Malaria transmission in two localities in north-western Argentina.

BACKGROUND: Malaria is one of the most important tropical diseases that affects people globally. The influence of environmental conditions in the patterns of temporal distribution of malaria vectors and the disease has been studied in different countries. In the present study, ecological aspects of the malaria vector Anopheles (Anopheles) pseudopunctipennis and their relationship with climatic variables, as well as the seasonality of malaria cases, were studied in two localities, El Oculto and Aguas Blancas, in north-western Argentina. METHODS: The fluctuation of An. pseudopunctipennis and the malaria cases distribution was analysed with Random Effect Poisson Regression. This analysis takes into account the effect of each climatic variable on the abundance of both vector and malaria cases, giving as results predicted values named Incidence Rate Radio. RESULTS: The number of specimens collected in El Oculto and Aguas Blancas was 4224 (88.07%) and 572 (11.93%), respectively. In El Oculto no marked seasonality was found, different from Aguas Blancas, where high abundance was detected at the end of spring and the beginning of summer. The maximum mean temperature affected the An. pseudopunctipennis fluctuation in El Oculto and Aguas Blancas. When considering the relationship between the number of malaria cases and the climatic variables in El Oculto, maximum mean temperature and accumulated rainfall were significant, in contrast with Aguas Blancas, where mean temperature and humidity showed a closer relationship to the fluctuation in the disease. CONCLUSION: The temporal distribution patterns of An. pseudopunctipennis vary in both localities, but spring appears as the season with better conditions for mosquito development. Maximum mean temperature was the most important variable in both localities. Malaria cases were influenced by the maximum mean temperature in El Oculto, while the mean temperature and humidity were significant in Aguas Blancas. In Aguas Blancas peaks of mosquito abundance and three months later, peaks of malaria cases were observed. The study reported here will help to increase knowledge about not only vectors and malaria seasonality but also their relationships with the climatic variables that influence their appearances and abundances.

Demographic history and population structure of Anopheles pseudopunctipennis in Argentina based on the mitochondrial COI gene.

BACKGROUND: Anopheles pseudopunctipennis is an important malaria vector in the Neotropical region and the only species involved in Plasmodium transmission in the Andean foothills. Its wide geographical distribution in America, high preference for biting humans and capacity to rest inside dwellings after feeding, are attributes contributing to its vector status. Previous reports have tried to elucidate its taxonomic status, distinguishing populations from North, Central and South America. In the present study we used a mitochondrial marker to examine the demographic history of An. pseudopunctipennis in northwestern Argentina. METHODS: Twelve localities were selected across 550 km of the distribution of this species in Argentina, including two near the Bolivian border and several in South Tucumán, for sampling. A fragment of the cytochrome oxidase I (COI) gene was sequenced and haplotype relationships were analyzed by a statistical parsimony network and a Neighbor-Joining (NJ) tree. Genetic differentiation was estimated with FST. Historical demographic processes were evaluated using diversity measures, neutrality tests and mismatch distribution. RESULTS: Forty-one haplotypes were identified, of which haplotype A was the most common and widely distributed. Neither the network nor the NJ tree showed any geographic differentiation between northern and southern populations. Haplotype diversities, Tajima's DT and Fu & Li's F and D neutrality tests and mismatch distribution supported a scenario of Holocene demographic expansion. CONCLUSION: The demographic pattern suggests that An. pseudopunctipennis has undergone a single colonization process, and the ancestral haplotype is shared by specimens from all localities, indicating mitochondrial gene flow. Genetic differentiation was minimal, observed only between one northern and one southern locality. The estimated time of the population expansion of this species was during the Holocene. These data suggest that regional vector control measures would be equally effective in both northern and southern localities sampled, but also that insecticide resistant genes may spread rapidly within this region.

New records of bat ectoparasites (Diptera, Hemiptera and Siphonaptera) from northern Argentina.

