A E Carbajo

University of Buenos Aires, Buenos Aires, Buenos Aires F.D., Argentina

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Publications (26)43.3 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: During 2009 the biggest dengue epidemic to date occurred in Argentina, affecting almost half the country. We studied the spatio-temporal dynamics of the outbreak in the second most populated city of the country, Córdoba city. Confirmed cases and the results of an Aedes aegypti monitoring during the outbreak were geolocated. The imported cases began in January, and the autochthonous in March. Thirty-three percent of the 130 confirmed cases were imported, and occurred mainly in the center of the city. The autochthonous cases were more frequent in the outskirts, specially in the NE and SE. Aedes aegypti infestation showed no difference between neighborhoods with or without autochthonous cases, neither between neighborhoods with autochthonous vs. imported cases. The neighborhoods with imported cases presented higher population densities. The majority of autochthonous cases occurred at ages between 25 and 44 years old. Cases formed a spatio-temporal cluster of up to 20 days and 12km. According to a mathematical model that estimates the required number of days needed for transmission according to daily temperature, the number of cases begun to fall when more than 15.5 days were needed. This may be a coarse estimation of mean mosquito survival in the area, provided that the study area is close to the global distribution limit of the vector, and that cases prevalence was very low.
    Acta tropica 04/2014; · 2.79 Impact Factor
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    ABSTRACT: Cities are unique ecosystems emerging and growing worldwide due to ongoing urbanising trends. The urban–rural gradient is an excellent setting to evaluate the effect of urbanisation on the distribution of species, a matter of public health concern in the case of disease vectors. Despite this, such distributions are affected by other co-occurring variables, mainly meteorological, that may be confounded by the urbanisation gradient due to the urban heat island effect and maritime climatological conditions in the case of coastal cities. To aid in the design of ecological studies within the urban–rural transition zone, a mapping protocol was designed and applied to Buenos Aires City and its surroundings. Based on road density and district-level population counts, a detailed (1 km2 pixel) urbanisation map was obtained which, combined with a temperature map, rendered a final urbanisation × temperature product with six classes. The resulting zonation was tested by modelling the distribution of the vector mosquitoes Aedes aegypti and Culex pipiens in artificial containers. The selected model explained the occurrence of mosquitoes 59% better than chance as a function of the urbanisation × temperature categories and the natural lighting condition of the container. This novel zonation approach allows partitioning of environmental heterogeneity prior to the selection of study sites to avoid confounding gradients and provides multiple advantages, such as making comparisons across cities easier, extrapolating the results of site-scale experiments and identifying priority areas for control measures.
    Area 03/2014; 46(1). · 1.37 Impact Factor
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    A Rubio, M V Cardo, A E Carbajo, D Vezzani
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    ABSTRACT: Dengue and Saint Louis encephalitis virus are among the most important emerging viruses transmitted by mosquitoes at the global scale, and from 2009 onward both diseases have reached temperate Argentina. To test whether the urbanization level can be used as a predictor for the infestation levels of container-breeding mosquito vectors, we searched for Aedes aegypti and Culex pipiens in 8,400 water-filled containers from 14 cemeteries of Buenos Aires Province and we used generalized linear models to relate positive containers with the impervious area quantified inside (internal PIA) and outside (external PIA) cemeteries. The best model for Ae. aegypti explained 91% of the variability and included the season, the internal PIA and the external PIA at 1km as a quadratic function, showing a parabolic response peaking in ∼75%. Regarding the infestation levels of Cx. pipiens, the final model explained 75% of the variability and included only the season. In view of these results, the percentage of impervious area efficiently predicted the infestation levels of Ae. aegypti but not of Cx. pipiens. Considering the worldwide relevance of the former in dengue transmission, the simple quantification of imperviousness proposed herein provides a helpful basis for vector surveillance and control in urbanized areas.
