Luis Adrian Díaz

National Scientific and Technical Research Council | conicet · CCT Cordoba

In Argentina, the Pampa ecoregion has been almost completely transformed into agroecosystems. To evaluate the environmental (agricultural area, tree coverage, distance to the nearest water body and urban site) and biological (dove, cowbird, and sparrow abundance) effects on free-ranging bird exposure to St. Louis encephalitis virus (SLEV) and West...

Freely available from: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4016945 Aedes aegypti (L.) (Diptera: Culicidae) survives in the egg stage under unfavorable environmental conditions. In this study, we assessed the survival of Ae. aegypti eggs under natural winter conditions as an overwintering mechanism. To address this, field collected...

We evaluated humoral immune-response elicited by Sputnik-V by measuring anti-Spike (S) IgG antibodies (Abs) and neutralizing antibodies (NAb) prior to, 14 and 42 days after-vaccination. The safety and disease rates among vaccinated individuals were also evaluated. Since SARS-CoV-2 lineage P.1 is rapidly spreading in Argentina, virus-neutralizing ac...

Chlamydias are obligated intracellular Gram-negative bacteria, considered important zoonotic pathogens, broadly present in several bird species and responsible for economic losses in animal production. We analyzed the presence of Chlamydial species with zoonotic risk in farm animals in a highly biodiverse area and with great human circulation, the...

Biobanks are instrumental for accelerating research. Early in SARS-CoV-2 pandemic, the Argentinean Biobank of Infectious Diseases (BBEI) initiated the COVID19 collection and started its characterization. Blood samples from subjects with confirmed SARS-CoV-2 infection either admitted to health institutions or outpatients, were enrolled. Highly expos...

Los Flavivirus constituyen virus transmitidos por artrópodos, principalmente mosquitos. Pueden producir enfermedades en humanos y animales, también incluyen virus específicos de insectos que solo infectan y se replican en los insectos, no así en vertebrados. En Paraguay los virus dengue, fiebre amarilla y Zika fueron detectados en infecciones human...

Se evaluó la respuesta de anticuerpos tipo IgG totales anti S y anticuerpos neutralizantes (AcNT) a la vacuna Sputnik V en 800 muestras tomadas a una cohorte de 285 personas en la ciudad de Córdoba. Las muestras fueron tomadas en tres momentos diferentes: una muestra basal previo a lo colocación de la vacuna (en los casos en que fue posible), una m...

Background To analyze the infectious extent of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) in different settings where prevention strategies are critical to limit infection spread, we evaluated SARS-COV-2 viability to guide public health policies regarding isolation criteria and infection control. Methods We attempted viral isolat...

Anthropogenic changes affect biological communities of host and vectors driving arbovirus activity. In general, urban and agricultural ecosystems harbor less avian and mosquito diversity than native ecosystems and are dominated by few species. Human activities have led to the emergence / re-emergence of different infectious pathogens particularly a...

Background West Nile virus (WNV) activity has been documented in the central region of Argentina since 2005, but its maintenance network has not been elucidated yet. Methods We evaluated the susceptibility to WNV oral infection and transmission in a Culex pipiens quinquefasciatus mosquito population by means of a dose-dependent vector competence a...

The Flavivirus genus encompasses a diverse group of mosquito-borne, tick-borne, insect-specific, and no-known vector viruses. All flaviviruses are enveloped, single-stranded positive RNA viruses that replicate integrally in the cytoplasm. Arthropod-borne flaviviruses represent a global burden for human and veterinary health. They have the ability t...

Arthropod-borne viruses represent the most important emerging viruses worldwide. Saint Louis encephalitis (SLEV) and West Nile (WNV) viruses are vectored by Culex spp. mosquitoes and amplified by several bird species. We carried out an extensive retrospective serosurvey study to analyze the exposure of free-ranging raptors to SLEV and WNV in centra...

Background: St. Louis encephalitis virus (SLEV) is endemic and autochthonous on the American continent. Culex pipiens quinquefasciatus is a vector of SLEV; however, Culex interfor and Culex saltanensis have also been found to be naturally infected with SLEV. The aim of this study was to determine the vector competence of C. interfor and C. saltane...

Saint Louis encephalitis (SLE) es un arbovirus que pertenece al género Flavivirus, y que es mantenido en la naturaleza a través de interacciones complejas entre distintas especies de mosquitos y aves. En Argentina, se identificó a Culex quinquefasciatus, Cx. interfor y Cx. saltanensis como potenciales vectores y a Zenaida auriculata y Columbina pic...

