Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 108
Filtrar
1.
Int J Infect Dis ; 102: 144-151, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33129964

RESUMO

BACKGROUND: Nipah virus (NiV) infection, often fatal in humans, is primarily transmitted in Bangladesh through the consumption of date palm sap contaminated by Pteropus bats. Person-to-person transmission is also common and increases the concern of large outbreaks. This study aimed to characterize the molecular epidemiology, phylogenetic relationship, and the evolution of the nucleocapsid gene (N gene) of NiV. METHODS: We conducted molecular detection, genetic characterization, and Bayesian time-scale evolution analyses of NiV using pooled Pteropid bat roost urine samples from an outbreak area in 2012 and archived RNA samples from NiV case patients identified during 2012-2018 in Bangladesh. RESULTS: NiV-RNA was detected in 19% (38/456) of bat roost urine samples and among them; nine N gene sequences were recovered. We also retrieved sequences from 53% (21 out of 39) of archived RNA samples from patients. Phylogenetic analysis revealed that all Bangladeshi strains belonged to NiV-BD genotype and had an evolutionary rate of 4.64 × 10-4 substitutions/site/year. The analyses suggested that the strains of NiV-BD genotype diverged during 1995 and formed two sublineages. CONCLUSION: This analysis provides further evidence that the NiV strains of the Malaysian and Bangladesh genotypes diverged recently and continue to evolve. More extensive surveillance of NiV in bats and human will be helpful to explore strain diversity and virulence potential to infect humans through direct or person-to-person virus transmission.


Assuntos
Variação Genética , Infecções por Henipavirus/virologia , Vírus Nipah/genética , Adolescente , Adulto , Animais , Bangladesh/epidemiologia , Teorema de Bayes , Criança , Surtos de Doenças , Feminino , Infecções por Henipavirus/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Adulto Jovem
2.
Transbound Emerg Dis ; 64(4): 1329-1333, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27062143

RESUMO

As in most low-income countries, adequate laboratory facilities are not available in Bangladesh to assist veterinarians in diagnosing animal diseases. We aimed to determine the efficiency of veterinary diagnoses for two common ruminant diseases in Bangladesh: Peste des petits ruminants (PPR) and foot-and-mouth disease (FMD). We conducted the study from May 2009 to August 2010 in three government veterinary hospitals where veterinarians collected samples from sick livestock and recorded the presumptive diagnosis on the basis of clinical presentations. Samples were tested for PPR and FMD using real-time RT-PCR. We estimated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the presumptive diagnoses when compared to laboratory tests. We tested 539 goats for PPR and 340 cattle and goats for FMD. Our results indicate that the veterinarians' presumptive diagnoses were different from laboratory findings for both PPR (P < 0.05) and FMD (P < 0.05). The overall sensitivity of the presumptive clinical diagnoses was 54% (95% CI: 47-61%) while specificity was 81% (95% CI: 78-84%) compared to real-time RT-PCR tests. The kappa value obtained in our validation process for PPR (kappa: 0.25) and FMD (kappa 0.36) indicated a poor performance of the presumptive diagnoses. Most of the animals (93%) were treated with antibiotics. Our findings indicate that veterinarians can detect animals not infected with FMD or PPR but miss the true cases. The clinical competency of these veterinarians needs to be improved and access to laboratory diagnostic facilities could help veterinarians to improve the diagnostics and outcomes. The rational use of antibiotics by veterinarians in animals must be ensured.


Assuntos
Antivirais/administração & dosagem , Doenças dos Bovinos/diagnóstico , Febre Aftosa/diagnóstico , Doenças das Cabras/diagnóstico , Peste dos Pequenos Ruminantes/diagnóstico , Reação em Cadeia da Polimerase/veterinária , Animais , Bangladesh , Bovinos , Vírus da Febre Aftosa/isolamento & purificação , Cabras , Hospitais Veterinários , Vírus da Peste dos Pequenos Ruminantes/isolamento & purificação , Valor Preditivo dos Testes , Sensibilidade e Especificidade
3.
Transbound Emerg Dis ; 64(4): 1287-1293, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27125493