    Acta tropica 09/2013; · 2.79 Impact Factor
  • María Victoria Cardo, Darío Vezzani, Aníbal Eduardo Carbajo
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    ABSTRACT: The distribution of mosquito populations is spatially heterogeneous and influenced by factors acting at a wide range of scales. The aim of this study was to assess the role of environmental heterogeneity at the landscape level in shaping the composition of immature mosquito communities inhabiting surface water habitats. The Paraná Lower Delta (Argentina) is a temperate wetland that extends along a 1º north–south gradient and presents high landscape heterogeneity, due to the combined action of geomorphology, hydrology and human intervention. Immature mosquitoes were collected every 2 weeks (Nov 2011–April 2012) from surface water habitats within 11 peridomestic areas interspersed along a 75 km north–south transect. The environment was quantified by 24 variables regarding the geomorphology, geography, economic use, climate, landcover and topography of each site and its surroundings at three radii. The association between the mosquito assemblage and the environment was tested by two multivariate approaches, the community-based outlying mean index and by-species generalized linear models. The former explained 93.6 % of the marginality of all taxa as a function of the type and diversity of landcover, precipitation, presence of cattle and altitude. The niche of six species, most of which were floodwater mosquitoes of the genera Ochlerotatus and Psorophora, deviated significantly from uniformity. The by-species approach rendered significant models for four species as a function of landcover type and precipitation. Both methodologies were broadly consistent in pointing that landscape elements affect the distribution of immature mosquitoes, thereby shaping the composition of the mosquito assemblage in peridomestic environments within wetlands.
    Wetlands Ecology and Management 02/2013; 21(1). · 1.08 Impact Factor
  • Maria Victoria Cardo, Dario Vezzani, Anibal Eduardo Carbajo
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    ABSTRACT: We studied the seasonal patterns of 3 community attributes (breeding site index, richness, and diversity) of groundwater mosquito immatures and their associations with meso- and microhabitat factors in the Parana Lower Delta, Argentina, from December 2009 to November 2010. Monthly collections at 4 sites yielded 2,313 mosquito immatures, belonging to 19 species assigned to 6 genera. Immatures developed in a wide range of microenvironmental conditions (water temperature 4.0-30.2 degrees C, pH 5.4-9.1, electrical conductivity 0.02-6.33 mS/cm, and dissolved oxygen 0-235.6%), and their occurrence was significantly associated with lower water temperature and dissolved oxygen values. Most frequently captured species were Culex dolosus s.l. (58.6%), Aedes crinifer (22.9%), and Cx. intrincatus (19.0%). Breeding site index was highest in winter (0.76) and lowest in spring (0.54). Species richness and diversity varied significantly among seasons (peaking in summer), land uses, and habitat types.
    Journal of the American Mosquito Control Association 09/2012; 28(3):151-9. · 0.76 Impact Factor
  • Maria Victoria Cardo, Dario Vezzani, Anibal Eduardo Carbajo
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    ABSTRACT: We studied the seasonal patterns of 3 community attributes (breeding site index, richness, and diversity) of groundwater mosquito immatures and their associations with meso- and microhabitat factors in the Parana Lower Delta, Argentina, from December 2009 to November 2010. Monthly collections at 4 sites yielded 2,313 mosquito immatures, belonging to 19 species assigned to 6 genera. Immatures developed in a wide range of microenvironmental conditions (water temperature 4.0-30.2 degrees C, pH 5.4-9.1, electrical conductivity 0.02-6.33 mS/cm, and dissolved oxygen 0-235.6%), and their occurrence was significantly associated with lower water temperature and dissolved oxygen values. Most frequently captured species were Culex dolosus s.l. (58.6%), Aedes crinifer (22.9%), and Cx. intrincatus (19.0%). Breeding site index was highest in winter (0.76) and lowest in spring (0.54). Species richness and diversity varied significantly among seasons (peaking in summer), land uses, and habitat types.
