILACS | ID: biblio-897012

ABSTRACT

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.


Subject(s)
Humans , Animals , Arthropod Vectors/physiology , Rhodnius/physiology , Triatoma/physiology , Trypanosoma cruzi/physiology , Sympatry , Arthropod Vectors/genetics , Arthropod Vectors/pathogenicity , Rhodnius/genetics , Rhodnius/pathogenicity , Species Specificity , Time Factors , Triatoma/genetics , Triatoma/pathogenicity , Trypanosoma cruzi/genetics , Trypanosoma cruzi/pathogenicity , Blood/parasitology , Brazil , Polymerase Chain Reaction , Chagas Disease/parasitology , Chagas Disease/transmission , Xenodiagnosis/methods , Host-Parasite Interactions/physiology , Intestines/parasitology , Mice
8.
Medicina (B.Aires) ; 76(2): 89-92, abr. 2016. tab
Article in English | LILACS | ID: biblio-841548

ABSTRACT

This work presents records of ticks infesting humans in northern Misiones Province, Argentina. Also, notes on potential transmission of tick-borne pathogens are included. A total of 282 ticks attached to researchers were collected and identified by their morphological characters. Eight tick species were found: Amblyomma brasiliense, Amblyomma coelebs, Amblyomma dubitatum, Amblyomma incisum, Amblyomma ovale, Haemaphysalis juxtakochi, Rhipicephalus sanguineus and Rhipicephalus microplus. Some of these species as A. dubitatum, A. ovale and R. sanguineus have been found infected with spotted fever group rickettsiae pathogenic to humans in Brazil and Argentina. The potential role as vectors of humans pathogens of the ticks found attached to humans in this study is discussed.


En este trabajo se presentan registros de garrapatas que infestan seres humanos en el norte de la provincia de Misiones, Argentina. Además, se incluyen notas sobre la posible transmisión de patógenos por garrapatas. Se colectó un total de 282 garrapatas adheridas a investigadores, las cuales fueron identificadas por sus caracteres morfológicos. Se encontraron ocho especies de garrapatas: Amblyomma brasiliense, Amblyomma coelebs, Amblyomma dubitatum, Amblyomma incisum, Amblyomma ovale, Haemaphysalis juxtakochi, Rhipicephalus sanguineus y Rhipicephalus microplus. Algunas de estas especies como A. dubitatum, A. ovale y R. sanguineus han sido halladas infectadas con rickettsias del grupo de las fiebres manchadas patógenas para los seres humanos en Brasil y Argentina. Se discute el papel potencial de las garrapatas encontradas infestando humanos en este estudio como vectores de patógenos de seres humanos.


Subject(s)
Humans , Animals , Arthropod Vectors/microbiology , Rickettsia/isolation & purification , Tick Infestations/epidemiology , Ticks/microbiology , Argentina , Ticks/classification , Cattle , Data Collection , Ixodidae/classification , Ixodidae/microbiology , Horses/parasitology
9.
Clinical and Experimental Vaccine Research ; : 58-77, 2014.
Article in English | WPRIM | ID: wpr-36952

ABSTRACT

In this review, we mainly focus on zoonotic encephalitides caused by arthropod-borne viruses (arboviruses) of the families Flaviviridae (genus Flavivirus) and Togaviridae (genus Alphavirus) that are important in both humans and domestic animals. Specifically, we will focus on alphaviruses (Eastern equine encephalitis virus, Western equine encephalitis virus, Venezuelan equine encephalitis virus) and flaviviruses (Japanese encephalitis virus and West Nile virus). Most of these viruses were originally found in tropical regions such as Africa and South America or in some regions in Asia. However, they have dispersed widely and currently cause diseases around the world. Global warming, increasing urbanization and population size in tropical regions, faster transportation and rapid spread of arthropod vectors contribute in continuous spreading of arboviruses into new geographic areas causing reemerging or resurging diseases. Most of the reemerging arboviruses also have emerged as zoonotic disease agents and created major public health issues and disease epidemics.


