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1.
Antibiotics (Basel) ; 10(6)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198805

RESUMO

Swine farming as a source of methicillin-resistant Staphylococcus aureus (MRSA) has been well documented. Methicillin-resistant coagulase-negative staphylococci (MRCoNS) have been less studied, but their importance as pathogens is increasing. MRCoNS are indeed considered relevant nosocomial pathogens; identifying putative sources of MRCoNS is thus gaining importance to prevent human health hazards. In the present study, we investigated MRSA and MRCoNS in animals and environment in five pigsties in a high farm-density area of northwestern Italy. Farms were three intensive, one intensive with antibiotic-free finishing, and one organic. We tested nasal swabs from 195 animals and 26 environmental samples from three production phases: post-weaning, finishing and female breeders. Phenotypic tests, including MALDI-TOF MS, were used for the identification of Staphylococcus species; PCR and nucleotide sequencing confirmed resistance and bacterial species. MRCoNS were recovered in 64.5% of nasal swabs, in all farms and animal categories, while MRSA was detected only in one post-weaning sample in one farm. The lowest prevalence of MRCoNS was detected in pigs from the organic farm and in the finishing of the antibiotic-free farm. MRCoNS were mainly Staphylococcus sciuri, but we also recovered S. pasteuri, S. haemolyticus, S. cohnii, S. equorum and S. xylosus. Fifteen environmental samples were positive for MRCoNS, which were mainly S. sciuri; no MRSA was found in the farms' environment. The analyses of the mecA gene and the PBP2-a protein highlighted the same mecA fragment in strains of S. aureus, S. sciuri and S. haemolyticus. Our results show the emergence of MRCoNS carrying the mecA gene in swine farms. Moreover, they suggest that this gene might be horizontally transferred from MRCoNS to bacterial species more relevant for human health, such as S. aureus.

2.
Emerg Infect Dis ; 27(7): 1919-1922, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33974535

RESUMO

We conducted a serologic survey among dogs and cats in Italy to detect antibodies against severe acute respiratory syndrome virus 2 (SARS-CoV-2). We found that SARS-CoV-2 seroprevalence was higher among cats (16.2%) than dogs (2.3%). In addition, seroprevalence was higher among animals living in close contact with SARS-CoV-2-positive owners.


Assuntos
COVID-19 , Doenças do Gato , Doenças do Cão , Animais , Gatos , Estudos Transversais , Doenças do Cão/epidemiologia , Cães , Humanos , Itália/epidemiologia , Animais de Estimação , SARS-CoV-2 , Estudos Soroepidemiológicos
3.
J Equine Vet Sci ; 92: 103180, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32797802

RESUMO

The objective of this study was to report recovery time, retirement rate, racing performance, and presence of compensation pattern after musculoskeletal injuries (MSIs) in Standardbred racehorses (STBRs). This is a retrospective single open-cohort study, enrolling 356 STBRs in training in a single racetrack. Musculoskeletal injury was defined as any training-related injury after which the horse did not train for at least 15 days. The first and second MSIs encountered during the horse's racing career were considered. Medical records, training logbooks, and racing data were reviewed to determine recovery time, retirement rate, racing performance, and compensation pattern after MSIs. Kaplan-Meier estimators considered the return to activity as primary endpoint. The hazard ratio (HR) for return to activity was determined using Cox proportional hazard models, after classifying horses based on the injury type. A total of 543 MSIs were considered. The 33.6% (95% confidence limits [CL]: 29.5, 37.8) of STBRs suffering from MSI had to be retired as consequence of that. The median recovery time after MSI was 119 days (95% CL: 47, 179). Horses with traumatic osteoarthritis had a greater likelihood of returning to athletic activity compared with horses with stress fractures (HR = 4.8, 95% CL: 3.5, 6.7) and tendon/ligament strains (HR = 4.1, 95% CL: 3.1, 5.4). Increased racing speed was recorded after injuries. The second MSI was more often localized to the contralateral limb compared with the first injury (odds ratio (OR) 6.35, 95% CL: 4.29, 8.51), diagonal (OR 4.59, 95% CL: 3.05, 6.27) and to the same limb (OR 3.17, 95% CL: 2.03, 4.47) than to the ipsilateral limb.