New species of bat-ectoparasite insects are added to the fauna of Argentina and distributional limits are extended for others, based on information obtained from 21 species of bats collected. New data is reported for the distribution of 23 species of bat ectoparasites, of which 17 belong to the Order Diptera [14 Streblidae: Anastrebla caudiferae Wenzel, Anatrichobius scorzai Wenzel, Aspidoptera phyllostomatis (Perty), Megistopoda aranea (Coquillett), M. proxima (Sèguy), Metelasmus pseudopterus Coquillett, Noctiliostrebla aitkeni Wenzel, N. dubia (Rudow), Paradyschiria fusca Speiser, Paradyschiria sp., Strebla chrotopteri Wenzel, Strebla diaemi Wenzel, Trichobius parasiticus Gervais y Xenotrichobius noctilionis Wenzel, and three Nycteribiidae: Basilia carteri Scott, B. plaumanni Scott y B.neamericana Schuurmans Stekhoven (Jr)], three belong to the Order Siphonaptera [one Ischnopsyllidae: Myodopsylla isidori (Weyenbergh), one Tungidae: Rhynchopsyllus pulex Haller, and one Stephanocircidae: Craneopsylla m. minerva (Rothschild)] and three belong to Order Hemiptera [two Polyctenidae: Hesperoctenes fumarius (Westwood) and H. vicinus Jordan, and one Cimicidae: Latrocimex spectans Lent]. Some records are new for Argentina, while others are new for the provinces of Corrientes, Chaco, Entre Ríos, Jujuy, Misiones and Salta. Also new host-parasite relationships are reported.

New records of bat ectoparasites (Diptera, Hemiptera and Siphonaptera) from northern Argentina / Nuevos registros de insectos ectoparásitos de murciélagos (Diptera, Hemiptera y Siphonaptera) del norte de la Argentina

New species of bat-ectoparasite insects are added to the fauna of Argentina and distributional limits are extended for others, based on information obtained from 21 species of bats collected. New data is reported for the distribution of 23 species of bat ectoparasites, of which 17 belong to the Order Diptera [14 Streblidae: Anastrebla caudiferae Wenzel, Anatrichobius scorzai Wenzel, Aspidoptera phyllostomatis (Perty), Megistopoda aranea (Coquillett), M. proxima (Sèguy), Metelasmus pseudopterus Coquillett, Noctiliostrebla aitkeni Wenzel, N. dubia (Rudow), Paradyschiria fusca Speiser, Paradyschiria sp., Strebla chrotopteri Wenzel, Strebla diaemi Wenzel, Trichobius parasiticus Gervais y Xenotrichobius noctilionis Wenzel, and three Nycteribiidae: Basilia carteri Scott, B. plaumanni Scott y B.neamericana Schuurmans Stekhoven (Jr)], three belong to the Order Siphonaptera [one Ischnopsyllidae: Myodopsylla isidori (Weyenbergh), one Tungidae: Rhynchopsyllus pulex Haller, and one Stephanocircidae: Craneopsylla m. minerva (Rothschild)] and three belong to Order Hemiptera [two Polyctenidae: Hesperoctenes fumarius (Westwood) and H. vicinus Jordan, and one Cimicidae: Latrocimex spectans Lent]. Some records are new for Argentina, while others are new for the provinces of Corrientes, Chaco, Entre Ríos, Jujuy, Misiones and Salta. Also new host-parasite relationships are reported.

Se agregan nuevas especies de insectos ectoparásitos de murciélagos a la fauna de Argentina y se extiende los límites de distribución de otras, mediante ejemplares colectados de 21 especies de murciélagos. Se reportan novedades distribucionales para 23 especies de ectoparásitos de las cuáles 17 pertenecen al Orden Diptera [14 Streblidae: Anastrebla caudiferae Wenzel, Anatrichobius scorzai Wenzel, Aspidoptera phyllostomatis (Perty), Megistopoda aranea (Coquillett), M. proxima (Sèguy), Metelasmus pseudopterus Coquillett, Noctiliostrebla aitkeni Wenzel, N. dubia (Rudow), Paradyschiria fusca Speiser, Paradyschiria sp., Strebla chrotopteri Wenzel, Strebla diaemi Wenzel, Trichobius parasiticus Gervais y Xenotrichobius noctilionis Wenzel, y tres Nycteribiidae: Basilia carteri Scott, B. plaumanni Scott y B.neamericana Schuurmans Stethoven (Jr)], tres pertenencen al Orden Siphonaptera [un Ischnopsyllidae: Myodopsylla isidori (Weyenbergh), un Tungidae: Rhynchopsyllus pulex Haller y un Stephanocircidae: Craneopsylla m. minerva (Rothschild)] y tres al Orden Hemiptera [dos Polyctenidae: Hesperoctenes fumarius (Westwood) y H. vicinus Jordan, y un Cimicidae: Latrocimex spectans Lent]. Algunos registros son nuevos para Argentina, mientras que otros son nuevos para las provincias de Corrientes, Chaco, Entre Ríos, Jujuy, Misiones y Salta. Además se registran nuevas asociaciones hospedador-ectoparásito.