Subject(s)
Humans , Africa , Alphavirus , Animals, Domestic , Arboviruses , Arthropod Vectors , Asia , Encephalitis , Encephalitis Virus, Venezuelan Equine , Encephalitis Virus, Western Equine , Encephalitis Viruses , Encephalomyelitis, Equine , Epidemiology , Flaviviridae , Flavivirus , Global Warming , Population Density , Public Health , South America , Togaviridae , Transportation , Urbanization , Zoonoses
10.
Rev. bras. parasitol. vet ; 22(3): 385-390, July-Sept. 2013. tab, ilus
Article in English | LILACS, VETINDEX | ID: lil-688717

ABSTRACT

Hemotrophic mycoplasmas (hemoplasmas), Bartonellasp., Hepatozoon sp. and Cytauxzoon felis are prominent pathogens that circulate between cats and invertebrate hosts. The present study aimed to detect the presence of DNA from hemoplasmas, Bartonella sp., Hepatozoon sp. and Cytauxzoon felis, and then confirm it by means of sequencing, in blood samples from cats in Cuiabá, MT, Brazil. From February 2009 to February 2011, blood samples with added EDTA were collected from 163 cats that were being housed in four different animal shelters in the city of Cuiabá, state of Mato Grosso, Brazil and from 15 cats that were admitted to the veterinary hospital of the Federal University of Mato Grosso (UFMT). Out of the 178 cats sampled, 15 (8.4%) were positive for hemoplasmas: four (2.2%) for Mycoplasma haemofelis, 12 (6.7%) for 'Candidatus M. haemominutum' and one (0.5%) for 'Candidatus M. turicensis'. One cat (0.5%), a patient that was attended at the veterinary hospital, was coinfected with M. haemofelis, 'Candidatus M. haemominutum' and 'Candidatus M. turicensis', based on sequencing confirmation. Four cats were positive for Bartonella spp.: three (1.7%) for B. henselae and one (0.5%) for B. clarridgeiae. None of the animals showed Cytauxzoon sp. or Hepatozoon sp. DNA in their blood samples. This study showed that cats housed in animal shelters in the city of Cuiabá, state of Mato Grosso, are exposed to hemoplasmas and Bartonella species.


Micoplasmas hemotróficos (hemoplasmas), Bartonellasp., Hepatozoon sp. e Cytauxzoon felis se destacam como importantes patógenos que circulam entre gatos e hospedeiros invertebrados. O presente estudo objetivou detectar e, posteriormente confirmar por seqüenciamento, a presença de DNA de hemoplasmas, Bartonella sp., Hepatozoon sp. e Cytauxzoon felis em amostras de sangue de gatos de Cuiabá, MT, Brasil. Entre fevereiro/2009 e fevereiro de 2011, amostras de sangue acrescidas de EDTA foram coletadas de 163 gatos mantidos em quatro diferentes abrigos na cidade de Cuiabá, estado do Mato Grosso, Brasil, e de 15 gatos atendidos no Hospital Veterinário da Universidade Federal do Mato Grosso (UFTM). Dos 178 gatos amostrados, 15 (8,4%) foram positivos para hemoplasmas: quatro (2,2%) para Mycoplasma haemofelis, 12 (6,7%) para 'Candidatus M. haemominutum' e um (0,5%) para 'Candidatus M. turicensis'. Um (0.5%) gato, atendido no Hospital Veterinário da UFMT, estava co-infectado com M. haemofelis, 'Candidatus M. haemominutum' e 'Candidatus M. turicensis', baseado na confirmação por sequenciamento. Quatro gatos mostraram-se positivos para Bartonella spp.: três (1,7%) para B. henselae e um (0.5%) para B. clarridgeiae. Todos os gatos amostrados mostraram-se negativos para Cytauxzoon sp. e Hepatozoon sp. Este estudo mostrou que gatos mantidos em abrigos na cidade de Cuiabá, estado do Mato Grosso, são expostos a hemoplasmas e espécies de Bartonella sp.


Subject(s)
Animals , Male , Female , Bartonella , Arthropod Vectors , Cats/blood , DNA, Bacterial/blood , Mycoplasma/genetics , Mycoplasma/isolation & purification , Polymerase Chain Reaction , Brazil
11.
Mem. Inst. Oswaldo Cruz ; 108(1): 123-125, Feb. 2013. ilus
Article in English | LILACS | ID: lil-666057

ABSTRACT

Specimens of the hard tick Amblyomma triste were found infected with Rickettsia parkeri in an area of Argentina (General Lavalle, Buenos Aires Province) where cases of human illness attributed to this microorganism have been reported. Molecular detection of R. parkeri was based on polymerase chain reactions that amplify a ca. 400-bp fragment of the 23S-5S intergenic spacer and a ca. 500-bp fragment of the gene encoding a 190-kDa outer membrane protein. Three (6.97%) of 43 A. triste ticks were determined to be positive for R. parkeri. These results provide strong evidence that A. triste is the vector of R. parkeri in the study area. The findings of this work have epidemiological relevance because human parasitism by A. triste ticks has been frequently recorded in some riparian areas of Argentina and Uruguay and new cases of R. parkeri rickettsiosis might arise in the South American localities where humans are exposed to the bites of this tick species.