Assuntos
Doenças dos Cavalos , Animais , Estudos de Coortes , Cavalos , Itália/epidemiologia , Prognóstico , Estudos Retrospectivos
4.
Animals (Basel) ; 10(3)2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32131557

RESUMO

The analysis of antimicrobial use (AMU) data in livestock allows for the identification of risk factors for AMU, thereby favoring the application of responsible AMU policies on-farm. Herewith, AMU in 36 finishing pig farms in northern Italy from 2015-2017 was expressed as defined daily doses for Italian pigs (DDDita) per population correction unit (DDDita/100kg). A retrospective analysis was then conducted to determine the effects of several husbandry practices on AMU. Overall, AMU ranged between 12 DDDita/100kg in 2015 and 8 DDDita/100kg in 2017, showing no significant trends, due to the large variability in AMU between farms. However, a 66% AMU reduction was observed in 19 farms during 2015-2017. Farm size, number of farm workers, air quality, average pig mortality, and presence of undocked pigs on the farm had no significant effects on AMU. Rather, welfare-friendly farms had 38% lower AMU levels (p < 0.05). In conclusion, animal welfare management seems to be relatively more important than farm structure and other managerial characteristics as drivers of AMU in finishing pig farms.

5.
Food Microbiol ; 89: 103433, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32138991

RESUMO

Listeriosis is a foodborne illness characterized by a relatively low morbidity, but a large disease burden due to the severity of clinical manifestations and the high case fatality rate. Increased listeriosis notifications have been observed in Europe since the 2000s. However, the reasons for this increase are largely unknown, with the sources of sporadic human listerioris often remaining elusive. Here we inferred the relative contributions of several putative sources of Listeria monocytogenes strains from listerioris patients in Northern Italy (Piedmont and Lombardy regions), using two established source attribution models (i.e. 'Dutch' and 'STRUCTURE') in comparative fashion. We compared the Multi-Locus Sequence Typing and Multi-Virulence-Locus Sequence Typing profiles of strains collected from beef, dairy, fish, game, mixed foods, mixed meat, pork, and poultry. Overall, 634 L. monocytogenes isolates were collected from 2005 to 2016. In total, 40 clonal complexes and 51 virulence types were identified, with 36% of the isolates belonging to possible epidemic clones (i.e. genetically related strains from unrelated outbreaks). Source attribution analysis showed that 50% of human listerioris cases (95% Confidence Interval 44-55%) could be attributed to dairy products, followed by poultry and pork (15% each), and mixed foods (15%). Since the contamination of dairy, poultry and pork products are closely linked to primary production, expanding actions currently limited to ready-to-eat products to the reservoir level may help reducing the risk of cross-contamination at the consumer level.


Assuntos
Laticínios/microbiologia , Contaminação de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Listeria monocytogenes/isolamento & purificação , Carne/microbiologia , Alimentos Marinhos/microbiologia , Animais , Bovinos , Galinhas , Surtos de Doenças , Itália , Tipagem de Sequências Multilocus , Suínos
6.
Eur Respir J ; 54(5)2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31439682

RESUMO

Information on the clinical traits associated with bronchial neutrophilia in asthma is scant, preventing its recognition and adequate treatment. We aimed to assess the clinical, functional and biological features of neutrophilic asthma and identify possible predictors of bronchial neutrophilia.The inflammatory phenotype of 70 mild-to-severe asthma patients was studied cross-sectionally based on the eosinophilic/neutrophilic counts in their bronchial lamina propria. Patients were classified as neutrophilic or non-neutrophilic. Neutrophilic asthma patients (neutrophil count cut-off: 47.17 neutrophils·mm-2; range: 47.17-198.11 neutrophils·mm-2; median: 94.34 neutrophils·mm-2) were further classified as high (≥94.34 neutrophils·mm-2) or intermediate (47.17- <94.34 neutrophils·mm-2). The effect of smoking ≥10 pack-years was also assessed.Neutrophilic asthma patients (n=38; 36 mixed eosinophilic/neutrophilic) had greater disease severity, functional residual capacity, inhaled corticosteroid (ICS) dose and exacerbations, and lower forced vital capacity (FVC) % pred and forced expiratory volume in 1 s (FEV1) reversibility than non-neutrophilic asthma patients (n=32; 28 eosinophilic and four paucigranulocytic). Neutrophilic asthma patients had similar eosinophil counts, increased bronchial CD8+, interleukin (IL)-17-F+ and IL-22+ cells, and decreased mast cells compared with non-neutrophilic asthma patients. FEV1 and FVC reversibility were independent predictors of bronchial neutrophilia in our cohort. High neutrophilic patients (n=21) had increased serum IgE levels, sensitivity to perennial allergens, exacerbation rate, oral corticosteroid dependence, and CD4+ and IL-17F+ cells in their bronchial mucosa. Excluding smokers revealed increased IL-17A+ and IL-22+ cells in highly neutrophilic patients.We provide new evidence linking the presence of high bronchial neutrophilia in asthma to an adaptive immune response associated with allergy (IgE) and IL-17/22 cytokine expression. High bronchial neutrophilia may discriminate a new endotype of asthma. Further research is warranted on the relationship between bronchoreversibility and bronchial neutrophilia.