    Journal of the American Mosquito Control Association 09/2012; 28(3):151-9. · 0.76 Impact Factor
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    Aníbal E Carbajo, María V Cardo, Darío Vezzani
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    ABSTRACT: BACKGROUND: Dengue cases have increased during the last decades, particularly in non-endemic areas, and Argentina was no exception in the southern transmission fringe. Although temperature rise has been blamed for this, human population growth, increased travel and inefficient vector control may also be implicated. The relative contribution of geographic, demographic and climatic of variables on the occurrence of dengue cases was evaluated. METHODS: According to dengue history in the country, the study was divided in two decades, a first decade corresponding to the reemergence of the disease and the second including several epidemics. Annual dengue risk was modeled by a temperature-based mechanistic model as annual days of possible transmission. The spatial distribution of dengue occurrence was modeled as a function of the output of the mechanistic model, climatic, geographic and demographic variables for both decades. RESULTS: According to the temperature-based model dengue risk increased between the two decades, and epidemics of the last decade coincided with high annual risk. Dengue spatial occurrence was best modeled by a combination of climatic, demographic and geographic variables and province as a grouping factor. It was positively associated with days of possible transmission, human population number, population fall and distance to water bodies. When considered separately, the classification performance of demographic variables was higher than that of climatic and geographic variables. CONCLUSIONS: Temperature, though useful to estimate annual transmission risk, does not fully describe the distribution of dengue occurrence at the country scale. Indeed, when taken separately, climatic variables performed worse than geographic or demographic variables. A combination of the three types was best for this task.
    International Journal of Health Geographics 07/2012; 11(1):26. · 2.62 Impact Factor
  • M V Cardo, D Vezzani, A E Carbajo
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    ABSTRACT: Wetlands have traditionally been associated with harbouring mosquitoes, a well-known nuisance and vectors of diseases. Within mosquito life cycle, oviposition is a determinant event by shaping their individual fitness and vectorial capacity. The study was conducted in one of the main temperate wetlands in South America. We used Generalized Linear Models to study the relation between temperature, precipitation, tidal regime, land use, microenvironment, and the occurrence of floodwater (Ochlerotatus and Psorophora spp.) and raft-laying (Culex and Uranotaenia spp.) mosquitoes using temporary pools as larval habitats. Pool occurrence was negatively associated with temperature, and positively related to precipitation and high tides. As regards the land use, it was lowest in domestic areas and plantations, intermediate in secondary forests, and highest in marshes. Each oviposition strategy was best modelled as a function of different environmental factors. The occurrence of floodwater mosquitoes was positively associated with high cumulative precipitation and low tide records. Raft-laying mosquitoes were related to low temperature records, while the effect of flooding varied with the land use. In view of these results, physical (water inputs and movement), chemical, and biological (egg and larval flushing, and predatory interactions) considerations are given to provide insight in the oviposition patterns of mosquitoes occurring in this complex wetland. We finally propose the generation of a tidal flow as a control measure against floodwater mosquitoes, which are the most anthropophilic in the study area.
    Bulletin of entomological research 05/2012; · 1.99 Impact Factor
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    Andrea Paola Albicócco, Aníbal Eduardo Carbajo, Darío Vezzani
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    ABSTRACT: Phytotelmata, or plant-held waters, are considered to be good model systems for the study of community ecology. The fauna of these natural container habitats, particularly the mosquitoes, have been extensively investigated in tropical regions, but there is little known about them in temperate South America. We assessed the structure of immature mosquito communities in leaf axils, tree holes, and bamboo stumps from a temperate wetland of Argentina. A total of 4,330 immature mosquitoes were collected among the 2,606 phytotelmata inspected. Leaf axils of eight plant species and tree holes were larval habitats for nine mosquito species belonging to the genus Culex, Wyeomyia, Isostomyia, and Toxorhynchites. The mosquito communities showed richness ranging from one to four species. Marked differences were detected in the plant specificity for the species collected. Some of them were exclusively found in one plant species (Isostomyia paranensis in Scirpus giganteus), whereas others were collected in up to five plant species but belonging to the same phytotelm class, the leaf axils. Those from tree holes are well-known dwellers of artificial containers and ground water habitats, such as Culex pipiens. Our results support the idea of low mosquito richness in phytotelmata from temperate regions in comparison with tropical areas, but the observed specificity patterns echo the findings of tropical forests.
