Andrés Visintin

Genotype III Saint Louis Encephalitis Virus Outbreak, Argentina, 2005

Twenty-six years after it was last detected, Saint Louis encephalitis virus (SLEV) genotype III reemerged in 2005 in Córdoba, Argentina, where it caused an outbreak. Two genotype III SLEV strains were isolated from Culex quinquefasciatus. A 71.43% prevalence for neutralizing antibodies was found in domestic fowl in the homestead of a patient with encephalitis.

Phlebotominae (diptera: psycodidae) fauna in the Chaco region and Cutaneous Leishmaniasis transmission patterns in Argentina

In Argentina, the incidence of American Cutaneous Leishmaniasis (ACL) has shown a steady increase over the last few decades. In the Chaco biogeographical region, specifically, several outbreaks of ACL were recently reported in addition to the usual time-space scattering of ACL cases. However, little is known about the sandfly composition in the eastern, humid Chaco (HC) region or the western, dry Chaco (DC) region. Therefore, phlebotomine captures were performed throughout this region and an analysis of the distribution of reported ACL cases was conducted in order to assess the vector diversity in ACL endemic and epidemic scenarios in the Chaco region. The results support the hypothesis of two distinct patterns: (1) the DC, where Lutzomyia migonei was the most prevalent species, had isolated ACL cases and a zoonotic cycle; (2) the HC, where Lutzomyia neivai was the most prevalent species, had an increase in ACL incidence and outbreaks and an anthropozoonotic cycle. The epidemic risk in the Chaco region may be associated with the current climate trends, landscape modification, connection with other ACL foci, and Lu. neivai predominance and abundance. Therefore, changes in sandfly population diversity and density in the Chaco region are an indicator of emergent epidemic risk in sentinel capture sites.

New records of mosquito species (Diptera: Culicidae) from Neuquén and La Rioja provinces, Argentina.

Relata-se a presenca de Aedes aegypti ao sul de seu limite atual de distribuicao na Argentina, na cidade de Neuquen, provincia de Neuquen. Ovitrampas foram instaladas de dezembro/2009 a abril/2010. A distribuicao geografica de Culex eduardoi, Psorophora ciliata e Ps. cingulata aumenta, incluindo novos registros para duas provincias.The presence of Aedes aegypti is reported beyond its current limit of distribution in Argentina, in the city of Neuquén, Neuquén Province. Ovitraps were placed to collect Ae. aegypti eggs between December 2009 and April 2010. The geographical distribution of Culex eduardoi, Psorophora ciliata and Ps. cingulata is extended with new records from two provinces.

Effectiveness of normalized difference water index in modelling Aedes aegypti house index

The application of remotely sensed data to public health has increased in Argentina in the past few years, especially to study vector-borne viral diseases such as dengue. The normalized difference vegetation index (NDVI) has been widely used for remote sensing of vegetation as well as the brightness temperature (BT) for many years. Another environmental variable obtained from satellites is the normalized difference water index (NDWI) for remote sensing of the status of the vegetation liquid water from space. The aim of the present article was to test the effectiveness of NDWI together with other satellite and meteorological data to develop two forecasting models, namely the SATMET (satellite and meteorological variables) model and the SAT (satellite environmental variables) model. The models were developed and validated by dividing the data file into two sets: the data between January 2001 and April 2004 were used to construct the models and the data between May 2004 and May 2005 were used to validate them. The regression analysis for the SATMET and SAT models showed an adjusted R 2 of 0.82 and 0.79, respectively. To validate the models, a correlation between the estimates and the observations was obtained for both the SATMET model (r = 0.57) and the SAT model (r = 0.64). Both models showed the same root mean square error (RMSE) of 0.04 and, therefore, the same forecasting power. For this reason, these models may have applications as decision support tools in assisting public health authorities in the control of Aedes aegypti and risk management planning programmes.

Prevention of dengue outbreaks through Aedes aegypti oviposition activity forecasting method.

