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1.
Exp Appl Acarol ; 92(3): 507-528, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38485886

ABSTRACT

The Sierra Nevada de Santa Marta (SNSM), located in northern Colombia, is considered a geographical island with high levels of biodiversity and endemism. However, little is known about tick species and their associated microorganisms at the SNSM. In this study we sampled host-seeking ticks in areas of the town of Minca within the SNSM. We collected 47 ticks identified as Amblyomma pacae, Amblyomma longirostre, Amblyomma ovale, Amblyomma mixtum, Haemaphysalis juxtakochi, Ixodes sp. cf. Ixodes affinis and Ixodes sp. Of these ticks, we tested for Rickettsia spp. by amplifying the gltA, SCA1, and 16S rRNA genes via PCR. Rickettsia amblyommatis was detected in one pool of 3 larvae and in a female of A. pacae. Additonally, we isolated Rickettsia sp. belonging to the group of spotted fevers in larvae of A. longirostre. This study reports new findings of six species of ticks and two species of Rickettsia within the SNSM.


Subject(s)
Ixodidae , Larva , Rickettsia , Animals , Rickettsia/isolation & purification , Colombia , Female , Larva/microbiology , Larva/growth & development , Ixodidae/microbiology , Male , RNA, Ribosomal, 16S/analysis , Nymph/microbiology , Nymph/growth & development , Amblyomma/microbiology , Amblyomma/growth & development , Amblyomma/physiology
2.
Vet Res Commun ; 48(1): 585-589, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37718328

ABSTRACT

The aim of this study was to report the first detection of Candidatus Ehrlichia pampeana in Haemaphysalis juxtakochi from Argentina. Free-living ticks were collected from vegetation by drag-flag method on five sample sites in Entre Ríos Province, central Argentina, belonging to the Espinal Phytogeographic Province. Molecular detection of order Rickettsiales agents was performed using gltA (Rickettsia spp.), 16 S rRNA and groEL (Anaplasmataceae) genes as targets. A total of 67 ticks of Amblyomma aureolatum (20 nymphs and 4 adults), Amblyomma dubitatum (15 nymphs) and Haemaphysalis juxtakochi (24 nymphs and 4 adults) were collected. While all tested ticks were negative for Rickettsia spp., and Anaplasmataceae agents could neither be detected in A. aureolatum nor in A. dubitatum, Candidatus Ehrlichia pampeana was detected in one male of H. juxtakochi. DNA sequences of this microorganism (16 S rDNA and groEL) are related to sequences of Ehrlichia ewingii. The findings of the current study represent the first report of this Ehrlichia strain for Argentina.


Subject(s)
Anaplasmataceae , Ixodidae , Rickettsia , Male , Animals , Ixodidae/microbiology , Rickettsiales , Anaplasmataceae/genetics , Argentina , Rickettsia/genetics , Ehrlichia/genetics
3.
Ticks Tick Borne Dis ; 14(6): 102222, 2023 11.
Article in English | MEDLINE | ID: mdl-37418999

ABSTRACT

Bacteria of the sister genera Ehrlichia and Anaplasma (Anaplasmataceae) are obligate intracellular Alphaproteobacteria that are transmitted mostly through arthropod vectors. These agents can infect different vertebrate cells, depending on the species involved, and can cause diseases in animals and humans. In this study, we evaluated the presence of Anaplasmataceae bacteria in Amblyomma calcaratum ticks collected from a road-killed Tamandua tetradactyla in the Rainforest ecoregion in Argentina. All samples were screened for Anaplasmataceae DNA using a real-time PCR assay targeting the 16S rRNA gene. Evidence of Anaplasmataceae DNA was detected in three out of thirty-nine Am. calcaratum ticks. Phylogenetic analysis of a portion of 16S rRNA gene positioned one sample (Ehrlichia sp. strain Ac124) with Ehrlichia sequences and the other two samples with Anaplasma sequences; Anaplasma sp. strain Ac145 close to Anaplasma odocoilei and Anaplasma sp. strain Ac152 in an ancestral position to most Anaplasma species. The groEL sequence obtained showed that Ehrlichia sp. strain Ac124 was phylogenetically related to Ehrlichia sp. strain Iberá reported infecting Amblyomma tigrinum from Iberá wetlands in Argentina. Phylogenetic analysis using the rpoB sequence positioned Anaplasma sp. strain Ac145 close to the canine pathogen Anaplasma platys, while Anaplasma sp. strain Ac152 was positioned close to the bovine pathogen Anaplasma marginale. In this study, three Anaplasmataceae agents were detected in adults of Am. calcaratum associated with a T. tetradactyla. These results suggest that the number of Anaplasmataceae species, as well as their distribution, is largely unknown.