Due to anthropic environmental changes, vector-borne diseases are emerging worldwide. Ticks are known vectors of several pathogens of concern among humans and animals. In recent decades, several examples of tick-borne emerging viral diseases have been reported (Crimean Congo hemorrhagic fever virus, Powassan virus, encephalitis virus, heartland vir...

Madariaga virus (MADV), previously known as South American eastern equine encephalitis virus (SA EEEV; family Togaviridae, genus Alphavirus), is a mosquito-borne virus associated mainly with equine disease. In 2010, the first human outbreak by MADV was reported in Central America, but the mosquito vectors and vertebrate hosts involved in the outbre...

Infectious diseases caused by mosquito-borne viruses constitute health and economic problems worldwide. St. Louis encephalitis virus (SLEV) is endemic and autochthonous in the American continent. Culex pipiens quinquefasciatus is the primary urban vector of SLEV; however, Culex interfor and Culex saltanensis have also been found naturally infected...

Many species of Amblyomma ticks are commonly found infesting wild birds in South America, where birds are important hosts for several arboviruses, such as West Nile virus (WNV) and Saint Louis encephalitis virus (SLEV). In this study, WNV and SLEV transmission experiments were performed to evaluate the vector competence of three South American tick...

We summarize and analyze historical and current data regarding the reemergence of St. Louis encephalitis virus (SLEV; genus Flavivirus) in the Americas. Historically, SLEV caused encephalitis outbreaks in the United States; however, it was not considered a public health concern in the rest of the Americas. After the introduction of West Nile virus...

Anthropogenic changes affect biological communities of host and vectors driving arbovirus activity. In general, urban and agricultural landscapes host less avian and mosquito diversity and frequently these are dominated by few species. The St. Louis encephalitis (SLEV) and West Nile viruses (WNV) are infectious agents that have emerged and re-emerg...

Los Virus St. Louis Encephalitis (VSLE) y el Virus West Nile (VWN) son endémicos en la región central de Argentina, donde re-emergieron en 2005 y en 2006, respectivamente, como patógenos ocasionando brotes de encefalitis en humanos y caballos en diferentes provincias. Para el VSLE sabemos que su red de mantenimiento involucra a mosquitos Cx. quinqu...

Los arbovirus St. Louis encephalitits (VSLE) y West Nile (VWN) son mantenidos en la naturaleza a través de interacciones dinámicas y complejas entre mosquitos, como los principales vectores y las aves como hospedadores amplificadores. En Argentina, estudios previos identificaron a Culex quinquefasciatus y a las palomas torcaza (Zenaida auriculata)...

Borrelia burgdorferi sensu lato (s. l.) spirochetes are associated with a wide range of vectors and hosts. Birds are important hosts in the ecology of some hard ticks (Ixodidae) in northwestern Argentina, where B. burgdorferi s.l. have been detected in Ixodes pararicinus. We evaluated Borrelia infection in ticks collected from wild birds by molecul...

St.Louis encephalitis virus (SLEV) is an emerging human pathogen flavivirus in Argentina. Recently, it has reemerged in the United States. We evaluated the role as amplifying host of six resident bird species and analyzed their capacity as host during the 2005 encephalitis outbreak of SLEV in Córdoba. Eared dove, picui ground dove, and house sparro...

Alphaviruses (Togaviridae) are arboviruses frequently associated with emerging infectious diseases. In this study, we aimed to investigate the presence of alphaviruses in Uruguay by detecting the viral genome in mosquitoes and neutralizing antibodies in equines. A total of 3,575 mosquitoes were analyzed for alphavirus genome detection. Serologic st...

Introduction: Alphaviruses can produce febrile illness and encephalitis in dead-end hosts such as horses and humans. Within this genus, the Venezuelan Equine Encephalitis virus (VEEV) complex includes pathogenic epizootic subtypes and enzootic subtypes that are not pathogenic in horses (except subtype IE, Mexican strains), although they can cause...

The Flavivirus genus currently includes 53 viral species, most of them transmitted by mosquitoes and tick bites and others with not known vector and specific insect flavivirus. Flaviviruses comprise important arthropod-transmitted human pathogens, including yellow fever virus (YFV), Dengue virus (DENV), Japanese encephalitis virus (JEV), West Nile...

The family Bunyaviridae, the most numerous family of RNA viruses, was established in 1975. In these days, it is integrated by more than 350 worldwide viral species, grouped into five genera: Orthobunyavirus; Hantavirus; Nairovirus; Phlebovirus, which infect vertebrates; and Tospovirus which are viruses that infect plants. From these four genera tha...