Dengue has affected the north provinces of Argentina, mainly Salta province. The 2009 outbreak, with 5 deaths and >27,000 infected, was the most important, and the first to extend into the central area of the country. This article includes research on seasonal Aedes aegypti abundance variation in Orán City (Salta province), and determination of the date of mosquito population increase and an estimation of the date of maximum rate of increase as well as the intrinsic rate of natural increase (r), to detect the optimal time to apply vector control measures. Between September 2005 and March 2007, ovitraps were randomly distributed in the city to collect Ae. aegypti eggs. The variation observed in the number of collected eggs was described by fitting a third-degree polynomial by the least square method, allowing to determine the time when population increase began (week 1), after the temperate and dry season. Eggs were collected throughout the year, with the highest variation in abundance during the warm and rainy season, and the maximum value registered in February 2007. The rate of increase of the number of eggs laid per week peaked between weeks 9 and 10 after the beginning of the population increase (week 1). Week 1 depends on temperature, it occurs after getting over the thermal threshold and the needed accumulation of 160 degree-day is reached. Consequently, week 1 changes depending on temperature. Peak abundance of eggs during 2005-2006 was recorded on week 15 (after week 1); during 2006-2007, the peak was observed on week 22. Estimation of the intrinsic rate of natural increase (r) of Ae. aegypti is useful not only to determine optimal time to apply vector control measures with better cost-benefit, but also to add an insecticide control strategy against the vector to diminish the possibility of resistance.

Two New Mosquito Species and Six New Provincial Records in Argentina

Abstract The geographical distribution of Aedes pennai, Anopheles galvaoi, Coquillettidia albicosta, Cq. nigricans, Culex usquatissimus, Cx. apicinus, Cx. chidesteri, Cx. coronator s.l., Cx. interfor, Cx. maxi, Cx. pipiens, Cx. saltanensis, Cx. educator, Cx. serratimarge, Cx. theobaldi, Psorophora cyanescens, Ps. cilipes, Ps. cingulata, Ps. pallescens, Uranotaenia lanei, Ur. nataliae, Wyeomyia diabolica, and Wy. melanocephala is extended, including new records for 6 provinces and 2 new records for the country, increasing the number of species in Argentina from 226 to 228.

New records of mosquito species for Central and Cuyo regions in Argentina.

Abstract The geographical distributions of Aedes aegypti, Culex apicinus, Cx. educator, Cx. interfor, Cx. quinquefasciatus, Mansonia humeralis, Ma. indubitans, and Psorophora albigenu/varipes are extended, including new records for 2 provinces.

Spread of Phlebotominae in temperate climates: province of Córdoba, Argentina

We report the presence of the competent vector for Leishmaniaspp, Migonemyia migonei, and theEvandromyia cortelezzii-sallesi complex south of its known distribution in the central temperate region of Argentina, in the province of Córdoba. The persistence of this phlebotomine in the northern border of the province, its association with a case of cutaneous leishmaniasis, and the new record in the outskirts of the city of Córdoba, the second most populated in the country, strengthens the need for regular vector surveillance and a case detection-sensitive health system in vulnerable regions, even in temperate climates.

CULEX SALTANENSIS MORPHOLOGICAL REDESCRIPTION OF THE IMMATURE AND ADULT STAGES

ABSTRACT Culex (Culex) saltanensis is redescribed in the adult, pupal, and larval stages. The male genitalia, pupae, and 4th-stage larvae are illustrated. Information about distribution, bionomics, and taxonomy is included. Culex saltanensis adults are separated from the closely related species Cx. (Cux.) coronator on the basis of morphometric characters.

Novo registro de mosquitos (Diptera: Culicidae) nas províncias de Neuquén e La Rioja, Argentina

Relata-se a presenca de Aedes aegypti ao sul de seu limite atual de distribuicao na Argentina, na cidade de Neuquen, provincia de Neuquen. Ovitrampas foram instaladas de dezembro/2009 a abril/2010. A distribuicao geografica de Culex eduardoi, Psorophora ciliata e Ps. cingulata aumenta, incluindo novos registros para duas provincias.The presence of Aedes aegypti is reported beyond its current limit of distribution in Argentina, in the city of Neuquén, Neuquén Province. Ovitraps were placed to collect Ae. aegypti eggs between December 2009 and April 2010. The geographical distribution of Culex eduardoi, Psorophora ciliata and Ps. cingulata is extended with new records from two provinces.