Subject(s)
Anaplasmataceae , Ticks , Humans , Animals , Cattle , Dogs , Anaplasmataceae/genetics , Vermilingua , Amblyomma/genetics , RNA, Ribosomal, 16S/genetics , Phylogeny , Argentina/epidemiology , Rainforest , Anaplasma/genetics , Ehrlichia/genetics , Ticks/microbiology , DNA, Bacterial/genetics
4.
Vet Parasitol Reg Stud Reports ; 39: 100850, 2023 04.
Article in English | MEDLINE | ID: mdl-36878633

ABSTRACT

The aim of this work was to describe the tick community associated to domestic mammals in rural areas from the Yungas lower montane forest of Argentina. The circulation of tick-borne pathogens was also analyzed. Samples of ticks parasitizing cattle, horses, sheep and dogs were carried out in different seasons, and questing ticks were collected from vegetation and analyzed to detect the presence of Rickettsia, Ehrlichia, Borrelia and Babesia by a battery of different PCRs. The structure of the tick communities was analyzed through the Chao1 species richness estimator, the Shannon-Wiener index and the Horn index of community similarity. Eight tick species were collected in the study area: Amblyomma sculptum, Rhipicephalus microplus, Amblyomma hadanii, Dermacentor nitens, Amblyomma ovale, Haemaphysalis juxtakochi, Ixodes pararicinus and Rhipicephalus sanguineus sensu stricto. However, A. sculptum was by far the dominant species in the tick assemblages analyzed, and this was reflected in the low diversity values obtained. Dermacentor nitens, A. sculptum and R. microplus were the three species associated to horses. The predominance of A. sculptum was also observed in the tick samples obtained from dogs, even on two tick species, namely A. ovale and R. sanguineus s.s., which have dogs as the principal domestic host. Rhipicephalus microplus and A. sculptum were the most abundant ticks on cattle, while few specimens of I. pararicinus, A. hadanii and D. nitens were found on bovines. Dermacentor nitens ticks were found to be infected with B. caballi, which indicate the circulation of this pathogen of horses in the Yungas area. The detection of a strain of Borrelia sp. belonging to the B. burgdorferi s.l. complex in I. pararicinus is consistent with previous findings made in Argentina, but the public health relevance of this vector-microorganism association is far from being similar to that occurs in the northern hemisphere because there are practically no records of these tick species parasitizing humans in South America. The tick community of rural areas of the Yungas lower montane forest is composed by species which are potential vectors of pathogenic microorganism with veterinary and public health importance, circulating in a human-wildlife-livestock interface.


Subject(s)
Borrelia , Ixodes , Rhipicephalus , Humans , Horses , Cattle , Animals , Dogs , Sheep , Argentina/epidemiology , Mammals , Amblyomma , Forests
5.
Ticks Tick Borne Dis ; 14(3): 102135, 2023 05.
Article in English | MEDLINE | ID: mdl-36773558

ABSTRACT

The aim of this study was to report tick infestations on wild birds from four Phytogeographic Provinces of Argentina. A total of 1085 birds was captured (124 species, 97 genera, 29 families and 13 orders), and ticks were collected from 265 birds (48 species, 40 genera and five orders). A total of 1469 ticks (1102 larvae, 363 nymphs and 4 females) belonging to 15 tick species (Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma nodosum, Amblyomma ovale, Amblyomma parvum, Amblyomma sculptum, Amblyomma tigrinum, Amblyomma triste, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris, Ixodes auritulus sensu lato, Ixodes pararicinus, Ixodes silvanus, Ixodes sp. cf. I. affinis and Ornithodoros sp. cf. O. mimon). Eighty-one new associations between bird species and stages of tick species are detected. The families Thamnophilidae, Turdidae, Thraupidae, Passerellidae, Furnariidae and Troglodytidae were the most prevalent. According to the Phytogeographic Provinces involved in this study, the prevalence of infection for each of them in birds was: (1) Chaco: 28.2% (11 tick species); (2) Yungas: 22.0% (8 tick species); (3) Espinal: 11.1% (2 tick species); and (4) Pampa: 3.9% (1 tick species). This study provided information on the diversity of tick species that parasitize wild birds, the variability of the specific tick-bird associations between the different Phytogeographic Provinces and the relevance of some families of birds as hosts of different tick species.