RESUMO

Bats are an important reservoir for emerging zoonotic pathogens. Close human-bat interactions, including the sharing of living spaces and hunting and butchering of bats for food and medicines, may lead to spillover of zoonotic disease into human populations. We used bat exposure and environmental data gathered from 207 Bangladeshi villages to characterize bat exposures and hunting in Bangladesh. Eleven percent of households reported having a bat roost near their homes, 65% reported seeing bats flying over their households at dusk, and 31% reported seeing bats inside their compounds or courtyard areas. Twenty percent of households reported that members had at least daily exposure to bats. Bat hunting occurred in 49% of the villages surveyed and was more likely to occur in households that reported nearby bat roosts (adjusted prevalence ratio [aPR] 2.3, 95% CI 1.1-4.9) and villages located in north-west (aPR 7.5, 95% CI 2.5-23.0) and south-west (aPR 6.8, 95% CI 2.1-21.6) regions. Our results suggest high exposure to bats and widespread hunting throughout Bangladesh. This has implications for both zoonotic disease spillover and bat conservation.


Assuntos
Quirópteros/fisiologia , Conservação dos Recursos Naturais , População Rural , Zoonoses/transmissão , Animais , Bangladesh , Humanos
4.
Rev Sci Tech ; 36(2): 499-512, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30152468

RESUMO

Emerging diseases are frequently caused by novel or previously unrecognised zoonotic viral pathogens, which tend to originate in and emerge from wildlife. When human or animal cases are first recognised, molecular or serological diagnostic assays specific to them do not yet exist, causing a delay in the identification of an outbreak's aetiologic agent as well as its source. Preparing for the next virus to emerge is a major public health challenge, impeded by a poor understanding of the diversity of potential candidates that exist in wildlife reservoirs. Characterising the diversity of viruses in key wildlife species will help to reduce the time between detection and response in an outbreak situation, and inform public health strategies that reduce the risk of spillover from animal reservoirs. Pathogen discovery techniques such as consensus polymerase chain reaction (cPCR) and next-generation sequencing (NGS) have been used to identify known and novel viruses in animals and humans, but have not been widely used in surveillance programmes. Metagenomic studies have identified novel viruses, new strains of known viruses, and have characterised host microbiomes. While NGS represents an unbiased approach to viral sequence detection, it is constrained by lower sensitivity than conventional PCR, requires substantial bioinformatics capabilities, and is cost prohibitive and therefore not widely available in the regions of the world that are most vulnerable to zoonotic disease emergence. In contrast, consensus PCR uses standard and widely available technologies, has greater sensitivity than NGS, and has also been used to identify novel viruses in wildlife, livestock and humans, though it is limited to detecting target genetic sequences conserved across known groups of viruses. The use of cPCR, in combination, if possible, with NGS and serology, can offer a powerful approach to rapidly identifying aetiologic agents in an outbreak and characterising the virome of key wildlife known to carry zoonotic viruses. Here, the authors review pathogen discovery techniques currently being used in human and animal surveillance programmes and the challenges of using viral discovery to identify novel zoonotic pathogens.