Assuntos
Corticosteroides/administração & dosagem , Asma/sangue , Asma/tratamento farmacológico , Imunoglobulina E/sangue , Interleucina-17/imunologia , Interleucinas/imunologia , Neutrófilos , Administração Oral , Adulto , Asma/imunologia , Asma/metabolismo , Estudos Transversais , Feminino , Humanos , Interleucina-17/biossíntese , Interleucinas/biossíntese , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade
7.
Ticks Tick Borne Dis ; 10(4): 862-867, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31014939

RESUMO

Ticks and ear biopsies were collected from wild small rodents in 2011 and 2012 in the northern Apennines (Italy), up to 1650 m above sea level. Apodemus spp. (n = 83) and Myodes glareolus (n = 22) were infested by Ixodes ricinus (192 larvae and two nymphs), Dermacentor marginatus (179 larvae and 29 nymphs), and Ixodes trianguliceps (three larvae and two nymphs). We detected several Borrelia burgdorferi sensu lato (s.l.) genospecies (B. afzelii, B. burgdorferi sensu stricto, B. garinii, B. lusitaniae, B. valaisiana) in I. ricinus and skin biopsies. The most common genospecies found in I. ricinus was B. valaisiana, while it was B. lusitaniae in tissues. Spotted fever group (SFG) rickettsiae (Rickettsia monacensis, R. slovaca and R. raoultii) infected I. ricinus, D. marginatus and rodent tissues. Rickettsia slovaca was the Rickettsia species most frequently found in our samples. Coinfections by B. burgdorferi s.l. and SFG rickettsiae indicate an overlap of transmission cycles and potential risk for humans to be infected by multiple pathogens, resulting in more severe symptoms. The findings of B. lusitaniae and R. slovaca in bank voles, and of B. valaisiana in small rodents, open new questions about host-pathogen interactions. In addition, our results highlight the importance of small rodents as data sources for studying tick-borne pathogens.


Assuntos
Reservatórios de Doenças/microbiologia , Doença de Lyme/epidemiologia , Roedores/parasitologia , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Carrapatos/microbiologia , Altitude , Animais , Biópsia , Borrelia burgdorferi/isolamento & purificação , Grupo Borrelia Burgdorferi , Dermacentor/microbiologia , Feminino , Itália/epidemiologia , Ixodes/microbiologia , Larva/microbiologia , Masculino , Ninfa/microbiologia , Rickettsia/isolamento & purificação , Pele/parasitologia , Pele/patologia
8.
Vet Sci ; 6(1)2019 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-30884896

RESUMO

We estimated the probability of exposure of people to questing ticks, infected with bacterial agents of the tick-borne zoonoses-in Aosta Valley, western Alps, Italy. We collected ticks by dragging, and from collectors' clothes in three hiking trails, which were divided into an internal path, with short vegetation, and an external part with taller grass. Dragging yielded 285 Ixodes ricinus nymphs and 31 adults, and two Dermacentor marginatus adults. Eleven I. ricinus nymphs and 9 adults were collected from collectors' clothes. Borrelia burgdorferi s.l. was identified by PCR in 12 out of 30 I. ricinus nymphs (prevalence = 40.0%, 95% confidence interval = 22.5, 57.5). The prevalence of infection by Rickettsia spp. was 13.3% (95% CI = 1.2, 25.5). The probability of encountering at least one questing I. ricinus infected by each bacterial agent (probability of exposure, E) in 100 m² was obtained by combining the number of collected nymphs, the prevalence of infection by each bacterial agent, the frequency of passage by visitors, and the probability of tick attachment to people. The mean number of nymphs collected by dragging was greatest in the internal part of hiking trails (mean = 7.9). Conversely, E was greater in the external part (up to 0.14 for B. burgdorferi s.l., and 0.07 for Rickettsia spp.), due to a greater probability of tick attachment to people in relatively tall vegetation.