Subject(s)
Argasidae , Ixodes , Ixodidae , Passeriformes , Songbirds , Tick Infestations , Animals , Female , Argentina/epidemiology , Animals, Wild , Tick Infestations/epidemiology , Tick Infestations/veterinary , Amblyomma
6.
Life (Basel) ; 13(1)2023 Jan 04.
Article in English | MEDLINE | ID: mdl-36676094

ABSTRACT

Birds are important hosts in the life cycle of some species of ticks. In Colombia, there are few eco-epidemiological studies of tick-borne diseases; the existing ones have been focused on areas where unusual outbreaks have occurred. This study describes the identification of ticks collected from birds and vegetation, and the detection of bacteria in those ticks and in blood samples from birds in an urban fragment of tropical dry forest in the department of Magdalena, Colombia. Bird sampling was carried out monthly in 2021, and 367 birds, distributed among 41 species, were captured. All collected ticks were identified as Amblyomma sp. or Amblyomma dissimile. The presence of rickettsiae in ticks collected from birds was evaluated by molecular analysis of the gltA, ompA and sca1 genes. 16S rRNA meta-taxonomy was used to evaluate rickettsiae in ticks collected from vegetation and in blood samples from birds. The presence of the species "Candidatus Rickettsia colombianensi" was detected in ticks from birds. Bacteria of the family Rickettsiacea was the most abundant in ticks collected from vegetation. Bacteria of the families Staphylococcaceae, Comamonadaceae and Pseudomonadaceae were prevalent in the samples of blood from birds. Rickettsia spp. was also detected in low abundance in some of the bird blood samples.

7.
Ticks Tick Borne Dis ; 13(6): 102043, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36150285

ABSTRACT

The aim of this study is to determine if there is circulation of microorganisms of the genus Ehrlichia in opossums Didelphis albiventris and their ticks from the Humid Chaco in Argentina. Blood samples of 15 specimens of the opossum D. albiventris were analysed. Immature stages of the ticks Amblyomma ovale (Larvae=26; Nymphs=10), Amblyomma sculptum (Larvae=86; Nymphs=6) and Ornithodoros sp. cf. O. mimon (Larvae=90) were also analyzed. DNA was extracted individually from blood samples and ticks. Molecular detection of Ehrlichia agents was performed targeting two different loci: 16S rRNA and dsb gen. The phylogenetic analyses showed that the Ehrlichia sp. detected in D. albiventris in this study is identical to Ehrlichia sp. strain Natal previously detected in two marsupials from Brazil. Furthermore, a new Ehrlichia strain was amplified from an A. ovale nymph (named as Ehrlichia sp. strain El Bagual) which is phylogenetically closely related to a strain of Ehrlichia sp. detected in Bradypus tridactylus in Brazil. The findings of the current study represent the first report of these two strains of Ehrlichia for Argentina, showing that the diversity of Ehrlichia spp. is greater than previously assumed. Further studies should determine the epidemiological relevance of these findings.

8.
Ticks Tick Borne Dis ; 12(6): 101810, 2021 11.
Article in English | MEDLINE | ID: mdl-34416568

ABSTRACT

To investigate the presence of Theileria equi in an endemic area of equine piroplasmosis 42 horses (Equus caballus) from Corrientes City, Argentina were sampled. Eighty-one percent (34 blood samples) of the analyzed horses were tested positive to the presence of piroplasmid 18S rDNA. All these samples could be identified as T. equi by amplifying the specific EMA-1 (merozoite antigen 1) gene of this species. Phylogenetic analysis of an obtained 18S rDNA complete sequence from one strain resulted in the identification of this sample as T. equi sensu stricto (genotype A). This study presents the first molecular detection and characterization of T. equi by the complete 18S rDNA sequence in Argentina. Based on these results further studies should be carried out to investigate the distribution and heterogeneity of presented genotypes of T. equi in Argentina, which is essential for the diagnosis, prevention and treatment of equine piroplasmosis.