Les maladies émergentes sont souvent causées par des virus nouveaux ou précédemment inconnus, de portée zoonotique, qui ont généralement leur source dans la faune sauvage, à partir de laquelle s'effectue leur émergence. Lorsque le premier cas d'infection par un virus de ce type est détecté chez l'homme ou chez les animaux, il n'existe encore aucune épreuve moléculaire ou sérologique de détection de l'agent étiologique, ce qui retarde son identification ainsi que l'élucidation de la source du foyer. La préparation aux futures émergences virales est un véritable défi de santé publique et se voit entravée par les lacunes des connaissances sur la diversité des virus potentiellement candidats. La caractérisation des différents virus qui affectent les principales espèces sauvages permettra de réduire le délai entre le moment où un nouveau foyer est détecté et celui où une réponse lui est apportée, et d'élaborer en connaissance de cause des stratégies de santé publique visant à limiter le risque d'un franchissement d'espèce à partir des réservoirs animaux. Les techniques de découverte d'agents pathogènes, par exemple l'amplification en chaîne par polymérase (PCR) pan-générique ou consensus et le séquençage de nouvelle génération (SNG) sont utilisées pour identifier des virus connus ou nouveaux chez l'homme et l'animal, mais ne sont pas d'une utilisation courante dans les programmes de surveillance. Les études métagénomiques permettent d'identifier des virus nouveaux ainsi que les souches nouvelles de virus connus et servent également à caractériser le microbiome de l'hôte. Le SNG constitue une méthode de détection des séquences virales exempte de biais mais sa sensibilité moindre que celle des PCR classiques, les capacités bio-informatiques considérables qu'il requiert et son coût prohibitif sont des contraintes importantes qui en limitent l'utilisation dans les régions du monde les plus vulnérables à l'émergence des maladies zoonotiques. En revanche, la PCR consensus fait appel à des technologies normalisées et largement disponibles, tout en présentant une meilleure sensibilité que le SNG ; elle permet également d'identifier des virus nouveaux présents dans la faune sauvage, chez les animaux domestiques ou chez l'homme, bien qu'elle ne détecte que des séquences génétiques cibles conservées d'un groupe connu de virus à l'autre. Le recours à la PCR consensus, si possible associé aux techniques de SNG et à la sérologie se révèle une stratégie puissante qui permet d'identifier rapidement les agents responsables d'un foyer et de caractériser le virome d'espèces sauvages jouant un rôle majeur en tant que réservoirs de virus zoonotiques. Après avoir passé en revue les techniques de découverte d'agents pathogènes actuellement utilisées dans les programmes de surveillance des maladies animales et humaines, les auteurs font le point sur les enjeux de ces techniques pour l'identification de nouveaux agents pathogènes zoonotiques.


La causa de las enfermedades emergentes reside muchas veces en virus zoonóticos de aparición reciente o hasta entonces no descritos, que en general se originan y surgen en animales salvajes. Cuando se detectan los primeros casos en personas o animales aún no existen pruebas específicas de diagnóstico, ya sea molecular o serológico, y ello retrasa la identificación del agente etiológico del brote y la determinación de su origen. Prepararse para el próximo virus que vaya a aparecer es un gran objetivo de salud pública, lastrado en la práctica por el escaso conocimiento de la gran diversidad de posibles candidatos que moran en los reservorios de la fauna salvaje. La caracterización de los diversos virus que existen en las principales especies de animales salvajes ayudará a reducir el lapso que media entre la detección y la respuesta en caso de brote y a fundamentar a partir de ahí estrategias de salud pública que reduzcan el riesgo de diseminación desde los reservorios animales. Hasta ahora las técnicas de descubrimiento de patógenos, como la reacción en cadena de la polimerasa (PCR) de consenso (PCRc) o la secuenciación de próxima generación, han servido para identificar virus nuevos o ya conocidos en personas y animales, pero no se han aplicado de forma generalizada a los programas de vigilancia. Gracias a estudios de metagenómica se han podido detectar virus recién aparecidos o nuevas cepas de virus ya conocidos y caracterizar los microbiomas de los organismos anfitriones. Aunque la secuenciación de próxima generación constituye un método exento de sesgos para detectar secuencias víricas, adolece de una menor sensibilidad que la PCR convencional, exige una considerable capacidad de gestión informática de datos biológicos y tiene un costo prohibitivo, por lo que no suele aplicarse en las regiones del mundo que están más expuestas a la aparición de enfermedades zoonóticas. La PCR de consenso, en cambio, reposa en técnicas habituales y muy extendidas, ofrece mayor sensibilidad que la secuenciación de próxima generación y también ha sido utilizada para identificar virus nuevos en personas o animales salvajes y domésticos, si bien solo permite detectar las secuencias genéticas «diana¼ conservadas de entre todos los grupos conocidos de virus. El uso de la PCRc, combinado con la secuenciación de próxima generación y técnicas serológicas cuando sea posible, puede ofrecer un potente método para identificar con rapidez los agentes etiológicos de un brote y caracterizar el viroma de los principales animales salvajes de los que se sabe que son portadores de virus zoonóticos. Los autores pasan revista a las técnicas de descubrimiento de patógenos que se utilizan actualmente en los programas de vigilancia sanitaria y zoosanitaria y exponen las dificultades que presenta el uso del descubrimiento de virus para identificar nuevos patógenos zoonóticos.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Pandemias , Viroses/veterinária , Vírus/isolamento & purificação , Zoonoses/virologia , Animais , Humanos , Internacionalidade , Vigilância da População , Fatores de Risco , Viroses/diagnóstico , Viroses/epidemiologia , Viroses/virologia
5.
Transbound Emerg Dis ; 61(3): 193-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24650238