    Journal of Vector Ecology 12/2011; 36(2):437-46. · 1.23 Impact Factor
  • M V Cardo, D Vezzani, A E Carbajo
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    ABSTRACT: Characterizing mosquito larval habitats is essential for understanding the complex interactions between immatures and the biotic and abiotic components of their environment. Using generalized linear mixed models, we studied the environmental predictors of the presence of three ubiquitous mosquito species breeding in ground water habitats in the Paraná Lower Delta, Argentina. During a year-round survey, 34.1% of the 419 ground water habitats inspected were positive for either Culex dolosus s.l. (Lynch Arribálzaga 1891), Aedes crinifer (Theobald 1903), or Culex intrincatus Brèthes 1916. Univariate analysis showed that the former two occurred throughout the year, whereas the latter during the summer and fall. Ae. crinifer and Cx. intrincatus were more frequently collected in secondary forests, whereas Cx. dolosus s.l. was homogeneously distributed among land uses. Best generalized linear mixed models included the sampling period and landscape variables in different combinations for each species. Spatial dependence of the data was evident for Cx. dolosus s.l. and Ae. crinifer. Our results showed that the most widespread species presented different spatio-temporal distribution patterns, related with land use, anthropic intervention, and seasonality, highlighting the complexity of the wetland under study. This methodological approach could aid in the selection of priority areas for vector control and disease risk management.
    Journal of Medical Entomology 09/2011; 48(5):991-8. · 1.86 Impact Factor
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    ABSTRACT: This study was aimed at understanding some aspects of the canine heartworm epidemiology in the southern distribution limit of the parasite in South America. With this objective, 19,298 blood samples of owned dogs from 65 localities of 13 municipalities of Buenos Aires Province were tested for Dirofilaria immitis circulating microfilariae and/or female antigens. The overall heartworm prevalence was 1.63% by microhematocrit tube technique (n=19,136), 3.65% by modified Knott (n=713), and 14.41% by antigen test kit (n=118). Microfilaremic dogs showed a median of 1933 microfilariae per millilitre (q1=375, q3=5625, n=100). Male dogs belonging to breeds of short hair and large size recorded significantly higher prevalences than the other categories. Also, the prevalence increased significantly with the age and only dogs younger than 12 months were not found infected. A clear decreasing trend of the annual prevalence was observed during the whole study period, from 3.91% in 2001 to 1.17% in 2006. D. immitis-infected dogs were detected in 32 localities of 9 municipalities (prevalence range: 0.2-6.7%). Generalized linear models were used to assess associations between heartworm prevalence and environmental variables. The resulting significant models were univariate and included variables related with soil cover and human population density. The best model predicted maximum heartworm prevalences around middle values of bare soil cover, and lower at high and low covers. According to our analyses, canine heartworm infection in urban temperate Argentina could be described as relatively low, endemic, and spatially heterogeneous. Host and environmental factors affecting heartworm transmission at local level were identified and discussed.