Subject(s)
Horse Diseases/parasitology , Theileria/isolation & purification , Theileriasis/parasitology , Animals , Argentina , Horses , Phylogeny , RNA, Protozoan/analysis , RNA, Ribosomal, 18S/analysis , Theileria/classification
9.
Parasitol Res ; 120(2): 725-729, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33415399

ABSTRACT

In this work, we analyze data that support an epidemiological link between cases of canine monocytic ehrlichiosis (CME) by Ehrlichia canis and the presence of Rhipicephalus sanguineus sensu stricto as vector in an endemic area for this tick in Argentina. In a blood sample of a 1-year-old toy poodle with CME compatible clinical signs, which showed CME typical morulae in monocytes in Giemsa-stained blood smear, DNA of E. canis was detected by PCR. Further, DNA of E. canis was also detected in a female of R. sanguineus s.s. collected on the infected dog. Rhipicephalus sanguineus s.s. is the only member of the R. sanguineus group that prevails in the study area. The results of this study suggest that R. sanguineus s.s. may play a more important role in the transmission of E. canis than it was assumed so far. The epidemiological link between CME cases and R. sanguineus s.s. as vector in temperate areas of Argentina described in this work contrast previous studies which found that R. sanguineus sensu lato "tropical lineage" (which is absent in the study area) is competent to transmit E. canis but not R. sanguineus s.s.


Subject(s)
Arachnid Vectors/parasitology , Dog Diseases/parasitology , Ehrlichia canis/isolation & purification , Ehrlichiosis/veterinary , Rhipicephalus sanguineus/parasitology , Animals , Argentina , Dog Diseases/epidemiology , Dog Diseases/transmission , Dogs , Ehrlichiosis/epidemiology , Ehrlichiosis/parasitology , Ehrlichiosis/transmission , Female , Monocytes/parasitology
10.
Ticks Tick Borne Dis ; 11(6): 101546, 2020 11.
Article in English | MEDLINE | ID: mdl-32993952

ABSTRACT

The aim of this work was to evaluate the presence of Borrelia infection in Ixodes sp. cf. Ixodes affinis ticks from Argentina. Specimens of Ixodes sp. cf. I. affinis were collected on vegetation and birds in five locations belonging the most humid part of the Chaco Biogeographic Province. Specimens were tested for Borrelia infection by nested-PCR targeting the flaB gene and the rrfA-rrlB intergenic spacer region (IGS), sequenced and phylogenetically analyzed. A total of 48 Ixodes sp. cf. I. affinis (12 questing adults from vegetation and 20 nymphs and 16 larvae on nine bird species: Arremon flavirostris, Basileuterus culicivorus, Campylorhamphus trochilirostris, Myiothlypis leucoblephara, Tachyphonus rufus, Thlypopsis sordida, Turdus amaurochalinus, Turdus rufiventris and Troglodytes aedon) were collected. Twelve adults, 14 nymphs and 11 larvae (3 individually and 8 in 3 pools) were analyzed. Partial sequences were detected in 6 adults, 11 nymphs and 4 larvae (2 individual and 2 pools). Phylogenetically, the Borrelia found in Ixodes sp. cf. I. affinis belongs to the B. burgdorferi sensu lato (s. l.) complex. The partial sequences obtained from the borrelian gene flaB and IGS were associated to two groups formed by sequences previously detected in Ixodes fuscipes, Ixodes longiscutatus and Ixodes pararicinus from the Southern Cone of America in northern Argentina, southern Brazil and Uruguay. The results of this work suggest that the haplotypes of B. burgdorferi s. l. complex detected in the three species of the I. ricinus complex distributed in the Southern Cone of America are related and widely distributed.