RESUMO

The genus pestivirus of the family flaviviridae consists of four recognized species: bovine viral diarrhoea virus 1 (BVDV-1), bovine viral diarrhoea virus 2 (BVDV-2), classical swine fever virus and border disease virus. A new putative pestivirus species tentatively named as either 'HoBi-like pestivirus' or BVDV-3 has recently been identified in Brazil, Italy and Thailand. Despite reports of serological evidence of BVDV in Bangladesh, the types of the virus circulating in cattle have not been identified. We conducted surveillance in cattle from May 2009 to August 2010 in three government veterinary hospitals to characterize BVDV in cattle of Bangladesh. We tested serum for BVDV using an antigen-capture ELISA. Of 638 cattle samples, 3% (16/638) tested positive for BVDV antigen. The ELISA-positive samples were selected for further molecular detection and characterization of BVDV. Molecular analysis of the partial 5' untranslated region (UTR) nucleotide sequences of BVDV-positive samples identified the rare HoBi-like pestivirus or BVDV-3 virus circulating in cattle of Bangladesh. The identification of this rare HoBi-like pestivirus or BVDV-3 strain in Bangladesh warrants further surveillance to evaluate its impact on livestock production.


Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Vírus da Diarreia Viral Bovina Tipo 1/classificação , Monitoramento Epidemiológico/veterinária , Animais , Bangladesh/epidemiologia , Sequência de Bases , Bovinos , Vírus da Diarreia Viral Bovina Tipo 1/genética , Vírus da Diarreia Viral Bovina Tipo 1/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/veterinária , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie , Suínos
6.
J Gen Virol ; 94(Pt 5): 1028-1038, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23364191

RESUMO

Bats are reservoirs for a wide range of human pathogens including Nipah, Hendra, rabies, Ebola, Marburg and severe acute respiratory syndrome coronavirus (CoV). The recent implication of a novel beta (ß)-CoV as the cause of fatal respiratory disease in the Middle East emphasizes the importance of surveillance for CoVs that have potential to move from bats into the human population. In a screen of 606 bats from 42 different species in Campeche, Chiapas and Mexico City we identified 13 distinct CoVs. Nine were alpha (α)-CoVs; four were ß-CoVs. Twelve were novel. Analyses of these viruses in the context of their hosts and ecological habitat indicated that host species is a strong selective driver in CoV evolution, even in allopatric populations separated by significant geographical distance; and that a single species/genus of bat can contain multiple CoVs. A ß-CoV with 96.5 % amino acid identity to the ß-CoV associated with human disease in the Middle East was found in a Nyctinomops laticaudatus bat, suggesting that efforts to identify the viral reservoir should include surveillance of the bat families Molossidae/Vespertilionidae, or the closely related Nycteridae/Emballonuridae. While it is important to investigate unknown viral diversity in bats, it is also important to remember that the majority of viruses they carry will not pose any clinical risk, and bats should not be stigmatized ubiquitously as significant threats to public health.