9.
Vet Sci ; 6(1)2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30717204

RESUMO

The objective of the present study was the identification of farming practices in the production of turkeys for human consumption, and their ranking in terms of the occupational probability of exposure to antimicrobial resistant (AMR) bacteria, for farm workers. We gathered evidence and data from scientific literature, on risk factors for AMR in farmers, and on the prevalence of those hazards across farming phases. We administered semi-structured interviews to public and private veterinarians in Northern Italy, to obtain detailed information on turkey farming phases, and on working practices. Data were then integrated into a semi-quantitative Failure Modes and Effect Analysis (FMEA). Those working practices, which are characterized by direct contact with numerous animals, and which are carried out frequently, with rare use of personal protection devices resulted as associated with the greatest probability of exposure to AMR. For methicillin resistant Staphylococcus aureus (MRSA), these included vaccination and administration of any individual therapy, and removal and milling of litter, given the exposure of farmers to high dust level. Indeed, levels of occupational exposure to MRSA are enhanced by its transmission routes, which include direct contact with animal, as well as airborne transmission. Level of exposure to extended spectrum beta lactamase (ESBL) is more strictly associated with direct contact and the oral-fecal route. Consequently, exposure to ESBL resulted and associated with the routinely tipping over of poults turned on their back, and with the individual administration of therapies.

10.
Exp Appl Acarol ; 75(2): 209-225, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29713917

RESUMO

Understanding and responding to the ecological, social and economic conditions that facilitate disease emergence and transmission represents a substantial challenge for epidemiologists and health professionals. In this article we integrate knowledge about the human and the vector population, to provide a context from which to examine the underlying causal factors of D. marginatus-borne diseases emergence in the study area. Within this framework we analyse the biotic and abiotic factors that drive D. marginatus population dynamics and the role of its typical host for dispersal. These investigations suggest that D. marginatus is a tick species prone to spatially overlap its presence with human population presence. Then we consider the public health implications for the residents, when simply carrying out trivial outdoor activities may increase the risk to contact an infected tick.


Assuntos
Distribuição Animal , Dermacentor/fisiologia , Interações Hospedeiro-Parasita , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Sus scrofa/parasitologia , Picadas de Carrapatos/epidemiologia , Animais , Ecossistema , França/epidemiologia , Incidência , Itália/epidemiologia , Risco , Picadas de Carrapatos/parasitologia
11.
Theor Popul Biol ; 116: 27-32, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28690096

RESUMO

Spirochetes belonging to the Borrelia burgdoferi sensu lato (sl) group cause Lyme Borreliosis (LB), which is the most commonly reported vector-borne zoonosis in Europe. B. burgdorferi sl is maintained in nature in a complex cycle involving Ixodes ricinus ticks and several species of vertebrate hosts. The transmission dynamics of B. burgdorferi sl is complicated by the varying competence of animals for different genospecies of spirochetes that, in turn, vary in their capability of causing disease. In this study, a set of difference equations simplifying the complex interaction between vectors and their hosts (competent and not for Borrelia) is built to gain insights into conditions underlying the dominance of B. lusitaniae (transmitted by lizards to susceptible ticks) and the maintenance of B. afzelii (transmitted by wild rodents) observed in a study area in Tuscany, Italy. Findings, in agreement with field observations, highlight the existence of a threshold for the fraction of larvae feeding on rodents below which the persistence of B. afzelii is not possible. Furthermore, thresholds change as nonlinear functions of the expected number of nymph bites on mice, and the transmission and recovery probabilities. In conclusion, our model provided an insight into mechanisms underlying the relative frequency of different Borrelia genospecies, as observed in field studies.