Subject(s)
Animals , Humans , Arthropod Vectors/microbiology , Rickettsia/isolation & purification , Ticks/microbiology , Argentina , Polymerase Chain Reaction , Rickettsia Infections/transmission
12.
EMHJ-Eastern Mediterranean Health Journal. 2013; 19 (10): 892-897
in English | IMEMR | ID: emr-159115

ABSTRACT

The viral haemorrhagic fevers [VHF] are a growing public health threat in the Eastern Mediterranean Region. Nearly all of them are of zoonotic origin. VHF often cause outbreaks with high fatalities and, except for yellow fever, currently there are no specific treatment or vaccination options available. In response to this growing threat, the Regional Office for the Eastern Mediterranean of the World Health Organization convened a technical consultation in Tehran on 27-30 November 2011 to review the current gaps in prevention and control of VHF outbreaks in the Region. The meeting recommended a number of strategic public health approaches for prevention and control of VHF outbreaks through synergizing effective collaboration between the human and animal health sectors on areas that involve better preparedness, early detection and rapid response. Implementation of these approaches would require working together with vision, commitment and a sense of purpose involving partnerships and cooperation from all relevant sectors


Subject(s)
Humans , Animals , Communicable Disease Control/methods , Hemorrhagic Fevers, Viral/epidemiology , Diagnostic Techniques and Procedures , Disease Outbreaks/prevention & control , Health Behavior , Arthropod Vectors , Pest Control/methods , Public Health , Sentinel Surveillance , World Health Organization
13.
Biomédica (Bogotá) ; 32(2): 189-195, abr.-jun. 2012. mapas, tab
Article in Spanish | LILACS | ID: lil-656827

ABSTRACT

Introducción. Los ectoparásitos son los principales vectores de rickettsiosis. En Panamá se tienen escasos datos sobre los artrópodos que pudieran considerarse vectores o reservorios. Objetivos. Presentar datos sobre la presencia de Rickettsia spp. en ectoparásitos de fauna silvestre y animales domésticos en la Reserva Natural Privada Cerro Chucantí y poblados vecinos. Materiales y métodos. Se revisaron 9 personas, 95 mamíferos domésticos y 48 silvestres. Los animales domésticos se examinaron con anuencia del propietario, mientras que la fauna silvestre se capturó con trampas Sherman y Tomahawk. Se extrajeron 21 especies de ectoparásitos: pulgas, piojos, garrapatas y otros ácaros, los cuales se preservaron en etanol al 95 %. Se extrajo material genético de garrapatas y pulgas para ser analizado por técnicas moleculares en la detección de Rickettsia spp. Resultados. Se practicaron 425 reacciones de PCR, de las cuales, 270 resultaron negativas y 155 positivas. De las positivas, 86 amplificaron para el gen gltA (55 % de las positivas); de estos también amplificaron 41 (26 %) para ompA. Se encontró material genético de Rickettsia amblyommii, en garrapatas de caballos (Amblyomma cajennense, Dermacentor nitens), de perros (Rhipicephalus sanguineus) y ninfas de Amblyomma recolectadas en el bosque. Además, se detectó ADN de R. felis en pulgas Ctenocephalides felis de perros. Conclusiones. Se pudo detectar la presencia de R. amblyommii y R. felis en garrapatas y pulgas de animales domésticos de los poblados cercanos a Cerro Chucantí, aun cuando no se pudo encontrar material genético de Rickettsia en ectoparásitos de la fauna silvestre.