Arboviruses do not represent a based-related phylogenetic group, but they are all transmitted by arthropods. Fifty arboviruses pathogenic for animals (including humans) have been reported, belonging to the families Asfarviridae, Bunyaviridae, Flaviviridae, Orthomyxoviridae, Rhabdoviridae, Reoviridae, and Togaviridae. A wide variety of hematophagous...

Alphavirus constitutes one of the two genera included in the family Togaviridae. This genus contains 31 viral species (with different variants and strains), grouped into seven antigenic complexes. Depending on the geographical location where they were isolated, this genus is divided into alphavirus in the New World (including Eastern equine encepha...

INTRODUCCIÓN El Virus de la Encefalitis de St. Louis (SLEV), se distribuye en América y se mantiene en diversos ecosistemas gracias a mosquitos Culex (vector) y aves Passeriformes y Columbiformes (hospedadores). Estudios realizados en el país han demostrado que los ciclos urbanos de transmisión involucran a mosquitos Cx. quinquefasciatus como vecto...

Viruses transmitted by arthropods represent the most important emerging virus in the world. The Saint Louis encephalitis (SLEV) and West Nile virus (WNV) are transmitting by Culex mosquitoes as vectors and several bird species as hosts. The purpose of this research was to study the exposure of birds of prey communities for SLEV and WNV in La Pampa...

Objective: to investigate the status of Alphavirus infections in Uruguay in mosquito vectors and hosts. Materials and Methods: A total of 3575 mosquitoes were collected at rural and suburban localities and pooled by locality, genus/species, sex, engorged/not engorged females. From years 2006 to 2014, 266 pools were analyzed. Total RNA extraction wa...

Saint Louis encephalitis virus (SLEV) reemerged in South America, and caused encephalitis outbreaks at the beginning of the 21st century. To enhance our knowledge about SLEV virulence, we performed comparative pathogenesis studies in Swiss albino mice inoculated with two different variants, the epidemic strain CbaAr-4005 and the non-epidemic strain...

The dynamics of a mosquito population depends heavily on climatic variables such as temperature and precipitation. Since climate change models predict that global warming will impact on the frequency and intensity of rainfall, it is important to understand how these variables affect the mosquito populations. We present a model of the dynamics of a...

St. Louis encephalitis virus (SLEV) (Flavivirus) is a reemerging arbovirus in the southern cone of South America. In 2005, an outbreak of SLEV in central Argentina resulted in 47 human cases with 9 deaths. In Argentina, the ecology of SLEV is poorly understood. Because certain birds are the primary amplifiers in North America, we hypothesized that...

Several tick-borne Rickettsia species are recognized human pathogens in Argentina. Here we evaluated rickettsial infection in ticks collected on passerine birds during 2011-2012 in two eco-regions of Argentina. The ticks were processed by molecular analysis through polymerase chain reaction (PCR) detection and DNA sequencing of fragments of two ric...

Our goal was to determine the presence of neutralizing antibodies against St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) in sera of wild and domestic birds from Buenos Aires City, Argentina. From October 2012 to April 2013, 180 samples were collected and processed by the microneutralization technique. A 7.2% of the sampled birds were...

St. Louis encephalitis virus (SLEV) is a re-emerging arbovirus in South America. In 2005, an encephalitis outbreak caused by SLEV was reported in Argentina. The reason for the outbreak remains unknown, but may have been related to virological factors, changes in vectors populations, avian amplifying hosts, and/or environmental conditions. The main...

The mite Ornithonyssus bursa (Berlese) (Mesostigmata: Macronyssidae) is considered a poultry pest causing important infestations in chickens and it is considered a potential vector of arbovirus. Despite being considered a common parasite in wild birds, there is scarce published information about its potential hosts and effects on them. Here we pres...

Bunyamwera virus (BUNV) (Bunyaviridae, genus Orthobunyavirus, serogroup Bunyamwera) is considered an emerging pathogen for humans and animals in American countries. The CbaAr-426 strain of BUNV was recovered from mosquitoes Ochlerotatus albifasciatus (Diptera: Culicidae) collected in Córdoba province (Argentina), where serological studies detected...

We evaluated the prevalence of WNV and SLEV neutralizing antibodies in captive and free-ranging raptors from Argentina by plaque-reduction neutralization test. Eighty plasma samples from 12 species were analyzed. Only one captive adult Crowned Eagle (Harpyhaliaetus coronatus) was WNV seropositive (prevalence: 1.25%; antibody titer of 1:80). Two cap...