Assuntos
Grupo Borrelia Burgdorferi , Borrelia , Comportamento Alimentar , Larva/microbiologia , Doença de Lyme/transmissão , Animais , Europa (Continente) , Lagartos , Camundongos , Modelos Biológicos , Dinâmica Populacional
12.
Exp Appl Acarol ; 69(2): 167-78, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26964552

RESUMO

Host-seeking ticks were collected in the Northern Apennines, Italy, by dragging at 35 sites, at altitudes ranging from 680 and 1670 m above sea level (asl), from April to November, in 2010 and 2011. Ixodes ricinus (4431 larvae, 597 nymphs and 12 adults) and Haemaphysalis punctata (11,209 larvae, 313 nymphs, and 25 adults) were the most abundant species, followed by Haemaphysalis sulcata (20 larvae, five nymphs, and 13 adults), Dermacentor marginatus (42 larvae and two adults) and Ixodes hexagonus (one nymph). Greatest numbers of ticks were collected at locations characterised by southern exposure and limestone substratum, at altitudes <1400 m asl; I. ricinus was most abundant in Turkey oak (Quercus cerris) wood, whereas H. punctata was mostly collected in hop hornbeam (Ostrya carpinifolia) wood and on exposed rocks. Ixodes ricinus was also found up to 1670 m asl, in high stand beech (Fagus sylvatica) wood. The overall prevalence of Borrelia burgdorferi sensu lato (sl) in 294 host-seeking I. ricinus nymphs was 8.5 %. Borrelia garinii was the most frequently identified genospecies (64.0 % of positive nymphs), followed by B. valaisiana, B. burgdorferi sensu stricto, B. afzelii, and B. lusitaniae. Based upon the comparison with the results of previous studies at the same location, these research findings suggest the recent invasion of the study area by the tick vector and the agents of Lyme borreliosis.


Assuntos
Grupo Borrelia Burgdorferi/isolamento & purificação , Ecossistema , Ixodes/microbiologia , Ixodes/fisiologia , Altitude , Distribuição Animal , Animais , Grupo Borrelia Burgdorferi/classificação , Feminino , Itália , Ixodes/crescimento & desenvolvimento , Ixodidae/crescimento & desenvolvimento , Ixodidae/microbiologia , Ixodidae/fisiologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/fisiologia , Densidade Demográfica , Análise de Sequência de DNA
13.
Ticks Tick Borne Dis ; 5(6): 970-4, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25139531

RESUMO

Immature ticks (Ixodes ricinus and Dermacentor marginatus) were collected from small rodents (Apodemus spp. and Myodes glareolus), in the Northern Apennines, Italy, at an altitude up to 1650 m above sea level (a.s.l.), from 2009 through 2012. While D. marginatus had been found at the same location in studies carried out in 1994, I. ricinus was very rare or absent. Prevalence (95% confidence interval) of infestation by I. ricinus larvae on Apodemus spp. was 54.4% (47.5, 61.2), and it was greater than prevalence of D. marginatus larvae on the same hosts (23.3%, 17.8, 29.5). The mean (standard deviation) numbers of I. ricinus and D. marginatus larvae per individual Apodemus spp. were similar: 2.3 (4.1) and 2.1 (9.8), respectively. The monthly infestation pattern of the two tick species on Apodemus spp. were different. I. ricinus larvae were more frequent in June and September, than in July-August. I. ricinus nymphs were generally rare, and were most frequently found in July. The prevalence of D. marginatus larvae peaked in July-August, whereas nymphs were mostly active in August-September. Increasing population densities of roe deer (Capreolus capreolus), and increasing temperatures, in the last decades, in the Apennine area might have contributed to the observed range expansion of I. ricinus.