Introduction. Ectoparasites are the main vectors of rickettsiosis. In Panama, however, limited data are available concerning the arthropod species that serve as vectors or reservoirs. Objectives. Data are presented concerning the presence of Rickettsia in ectoparasites of wildlife and domestic animals in the Cerro Chucantí private nature reserve and in neighboring villages. Materials and methods. Nine humans, 95 domestic mammals and 48 wild mammals were examined. Twenty-one species of ectoparasites were obtained, including fleas, lice, ticks and mites. These were preserved in 95% ethanol. Later, the DNA was extracted from the ticks and fleas and analyzed by molecular techniques to detect presence of Rickettsia. Results. Of a total of 425 PCR reactions, 270 were positive for Rickettsia and 155 negative. Among the positive samples, 86 PCR amplified for the gltA gene (55% of positives) and 41 of these also amplified the ompA gene. DNA of Rickettsiaamblyommii was found in horses ticks (Amblyomma cajennense, Dermacentor nitens), dogs ticks (Rhipicephalus sanguineus) and free living nymphs in the forest. Additionally, DNA of R. felis was found in fleas from dogs Ctenocephalides felis. Conclusions. The presence of R. amblyommii and R. felis was detected in ticks and fleas of domestic animals in villages near Cerro Chucanti; however no Rickettsia DNA was found in ectoparasites of non-domestic wildlife.


Subject(s)
Animals , Cats , Cattle , Dogs , Female , Humans , Male , Animals, Domestic/microbiology , Animals, Wild/microbiology , Arthropod Vectors/microbiology , Disease Reservoirs/microbiology , Ectoparasitic Infestations/parasitology , Ectoparasitic Infestations/veterinary , Mammals/microbiology , Rickettsia/isolation & purification , Cat Diseases/parasitology , Cattle Diseases/parasitology , DNA, Bacterial/analysis , Dog Diseases/parasitology , Ectoparasitic Infestations/microbiology , Genes, Bacterial , Horses , Horse Diseases/parasitology , Larva , Mites/microbiology , Panama , Polymerase Chain Reaction , Phthiraptera/microbiology , Sheep , Species Specificity , Sheep Diseases/parasitology , Siphonaptera/microbiology , Trees , Ticks/growth & development , Ticks/microbiology
14.
Rev. Inst. Med. Trop. Säo Paulo ; 54(3): 131-134, May-June 2012. ilus, graf, mapas
Article in English | LILACS | ID: lil-625272

ABSTRACT

At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.


Inicialmente, Rickettsia conorii fue señalada como el agente causal de la fiebre manchada en Uruguay, diagnosticada mediante pruebas serológicas. Posteriormente, Rickettsia parkeri fue detectada mediante técnicas moleculares en garrapatas Amblyomma triste colectadas sobre humanos. El vector natural de R. conorii, Rhipicephalus sanguineus, no ha sido estudiado en cuanto a rickettsias en Uruguay. Para abordar este tema, 180 R. sanguineus fueron colectados sobre perros y 245 A. triste sobre vegetación en tres localidades consideradas endémicas para fiebres manchadas en el sur de Uruguay. El ADN de las garrapatas fue extraído en pools y sometido a una primera PCR utilizando cebadores que amplifican un fragmento del gen gltA, presente en prácticamente todas las especies de Rickettsia. Las muestras positivas fueron sometidas a una segunda PCR con cebadores que amplifican un fragmento del gen ompA, presente sólo en rickettsias del grupo de las fiebres manchadas (GFM). No se detectó ADN rickettsial en R. sanguineus. Sin embargo, muestras de A. triste fueron positivas a rickettsiales en dos de las tres localidades estudiadas, con prevalencias de pools positivos del 11.8 y 37.5% respectivamente. La secuenciación del ADN evidenció la presencia de R. parkeri. Basados en estos resultados junto a los anteriores y la agresividad de A. triste hacia los humanos, se concluye que esta garrapata es vector de rickettsiosis humana por R. parkeri en Uruguay.


Subject(s)
Animals , Dogs , Female , Humans , Male , Arthropod Vectors/microbiology , Ixodidae/microbiology , Rickettsia/genetics , DNA Primers/analysis , DNA, Bacterial/analysis , Polymerase Chain Reaction , Rhipicephalus sanguineus/microbiology , Rickettsia Infections/transmission , Rickettsia/isolation & purification , Uruguay
15.
CES med ; 24(2)jul.-dic. 2010. tab, ilus
Article in Spanish | LILACS | ID: lil-612534