Subject(s)
Borrelia/isolation & purification , Ixodes/microbiology , Animals , Argentina , Borrelia/classification , Borrelia/genetics , Female , Genes, Bacterial , Haplotypes , Ixodes/growth & development , Larva/growth & development , Larva/microbiology , Male , Nymph/growth & development , Nymph/microbiology , Passeriformes/parasitology , Phylogeny , Tick Infestations/parasitology , Tick Infestations/veterinary
12.
Trans R Soc Trop Med Hyg ; 114(10): 725-729, 2020 10 05.
Article in English | MEDLINE | ID: mdl-32722771

ABSTRACT

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. saltanensis for SLEV from Argentina compared with C. p. quinquefasciatus. METHODS: Female of the Culex species were orally infected by feeding on viraemic chicks that had been inoculated with SLEV. Abdomens, legs and saliva blood-fed mosquitoes were analysed by viral plaque assay. RESULTS: Mosquitoes were susceptible to orally acquired infection, dissemination and transmission of SLEV in the saliva. CONCLUSIONS: Our results demonstrate that C. saltanensis and C. interfor are susceptible to SLEV and competent for its transmission.


Subject(s)
Culex/virology , Encephalitis Virus, St. Louis , Encephalitis, St. Louis/transmission , Mosquito Vectors/virology , Animals , Argentina , Culicidae , Encephalitis, St. Louis/diagnosis , Encephalitis, St. Louis/virology , Female , Humans
13.
Acta Trop ; 210: 105588, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32553859

ABSTRACT

To obtain information about rickettsial bacteria in ticks of the genus Ixodes from Argentina and Uruguay, specimens of I. fuscipes (previously named as I. aragaoi), Ixodes pararicinus, Ixodes sp. cf. I. affinis, and Ixodes sp. were tested targeting the rickettsial gltA and ompA genes. Rickettsial bacteria was detected in all of these species. Rickettsia found in Ixodes sp. is closely related to Ca. Rickettsia mendelii, which was previously detected in I. ricinus of the Czech Republic and later in I. brunneus from the USA. Phylogenetic analyses of the Rickettsia strains found in I. fuscipes, I. pararicinus, and Ixodes sp. cf. I. affinis showed that these strains form a clade together with R. buchneri detected in I. scapularis from the USA, which is closely related to R. monacensis from Europe. Rickettsia buchneri, R. cooleyi and the Rickettsia detected in I. fuscipes, I. pararicinus, and Ixodes sp. cf. I. affinis clustered together in a clade well supported, which suggest that they are different strains of R. buchneri. The phylogenetic analysis shows that Ixodes ticks that are closely related in evolutionary terms (i.e. Ixodes species from the I. ricinus complex, I. brunneus-Ixodes sp.) share closely related rickettsial strains. The results of this study show that rickettsial bacteria are present in Ixodes ticks from Argentina and describe the first detection of Ca. R. mendelii in South America.


Subject(s)
Ixodes/microbiology , Rickettsia/isolation & purification , Animals , Female , Male , Phylogeny , Rickettsia/classification , Rickettsia/genetics , South America
14.
Food Environ Virol ; 11(2): 198-203, 2019 06.
Article in English | MEDLINE | ID: mdl-30895523

ABSTRACT

Environmental surveillance is an effective approach to investigate the circulation of human enteroviruses (EVs) in the population. EVs excreted by patients who present diverse clinical syndromes can remain infectious in the environment for several weeks, and limited data on circulating environmental EVs are available. A 6-year (2009-2014) surveillance study was conducted to detect non-polio enteroviruses (NPEVs) in the urban sewage of Cordoba city, Argentina. Echovirus 6 (E-6) was the most prevalent (28%), followed by E-14 (17%), E-16 (14%), Coxsackievirus (CV) A9 (11%), E-20 (9%), and CVA24 (6%). Other minority serotypes (E-7, E-13, E-21, E-25, and CVB4) were found, which together represented 14% of the total. In the absence of a systematic EV disease surveillance system, the detection and characterization of sewage-borne NPEVs will help us better understand the changes in EV disease trends and the epidemic background of circulating EVs, which could help interpret the EV trends and warn of future outbreaks in this area.


Subject(s)
Enterovirus Infections/virology , Enterovirus/isolation & purification , Argentina/epidemiology , Enterovirus/classification , Enterovirus/genetics , Enterovirus Infections/epidemiology , Environmental Monitoring , Humans , Phylogeny , Serogroup , Sewage/virology
15.
Am J Trop Med Hyg ; 100(5): 1230-1235, 2019 05.
Article in English | MEDLINE | ID: mdl-30887949