    Veterinary Parasitology 10/2010; 176(2-3):240-9. · 2.38 Impact Factor
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    Aníbal E Carbajo, Carolina Vera, Paula Lm González
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    ABSTRACT: Oligoryzomys longicaudatus (colilargo) is the rodent responsible for hantavirus pulmonary syndrome (HPS) in Argentine Patagonia. In past decades (1967-1998), trends of precipitation reduction and surface air temperature increase have been observed in western Patagonia. We explore how the potential distribution of the hantavirus reservoir would change under different climate change scenarios based on the observed trends. Four scenarios of potential climate change were constructed using temperature and precipitation changes observed in Argentine Patagonia between 1967 and 1998: Scenario 1 assumed no change in precipitation but a temperature trend as observed; scenario 2 assumed no changes in temperature but a precipitation trend as observed; Scenario 3 included changes in both temperature and precipitation trends as observed; Scenario 4 assumed changes in both temperature and precipitation trends as observed but doubled. We used a validated spatial distribution model of O. longicaudatus as a function of temperature and precipitation. From the model probability of the rodent presence was calculated for each scenario. If changes in precipitation follow previous trends, the probability of the colilargo presence would fall in the HPS transmission zone of northern Patagonia. If temperature and precipitation trends remain at current levels for 60 years or double in the future 30 years, the probability of the rodent presence and the associated total area of potential distribution would diminish throughout Patagonia; the areas of potential distribution for colilargos would shift eastwards. These results suggest that future changes in Patagonia climate may lower transmission risk through a reduction in the potential distribution of the rodent reservoir. According to our model the rates of temperature and precipitation changes observed between 1967 and 1998 may produce significant changes in the rodent distribution in an equivalent period of time only in certain areas. Given that changes maintain for 60 years or double in 30 years, the hantavirus reservoir Oligoryzomys longicaudatus may contract its distribution in Argentine Patagonia extensively.
    International Journal of Health Geographics 02/2009; 8:44. · 2.62 Impact Factor
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    ABSTRACT: Dengue is an emerging disease that has become important in Argentina because of its vector’s presence (Aedes aegypti) and its endemicity in neighbouring countries. Thematic maps were built for Argentina considering four main factors: population susceptibility to dengue virus infection (population density); entrance of the virus from endemic countries (main roads and airports); conditions for the vector (urbanization, altitude, minimum, maximum and mean daily temperatures) and virus extrinsic incubation period (EIP) completion in the mosquito before its death. EIP duration was modelled with a temperature-dependent function and considering life expectancies of 10, 15 and 20 days for the adult mosquito. The results show maximum risk of dengue transmission in the northern and north-eastern part of the country year-round and in the centre during the summer. Although life expectancy of the adult mosquito has a considerable influence on EIP completion, the north-east to south-west decreasing gradient is maintained. Assuming 20-day life expectancy, the EIP would be completed in almost any region of the country; whereas with 15-day life expectancy it would be limited to vector distribution area, and at 10 days it would be restricted to the northern extreme of the country.
    Tropical Medicine & International Health 07/2008; 6(3):170 - 183. · 2.94 Impact Factor
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    Darío Vezzani, Aníbal E Carbajo
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    ABSTRACT: Since the reinfestation of South American countries by Ae. aegypti, dengue fever (DF) and dengue hemorrhagic fever (DHF) have become a major public health concern. The aim of this paper was to review the information related with Aedes vectors and dengue in Argentina since the reintroduction of Ae. aegypti in 1986. The geographic distribution of Ae. albopictus is restricted to the Northeast, and that of Ae. aegypti has expanded towards the South and the West in comparison with the records during the eradication campaign in the 1960s. Since 1998, 4,718 DF cases have been reported concentrated in the provinces of Salta, Formosa, Misiones, Jujuy and Corrientes. Despite the circulation of three dengue virus serotypes (DENV-1, -2 and -3) in the North of the country, DHF has not occurred until the present. The information published over the last two decades regarding mosquito abundance, temporal variations, habitat characteristics, competition, and chemical and biological control, was reviewed. Considering the available information, issues pending in Argentina are discussed. The presence of three DENV, the potential spread of Ae. albopictus, and the predicted climate change suggest that dengue situation will get worse in the region. Research efforts should be increased in the Northern provinces, where DHF is currently an actual risk.
