An ecoregional classification for the state of Roraima, Brazil: the importance of landscape in malaria biology

Rosa-Freitas, María Goreti; Tsouris, Pantelis; Peterson, A. Townsend; Honório, Nildimar Alves; Barros, Fábio Saito Monteiro de; Aguiar, Ducinéia Barros de; Gurgel, Helen; Arruda, Maria Augusta; Vasconcelos, Simão Dias; Luitgards-Moura, José Francisco

doi:10.1590/s0074-02762007005000052

Cited by 42 publications

(39 citation statements)

References 15 publications

(24 reference statements)

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“…15,16 Most settlements in the Anauá region of southern Roraima are recent (< 10 years of the collection period) and are composed of multiple side roads that run perpendicular to a main road or feeding artery, forming a characteristic fishbone pattern. Side road 19 is a typical secondary road, branching perpendicularly from the main road for 18.8 km into the rainforest, which entirely surrounds the area.…”

Section: Introductionmentioning

confidence: 99%

Deforestation and Malaria on the Amazon Frontier: Larval Clustering of Anopheles darlingi (Diptera: Culicidae) Determines Focal Distribution of Malaria

Barros¹,

Honório²

2015

The American Society of Tropical Medicine and Hygiene

103

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Abstract. We performed bimonthly mosquito larval collections during 1 year, in an agricultural settlement in the Brazilian Amazon, as well as an analysis of malaria incidence in neighboring houses. Water collections located at forest fringes were more commonly positive for Anopheles darlingi larvae and Kulldorff spatial analysis pinpointed significant larval clusters at sites directly beneath forest fringes, which were called larval "hotspots." Remote sensing identified 43 "potential" hotspots. Sampling of these areas revealed an 85.7% positivity rate for A. darlingi larvae. Malaria was correlated with shorter distances to potential hotpots and settlers living within 400 m of potential hotspots had a 2.60 higher risk of malaria. Recently arrived settlers, usually located closer to the tip of the triangularly shaped deforestation imprints of side roads, may be more exposed to malaria due to their proximity to the forest fringe. As deforestation progresses, transmission decreases. However, forest remnants inside deforested areas conferred an increased risk of malaria. We propose a model for explaining frontier malaria in the Amazon: because of adaptation of A. darlingi to the forest fringe ecotone, humans are exposed to an increased transmission risk when in proximity to these areas, especially when small dams are created on naturally running water collections.

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Section: Introductionmentioning

confidence: 99%

Deforestation and Malaria on the Amazon Frontier: Larval Clustering of Anopheles darlingi (Diptera: Culicidae) Determines Focal Distribution of Malaria

Barros¹,

Honório²

2015

The American Society of Tropical Medicine and Hygiene

103

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“…Its capital, Boa Vista (02º49'11"N 60º40'24"W 85 m), has an area of 5,687 km 2 and 249,853 inhabitants (IBGE 2008a). Boa Vista is located in a savannah ecoregion (Rosa-Freitas et al 2007). The climate is tropical wet and dry, with an average temperature of 27.8ºC (10-year average) (NASA 2001) and very low intra-annual variability.…”

Section: Methodsmentioning

confidence: 99%

Seasonal dynamics of Aedes aegypti (Diptera: Culicidae) in the northernmost state of Brazil: a likely port-of-entry for dengue virus 4

Codeço¹,

Honório

Ríos-Velásquez

et al. 2009

Mem. Inst. Oswaldo Cruz

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The highest infestation rates occurred during the peak of the rainy seasons, but a large presence was also observed during the early dry season (although with more variation among years). Spatial distribution of positive houses changed from a sparse and local pattern to a very dense pattern during the dry-wet season transition. These results suggest that the risk of dengue transmission and the potential for the new serotype invasions are high for most of the year.Key words: Aedes aegypti -dengue fever -ovitraps -seasonality -Amazon Separated from the rest of country by the Amazonian Forest, Roraima (RR) is the most isolated state in Brazil. Boa Vista, its capital, is a medium-sized city (249,853 inhabitants) (IBGE 2008a) located in the middle of a sparsely populated savannah. A highway is the only paved interstate route, connecting Boa Vista to the city of Manaus 805 km to the south and the Venezuelan border 220 km to the north. Despite its isolation, Boa Vista (and RR as a whole) has received -and continues to receive -a large inflow of visitors and migrants from Venezuela, Guyana and the Caribbean countries, as well as migrants from other regions of Brazil. As a consequence, RR's population increased from 79,400 inhabitants in 1980 to 395,725 inhabitants in 2008, a 5-fold increase in fewer than 30 years. Today, 53.7% of RR's population are immigrants, the highest proportion observed in Brazil (IBGEb 2008).The first dengue fever epidemic in Brazil after the re-invasion by Aedes aegypti occurred in Boa Vista in 1981-1982 with 11,000 reported cases (Osanai et al. 1983, Travassos-da-Rosa et al. 1998. DENV-1 and DENV-4 were isolated. For four years prior to this, DENV-1 was spreading throughout the Caribbean Islands, Central America and Northern South America (Moros et al. 2003, Uzcategui et al. 2003. The year 1981 also marked the arrival of DENV-4 in the Americas (Lanciotti et al. 1997). In Boa Vista, this first invasion was interrupted through vector control programs and the country was spared any new dengue invasions until 1986, when DENV-1 arrived in Rio de Janeiro, triggering nationwide epidemics (Nogueira et al. 2007). Dengue fever has become an endemic disease in Brazil, with the cocirculation of DENV-1, DENV-2 and DENV-3 in most of the 27 Brazilian states. DENV-4 did not persist in Brazil after RR's 1981-1982 outbreak (Nogueira et al. 2007). For several years now, RR has consistently had one of the highest dengue incidence rates among Brazilian states. In 2007, RR registered an incidence rate of 594.8 cases per 10,000 inhabitants. This was the highest rate after Amapá (877.7), Tocantins (TO) (1415.3) and Mato Grosso do Sul (MS) (3213). In 2006, the incidence rate in RR was 657.8, highest after MS (688.3) and TO (665.7) (MS 2007).Ae. aegypti in Boa Vista, RR • Cláudia Torres Codeço et al. 615Its proximity to Venezuela, where all four dengue serotypes are found, and appropriate vector and climate conditions for dengue transmission, make Boa Vista a strategic point for dengue surveillance in Brazil. Despite th...