ABSTRACT

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 St. Louis encephalitis virus (SLEV). In this study, WNV and SLEV transmission experiments were performed to evaluate the vector competence of three South American tick species: Amblyomma ovale, Amblyomma tigrinum, and Amblyomma tonelliae. Larval and nymphal ticks of each species were allowed to feed on chicks needle inoculated with WNV or SLEV. All three Amblyomma species acquired either WNV or SLEV through larval feeding, with infection rates varying from 3.1% to 100% for WNV and from 0% to 35.7% for SLEV in engorged larvae. Transstadial perpetuation of the viruses was demonstrated in the molted nymphs, with WNV infection rates varying from 0% to 33.7% and SLEV infection rates from 13.6% to 23.8%. Although nymphal ticks also acquired either virus through feeding, transstadial perpetuation to adult ticks was lower, with virus detection in only 3.2% of A. tigrinum and 11.5% of A. tonelliae unfed adult ticks. On the other hand, vector competence for nymphs (exposed to WNV or SLEV through larval feeding) and adult ticks (exposed to WNV or SLEV through larval or nymphal feeding) was null in all cases. Although our results indicate transstadial perpetuation of WNV or SLEV in the three tick species, the ticks were not competent to transmit these agents to susceptible hosts. The role of these ixodid tick species in the epidemiology of WNV and SLEV might be insignificant, even though at least A. ovale and A. tigrinum are frequent bird ticks in Latin America, so the virus could survive winter in the fed larvae. However, future studies are required to determine the implications that this could have, as well as analyze the vector competence of other common bird tick species in South America.


Subject(s)
Birds/parasitology , Disease Vectors , Encephalitis, St. Louis/transmission , Ixodidae/physiology , Ixodidae/virology , West Nile Fever/transmission , Animals , Bird Diseases/virology , Encephalitis Virus, St. Louis , Larva/virology , Nymph/virology , South America , West Nile virus
16.
Ticks Tick Borne Dis ; 9(6): 1586-1589, 2018 09.
Article in English | MEDLINE | ID: mdl-30104124

ABSTRACT

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 molecular analysis through the presence of Borrelia DNA (by nested-PCR targeting the fla gene). A total of 381 ticks (357 larvae and 24 nymphs) belonging to four species (I. pararicinus, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris and Amblyomma sp.) were collected. Partial sequences of the fla gene of Borrelia (100% identical to Borrelia sp. haplotype I from Argentina) were detected in 9 of 70 tick pools (6 pools of larvae and 1 pool of nymphs of I. pararicinus, and in 2 pools of H. juxtakochi larvae) collected on Turdus rufiventris, Syndactila rufosuperciliata and Troglodytes aedon. The results of this study suggest that resident birds have reservoir capacity for Borrelia sp. haplotype I.


Subject(s)
Borrelia burgdorferi Group/isolation & purification , Ixodidae/microbiology , Passeriformes/parasitology , Animals , Argentina , Disease Reservoirs/microbiology , Disease Reservoirs/parasitology , Ixodidae/growth & development , Larva/growth & development , Larva/microbiology , Nymph/growth & development , Nymph/microbiology , Passeriformes/microbiology
17.
Am J Trop Med Hyg ; 99(1): 216-221, 2018 07.
Article in English | MEDLINE | ID: mdl-29761767

ABSTRACT

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 Sparrow were the three species with highest host competence index. At a city level, Eared Dove and Picui Ground Dove were the most important amplifying hosts during the 2005 SLEV human outbreak in Córdoba city. This finding highlighted important differences in the SLEV ecology between Argentina and the United States. Characterizing and evaluating the SLEV hosts contribute to our knowledge about its ecology and could help us to understand the causes that promote its emergence as a human pathogen in South America.


Subject(s)
Columbidae/virology , Disease Outbreaks , Encephalitis Virus, St. Louis/isolation & purification , Encephalitis, St. Louis/epidemiology , Sparrows/virology , Animals , Argentina/epidemiology , Disease Reservoirs/virology , Encephalitis, St. Louis/transmission , Encephalitis, St. Louis/virology , Humans , Viral Load
18.
Food Environ Virol ; 10(1): 121-126, 2018 03.
Article in English | MEDLINE | ID: mdl-28840537

ABSTRACT

Environmental surveillance is an effective approach to investigate the circulation of human enteroviruses in the population. Enteroviruses E14, CVA9, E-6, E16, E20, E25, E13, and CVA24 were detected in sewage and a watercourse in central Argentina. E14 was the most frequent serotype and was found for the first time in environmental samples in our region. Phylogenetic and coalescence analyses showed at least two recent introduction events.