ABSTRACT

Los sistemas de información geográfica y los sensores remotos son poderosas herramientas para estudiar la distribución actual y predecir áreas de riesgo de presencia de insectos vectoresde enfermedades; así mismo, se constituyen en excelentes aliados para la focalización de acciones de prevención y control. Aunque el uso de estas herramientas en investigación de enfermedades transmitidas por vectores se ha incrementado en los últimos años, su aplicación en los programas oficiales de control ha sido limitada. En esta revisión se aborda esta temática de trabajo, se discuten investigaciones con aplicaciones de ambos sistemas en diferentes especies vectores de enfermedades y los retos a futuro de su aplicación potencial en los programas oficiales de control de dichas enfermedades en Colombia. Finalmente, se enfatiza que para avanzar adecuadamente en los programas de control de las enfermedades, es recomendable el entrenamiento de investigadores y tomadores dedecisiones en estas herramientas, incrementar la colaboración interinstitucional, estandarizar la colecta de datos referentes a la distribución de las especies de vectores y el desarrollo de una plataformacomún de datos.


Geographic Information Systems (GIS) and RemoteSensing (RS) are powerful tools for the study of actualdistribution and to predict risk areas for insect vectorsof diseases. Both have been using increasingly to targetprevention and control actions. The use of these techniquesin research about vector-borne tropical diseasesis growing in the last years; however its application inofficial control programs has been limited. This paperbriefly reviews the use of spatial analysis, GeographicInformation Systems and Remote Sensing in differentvector species and deal with the future challenges for the potential application of these techniques in official controlprograms in Colombia. Finally, to advance in vectorbornecontrol programs, training of researchers and decisionmakers in these tools are recommended. The increaseof collaboration between institutions and the collection ofinformation about the distribution of vector species in astandardized way and the development of a common dataplatform is recommended too.


Subject(s)
Humans , Arthropod Vectors , Geographic Information Systems , Remote Sensors , Zoonoses/transmission
16.
Cad. saúde pública ; 25(12): 2583-2602, dez. 2009. tab, ilus
Article in Portuguese | LILACS | ID: lil-538397

ABSTRACT

O presente estudo descreve os aspectos eco-epidemiológicos sobre arbovírus nos Municípios de Novo Progresso e Trairão, Estado do Pará, Brasil, na área de influência da BR 163. Anticorpos IH foram detectados para diferentes arbovírus, com reações monotípicas para os VMAY e VORO, dois importantes arbovírus associados a epidemias na Amazônia. Anticorpos IgM para o VORO e VMAY foram detectados em soros humanos, sugerindo infecção recente por esses arbovírus. Duas cepas do VDEN-3 foram isoladas de pacientes febris residentes em Novo Progresso e identificadas como genótipo III. Em termos gerais, os dados obtidos sugerem uma área propícia para a circulação e manutenção de arbovírus e uma população pouco imunizada. Portanto, é importante um monitoramento dinâmico das populações locais e de imigrantes e de animais silvestres quanto à presença de anticorpos e isolamentos de arbovírus, o que permitirá um efetivo controle das infecções por esses agentes virais em residentes da área da rodovia dentro do território paraense.


The current study describes the eco-epidemiological aspects of arbovirus diseases in the municipalities (counties) of Novo Progresso and Trairão, Para State, Brazil, in the area affected by highway BR-163. Hemagglutination inhibition (HI) antibodies to different arboviruses were detected, with monotypic reactions to MAYV and OROV, two important arboviruses associated with epidemics in the Amazon. IgM antibodies to OROV and MAYV were found in human sera, suggesting recent infections by these viruses. Two DENV-3 strains were isolated from febrile patients in Novo Progresso and identified as genotype III strains. In general, the data suggest that the area displays ideal conditions for maintenance and circulation of arboviruses, plus a population with low immunization levels. Dynamic surveillance of local immigrants and wild animals is thus important, focusing on antibody prevalence and isolation of arboviruses, thereby allowing effective control of infections by these viral agents in the resident population along highway BR-163 in Pará State.