Catalogue of American Nycteribiidae (Diptera, Hippoboscoidea)

A catalogue of the family Nycteribiidae (Diptera, Hippoboscoidea) of the New World is presented. Two genera and 52 species are listed in alphabetical order. Each genus account lists synonymies and type species, and each species account lists type locality and host, disposition of type material, geographic and host distribution, and a detailed bibliography.

Um catálago da família Nycteribiidae (Diptera, Hippoboscoidea) no Novo Mundo é apresentado. Dois gêneros e 52 espécies são listados em ordem alfabética. São disponibilizados abaixo de cada gênero, sinônimos e espécies-tipo e sob cada espécie, informações sobre localidade-tipo, hospedeiro-tipo, acrônimos da instituição onde o material-tipo está depositado, distribuição geográfica, hospedeiros e detalhada referências bibliográficas.

Intervención sobre formas inmaduras de Aedes Aegypti en la ciudad de San Miguel de Tucumán: estudio controlado de antes y después / Intervention on immature Aedes aegypti in teh city of San Miguel de Tucumán: controlled before and after study

INTRODUCCION: El dengue es una grave enfermedad, para cuya prevención es necesario disminuir la densidad del vector. Tucumán sufrió su primera epidemia en 2009, lo que obligó a generar estrategias de control para disminuir las formas inmaduras de Aedes aegypti y optimizar los recursos existentes.OBJETIVO: Medir la efectividad de intervenciones educativas, mecánicas y químicas sobre índices larvarios. Valorar los conocimientos sobre la enfermedad y su prevención, así como la fuente de esos conocimientos. Buscar asociaciones entre variables ambientales/sociodemográficas y la presencia de larvas domiciliarias. Conocer qué recipientes son los focos más frecuentes de larvas de Aedes aegypti.METODOS: El trabajo se desarrolló en domicilios de dos barrios de la ciudad de San Miguel de Tucumán (uno de ellos fue sorteado para intervención y el otro fue control). Se seleccionaron 62 viviendas en cada barrio. Se trató de un estudio cuasiexperimental, controlado antes y después. Se realizó una encuesta de datos personales y conocimientos previos. Se efectuaron evaluaciones entomológicas mensuales, se confeccionaron indicadores y se identificaron larvas y pupas encontradas.RESULTADOS: Hubo un efecto de corto alcance de la intervención realizada en octubre, que se manifestó en los indicadores de noviembre y diciembre. Se observó una asociación positiva de presencia de Aedes aegypti en domicilios con patios de tierra y en aquellos con conocimientos deficientes de la enfermedad. Los recipientes potenciales criaderos más frecuentes fueron de pequeño tamaño.CONCLUSIONES: Es necesario desarrolla estrategias con motivación permanente para el control a largo plazo. Las variables con asociaciones positivas pueden seleccionar viviendas con mayor riesgo a fin de priorizar el trabajo sobre ellas. La mayoría de los recipientes evaluados no ameritan tareas de descacharrado, pues son transportables por el servicio de recolección habitual.