    Memórias do Instituto Oswaldo Cruz 03/2008; 103(1):66-74. · 1.36 Impact Factor
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    ABSTRACT: We described the transmission dynamics of Fasciola hepatica at its southern distribution range. Studies of prevalence and egg output in cattle and population dynamics and infection in snails were performed in a farm in the Andean Patagonian valleys, Argentina, between December 1998 and February 2002. Snail surveys were conducted from spring to autumn. Infection was diagnosed coprologically in the whole herd at the beginning and end of the study, and in a cohort of heifers at the beginning and end of 2001. A twice-a-year anthelmintic treatment was implemented in 1999. The relationship of the variables mentioned above with temperature and rainfall was determined. Lymnaea viatrix showed a life-span of about 15 months and an annual pattern of population dynamics. Specimens were frequently found in temporary environments and lagoons, and rarely in streams. Snail abundance and soil-water availability were directly related in temporary environments and inversely related in lagoons. Overall prevalence in L. viatrix was 0.67% (range: 0.9-14%) and infection was detected in summer and autumn. At the beginning of the study, calves were the least infected age group (15%). Prevalences and median egg counts in grazing animals were similar at the beginning (heifers: 81%, 3.3 epg; cows: 60%, 1.3 epg) and end of the study (heifers and cows: around 51%, 1 epg). Likewise, the prevalence in the cohort of heifers remained similar (around 40%) between surveys. Transmission to cattle was highly effective despite of the short activity period and the low infection rate of snails, and the regular anthelminthic treatment. There would be two seasonal transmission peaks, one in summer-autumn, when infected snails were present, and the other in early spring due to overwintering metacercariae. Some recommendations based on the climatic conditions of the region are provided to minimize snail infection and ultimately to reduce the incidence of fasciolosis in cattle.
    Veterinary Parasitology 05/2007; 145(3-4):274-86. · 2.38 Impact Factor
  • Darío Vezzani, Aníbal E Carbajo
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    ABSTRACT: The aim of this work was to assess spatial and seasonal Dirofilaria immitis transmission risk throughout Argentina with models based on the temperature threshold below which filarial development will not proceed in the mosquito (i.e. 14 degrees C), the occurrence and the number of potential vector mosquito species, and the Heartworm Development Units derived from the degree-days concept. The four models showed a similar increasing southwest-northeast tendency and correlated significantly with canine prevalences used as external validation data. About one-third of Argentina would be suitable for heartworm transmission and the highest risk areas include the north-eastern provinces. According to our models, heartworm transmission is markedly seasonal with peaks in January and February; no region would support transmission throughout the year. To improve the present models, it is necessary to know which mosquito species are competent rather than potential vectors in the country. We believe the present study provides the first risk assessment maps for D. immitis transmission in the Southern Hemisphere and provides a useful guide for heartworm prevention during the transmission periods in different regions of Argentina.
    International Journal for Parasitology 01/2007; 36(14):1463-72. · 3.64 Impact Factor
  • Aníbal E. Carbajo, Ulyses F. J. Pardiñas
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    ABSTRACT: A 1st step in understanding the ecology of rodents as reservoirs and their relation with the disease they transmit is to determine their geographical distribution. This distribution can be modeled as a function of environmental variables. We georeferenced an extensive database of records of the hantavirus reservoir Oligoryzomys longicaudatus (Cricetidae: Sigmodontinae) in Argentina and used generalized linear models to model the probability of the presence of this reservoir as a function of environmental variables. The variables used in the multiple logistic regression were temperature, precipitation, evapotranspiration, altitude, tree cover, grass cover, bare soil cover, and distance to rivers, to water bodies, and to roads; 2 phytogeographic classifications also were included. Spatial autocorrelation was considered in the model by including a spatial dependence covariate. The best model included temperature and precipitation as explanatory variables. External validation showed that the model without the space covariate correctly classified 95% of the sites with the rodent and 70% of the sites without it; the model including the spatial term correctly classified 100% of the sites with the rodent and 70% of the sites without it. A secondary model included days with frost and percent cover by bare soil as explanatory variables. O. longicaudatus was recorded in 97% of sites in the High Andean-Subantarctic regions, 65% of sites in the Monte-Espinal-Patagonian regions, and 0% of sites in the Pampean region.
    Journal of Mammalogy - J MAMMAL. 01/2007; 88(6):1555-1568.
