oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 9 )

2018 ( 19 )

2017 ( 23 )

2016 ( 40 )

Custom range...

Search Results: 1 - 10 of 16307 matches for " Marta Silvia Contigiani "
All listed articles are free for downloading (OA Articles)
Page 1 /16307
Display every page Item
Silent Circulation of St. Louis Encephalitis Virus Prior to an Encephalitis Outbreak in Cordoba, Argentina (2005)
Luis Adrian Díaz ,Guillermo Albrieu Llinás,Ana Vázquez,Antonio Tenorio,Marta Silvia Contigiani
PLOS Neglected Tropical Diseases , 2012, DOI: 10.1371/journal.pntd.0001489
Abstract: St. Louis encephalitis virus is a complex zoonoses. In 2005, 47 laboratory-confirmed and probable clinical cases of SLEV infection were reported in Córdoba, Argentina. Although the causes of 2005 outbreak remain unknown, they might be related not only to virological factors, but also to ecological and environmental conditions. We hypothesized that one of the factors for SLE reemergence in Córdoba, Argentina, was the introduction of a new SLEV genotype (SLEV genotype III), with no previous activity in the area. In order to evaluate this hypothesis we carried out a molecular characterization of SLEV detections from mosquitoes collected between 2001 and 2004 in Córdoba city. A total of 315 mosquito pools (11,002 individuals) including 12 mosquitoes species were analyzed. Overall, 20 pools (8 mosquitoes species) were positive for SLEV. During this study, genotypes II, V and VII were detected. No mosquito pool infected with genotype III was detected before the 2005 outbreak. Genotype V was found every year and in the 8 sampled sites. Genotypes II and VII showed limited temporal and spatial activities. We cannot dismiss the association of genotype II and V as etiological agents during the outbreak. However, the silent circulation of other SLEV strains in Córdoba city before the 2005 outbreak suggests that the introduction of genotype III was an important factor associated to this event. Not mutually exclusive, other factors such as changes in avian hosts and mosquitoes vectors communities, driven by climatic and environmental modifications, should also be taken into consideration in further studies.
Age-related seroprevalence study for St. Louis encephalitis in a population from Cordoba, Argentina
SPINSANTI, Lorena Ivana;Ré, Viviana Elizabeth;DíAZ, María Pilar;CONTIGIANI, Marta Silvia;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2002, DOI: 10.1590/S0036-46652002000200001
Abstract: a serological screening was performed in 615 individuals aged 0-87 years, living in the city of cordoba, argentina to study the relationship between antibody prevalence for the sle virus and age. a 13.98% prevalence of neutralizing antibodies was obtained and its relation to age was significantly high (p = 0.045). the highest seroprevalence was noted on individuals over 60 years old (>20%), whereas no subject under 10 was seropositive for this virus. our results confirm that the agent is endemic in this area and neurological pathology studies should be performed on those individuals aged 60 since they represent the most susceptible group to sle virus.
UNA virus: first report of human infection in Argentina
Diaz, Luis Adrián;Spinsanti, Lorena Ivana;Almiron, Walter Ricardo;Contigiani, Marta Silvia;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2003, DOI: 10.1590/S0036-46652003000200012
Abstract: una virus (unav), togaviridae family, is widely distributed in south america, where infections have been detected in mosquitoes and vertebrate hosts (humans, birds and horses). we analyzed human sera from córdoba inhabitants aged 44 to 89 years and using a neutralization test, we found a prevalence of unav antibodies of 3.8% (3/79). the low titers detected suggest past infections probably acquired in rural areas of the province of córdoba (central argentina). none sera were found positive for mayv neutralizing antibodies. this is the first report of human infections by unav in argentina.
Age-related seroprevalence study for St. Louis encephalitis in a population from Cordoba, Argentina
SPINSANTI Lorena Ivana,Ré Viviana Elizabeth,DíAZ María Pilar,CONTIGIANI Marta Silvia
Revista do Instituto de Medicina Tropical de S?o Paulo , 2002,