Subject(s)
Enterovirus Infections/virology , Enterovirus/growth & development , Fresh Water/virology , Phylogeny , Serogroup , Sewage/virology , Argentina , Biological Evolution , Enterovirus/genetics , Environmental Monitoring , Humans
19.
Acta Trop ; 146: 53-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25792419

ABSTRACT

In Argentina the St. Louis Encephalitis virus (SLEV) is an endemic and widely distributed pathogen transmitted by the cosmopolitan mosquito Culex quinquefasciatus. During two outbreaks in Córdoba city, in 2005 and 2010, Culex interfor was also found infected, but its role as vector of SLEV is poorly known. This mosquito species is distributed from central Argentina to southern Brazil. The primary aim of this study was to analyze the population dynamic of Cx. interfor and Cx. quinquefasciatus in three different environments (urban, suburban and non-urban) in relation to remotely sensed environmental data for vegetation (NDVI and NDWI) and temperature (brightness temperature). Cx. quinquefasciatus and Cx. interfor were found at the three sampled sites, being both the most abundant Culex species, with peaks in early and midsummer. Temporal distribution patterns of both mosquito species were highly correlated in a non-urban area of high SLEV risk transmission. Cx. quinquefasciatus and Cx. interfor were associated with the most urbanized site and the non-urban environment, respectively; high significant correlations were detected between vegetation indices and abundance of both mosquito species confirming these associations. These data provide a foundation for building density maps of these two SLEV mosquito vectors using remotely sensed data to help inform vector control programs.


Subject(s)
Culex/virology , Encephalitis, St. Louis/epidemiology , Encephalitis, St. Louis/transmission , Environmental Monitoring/methods , Insect Vectors/virology , Remote Sensing Technology , Animals , Argentina , Encephalitis Virus, St. Louis , Environment , Population Dynamics , Rural Population , Suburban Population , Urban Population
20.
Ticks Tick Borne Dis ; 5(6): 715-21, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25108788

ABSTRACT

Ixodid ticks were collected from wild birds in five ecoregions in north-central Argentina, namely: Selva de las Yungas, Esteros del Iberá, Delta e Islas del Paraná, Selva Paranaense and Chaco Seco. A total of 2199 birds belonging to 139 species, 106 genera, 31 families and 11 orders were captured, but ticks were collected only from 121 birds (prevalence=5.5%) belonging to 39 species (28.1%) and three Orders: Tinamiformes (Tinamidae) and Falconiformes (Falconidae) in Selva de las Yungas and Passeriformes (Conopophagidae, Corvidae, Emberizidae, Furnariidae, Icteridae, Parulidae, Thamnophilidae, Thraupidae, Troglodytidae, Turdidae) for all ecoregions. The following tick species were found: Haemaphysalis juxtakochi, Haemaphysalis leporispalustris, Ixodes pararicinus plus Amblyomma sp. and Haemaphysalis sp. in Selva de las Yungas; Amblyomma triste and Ixodes auritulus in Delta e Islas del Paraná; Amblyomma dubitatum, A. triste and Amblyomma sp. in Esteros del Iberá; Amblyomma ovale and Amblyomma sp. in Selva Paranaense, and Amblyomma tigrinum in Chaco Seco. Amblyomma dubitatum was found for the first time on Passeriformes, while the records of A. ovale on avian hosts are the first for Argentina. Birds are also new hosts for I. pararicinus females. Besides 2 larvae and 1 nymph, and 1 larvae found on Tinamidae (Tinamiformes) and Falconidae (Falconiformes), respectively, all other ticks (691 larvae, 74 nymphs and 2 females) were found on Passeriformes with a relevant contribution of the family Turdidae. Birds are important hosts for I. pararicinus as shown by a prevalence of 45% while all others prevalence were below 15%. All the species of Amblyomma and Haemaphysalis found on birds in Argentina have been also detected on humans and are proven or potential vectors for human diseases. Therefore, their avian hosts are probable reservoirs of human pathogens in Argentina.


Subject(s)
Animals, Wild/parasitology , Birds/parasitology , Ixodidae/classification , Animals , Animals, Wild/classification , Argentina , Birds/classification , Female , Ixodidae/physiology , Male
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