Assuntos
Quirópteros/virologia , Infecções por Coronavirus/veterinária , Coronavirus/isolamento & purificação , Variação Genética , Animais , Sequência de Bases , Coronavirus/classificação , Coronavirus/genética , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , DNA Complementar/química , DNA Complementar/genética , Reservatórios de Doenças , Ecossistema , Humanos , México/epidemiologia , Dados de Sequência Molecular , Filogenia , Saúde Pública , RNA Viral/genética , Análise de Sequência de DNA , Zoonoses
7.
Epidemiol Infect ; 139(10): 1570-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21524339

RESUMO

This study aimed to describe the transmission dynamics, the serological and virus excretion patterns of Nipah virus (NiV) in Pteropus vampyrus bats. Bats in captivity were sampled every 7-21 days over a 1-year period. The data revealed five NiV serological patterns categorized as high and low positives, waning, decreasing and increasing, and negative in these individuals. The findings strongly suggest that NiV circulates in wild bat populations and that antibody could be maintained for long periods. The study also found that pup and juvenile bats from seropositive dams tested seropositive, indicating that maternal antibodies against NiV are transmitted passively, and in this study population may last up to 14 months. NiV was isolated from the urine of one bat, and within a few weeks, two other seronegative bats seroconverted. Based on the temporal cluster of seroconversion, we strongly believe that the NiV isolated was recrudesced and then transmitted horizontally between bats during the study period.


Assuntos
Anticorpos Antivirais/sangue , Quirópteros/virologia , Infecções por Henipavirus/veterinária , Vírus Nipah/isolamento & purificação , Animais , Feminino , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/virologia , Imunidade Materno-Adquirida , Masculino , Vírus Nipah/imunologia , Recidiva
8.
Open Vet J ; 1(1): 10-2, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-26623273

RESUMO

A six years eight months pregnant lioness at the Dulahajara Safari Park, Chakoria, Cox's Bazar, Bangladesh, was presented with dystocia. This paper described the pre-, intra- and postoperative procedures including anesthetic protocol carried out and performing a caesarean section to remove dead fetuses and the successful recovery of the lioness without complications.

9.
Open Vet J ; 1(1): 13-20, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-26623274

RESUMO

Hematology and serum chemistry values were obtained from 28 male and 22 female stray dogs in Chittagong Metropolitan area, Bangladesh. The goal of the study was to establish reference value for hematology and serum chemistry for these semi wild animals in relation to age, sex, reproductive stage and body condition. No significant differences were found for mean values of hemoglobin, packed cell volume, mean corpuscular hemoglobin concentration, white blood cell, differential leukocyte count, total protein, albumin, glucose, cholesterol, phosphorus and potassium among or between sexes, ages, reproductive states or body conditions. Significant differences were noted for erythrocyte sedimentation rate (p<0.02) between sexes. Among different age groups significant differences were found for total red blood cell count (p<0.001). Different body conditions have significant differences in red blood cell count, mean corpuscular volume and mean corpuscular hemoglobin (p<0.001). Pregnant and non-pregnant females differed significantly in their red blood cell count, mean corpuscular volume and mean corpuscular hemoglobin (p<0.001).

10.
Epidemiol Infect ; 138(11): 1630-6, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20380769

RESUMO

In February 2007 an outbreak of Nipah virus (NiV) encephalitis in Thakurgaon District of northwest Bangladesh affected seven people, three of whom died. All subsequent cases developed illness 7-14 days after close physical contact with the index case while he was ill. Cases were more likely than controls to have been in the same room (100% vs. 9.5%, OR undefined, P<0.001) and to have touched him (83% vs. 0%, OR undefined, P<0.001). Although the source of infection for the index case was not identified, 50% of Pteropus bats sampled from near the outbreak area 1 month after the outbreak had antibodies to NiV confirming the presence of the virus in the area. The outbreak was spread by person-to-person transmission. Risk of NiV infection in family caregivers highlights the need for infection control practices to limit transmission of potentially infectious body secretions.