Assuntos
Dermacentor/fisiologia , Ixodes/fisiologia , Doenças dos Roedores/epidemiologia , Infestações por Carrapato/veterinária , Animais , Arvicolinae , Feminino , Itália/epidemiologia , Masculino , Murinae , Estações do Ano , Infestações por Carrapato/epidemiologia
14.
Exp Appl Acarol ; 64(1): 121-35, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24682615

RESUMO

Questing ticks were collected during monthly dragging sessions (March-August 2011) in three provinces of the Liguria region, north-western Italy, to evaluate the species occurrence, spatial distribution and relative abundance. A total of 1,464 specimens were collected in 94 dragging sites. Ixodes ricinus was the most abundant species (81.3 % of collected ticks), followed by Haemaphysalis punctata (10.9 %), Dermacentor marginatus (5.5 %), Ixodes frontalis (1.3 %), and Rhipicephalus spp. (0.9 %). Ixodes frontalis is reported for the first time in Liguria. An aggregation of I. ricinus positive sites was observed in inland areas characterized by dense forests dominated by deciduous trees (Castanetum and Fagetum phytoclimatic zones), especially in the west of the region where the differences in the Normalized Difference Vegetation Index (NDVI) were higher between inland and coastal sites. Random-effect logistic regression was used to model the associations of NDVI and season with the probability of finding host-seeking I. ricinus nymphs [corrected]. The NDVI was a good predictor of I. ricinus nymphs abundance, and confirmed its utility in discriminating habitat suitability for this vector in north-western coastal Italy, where dry habitat conditions may limit the distribution of this species.


Assuntos
Ecossistema , Ixodidae/classificação , Animais , Biodiversidade , Itália , Densidade Demográfica
15.
Ticks Tick Borne Dis ; 4(6): 518-21, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24120274

RESUMO

Immature Dermacentor marginatus ticks and tissues from small rodents were tested for infection with Rickettsia slovaca in the northern Apennines, Lucca Province, where tick-borne lymphadenopathy (TIBOLA) was previously reported in people. Prevalence of infestation with D. marginatus was 30.5% (n=131, 95% CI: 22.8-39.2%) in Apodemus spp. and 26.5% (n=34, 95% CI: 12.9-44.4%) in Myodes glareolus, which were captured during 1980 trap nights in 2009 and 2010. Rickettsia slovaca was identified by polymerase chain reaction, targeting the gltA and OmpA genes, in ear biopsies from 8 out of 37 tested Apodemus (22%, 95% CI: 9.8-38.2%), but not from 9 M. glareolus. The prevalence of R. slovaca in D. marginatus feeding on Apodemus spp. was 53% in larvae (n=51, 95% CI: 38.5-67.1%) and 47.5% in nymphs (n=59, 95% CI: 34.3-60.9%). No larvae (0.0%, 95% CI: 0-36.9%), but one nymph removed from M. glareolus was positive (10%, 95% CI: 0.3-44.5%). Prevalence of R. slovaca in host-seeking D. marginatus larvae, collected in the same area, was 42% (n=38; 95% CI: 26.3-59.2%). Prevalence of R. slovaca was greater in larvae feeding on PCR-positive Apodemus than in those feeding on negative mice (78.6% vs. 37.1%). Furthermore, levels of infestation with D. marginatus larvae were greater for R. slovaca-positive mice. The infection of Apodemus spp. was probably the result of repeated bites by transovarially infected larvae. On the other hand, the finding of R. slovaca in mice tissues would be compatible with transmission from these hosts to feeding D. marginatus. Based on such a hypothesis, the most heavily infested Apodemus might play a role as amplifiers of the infection.


Assuntos
Dermacentor/microbiologia , Murinae/microbiologia , Infecções por Rickettsia/epidemiologia , Rickettsia/isolamento & purificação , Doenças dos Roedores/transmissão , Infestações por Carrapato/veterinária , Animais , Arvicolinae/microbiologia , Arvicolinae/parasitologia , Sequência de Bases , DNA Bacteriano/isolamento & purificação , Feminino , Itália/epidemiologia , Larva , Masculino , Dados de Sequência Molecular , Murinae/parasitologia , Ninfa , Reação em Cadeia da Polimerase/veterinária , Prevalência , Rickettsia/genética , Infecções por Rickettsia/microbiologia , Infecções por Rickettsia/transmissão , Doenças dos Roedores/microbiologia , Doenças dos Roedores/parasitologia , Roedores , Análise de Sequência de DNA/veterinária , Infestações por Carrapato/epidemiologia
16.
FEMS Microbiol Rev ; 36(4): 837-61, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22091928