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“…Considerando análisis más exhaustivos, esta clasificación ecorregional puede ser insuficiente cuando se entran en los detalles de los biomas locales. Rosas-Freitas, et al (2007), en un análisis para Roraima, Brasil, cruzando información de la distribución de las especies vectores dominantes de esta región, con datos de la geomorfología, vegetación, mapas del clima, población humana y patrones de distribución de la malaria, identificaron ocho ecorregiones, en vez de las dos obtenidas con la clasificación anterior para esta misma región. Sin embargo, la aproximación de estos autores puede darnos una visión amplia de la problemática ambiental general de malaria en el neotrópico y puede ser de utilidad general para orientar la planeación de actividades que lleven al control de esta enfermedad.…”

Section: Reemergencia De La Transmisión Oral De La Enfermedad De Chagasunclassified

Ecoepidemiología de enfermedades transmitidas por vectores

Lounibos

2011

biomedica

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Las leishmaniasis son un conjunto de enfermedades causadas por diferentes especies de parásitos protozoarios intracelulares del género Leishmania (Kinetoplastida: Trypanosomatidae) que son transmitidas a los humanos por la picadura de un flebótomo hembra de la subfamilia Phlebotominae (Diptera: Psychodidae). El vector se infecta con Leishmania spp. al tomar sangre de un reservorio mamífero infectado, en donde el parásito desarrolla parte de su ciclo de vida y quien es el responsable de mantener latente la infección en un foco de transmisión.En el hombre las manifestaciones clínicas de la enfermedad pueden ser variables e incluir lesiones cutáneas, mucosas o viscerales dependiendo de una serie de factores, entre ellos la especie de parásito infectante, la respuesta inmune del huésped y factores inherentes a la saliva del insecto vector en el momento de la picadura.Estas parasitosis son prevalentes en diferentes hábitats desde bosque húmedo en Centroamérica y Suramérica hasta regiones desérticas y semidesérticas en Asia occidental y las Américas.En cada foco, la transmisión del parásito depende, entre otros, de condiciones microclimáticas específicas que definen los patrones temporales de abundancia cíclica anual de los vectores. Cada vector tiene intervalos específicos de transmisión que llega al punto máximo cuando su población presenta un mayor número de hembras con huevos listos para ser depositados.En conjunto, las leishmaniasis constituyen una enfermedad emergente, registrada en 88 países del mundo: 66 en el Viejo Mundo y 22 en el Nuevo Mundo; de ellos, 72 países están en desarrollo. El aumento en la distribución y en el número de casos obedece, principalmente, a cambios ambientales, tanto naturales como antrópicos, que favorecen el establecimiento o el aumento de las poblaciones de vectores en cercanía de asentamientos humanos, incrementando el problema de salud pública alrededor del mundo.La distribución de las leishmaniasis en un contexto ecológico es variable, incluye migraciones de los vectores o adaptaciones sucesivas del parásito a otros vectores. Un ejemplo es Leishmania (Leishmania) infantum que migró durante la colonización europea del Nuevo Mundo, desde el Mediterráneo a Latinoamérica, donde el parásito se adaptó a nuevos vectores en sus respectivos hábitats.Recientemente, en Colombia se detectó la migración de Leishmania (Viannia) guyanensis desde los bosques de la Amazonía y la Orinoquía a dos hábitats diferentes: los valles andinos localizados por encima de los 1.000 msnm en el municipio de Chaparral (Tolima), y en Sucre, en la costa Caribe colombiana. Desde esta perspectiva, el conocer la distribución de los insectos vectores resulta de gran relevancia en salud pública ya que permite identificar las especies presentes en los focos de transmisión y hacer inferencias sobre vectores potenciales.En Colombia, actualmente, existen diferentes ciclos de transmisión de los parásitos del género Leishmania que van desde ciclos silvestres en las regiones selváticas, domésticos en varias áreas rurales del ...

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An ecoregional classification for the state of Roraima, Brazil: the importance of landscape in malaria biology

Cited by 42 publications

References 15 publications

Deforestation and Malaria on the Amazon Frontier: Larval Clustering of Anopheles darlingi (Diptera: Culicidae) Determines Focal Distribution of Malaria

Deforestation and Malaria on the Amazon Frontier: Larval Clustering of Anopheles darlingi (Diptera: Culicidae) Determines Focal Distribution of Malaria

Seasonal dynamics of Aedes aegypti (Diptera: Culicidae) in the northernmost state of Brazil: a likely port-of-entry for dengue virus 4

Ecoepidemiología de enfermedades transmitidas por vectores

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