Assuntos
Surtos de Doenças , Infecções por Henipavirus/epidemiologia , Vírus Nipah , Adulto , Animais , Bangladesh/epidemiologia , Estudos de Casos e Controles , Quirópteros/virologia , Evolução Fatal , Feminino , Infecções por Henipavirus/transmissão , Humanos , Masculino , Fatores de Risco , Adulto Jovem
11.
Curr Top Microbiol Immunol ; 315: 463-75, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17848075

RESUMO

Emerging infectious diseases are a key threat to public health and the majority are caused by zoonotic pathogens. Here we discuss new collaborative approaches to understanding the process of zoonotic disease emergence that link veterinary medicine, public health, and ecological approaches: conservation medicine and one health. We demonstrate how studies on the underlying drivers of disease emergence (bushmeat hunting, wildlife trade, and deforestation) can provide ways to model, predict, and ultimately prevent zoonotic disease emergence and spread.


Assuntos
Doenças dos Animais/transmissão , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/veterinária , Pesquisa/organização & administração , Zoonoses , Doenças dos Animais/epidemiologia , Animais , Animais Selvagens , Comércio , Doenças Transmissíveis Emergentes/epidemiologia , Cooperação Internacional , Dinâmica Populacional , Projetos de Pesquisa , Medição de Risco , Vigilância de Evento Sentinela/veterinária , Especificidade da Espécie
12.
J Dermatol ; 27(6): 361-9, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10920581

RESUMO

OBJECTIVE: To characterize photosensitivity in HIV-infected individuals using minimal erythema dosage (MED) UVA (ultraviolet A light) and UVB (ultraviolet B light) photoprovocation light testing. DESIGN: Prospective, controlled analytical study. SETTING: University of California, San Francisco, between March 1995 and January 1997. PATIENTS: 13 HIV-seropositive patients with clinical and pathological features consistent with photodermatitis, 13 HIV-seropositive patients with biopsy-proven eosinophilic foliculitis (EF), and 10 HIV-seropositive patients with CD4 (T helper cell) count below 200 cells/uL and no history of photosensitivity or EF. INTERVENTION: Each patient underwent MED testing for UVB. All 13 patients with suspected photodermatitis underwent full photochallenge testing with UVA and UVB for up to 10 consecutive week days. RESULTS: Mean MED to UVB in patients with clinical photosensitivity and EF was lower (p = 0.004 and p = 0.022 respectively) than that of patients without a clinical history of photodermatitis. There were no significant differences in mean CD4 count or Fitzpatrick skin type. Positive photochallenge tests (papular changes at site of provocative light testing) to UVB (9 of 13 patients) were much more common than reactions to UVA (3 of 13 patients) in the photodermatitis group. All patients with clinically active photodermatitis developed papular changes at the site of UVB photochallenge testing, but only 1 of 5 patients with photodermatitis in remission developed papular changes with UVB photochallenge testing. Seven of the 13 patients with photodermatitis had Native American ancestry. Photosensitive patients were commonly taking trimethoprim-sulfamethoxazole (TMP-SMX), but no more commonly than EF or control patients. CONCLUSIONS: Photosensitivity in HIV-infected individuals appears to be a manifestation of advanced disease. Most patients are sensitive to UVB. The most severely affected individuals are both UVB and UVA sensitive, and may show reactions to visible light. A significant Native American ancestry may be a risk factor for development of photodermatitis in patients with advanced HIV disease. Finally, patients with eosinophilic folliculitis may be subclinically photosensitive.


Assuntos
Dermatite Fotoalérgica/diagnóstico , Dermatite Fotoalérgica/etiologia , Infecções por HIV/complicações , Raios Ultravioleta/efeitos adversos , Adulto , Dermatite Fotoalérgica/epidemiologia , Feminino , Infecções por HIV/diagnóstico , Soropositividade para HIV , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Valores de Referência , Fatores de Risco , Índice de Gravidade de Doença , Testes Cutâneos/métodos
13.
Emerg Infect Dis ; 6(3): 259-64, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10827115

RESUMO

Two human deaths caused by Australian bat lyssavirus (ABL) infection have been reported since 1996. Information was obtained from 205 persons (mostly adults from south Brisbane and the South Coast of Queensland), who reported potential ABL exposure to the Brisbane Southside Public Health Unit from November 1,1996, to January 31, 1999. Volunteer animal handlers accounted for 39% of potential exposures, their family members for 12%, professional animal handlers for 14%, community members who intentionally handled bats for 31%, and community members with contacts initiated by bats for 4%. The prevalence of Lyssavirus detected by fluorescent antibody test in 366 sick, injured, or orphaned bats from the area was 6%. Sequelae of exposure, including the requirement for expensive postexposure prophylaxis, may be reduced by educating bat handlers and the public of the risks involved in handling Australian bats.