RESUMO

The analysis of different multi-host systems suggests that even hosts that are not capable of transmitting Borrelia burgdorferi sensu lato (s.l.) to the tick vector, Ixodes ricinus, or that are secondary reservoirs for these agents contribute to the intensity of transmission and to the overall risk of Lyme borreliosis, through the process of vector augmentation and pathogen amplification. On the other hand, above certain threshold densities, or in the presence of competition with primary reservoir hosts or low attachment rate of ticks to reservoir hosts, incompetent or less competent hosts may reduce transmission through dilution. The transmission of B. burgdorferi s.l. is affected by molecular processes at the tick-host interface including mechanisms for the protection of spirochaetes against the host's immune response. Molecular biology also increasingly provides important identification tools for the study of tick-borne disease agents. Ixodes ricinus and B. burgdorferi s.l. are expanding their geographical range to northern latitudes and to higher altitudes through the effects of climate change on host populations and on tick development, survival and seasonal activity. The integration of quantitative ecology with molecular methodology is central to a better understanding of the factors that determine the main components of Lyme borreliosis eco-epidemiology and should result in more accurate predictions of the effects of climate change on the circulation of pathogens in nature.


Assuntos
Borrelia burgdorferi/fisiologia , Doença de Lyme/microbiologia , Doença de Lyme/transmissão , Animais , Vetores Aracnídeos/microbiologia , Borrelia burgdorferi/genética , Borrelia burgdorferi/isolamento & purificação , Mudança Climática , Europa (Continente)/epidemiologia , Especificidade de Hospedeiro , Humanos , Ixodes/microbiologia , Doença de Lyme/epidemiologia
17.
Vector Borne Zoonotic Dis ; 11(1): 21-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20482342

RESUMO

To estimate the basic reproduction number (R(0)) of Borrelia lusitaniae and Borrelia afzelii, we formulated a mathematical model considering the interactions among the tick vector, vertebrate hosts, and pathogens in a 500-ha enclosed natural reserve on Le Cerbaie hills, Tuscany, central Italy. In the study area, Ixodes ricinus were abundant and were found infected by B. lusitaniae and B. afzelii. Lizards (Podarcis spp.) and mice (Apodemus spp.), respectively, are the reservoir hosts of these two Borrelia burgdorferi sensu lato (s.l.) genospecies and compete for immature ticks. B. lusitaniae R(0) estimation is in agreement with field observations, indicating the maintenance and diffusion of this genospecies in the study area, where lizards are abundant and highly infested by I. ricinus immature stages. In fact, B. lusitaniae shows a focal distribution in areas where the tick vector and the vertebrate reservoir coexist. Mouse population dynamics and their relatively low suitability as hosts for nymphs seem to determine, on the other hand, a less efficient transmission of B. afzelii, whose R(0) differs between scenarios in the study area. Considering host population dynamics, the proposed model suggests that, given a certain combination of the two host population sizes, both spirochete genospecies can coexist in our study area. Additional incompetent hosts for B. burgdorferi s.l. have a negative effect on B. afzelii maintenance, whose R(0) results > 1 only with high mouse population densities and/or low lizards abundance, but they do not seem to influence B. lusitaniae transmission cycle on Le Cerbaie. Secondly, our model confirms the importance of nymphs' infestation, of host population density and diversity, and spirochetes host association for the maintenance of the transmission cycle of B. burgdorferi s.l.


Assuntos
Grupo Borrelia Burgdorferi/fisiologia , Ixodes/microbiologia , Lagartos/microbiologia , Doença de Lyme/transmissão , Murinae/microbiologia , Infestações por Carrapato/veterinária , Animais , Vetores Aracnídeos/microbiologia , Reservatórios de Doenças/veterinária , Interações Hospedeiro-Parasita , Itália/epidemiologia , Larva/microbiologia , Lagartos/parasitologia , Doença de Lyme/epidemiologia , Doença de Lyme/veterinária , Modelos Biológicos , Murinae/parasitologia , Reação em Cadeia da Polimerase/veterinária , Dinâmica Populacional , Reprodução , Infestações por Carrapato/epidemiologia
18.
PLoS One ; 5(11): e13796, 2010 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-21103064