Subject(s)
Adult , Animals , Female , Humans , Male , Antibodies, Viral/blood , Arbovirus Infections/epidemiology , Arbovirus Infections/veterinary , Arboviruses/immunology , Disease Outbreaks , Environmental Monitoring/statistics & numerical data , Arbovirus Infections/virology , Arthropod Vectors/virology , Brazil/epidemiology , Disease Vectors , Ecosystem , Immunoglobulin M/blood , Species Specificity , Urbanization
17.
Braz. j. microbiol ; 40(1): 90-95, Jan.-Mar. 2009. tab
Article in English | LILACS | ID: lil-513122

ABSTRACT

We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of the genus Drosophila, in two Atlantic Rain Forest fragments in state of Minas Gerais, Brazil. A total of 456 samples were collected from Rio Doce State Park and 142 from Ecological Station of Universidade Federal de Minas Gerais. From these samples, 608 yeast isolates were obtained, belonging to 71 different species. Among the yeasts isolated from Rio Doce State Park, 17 isolates were recovered from fruits, 12 from mushrooms, 13 from tree exudates, and 299 from Drosophila spp. In the Ecological Station of Universidade Federal de Minas Gerais, 24 isolates were recovered from fruits and 243 from Drosophila spp. Distinct communities of yeast were observed in Drosophila flies, fruits, mushrooms and tree exudates. The highest number of yeast species was recovered from Drosophila flies suggesting that flies are the natural vectors of these microorganisms.


O objetivo deste trabalho foi estudar as comunidades de leveduras associadas a frutos, cogumelos, exudatos de árvores e moscas do gênero Drosophila, em dois fragmentos de Mata Atlântica no Estado de Minas Gerais, Brasil. Foram coletadas 456 amostras no Parque Estadual do Rio Doce e 142 na Estação Ecológica da Universidade Federal de Minas Gerais. Destas amostras foram obtidas 608 isolados de levedura, distribuídas em 71 espécies. Entre os isolados obtidos a partir do Parque Estadual do Rio Doce, 17 foram provenientes de frutos, 12 de cogumelos, 13 de exudatos de árvores e 299 de Drosophila spp. A Estação Ecológica da Universidade Federal de Minas Gerais possibilitou a obtenção de 24 isolados de frutos e 243 de Drosophila spp. Foram observadas comunidades distintas de leveduras associadas a Drosophila, frutos, cogumelos e exudatos de árvores. O maior número de espécies foi obtido em drosófilas, sugerindo que estas moscas são vetores naturais destes microrganismos.


Subject(s)
Agaricales , DNA Fragmentation , Drosophila/genetics , Fruit , In Vitro Techniques , Yeasts/isolation & purification , Arthropod Vectors/genetics , Food Samples , Methods , Methods
18.
Rio de Janeiro; s.n; 2009. xi,76 p. ilus, graf.
Thesis in Portuguese | LILACS | ID: lil-540911

ABSTRACT

Várias populações de Aedes aegypti, vetor da dengue e da febre amarela urbana, apresentaram resistência aos inseticidas clássicos utilizados em seu controle. Sendo assim, torna-se imperativo o estabelecimento de estratégias alternativas. Nesse sentido, a biossíntese de quitina é um alvo potencial. Em artrópodes, a quitina é considerada o principal constituinte da cutícula (ou exoesqueleto). A quitina Sintase (do inglês Chitin Synthase, CHS) é uma enzima-chave na biossíntese desta molécula, e os compostos benzoil-fenil-uréias (BPUs) possuem atividade inibidora da síntese de quitina, interferindo na formação da cutícula em diversas espécies de insetos. Novaluron é um BPU recentemente recomendado pela WHO para uso em água potável, o que o qualifica como uma alternativa viável para o controle de larvas do vetor da dengue. Neste trabalho investigamos, durante o desenvolvimento larvar de Ae. aegypti, a influência de novaluron sobre: 1) o conteúdo de quitina; 2) a expressão do gene AaCHS1, evidenciada por seus transcritos alternativos AaCHS1a e AaCHS1b e, 3) a estrutura do exoesqueleto e da membrana peritrófica. Para tanto, inicialmente foi necessário observar os momentos das ecdises larvais. Os pontos definidos para a coleta das amostras levaram em conta o processo de síntese de cutícula a cada instar larvar. Foram escolhidos pontos tentativamente representativos do início (i), meio (int) e fim (f) do terceiro (L3) e do quarto (L4) instares. Os pontos de L3i, L3int, L3f, L4i, L4int e L4f foram definidos como 53, 59,5, 68, 75, 92,5 e 98 horas após a eclosão (HAE), respectivamente. Novaluron foi então administrado continuamente a larvas L3, a partir de 51 HAE, em concentrações definidas em relação ao seu percentual de inibição de emergência do adulto (IE): IE20, IE50 e IE99. Foi observado um aumento significativo no conteúdo de quitina de larvas controle, desde L3i até L4f. Novaluron afetou significativamente a produção de quitina de forma dose-dependente, ao longo do desenvolvimento larvar. A abundância relativa de mRNA dos transcritos AaCHS1a e AaCHS1b foi avaliada por PRC quantitativo em tempo real, de L3i e L4f, em larvas controle e tratadas com dose de IE99. O perfil de expressão dos transcritos AaCHS1a e AaCHS1b é similar em larvas controle, ainda que a variação temporal de AaCHS1b seja maior. O BPU parece ter um efeito mais proeminente sobre o perfil de expressão de AaCHS1b, que se acentua nas primeiras horas após tratamento. Com base nos resultados obtidos, duas hipóteses são discutidas: mecanismo de feedback positivo ou atraso fisiológico do desenvolvimento. Ensaios histológicos preliminares validaram a metodologia utilizada para preparo e observação da morfologia de larvas tratadas e controle. Cortes longitudinais evidenciaram a preservação de estruturas internas, inclusive as quitinosas, o que abre a perspectiva de ensaios futuros de marcação específica para quitina.