Background: St Louis encephalitis virus (SLEV) is a re-emerging human pathogen widely distributed in the American continent. Although it is not fully understood, the SLEV transmission network may involve Culex quinquefasciatus mosquitoes as vectors and Columbidae species as hosts. Methods: To calculate infection rates, we inoculated Cx. quinquef...

St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) belong to the Japanese encephalitis antigenic complex (Flavivirus genus, Flaviviridae family). They show antigenic close relationships and share many similarities in their ecology. Both are responsible for serious human diseases. The aim of this study was to investigate the presence of n...

St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) present ecological and antigenic similarities and are responsible for serious human diseases. In addition, WNV is a significant pathogen in terms of equine health. The purpose of our study was to analyse the seroprevalence of SLEV and WNV in equine sera collected in Santa Fe Province, Ar...

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 mol...

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...

Arboviruses are emerging/reemerging infectious agents worldwide. The factors within this scenario include vector and host population fluctuations, climatic changes, anthropogenic activities that disturb ecosystems, an increase in international flights, human mobility, and genetic mutations that allow spill-over phenomenon. Arboviruses are maintaine...

El virus West Nile es un flavivirus patógeno para humanos en el Viejo Mundo que ha experimentado recientemente un proceso de emergencia en el continente americano. Desde su introducción en 1999 en EEUU, se ha convertido en un patógeno de preocupación para las poblaciones de aves silvestres al haber provocado allí eventos masivos de mortalidad y por...

The West Nile virus, a human pathogen flavivirus, has recently shown an emerging process through the American continent. Since its introduction in 1999 into the United States, it became a concerned pathogen for wild bird populations, because of massive bird deaths events and significant bird population declines. By 2001 the virus has reached countr...

Author Summary St. Louis encephalitis virus (SLEV, Flavivirus, Flaviviridae) is an emerging arbovirus in South America, with human SLEV encephalitis cases reported in Argentina and Brazil. Genotype III strains of SLEV were isolated from mosquitoes during the largest SLEV outbreak ever reported in South America (Córdoba, Argentina, 2005). These stra...

West Nile virus (WNV) is an emerging Flavivirus dispersing throughout the American continent. It has emerged in the United States as an important medical and veterinary pathogen. It was introduced into Argentina late in 2004 with reported activity in human, wild birds and equines. Field evidence supports the hypothesis of an enzootic transmission c...

Arbovirus vector transmission is interrupted when vector abundance decreases or disappears in temperate regions during the winter season. Although the primary overwintering mechanism for many arboviruses in nature remains unknown, vertical transmission is one potential mechanism. Vertical transmission functions as an overwintering mechanism for St....

Venezuelan equine encephalitis complex includes viruses considered emerging pathogens for humans and animals in the Americas. Two members of this complex have been detected previously in Argentina: Rio Negro Virus (RNV), detected in mosquitoes from Chaco province and rodents from Formosa province, and Pixuna Virus (PIXV), detected in mosquitoes fro...

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.

Infection by Bunyamwera virus (BUNV) species (Family Bunyaviridae, Genus Orthobunyavirus) has been detected in ewes, goats, cows, horses and humans all the way through America. However, there are no evidences of such infection in birds. To detect BUNV (CbaAr-426) infection in free ranging birds, a serological survey was carried out in Córdoba city...

Venezuelan Equine Encephalitis complex viruses cause epidemics and epizootics periodically in some regions of the Americas. In Argentina, only enzootic Rio Negro virus (AG80-663) (RNV) has been isolated. To survey and identify activity of viruses that belong to Venezuelan Equine Encephalitis complex in a template region of the country, a generic Al...

An outbreak of flavivirus encephalitis occurred in 2005 in Córdoba province, Argentina. To characterize the epidemiologic and clinical features of that outbreak and provide the serologic results that identified St. Louis encephalitis virus (SLEV) as the etiologic agent. From January to May 2005, patients with symptoms of encephalitis, meningitis, o...

St. Louis encephalitis virus (SLEV) is an emerging Flavivirus in South American countries. Its ecology and biological transmission cycles are scarcely known. Eared doves (Zenaida auriculata) have frequently been found infected by SLEV, and therefore, could be suspected as SLEV hosts. Thirty post-hatch-year eared doves were subcutaneously inoculated...

West Nile Virus in Birds, Argentina