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    A E Carbajo, S I Curto, N J Schweigmann
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    ABSTRACT: The distribution of Aedes aegypti (L) (Diptera: Culicidae) oviposition in Buenos Aires City is spatially heterogeneous. Oviposition activity was monitored for a year with a grid of 279 traps at 850-m intervals that were serviced weekly. Geostatistics were used for the spatial analysis and generalized linear regression to model oviposition as a function of demographic and environmental variables. The proportion of weeks infested and the total number of eggs showed spatial continuity and were higher in areas that had higher densities of houses and were closer to industrial sites; they were lower in areas with higher human populations or higher densities of flats. When all sites were considered, the spatial structure showed a strong trend, but after regression, the residuals presented lower spatial dependence. When only infested sites were considered, the oviposition variables were spatially autocorrelated and the regression residuals showed little or no spatial dependence. The spatial pattern of Ae. aegypti oviposition in a highly urbanized city such as Buenos Aires seems to be related to the urbanization gradient. These urban environments might present different resource availability or continuity between patches of resources.
    Medical and Veterinary Entomology 07/2006; 20(2):209-18. · 2.21 Impact Factor
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    ABSTRACT: We studied the spatial and temporal distribution of Hantavirus Pulmonary Syndrome (HPS) cases from 1998 to 2001 in the Buenos Aires Province, Argentina. HPS is a severe viral disease whose natural reservoir are rodents of the subfamily Sigmodontinae (Muridae) and which occurs in many countries of South and North America. We considered two spatial arrangements: cells of 18.5 x 18.5 km(2); and departments, the political subdivisions of the province, as spatial units. We tested the departure from a Poisson distribution of the number of cases per cell and per month with the Variance/Mean index, while the interaction between spatial and temporal clustering was tested by means of the Knox and Mantel tests. We constructed probability maps in which the HPS rates per department were considered Poisson variates according to population, area and the product of population and area. We analysed the relation between rodent distribution, environmental and demographic variables and HPS cases conducting preliminary univariate analysis from which we selected variables to enter in general linearized models. We found that both the spatial and temporal distribution of cases is strongly aggregated. The spatiotemporal interaction appears to be related to a strong seasonality and the existence of particular ecological conditions rather than epidemic transmission of the disease. The main explanatory variables for the distribution of HPS cases among the departments of the Buenos Aires Province were human population, the distribution of the rodent Oxymycterus rufus and evapotranspiration. The last two variables are probably indicators of favourable ecological conditions for the reservoirs, which encompass other variables not taken into account in this study.
    Tropical Medicine & International Health 05/2004; 9(4):508-19. · 2.94 Impact Factor
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    ABSTRACT: Cases of dengue detected in Buenos Aires City between 1999 and 2000 confirmed the possibility of epidemic outbreaks. The activity of its vector Aedes aegypi was monitored to study the spatial and temporal risk of dengue transmission. Adult oviposition activity of Aedes aegypti showed an heterogeneous spatio-temporal distribution pattern. It was detected between October and May. The vector was detected from spring to fall in the Northern, Western and Southern areas of the city (periphery) and only in summer in the Eastern part (downtown-river). The proportion of infested sites differed between the three periods but the infested areas coincided spatially. Although a spatial and temporal heterogeneity exists, the pattern repeated itself during the three periods suggesting stable dynamics. The not infested areas presented the highest population and employees densities while the areas infested during the three periods the lowest. This might represent an attenuation of the risk, because higher densities do not coincide with higher infestation. From the point of view of the vector the risk of transmission would concentrate between January and March and occupy 50% of the city surface in the periphery.
    Medicina 02/2004; 64(3):231-4. · 0.42 Impact Factor

Publication Stats

224 Citations
43.30 Total Impact Points

Institutions

  • 2000–2012
    • University of Buenos Aires
      • • Faculty of Exact and Natural Sciences
      • • Biological Sciences Department
      • • Department of Atmospheric and Ocean Sciences
      Buenos Aires, Buenos Aires F.D., Argentina
  • 2006
    • THE UNIVERSITY OF BAMENDA
      Bamenda, North-West Province, Cameroon