RESUMO

BACKGROUND: Vector-borne diseases for which transmission occurs exclusively between vectors and hosts can be modeled as spreading on a bipartite network. METHODOLOGY/PRINCIPAL FINDINGS: In such models the spreading of the disease strongly depends on the degree distribution of the two classes of nodes. It is sufficient for one of the classes to have a scale-free degree distribution with a slow enough decay for the network to have asymptotically vanishing epidemic threshold. Data on the distribution of Ixodes ricinus ticks on mice and lizards from two independent studies are well described by a scale-free distribution compatible with an asymptotically vanishing epidemic threshold. The commonly used negative binomial, instead, cannot describe the right tail of the empirical distribution. CONCLUSIONS/SIGNIFICANCE: The extreme aggregation of vectors on hosts, described by the power-law decay of the degree distribution, makes the epidemic threshold decrease with the size of the network and vanish asymptotically.


Assuntos
Algoritmos , Vetores Aracnídeos , Doenças Transmissíveis/transmissão , Modelos Biológicos , Animais , Simulação por Computador , Interações Hospedeiro-Parasita , Ixodes/fisiologia , Lagartos , Camundongos , Murinae , Infestações por Carrapato/parasitologia
19.
Prev Vet Med ; 95(3-4): 267-74, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20451272

RESUMO

Exposure to the risk of neighbourhood infection was estimated for the H7N1 Highly Pathogenic Avian Influenza (HPAI) epidemic that affected Northern Italy between 1999 and 2000. The two most affected regions (Lombardy and Veneto) were analyzed and the epidemic was divided into three phases. Q statistics were used to evaluate exposure to the risk of neighbourhood infection using two measures. First, a local Q statistic (Qikt) assessed daily exposure for each farm as a function of the number of neighbouring infected farms that were in their infectious period, weighted by the distance between farms. This allowed us to identify the daily time course of risk for each farm and, at any given time, local groups of farms defined by high risk. Second, for each farm a summary statistic of exposure risk within each phase (Qiph) was obtained by summing Qikt over the duration of each phase. This allowed identification of farms defined by persistent, high exposure risk within each phase of the epidemic. Statistical significance was evaluated using conditional Monte Carlo simulation, and significant values of Qiph were mapped to assess the variation of the risk of neighbourhood infection through the phases. Qikt was larger for farms in Lombardy and the reduction of exposed farms was more marked for Veneto. Although the highest value of Qiph was observed in Veneto, in each phase most of the significant values were in Lombardy. In the last phase of the epidemic, a large reduction in the number of farms significantly exposed to the risk of neighbourhood infection was observed in the Veneto region, along with generally low values of Qiph. This may be explained by differences in control measures in the two regions, including pre-emptive slaughtering of farms considered at high risk of infection. The Q statistic allowed us to quantify geographic, time-dynamic variations in exposure to neighbourhood infection, and to generate hypotheses on the efficacy of control measures.


Assuntos
Vírus da Influenza A , Influenza Aviária/epidemiologia , Influenza Aviária/transmissão , Medição de Risco , Animais , Surtos de Doenças/veterinária , Influenza Aviária/prevenção & controle , Itália/epidemiologia , Método de Monte Carlo , Aves Domésticas , Fatores de Risco , Conglomerados Espaço-Temporais
20.
J Immunoassay Immunochem ; 29(3): 244-56, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18569373

RESUMO

In this study, a recombinant chimeric antigen (CA) ELISA was validated as a single test for both human and dog leishmaniasis. Serum panels included 327 human and 339 canine IFAT-positive and 1113 human and 1078 canine IFAT-negative samples. CA-ELISA was carried out using the same serum dilution, and labelled protein A as secondary reagent. Test performances were calculated using ROC analysis. For the human panel, the test showed diagnostic accuracy (DA) 0.974, specificity (Sp) 97.12%, sensitivity (Se) 91.44%, and concordance (K) 0.88. The dog panel showed DA 0.998, Sp 99.54%, Se 98.54%, and K 0.98. The proposed method is the best recombinant antigen-based ELISA, and can be used as IFAT substitute for mass screening.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Doenças do Cão/diagnóstico , Ensaio de Imunoadsorção Enzimática/métodos , Leishmania/imunologia , Leishmaniose/diagnóstico , Leishmaniose/veterinária , Animais , Doenças do Cão/imunologia , Cães , Humanos , Leishmaniose/imunologia , Proteínas Recombinantes de Fusão/imunologia , Sensibilidade e Especificidade
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