Subject(s)
Aedes , Arthropod Vectors , Chitin , Dengue/prevention & control , Insecticides/antagonists & inhibitors , Vector Control of Diseases
19.
The Korean Journal of Parasitology ; : 13-17, 2009.
Article in English | WPRIM | ID: wpr-53285

ABSTRACT

Dung beetles (family Scarabaeidae) are one of the largest families of beetles worldwide. Due to biological behavior of these arthropods, they are considered to play an important role in the life cycle of some helminths. In the present study, dung beetles collected from cattle pastures in rural areas of Ardabil province, north-west of Iran were examined for infection with larval stages of helminths. According to the results, nematodes of 2 genera were identified including Rhabditis and Gongylonema. The more common species was Rhabditis sp. which was found in 9 species of beetles. Out of 15 different species of dung beetles, Copris lunaris was the only scarabaeid to be found naturally infected with the larval stages of Gongylonema sp. Our new findings introduce C. lunaris as a potential biological vector for transmission of Gongylonema sp. to vertebrates in the surveyed region.


Subject(s)
Animals , Humans , Arthropod Vectors/parasitology , Coleoptera/parasitology , Iran/epidemiology , Larva/physiology , Rhabditoidea/isolation & purification , Spirurida Infections/epidemiology , Spiruroidea/isolation & purification
20.
Journal of Bacteriology and Virology ; : 353-362, 2009.
Article in English | WPRIM | ID: wpr-30834

ABSTRACT

A survey was performed in Korea to monitor the prevalence of five bovine arboviruses [Akabane virus, Aino virus, Chuzan virus, bovine ephemeral fever (BEF) virus, and Ibaraki virus] in arthropod vectors, such as Culicoides species. To determine the possible applications of survey data in annual monitoring and warning systems in Korea, we examined the prevalence of bovine arboviruses in arthropod vectors using RT-PCR. To compare the sensitivity and specificity of virus detection, nested PCR was also performed in parallel for all five viruses. Using the RT-PCR, the detection limits were at least up to 10(1.5), 10(2.8), 10(2.0), 10(1.8), and 10(4.0) TCID50/ml for Akabane virus, Aino virus, Chuzan virus, BEF virus, and Ibaraki virus, respectively. When nested PCR was performed using 1 micronl of PCR product, the detection limits were increased, to 10(0.05), 10(1.8), 10(1.0), 10(0.008), and 10(2.0) TCID50/ml for Akabane virus, Aino virus, Chuzan virus, BEF virus, and Ibaraki virus, respectively. Thus, nested PCR increased the sensitivity of the virus detection limit by 1~2 log. We pooled 30~40 mosquitoes in one sample. We collected 113 samples in 2006, 135 samples in 2007, and 100 samples in 2008. Among these samples, Chuzan virus and BEF virus genes were detected at a range between 0.82% and 1.19%, and Akabane virus, Aino virus, and Ibaraki virus genes were detected at less than 0.20%. These data may provide some insight into future epidemiological studies of bovine arboviral diseases in Korea.


Subject(s)
Animals , Cattle , Arboviruses , Arthropod Vectors , Arthropods , Ceratopogonidae , Culicidae , Ephemeral Fever , Epidemiologic Studies , Korea , Limit of Detection , Organothiophosphorus Compounds , Palyam Virus , Polymerase Chain Reaction , Prevalence , Sensitivity and Specificity , Viruses
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