INTRODUCTION: Dengue is a serious disease whose prevention requires reducing the density of the vector. Tucumán suffered its first outbreak in 2009, showing the need to develop control strategies that may decrease the immature forms of Aedes aegypti and optimize the existing resources.OBJECTIVE: To measure the effect of educational, mechanical and chemical interventions on larval indices. To evaluate knowledge of the disease, its prevention and the source thereof. To look for associations between environmental/socio-demographic variables and the presence of larvae at home. To know which containers are the more frequent foci of Aedes aegypti larvae.METHODS: The study was conducted in two neighborhoods in the city of San Miguel de Tucumán - one of them was drawn for the intervention and the other was control. 62 homes were selected in each neighborhood. It was a quasi-experimental, controlled before and after study. A survey of personal data and prior knowledge was performed. The study also included monthly entomological evaluations, production of indicators and identification of larvae and pupae.RESULTS: The indicators of November and December revealed a short-range effect of the intervention, performed in October. There was a positive association between presence of Aedes aegypti in houses with dirt yards and those with poor knowledge of the disease. The most frequent breeding potential recipients were of small size.CONCLUSIONS: Permanent motivation strategies are needed for long-term control. The variables with positive associations can select homes most at risk in order to prioritize work on them. Most of the evaluated containers do not require special removal tasks, as they can be transported by the normal collection service.

Intervención sobre formas inmaduras de Aedes Aegypti en la ciudad de San Miguel de Tucumán: estudio controlado de antes y después / Intervention on immature Aedes aegypti in teh city of San Miguel de Tucumán: controlled before and after study

INTRODUCCION: El dengue es una grave enfermedad, para cuya prevención es necesario disminuir la densidad del vector. Tucumán sufrió su primera epidemia en 2009, lo que obligó a generar estrategias de control para disminuir las formas inmaduras de Aedes aegypti y optimizar los recursos existentes.OBJETIVO: Medir la efectividad de intervenciones educativas, mecánicas y químicas sobre índices larvarios. Valorar los conocimientos sobre la enfermedad y su prevención, así como la fuente de esos conocimientos. Buscar asociaciones entre variables ambientales/sociodemográficas y la presencia de larvas domiciliarias. Conocer qué recipientes son los focos más frecuentes de larvas de Aedes aegypti.METODOS: El trabajo se desarrolló en domicilios de dos barrios de la ciudad de San Miguel de Tucumán (uno de ellos fue sorteado para intervención y el otro fue control). Se seleccionaron 62 viviendas en cada barrio. Se trató de un estudio cuasiexperimental, controlado antes y después. Se realizó una encuesta de datos personales y conocimientos previos. Se efectuaron evaluaciones entomológicas mensuales, se confeccionaron indicadores y se identificaron larvas y pupas encontradas.RESULTADOS: Hubo un efecto de corto alcance de la intervención realizada en octubre, que se manifestó en los indicadores de noviembre y diciembre. Se observó una asociación positiva de presencia de Aedes aegypti en domicilios con patios de tierra y en aquellos con conocimientos deficientes de la enfermedad. Los recipientes potenciales criaderos más frecuentes fueron de pequeño tamaño.CONCLUSIONES: Es necesario desarrolla estrategias con motivación permanente para el control a largo plazo. Las variables con asociaciones positivas pueden seleccionar viviendas con mayor riesgo a fin de priorizar el trabajo sobre ellas. La mayoría de los recipientes evaluados no ameritan tareas de descacharrado, pues son transportables por el servicio de recolección habitual.

INTRODUCTION: Dengue is a serious disease whose prevention requires reducing the density of the vector. Tucumán suffered its first outbreak in 2009, showing the need to develop control strategies that may decrease the immature forms of Aedes aegypti and optimize the existing resources.OBJECTIVE: To measure the effect of educational, mechanical and chemical interventions on larval indices. To evaluate knowledge of the disease, its prevention and the source thereof. To look for associations between environmental/socio-demographic variables and the presence of larvae at home. To know which containers are the more frequent foci of Aedes aegypti larvae.METHODS: The study was conducted in two neighborhoods in the city of San Miguel de Tucumán - one of them was drawn for the intervention and the other was control. 62 homes were selected in each neighborhood. It was a quasi-experimental, controlled before and after study. A survey of personal data and prior knowledge was performed. The study also included monthly entomological evaluations, production of indicators and identification of larvae and pupae.RESULTS: The indicators of November and December revealed a short-range effect of the intervention, performed in October. There was a positive association between presence of Aedes aegypti in houses with dirt yards and those with poor knowledge of the disease. The most frequent breeding potential recipients were of small size.CONCLUSIONS: Permanent motivation strategies are needed for long-term control. The variables with positive associations can select homes most at risk in order to prioritize work on them. Most of the evaluated containers do not require special removal tasks, as they can be transported by the normal collection service.