ABSTRACT
The city of Campinas is located in an endemic area for Brazilian spotted fever in São Paulo State, where several cases have recently occurred. Capybaras have been associated with the cycle of this disease, for they present positive serology and serve as host for ticks of the genus Amblyomma, the main vectors of Brazilian spotted fever. Ticks were collected both from Capybaras and from the vegetation in the city park Lago do Café, located in the urban area of Campinas City, SP, a site associated with suspected human cases of Brazilian spotted fever. The ticks collected were examinated for the presence of rickettsiae using polymerase chain reaction and the haemolymph test. Through analysis of the gene gltA nucleotide sequence, adults of Amblyomma cajennense and Amblyomma cooperi were found to be infected with the non pathogenic Rickettsia bellii. However, no rickettsiae of the Spotted Fever Group were detected. These results indicate that the role of capybaras as reservoirs of rickettsiae of the Spotted Fever Group is still uncertain and further studies are required.
Subject(s)
Disease Reservoirs/veterinary , Disease Vectors , Ixodidae/microbiology , Rickettsia/isolation & purification , Rodentia/parasitology , Animals , Brazil/epidemiology , Endemic Diseases , Female , Humans , Male , Polymerase Chain Reaction , Rickettsia/classification , Rickettsia/genetics , Rickettsia Infections/epidemiology , Rickettsia Infections/transmission , Urban PopulationABSTRACT
O Município de Campinas situa-se em região endêmica para febre maculosa brasileira do Estado de São Paulo, onde vários casos desta doenca vem ocorrendo. Capivaras têm sido associadas ao ciclo dessa riquetsiose por apresentarem sorologia positiva e serem hospedeiras de carrapatos Amblyomma spp principais vetores da doenca. Carrapatos foram coletados no parque urbano do Lago do Café, Campinas, SP, local associado a casos humanos suspeitos de febre maculosa brasileira, sobre a vegetacão e das capivaras ali presentes, e pesquisados quanto à presenca de riquétsias pela reacão em cadeia da polimerase e pelo teste de hemolinfa. Adultos de Amblyomma cajennense e Amblyomma cooperi albergavam Rickettsia bellii, não patogênica, identificada pela análise das seqüências de nucleotídeos do gene gltA, porém, não foram constatadas riquétsias do Grupo da Febre Maculosa. Estes resultados associados à ausência de um isolado de riquétsias do Grupo da Febre Maculosa de capivaras indicam que seu papel, enquanto reservatório, necessita de maior investigacão.
Subject(s)
Animals , Humans , Male , Female , Disease Reservoirs/veterinary , Disease Vectors , Ixodidae/microbiology , Rickettsia/isolation & purification , Rodentia/parasitology , Brazil/epidemiology , Endemic Diseases , Polymerase Chain Reaction , Rickettsia Infections/epidemiology , Rickettsia Infections/transmission , Rickettsia/classification , Rickettsia/genetics , Urban PopulationABSTRACT
La identificación correcta de las hembras es esencial para el éxito de cualquier estudio de epidemiología, resistencia a insecticidas o de control de vectores. En el departamento del Putumayo, en el sur de Colombia, la transmisión de malaria continúa siendo un problema, a pesar de la ausencia de los vectores principales de Latinoamérica (Anopheles darlingi Root, Anopheles nuneztovari Gabaldón, Anopheles albimanus Wideman, Anopheles trinkae Faran) en esta región. Se recolectaron. con cebo humano, hembras de Anopheles y se encontró una variante morfológica de Anopheles benarrochi, que en su estadio adulto fácilmente se confunde con Anopheles oswaldoi. La identificación de hembras de Anopheles, particularmente del subgénero Nyssorhynchus, es en general notoriamente difícil debido a la superposición de caracteres morfológicos en el estadio adulto; por tanto, las colecciones deben estar ligadas a la cría de material asociado para identificar correctamente las especies. Esto requiere tiempo y es difícil de obtener en muchas ocasiones. Se presenta un método indirecto de identificación de las especies A. benarrochi, A. oswaldoi y Anopheles rangeli del sur de Colombia usando la morfología de los huevos de hembras silvestres. Los huevos de A. rangeli y A. benarrochi se diferencian por la corona anterior, la cual es apical en A. rangeli y con paredes altas, mientras que en A. benarrochi es ventral y con paredes más cortas. Esta corona está ausente en A. oswaldoi. Estas diferencias fueron obvias incluso bajo un microscopio de luz, lo que hace posible una identificación correcta de estas especies en condiciones de campo. Se muestra cómo la observación de la morfología de los huevos puede permitir la determinación taxonómica correcta, aunque indirecta, de estas tres especies de Nyssorhynchus encontradas en el sur de Colombia, el cual puede ser útil también en otras regiones de Latinoamérica, en donde se encuentre la variante morfológica de A. benarrochi en simpatría con A. oswaldoi.Palabras clave: Nyssorhynchus, huevos, Anopheles, Colombia, microscopia electrónica.Egg morphology as an indirect method to identify Anopheles benarrochi, Anopheles oswaldoi and Anopheles rangeli (Diptera: Culicidae).
Subject(s)
Anopheles , Microscopy, Electron , EggsABSTRACT
In the Department of Putumayo in southern Colombia, malaria transmission has continued in the absence of the 4 traditional Latin American vector species--Anopheles darlingi, Anopheles nuneztovari, Anopheles albimanus or Anopheles trinkae. Human bait collections yielded Anopheles mosquitoes and a morphological variant of Anopheles benarrochi, the adult females of which can easily be misidentified as Anopheles oswaldoi. Species identification of females of Anopheles in the subgenus Nyssorhynchus is generally difficult due to overlapping morphological characters; therefore, progeny of field collected females were link-reared to assess species identity. Herein a robust method is presented to identify the species Anopheles benarrochi, Anopheles oswaldoi and Anopheles rangeli from southern Colombia, using the morphology of the eggs induced from wild-caught females. Eggs of A. rangeli and A. benarrochi were differentiated on the basis of the anterior crown. In A. rangeli, this feature is positioned apically with high walls. In A. benarrochi, anterior crown is positioned more ventrally with comparatively shorter walls. No crown is present in A. oswaldoi. These differences are clear with the aid of a dissecting microscope and make accurate species determination possible even in field conditions. Egg morphology is shown to be an accurate, albeit indirect, method for the taxonomic determination for the three southern Colombian species and may also be useful in other regions of Latin America where the morphological variant of A. benarrochi is sympatric with A. oswaldoi.