Assuntos
Técnicos em Manejo de Animais , Quirópteros/virologia , Lyssavirus/isolamento & purificação , Exposição Ocupacional , Infecções por Rhabdoviridae/epidemiologia , Infecções por Rhabdoviridae/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Notificação de Doenças , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Queensland/epidemiologia , Fatores de Risco , Inquéritos e Questionários
14.
Semin Cutan Med Surg ; 18(4): 274-84, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10604793

RESUMO

Photosensitivity may be phototoxic or photoallergic. Phototoxicity is much more common. There are 2 types of phototoxicity: photodynamic, which requires oxygen, and nonphotodynamic, which does not. Reactions induced by porphyrin molecules, coal tar derivatives, and many drugs are photodynamic. The reaction induced by psoralens, for the most part, is nonphotodynamic. Acute phototoxic reactions are characterized by erythema and edema followed by hyperpigmentation. Long-term ultraviolet phototoxicity results in chronic sun damage and skin cancer formation. Also, certain chemicals such as psoralen molecules and coal tar are photocarcinogenic. Phototoxic reactions to certain drugs produce unusual clinical patterns, that is lichenoid eruptions, dyschromia, photo-onycholysis, and pseudoporphyria. Photoallergy is an uncommon acquired altered reactivity dependent on an immediate antibody or a delayed cell mediated reaction. Solar urticaria is an example of the former, whereas photoallergy to exogenous chemicals is an example of the latter. Photoallergy to systemic drugs does occur but is difficult to characterize. The action spectrum for photoreactions to exogenous agents usually at least includes the ultraviolet A rays for both phototoxicity and photoallergy.


Assuntos
Dermatite Fotoalérgica/diagnóstico , Dermatite Fotoalérgica/fisiopatologia , Dermatite Fototóxica/diagnóstico , Dermatite Fototóxica/fisiopatologia , Diagnóstico Diferencial , Humanos , Fármacos Fotossensibilizantes/efeitos adversos
17.
Photodermatol Photoimmunol Photomed ; 13(4): 117-28, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9453079

RESUMO

Ultraviolet light (UVR) induces a myriad of cutaneous changes, including delayed disruption of the permeability barrier with higher doses. To investigate the basis for the UVB-induced barrier alteration, we assessed the epidermal lamellar body secretory system at various time points before and after barrier disruption with a single high dose of UVB (7.5 MED) to murine epidermis. Morphological data were correlated with changes in epidermal proliferation and lipid synthesis, indicative of lamellar body generation. Twenty-four hours following UVB, the stratum corneum (SC) is normal, but a layer of abnormal, vacuolated, and lamellar body (LB)-deficient cells is present, immediately beneath the stratum granulosum (SG)/SC interface. Immediately subjacent to this band of damaged cells, normal keratinocytes that contain intact LBs are present. By 72 h, concomitant with the appearance of a barrier abnormality, extensively damaged cells persist at the SC/SG interface, and abnormal lamellar membrane structures appear in the lower SC. Upper stratum spinosum (SS) and lower SG cells appear normal, with increased numbers of LBs. A barrier abnormality is still present at 96 h, in association with membrane abnormalities in the lower SC interstices, but up to four normal appearing, subjacent SG cell layers are present. By 120 h, accelerated LB formation and precocious LB extrusion occur throughout the thickened SG; normal lamellar membranes are present in the lower SC; and barrier recovery is almost complete. Whereas, epidermal synthesis of the major barrier lipid species (i.e., cholesterol, fatty acids, and ceramides, including acylceramides) is reduced or unchanged at 24 and 48 h, it increases significantly 72 h after exposure to UVB. Therefore, the delayed disruption of the permeability barrier following acute UVB exposure results from the arrival of a band of lamellar body-incompetent (i.e., damaged) cells at the SG/SC interface. The subsequent, rapid recovery of the barrier, in turn, results from compensatory hyperplasia of subjacent, undamaged SS/SG cells, generating increased numbers and contents of LB. These results underscore the critical role of the stratum compactum in mediating barrier function, and suggest that beneficial therapeutic effects of UV exposure may be due to enhanced lipid production and barrier regeneration.