Abstract: A serological screening was performed in 615 individuals aged 0-87 years, living in the city of Cordoba, Argentina to study the relationship between antibody prevalence for the SLE virus and age. A 13.98% prevalence of neutralizing antibodies was obtained and its relation to age was significantly high (p = 0.045). The highest seroprevalence was noted on individuals over 60 years old (>20%), whereas no subject under 10 was seropositive for this virus. Our results confirm that the agent is endemic in this area and neurological pathology studies should be performed on those individuals aged 60 since they represent the most susceptible group to SLE virus.
UNA virus: first report of human infection in Argentina
Diaz Luis Adrián,Spinsanti Lorena Ivana,Almiron Walter Ricardo,Contigiani Marta Silvia
Revista do Instituto de Medicina Tropical de S?o Paulo , 2003,
Abstract: Una virus (UNAV), Togaviridae family, is widely distributed in South America, where infections have been detected in mosquitoes and vertebrate hosts (humans, birds and horses). We analyzed human sera from Córdoba inhabitants aged 44 to 89 years and using a neutralization test, we found a prevalence of UNAV antibodies of 3.8% (3/79). The low titers detected suggest past infections probably acquired in rural areas of the Province of Córdoba (central Argentina). None sera were found positive for MAYV neutralizing antibodies. This is the first report of human infections by UNAV in Argentina.
First detection of Rio Negro virus (Venezuelan equine encephalitis complex subtype VI) in Córdoba, Argentina
Pisano, María Belén;Spinsanti, Lorena Ivana;Díaz, Luis Adrián;Farías, Adrián Alejandro;Almirón, Walter Ricardo;Ré, Viviana Elizabeth;Contigiani, Marta Silvia;
Memórias do Instituto Oswaldo Cruz , 2012, DOI: 10.1590/S0074-02762012000100017
Abstract: rio negro virus (rnv) (venezuelan equine encephalitis subtype vi) circulates only in argentina; in northern provinces, isolates have been obtained from mosquitoes and rodents since 1980 and have been associated with acute febrile illness in humans. however, no studies of rnv have been performed in the central area of the country. we carried out molecular and serological detection of rnv in córdoba, a province of the central part of the country, in mosquitoes and humans, respectively. one mosquito pool tested positive for alphavirus rna by reverse transcriptase-nested polymerase chain reaction (rt-nested pcr). subsequent sequencing determined that this alphavirus grouped with rnv. serological studies detected antibodies to rnv in one human serum sample, which was obtained during the same period that rnv was detected using the aforementioned molecular methods. this is the first report of rnv circulation in the central area of argentina, indicating an expansion of its original distribution. these results highlight the importance of strengthening surveillance procedures in endemic areas, as well as in new regions where rnv may emerge.
Venezuelan Equine Encephalitis Viruses (VEEV) in Argentina: Serological Evidence of Human Infection
María Belén Pisano ,Griselda Oria,Geraldine Beskow,Javier Aguilar,Brenda Konigheim,María Luisa Cacace,Luis Aguirre,Marina Stein,Marta Silvia Contigiani
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002551
Abstract: Venezuelan equine encephalitis viruses (VEEV) are responsible for human diseases in the Americas, producing severe or mild illness with symptoms indistinguishable from dengue and other arboviral diseases. For this reason, many cases remain without certain diagnosis. Seroprevalence studies for VEEV subtypes IAB, ID, IF (Mosso das Pedras virus; MDPV), IV (Pixuna virus; PIXV) and VI (Rio Negro virus; RNV) were conducted in persons from Northern provinces of Argentina: Salta, Chaco and Corrientes, using plaque reduction neutralization test (PRNT). RNV was detected in all studied provinces. Chaco presented the highest prevalence of this virus (14.1%). Antibodies against VEEV IAB and -for the first time- against MDPV and PIXV were also detected in Chaco province. In Corrientes, seroprevalence against RNV was 1.3% in the pediatric population, indicating recent infections. In Salta, this was the first investigation of VEEV members, and antibodies against RNV and PIXV were detected. These results provide evidence of circulation of many VEE viruses in Northern Argentina, showing that surveillance of these infectious agents should be intensified.
Phylodynamics of Hepatitis C Virus Subtype 2c in the Province of Córdoba, Argentina
Viviana E. Ré,Andrés C. A. Culasso,Silvia Mengarelli,Adrián A. Farías,Fabián Fay,María B. Pisano,Osvaldo Elbarcha,Marta S. Contigiani,Rodolfo H. Campos
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0019471
Abstract: The Hepatitis C Virus Genotype 2 subtype 2c (HCV-2c) is detected as a low prevalence subtype in many countries, except in Southern Europe and Western Africa. The current epidemiology of HCV in Argentina, a low-prevalence country, shows the expected low prevalence for this subtype. However, this subtype is the most prevalent in the central province of Córdoba. Cruz del Eje (CdE), a small rural city of this province, shows a prevalence for HCV infections of 5%, being 90% of the samples classified as HCV-2c. In other locations of Córdoba Province (OLC) with lower prevalence for HCV, HCV-2c was recorded in about 50% of the samples. The phylogenetic analysis of samples from Córdoba Province consistently conformed a monophyletic group with HCV-2c sequences from all the countries where HCV-2c has been sequenced. The phylogeographic analysis showed an overall association between geographical traits and phylogeny, being these associations significant (α = 0.05) for Italy, France, Argentina (places other than Córdoba), Martinique, CdE and OLC. The coalescence analysis for samples from CdE, OLC and France yielded a Time for the Most Common Recent Ancestor of about 140 years, whereas its demographic reconstruction showed a “lag” phase in the viral population until 1880 and then an exponential growth until 1940. These results were also obtained when each geographical area was analyzed separately, suggesting that HCV-2c came into Córdoba province during the migration process, mainly from Europe, which is compatible with the history of Argentina of the early 20th century. This also suggests that the spread of HCV-2c occurred in Europe and South America almost simultaneously, possibly as a result of the advances in medicine technology of the first half of the 20th century.
Identification of hepatitis C virus subtype 2c by sequencing analysis in patients from Córdoba, Argentina
, Viviana;Contigiani, Marta;Yoshida, Clara Fumiko Tachibana;Lampe, Elisabeth;
Memórias do Instituto Oswaldo Cruz , 2007, DOI: 10.1590/S0074-02762007000800016
Abstract: in argentina, most information on hepatitis c virus (hcv) genotype distribution comes from studies carried out in buenos aires (east province). in order to identify hcv subtypes in central argentina, nucleotide sequencing of core region was performed in samples from 36 patients living in córdoba, the second most populated province of argentina. the sequence analysis identified subtype 2c as the most prevalent (50%), followed by subtype 1b (33%) and to a lesser extent by subtypes 1a (11%), 3a (3%) and 4a (3%). this is the first report of circulation of hcv subtype 2c in this region of argentina and also such high prevalence has never been found before in the genotype distribution of south america.
An indirect immunofluorescence assay to detect antibodies against St. Louis Encephalitis virus
SPINSANTI, Lorena;RE, Viviana;AGUILAR, Javier;CONTIGIANI, Marta;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2001, DOI: 10.1590/S0036-46652001000600008
Abstract: an in house indirect immmunofluorescence assay ( ifa ) in relation to neutralization (nt) reference test, was assessed as a fast and cheap method to carry out serological surveys for st. louis encephalitis virus (sle). sera obtained from 213 blood donors were analyzed by both tests. the prevalence of seropositivity obtained with ifa was lower than (30.98%) that observed on nt (41.78%). the relative specificity rate of ifa was 96.77% whereas its relative sensitivity rate was 69.66%. kappa index showed a good correlation between both tests. the results indicate that neutralization assay is still the serological test with the highest sensitivity and specificity relative rates for detecting antibodies against sle virus. nevertheless, the ifa could be useful as an alternative test in order to learn the circulation of the flavivirus genus in a certain area.
Page 1 /16307
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.