Assuntos
Pele/efeitos da radiação , Raios Ultravioleta , Perda Insensível de Água/efeitos da radiação , Aciltransferases/metabolismo , Aciltransferases/efeitos da radiação , Animais , Contagem de Células , Divisão Celular/efeitos da radiação , Ceramidas/biossíntese , Ceramidas/efeitos da radiação , Colesterol/biossíntese , Colesterol/efeitos da radiação , Epiderme/química , Epiderme/efeitos da radiação , Epiderme/ultraestrutura , Ácidos Graxos/biossíntese , Ácidos Graxos/efeitos da radiação , Seguimentos , Hiperplasia , Queratinócitos/química , Queratinócitos/efeitos da radiação , Queratinócitos/ultraestrutura , Lipídeos/biossíntese , Lipídeos/efeitos da radiação , Camundongos , Camundongos Pelados , Organelas/química , Organelas/metabolismo , Organelas/efeitos da radiação , Organelas/ultraestrutura , Permeabilidade/efeitos da radiação , Regeneração , Serina C-Palmitoiltransferase , Pele/química , Pele/ultraestrutura , Esfingolipídeos/biossíntese , Esfingolipídeos/efeitos da radiação , Vacúolos/química , Vacúolos/efeitos da radiação , Vacúolos/ultraestrutura
19.
J Invest Dermatol ; 108(5): 769-75, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9129231

RESUMO

UV irradiation induces a variety of cutaneous responses, including disruption of epidermal permeability barrier function, the basis for which is not known. Herein, we investigated the separate roles of hyperproliferation and inflammation in the pathogenesis of UVB-induced barrier disruption. Adult hairless mice were exposed to increasing doses of UVB (1.5-7.5 MED), and transepidermal water loss (TEWL) was monitored daily for up to 7 d. The extent of TEWL increase was dependent on the UVB dose, but with all doses, the increase began after > or =48 h and peaked at 96 h, decreasing by 120 h. Epidermal [(3)H]thymidine incorporation increased at 24 h and peaked at 48 h (570%), preceding the maximal increase in TEWL. Cyclosporin A, methotrexate, 5-fluorouracil, or arabinosylcytosine significantly diminished the UVB-induced TEWL increase. Athymic nude mice also displayed a markedly diminished response to UVB, and DNA synthesis did not increased at 48 h. Transplantation of athymic mice with T-cell-enriched mixed immune cells significantly restored sensitivity to both the UVB-induced hyperproliferation and the barrier defect. Finally, although UVB exposure increased PGE2 levels in whole skin samples (2- to 3-fold within 1-3 h; p < 0.005), this increase was completely blocked by topical indomethacin, and neither topical indomethacin nor topical glucocorticoids blocked development of the barrier abnormality. These results show that (i) UVB produces delayed alteration in barrier function and (ii) both an epidermal proliferative response and thymocyte-mediated events (but not PGE2 production and nonspecific inflammation) appear to contribute to UVB-induced abrogation of the permeability barrier.


Assuntos
Permeabilidade da Membrana Celular/fisiologia , Permeabilidade da Membrana Celular/efeitos da radiação , Raios Ultravioleta , Corticosteroides/fisiologia , Animais , Divisão Celular , DNA/biossíntese , Dinoprostona/biossíntese , Relação Dose-Resposta à Radiação , Hiperplasia , Masculino , Camundongos , Camundongos Pelados , Camundongos Endogâmicos BALB C , Camundongos Nus , Pele/patologia , Pele/efeitos da radiação , Timo/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA