RESUMO
BACKGROUND: Bovine herpesvirus 5 (BoHV-5) is an alphaherpesvirus responsible for meningoencephalitis in young cattle and it is antigenically and genetically related to bovine herpesvirus 1. BoHV-5 outbreaks are sporadic and restricted in their geographical distribution, being mostly detected in the Southern hemisphere. The N569 and A663 strains are prototypes of the "a" and "b" subtypes of BoHV-5, however, scarce information about their in vitro and in vivo properties is currently available. METHODS: For the in vitro comparison between BoHV-5 A663 and N569 strains, viral growth kinetics, lysis and infection plaque size assays were performed. Additionally, an experimental infection of cattle with BoHV-5 A663 and N569 strains was carried out. Viral excretion, development of neurological signs, presence of specific antibodies in serum and nasal swabs and presence of latent BoHV-5 DNA in trigeminal ganglion, were analyzed. Histopathological examination of samples belonging to inoculated animals was also performed. RESULTS: The lytic capacity and the cell-to-cell spread was lower for the A663 strain compared to the N569 strain, however, the production of total infectious viral particles was similar between both strains. Concerning the in vivo properties, the A663 and N569 strains are able to induce similar degrees of pathogenicity in cattle. CONCLUSIONS: Our results show that the A663 strain used in this study is less adapted to in vitro replication in MDBK cells than the N569 strain and, although slight differences were observed, both strains are able to induce a similar degree of virulence in the natural host.
Assuntos
Doenças dos Bovinos/virologia , Encefalite Viral/veterinária , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 5/fisiologia , Meningoencefalite/veterinária , Animais , Bovinos , Doenças dos Bovinos/fisiopatologia , Doenças dos Bovinos/transmissão , Linhagem Celular , Encefalite Viral/fisiopatologia , Encefalite Viral/transmissão , Encefalite Viral/virologia , Infecções por Herpesviridae/fisiopatologia , Infecções por Herpesviridae/transmissão , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 5/classificação , Herpesvirus Bovino 5/patogenicidade , Meningoencefalite/fisiopatologia , Meningoencefalite/transmissão , Meningoencefalite/virologia , VirulênciaRESUMO
BACKGROUND: Dengue, one of the most important arboviral diseases of humans, may cause severe systemic disease. Although dengue virus (DENV) has been considered to be a non-neurotropic virus, dengue infection has been associated recently with a series of neurological syndromes, including encephalitis. In this work, we evaluated behavioral changes and inflammatory parameters in C57BL/6 mice infected with non-adapted dengue virus 3 (DENV-3) genotype I. METHODS: C57BL/6 mice received 4×10(3) PFU of DENV-3 by an intracranial route. We evaluated the trafficking of leukocytes in brain microvasculature using intravital microscopy, and evaluated chemokine and cytokine profiling by an ELISA test at 3 and 6 days post infection (p.i.). Furthermore, we determined myeloperoxidase activity and immune cell populations, and also performed histopathological analysis and immunostaining for the virus in brain tissue. RESULTS: All animals developed signs of encephalitis and died by day 8 p.i. Motor behavior and muscle tone and strength parameters declined at day 7 p.i. We observed increased leukocyte rolling and adhesion in brain microvasculature of infected mice at days 3 and 6 p.i. The infection was followed by significant increases in IFN-γ, TNF-α, CCL2, CCL5, CXCL1, and CXCL2. Histological analysis showed evidence of meningoencephalitis and reactive gliosis. Increased numbers of neutrophils, CD4+ and CD8+ T cells were detected in brain of infected animals, notably at day 6 p.i. Cells immunoreactive for anti-NS-3 were visualized throughout the brain. CONCLUSION: Intracerebral infection with non-adapted DENV-3 induces encephalitis and behavioral changes that precede lethality in mice.
Assuntos
Comportamento Animal/fisiologia , Vírus da Dengue/patogenicidade , Dengue/mortalidade , Dengue/fisiopatologia , Meningoencefalite/mortalidade , Meningoencefalite/fisiopatologia , Meningoencefalite/virologia , Animais , Dengue/patologia , Dengue/virologia , Vírus da Dengue/genética , Humanos , Masculino , Meningoencefalite/patologia , Camundongos , Camundongos Endogâmicos C57BL , Taxa de SobrevidaRESUMO
INTRODUCTION: To compare the effectiveness and safety of short term 6 month-treatment and long term 12 month-treatment schedules for meningoencephalitis due to tuberculosis in two hospitals from Lima-Peru. METHODS: Comparative, retrospective and observational study. The patients were divided in two groups: Group 1: long term 12 month-treatment with isoniazid, rifampin, pyrazinamide, and ethambutol for the first 2 months; then isoniazid and rifampin for 10 months. Group 2: short term 6 month-treatment with isoniazid and rifampin, pyrazinamide and ethambutol for the first 2 months; then isoniazid and rifampin for 4 months. Clinical records, effectiveness, treatment failure, treatment side effects, mortality and late consequences after treatment were reviewed. RESULTS: Twenty-six patients with meningoencephalitis level I were included, 10 received the long term schedule and 16 the short term schedule treatment. From 51 patients with meningoencephalitis level II, 27 received the long term schedule and 24 the short term schedule treatment and of 31 patients with meningoencephalitis level III, 18 received the long term schedule treatment and 13 the short term schedule treatment. There was no statistically significant differences among levels I, II and III when effectiveness of short and long term schedule was evaluated. Moreover, there was no statistically significant difference in the frequency of treatment failure, treatment side effects, mortality and late consequences among groups. CONCLUSIONS: Long term 12 month-treatment and short term 6 month-treatment had similar effectiveness and safety in the treatment of meningoenchephalitis due to tuberculosis in HIV negative patients.
Assuntos
Antituberculosos/uso terapêutico , Esquema de Medicação , Hospitais , Meningoencefalite/tratamento farmacológico , Meningoencefalite/microbiologia , Tuberculose Meníngea/tratamento farmacológico , Adolescente , Adulto , Idoso , Antituberculosos/administração & dosagem , Antituberculosos/efeitos adversos , Quimioterapia Combinada , Etambutol/administração & dosagem , Etambutol/efeitos adversos , Etambutol/uso terapêutico , Feminino , Humanos , Isoniazida/administração & dosagem , Isoniazida/efeitos adversos , Isoniazida/uso terapêutico , Masculino , Meningoencefalite/mortalidade , Meningoencefalite/fisiopatologia , Pessoa de Meia-Idade , Peru , Pirazinamida/administração & dosagem , Pirazinamida/efeitos adversos , Pirazinamida/uso terapêutico , Estudos Retrospectivos , Rifampina/administração & dosagem , Rifampina/efeitos adversos , Rifampina/uso terapêutico , Resultado do Tratamento , Tuberculose Meníngea/mortalidade , Tuberculose Meníngea/fisiopatologia , Adulto JovemRESUMO
We herein report an investigation of nitric oxide (NO) levels, a candidate molecule for neuronal toxicity and dysfunction, in the brain of rabbits during experimental neurological infection by bovine herpesvirus 5 (BoHV-5). Spectrophotometry for NO products (NO(2) and NO(3)) revealed that NO levels were significantly increased (F(4, 40) = 3.33; P <.02) in several regions of the brain of rabbits with neurological disease, correlating with moderate to high BoHV-5 titers. Immunohistochemistry of brain regions revealed a group of cells with neuronal and astrocyte morphology expressing the enzyme inducible NO synthase (iNOS) close to virus antigen-positive neurons. In addition, the investigation of nitric oxide levels between 2 and 6 days post infection (d.p.i.) revealed an initial increase in NO levels in the olfactory bulb and cortex (OB/OC) and anterior cortex (AC) at day 3 p.i., correlating with the initial detection of virus. As the infection proceeded, increased NO levels-and infectivity-were progressively being detected in the OB/CO and AC at day 4 p.i. (F(12, 128) = 2.82; P <.003); at day 5 p.i. in several brain regions (P <.003 in the OB/OC); and at day 6 p.i. in all regions (P <.003) but the thalamus. These results show that BoHV-5 replication in the brain of rabbits induces an overproduction of NO. The increase in NO levels in early infection correlated spatially and temporally with virus dissemination within the brain and preceded the development of neurological signs. Thus, the overproduction of NO in the brain of BoHV-5-infected rabbits may be a component of the pathogenesis of BoHV-5-induced neurological disease.
Assuntos
Discinesias , Encefalite Viral/virologia , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 5/patogenicidade , Meningoencefalite/virologia , Óxido Nítrico/biossíntese , Replicação Viral , Animais , Química Encefálica , Encefalite Viral/metabolismo , Encefalite Viral/fisiopatologia , Infecções por Herpesviridae/metabolismo , Infecções por Herpesviridae/fisiopatologia , Herpesvirus Bovino 5/isolamento & purificação , Meningoencefalite/metabolismo , Meningoencefalite/fisiopatologia , Óxido Nítrico/química , Óxido Nítrico Sintase Tipo II/biossíntese , Coelhos , Fatores de Tempo , Regulação para CimaRESUMO
This report describes an alternative technique to inoculate rabbits and to reproduce infection by Bovine herpesvirus 1 and 5. First, the nostrils are anaesthetized by aspersion with local anaesthetic. A few seconds later, and after proving the insensitivity of the zone, the rabbits are put on their back legs with their nostrils upwards and the inoculum is introduced slowly into each nostril by using disposable droppers. Clinical signs, viral isolation from nasal swabs, histological lesions found, positive polymerase chain reaction and antibodies production confirm the infection. This very simple and bloodless technique, where the animals are exposed to minor distress, may be useful for evaluating the virulence of BoHV-1 and BoHV-5 strains, to study the establishment of latent virus infection and to test the potential of experimental vaccines or properties of antiviral drugs. It may be also suitable for experimental infection with other respiratory viruses in this animal model.
Assuntos
Encefalite Viral/virologia , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 1/crescimento & desenvolvimento , Herpesvirus Bovino 5/crescimento & desenvolvimento , Meningoencefalite/virologia , Virologia/métodos , Administração Intranasal , Animais , Anticorpos Antivirais/sangue , Modelos Animais de Doenças , Encefalite Viral/fisiopatologia , Feminino , Infecções por Herpesviridae/fisiopatologia , Herpesvirus Bovino 1/isolamento & purificação , Herpesvirus Bovino 5/isolamento & purificação , Fígado/patologia , Pulmão/patologia , Masculino , Meningoencefalite/fisiopatologia , Nariz/virologia , CoelhosRESUMO
Naegleria fowleri is a free-living amoeba and the etiologic agent of primary amoebic meningoencephalitis (PAM). Trophozoites reach the brain by penetrating the olfactory epithelium, and invasion of the olfactory bulbs results in an intense inflammatory reaction. The contribution of the inflammatory response to brain damage in experimental PAM has not been delineated. Using both optical and electron microscopy, we analyzed the morphologic changes in the brain parenchyma due to inflammation during experimental PAM. Several N. fowleri trophozoites were observed in the olfactory bulbs 72 h post-inoculation, and the number of amoebae increased rapidly over the next 24 h. Eosinophils and neutrophils surrounding the amoebae were then noted at later times during infection. Electron microscopic examination of the increased numbers of neutrophils and the interactions with trophozoites indicated an active attempt to eliminate the amoebae. The extent of inflammation increased over time, with a predominant neutrophil response indicating important signs of damage and necrosis of the parenchyma. These data suggest a probable role of inflammation in tissue damage. To test the former hypothesis, we used CD38-/- knockout mice with deficiencies in chemotaxis to compare the rate of mortality with the parental strain, C57BL/6J. The results showed that inflammation and mortality were delayed in the knockout mice. Based on these results, we suggest that the host inflammatory response and polymorphonuclear cell lysis contribute to a great extent to the central nervous system tissue damage.
Assuntos
Amebíase , Encéfalo , Inflamação , Meningoencefalite , Naegleria fowleri/patogenicidade , ADP-Ribosil Ciclase 1/genética , Amebíase/imunologia , Amebíase/mortalidade , Amebíase/parasitologia , Amebíase/fisiopatologia , Animais , Encéfalo/imunologia , Encéfalo/fisiopatologia , Encéfalo/ultraestrutura , Infecções Protozoárias do Sistema Nervoso Central/imunologia , Infecções Protozoárias do Sistema Nervoso Central/mortalidade , Infecções Protozoárias do Sistema Nervoso Central/parasitologia , Infecções Protozoárias do Sistema Nervoso Central/fisiopatologia , Humanos , Inflamação/imunologia , Inflamação/mortalidade , Inflamação/parasitologia , Inflamação/fisiopatologia , Masculino , Meningoencefalite/imunologia , Meningoencefalite/mortalidade , Meningoencefalite/parasitologia , Meningoencefalite/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica de TransmissãoRESUMO
Um cão da raça Yorkshire macho de 5 anos foi apresentado ao clínico com crises convulsivas. Na ressonância magnética havia importantes alterações multifocais sugestivas de necrose e inflamação. No exame do líquido cefalorraquidiano observa-se discreta pleocitose. Não foram observadas alterações na necropsia. Histologicamente, havia meningoencefalite não supurativa necrosante multifocal moderada a acentuada, principalmente no córtex telencefálico, hipocampo e tálamo. Os sinais clínicos e as lesões histológicas são compatíveis com a meningoencefalite necrosante descrita em cães Yorkshire(AU)
A male five-year-old Yokshire dog was presentedwith convulsions. In the MRI, there were multifocal changs suggesting necrosis and inflammation. In the cerebrospinal fluid, mild pleocitosis was present. Macroscopic changes moderate to accentuated multifocal non supurative necrotizing meningoencephalitis, mainly in the cerebral cortex, hippocampus and thalamus. The clinical signs and histological lesions are compatible with the necrotizing meningoencephalitis reported in the Yorshire breed(AU)
Assuntos
Cães , Meningoencefalite/fisiopatologia , Meningoencefalite/diagnóstico , Cães , Convulsões , Exame NeurológicoRESUMO
Um cão da raça Yorkshire macho de 5 anos foi apresentado ao clínico com crises convulsivas. Na ressonância magnética havia importantes alterações multifocais sugestivas de necrose e inflamação. No exame do líquido cefalorraquidiano observa-se discreta pleocitose. Não foram observadas alterações na necropsia. Histologicamente, havia meningoencefalite não supurativa necrosante multifocal moderada a acentuada, principalmente no córtex telencefálico, hipocampo e tálamo. Os sinais clínicos e as lesões histológicas são compatíveis com a meningoencefalite necrosante descrita em cães Yorkshire
A male five-year-old Yokshire dog was presentedwith convulsions. In the MRI, there were multifocal changs suggesting necrosis and inflammation. In the cerebrospinal fluid, mild pleocitosis was present. Macroscopic changes moderate to accentuated multifocal non supurative necrotizing meningoencephalitis, mainly in the cerebral cortex, hippocampus and thalamus. The clinical signs and histological lesions are compatible with the necrotizing meningoencephalitis reported in the Yorshire breed
Assuntos
Cães , Convulsões , Cães , Exame Neurológico , Meningoencefalite/diagnóstico , Meningoencefalite/fisiopatologiaRESUMO
O presente trabalho relata quatro casos de meningoencefalite por BHV-5 em quatro municípios no estado do Pará afetando bovinos de 1-2 anos, criados extensivamente. Três casos ocorreram de forma isolada e em um caso foram atingidos 3 animais do rebanho. Os principais sinais clínicos observados foram incoordenação, depressão acentuada, cegueira, decúbito lateral, opistótono e morte. O curso clínico foi de 3-4 dias. Macroscopicamente observaram-se áreas amolecidas, amareladas e cavitações no córtex cerebral. Microscopicamente observaram-se poliencefalomalacia no córtex cerebral, tálamo e núcleos da base, encefalite e meningite não supurativa e corpúsculos de inclusão intranucleares eosinofílicos em astrócitos. O diagnóstico foi realizado com base nos achados histológicos característicos.
Assuntos
Bovinos/anatomia & histologia , Herpesvirus Bovino 5 , Meningoencefalite/diagnóstico , Meningoencefalite/epidemiologia , Meningoencefalite/fisiopatologia , Mielite/diagnóstico , Mielite/epidemiologia , Mielite/fisiopatologiaRESUMO
O presente trabalho relata quatro casos de meningoencefalite por BHV-5 em quatro municípios no estado do Pará afetando bovinos de 1-2 anos, criados extensivamente. Três casos ocorreram de forma isolada e em um caso foram atingidos 3 animais do rebanho. Os principais sinais clínicos observados foram incoordenação, depressão acentuada, cegueira, decúbito lateral, opistótono e morte. O curso clínico foi de 3-4 dias. Macroscopicamente observaram-se áreas amolecidas, amareladas e cavitações no córtex cerebral. Microscopicamente observaram-se poliencefalomalacia no córtex cerebral, tálamo e núcleos da base, encefalite e meningite não supurativa e corpúsculos de inclusão intranucleares eosinofílicos em astrócitos. O diagnóstico foi realizado com base nos achados histológicos característicos.(AU)
Four outbreaks of meningoencephalitis in 1 to 2 years old cattle caused by Bovine herpesvirus-5 are reported in four municipalities in the state of Pará, northern Brazil. In three outbreaks only one animal was affected, in another 3 cattle were affected. Main clinical signs were incoordination, dullness, blindness, recumbence, and opisthotonus. Death occurred after a clinical manifestation period of 3-4 days. Softening and yellowish areas were observed grossly in the cerebral cortex. The histology revealed poliencephalomalacia in the cerebral cortex, thalamus and basal nuclei, and non suppurative encephalitis and meningitis, and eosinophilic intranuclear inclusion bodies in astrocytes. The diagnosis was based on the typical microscopic lesions.(AU)
Assuntos
Animais , Meningoencefalite/diagnóstico , Meningoencefalite/epidemiologia , Meningoencefalite/fisiopatologia , Mielite/diagnóstico , Mielite/epidemiologia , Mielite/fisiopatologia , Herpesvirus Bovino 5/isolamento & purificação , Bovinos/anatomia & histologiaRESUMO
In the present study, cross-protection to bovine herpesvirus type 5 (BHV-5) induced by bovine herpesvirus type 1 (BHV-1) vaccination was examined following inoculation of rabbits and calves with a glycoprotein E (gE)-negative BHV-1 vaccine and subsequent challenge with BHV-5. Rabbits (n=5) and calves (n=8) were vaccinated [five rabbits intranasally (IN), four calves IN and four intramuscularly (IM)] with 7.1 log(10)median tissue culture infective dose (TCID(50)) of the BHV-1 vaccine. Rabbits and calves were challenged IN [rabbits 2 weeks post-vaccination (pv); calves 5 weeks pv] with 9.1log(10)TCID(50) of BHV-5. Two out of five vaccinated rabbits died after challenge with typical BHV-5 disease, as did 3/5 non-vaccinated controls. In calves, 4/8 vaccinated animals displayed mild signs of disease, whereas 6/6 non-vaccinated controls developed signs of disease, so severe that 2/6 had to be killed. Besides, nasal virus shedding post-challenge was not reduced by vaccination. At necropsy, on day 21 post-challenge, typical BHV-5 lesions were evident in brain tissues of both vaccinated and non-vaccinated calves. Dexametasone administration at 180 days post-infection did not reactivate clinical signs despite BHV-5 shedding in nasal secretions of both vaccinated and non-vaccinated calves. These results show that the BHV-1 vaccine evaluated here did not confer protection to BHV-5 in rabbits. In calves, BHV-1 vaccination did confer some protection to BHV-5 induced clinical disease, but it did not prevent infection and had no effect on nasal virus shedding or on the development of encephalitic lesions.
Assuntos
Doenças dos Bovinos/prevenção & controle , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/imunologia , Herpesvirus Bovino 5/imunologia , Vacinas Virais/imunologia , Administração Intranasal , Animais , Anticorpos Antivirais/sangue , Encéfalo/patologia , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/fisiopatologia , Reações Cruzadas , Dexametasona/administração & dosagem , Dexametasona/farmacologia , Encefalite Viral/imunologia , Encefalite Viral/fisiopatologia , Encefalite Viral/prevenção & controle , Encefalite Viral/veterinária , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/fisiopatologia , Infecções por Herpesviridae/prevenção & controle , Herpesvirus Bovino 1/genética , Injeções Intramusculares , Meningoencefalite/imunologia , Meningoencefalite/fisiopatologia , Meningoencefalite/prevenção & controle , Meningoencefalite/veterinária , Testes de Neutralização , Nariz/virologia , Coelhos , Recidiva , Análise de Sobrevida , Proteínas do Envelope Viral/genética , Proteínas Virais , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Eliminação de Partículas ViraisRESUMO
The initial stages of Naegleria fowleri meningoencephalitis in mice were immunohistochemically characterized following the first 8 h post-intranasal inoculation. The events found after 8 h were: (1) amebas in contact with the mucous layer of the olfactory epithelium, (2) numerous parasites eliminated by extensive shedding of the mucous layer, and (3) many organisms reaching the nasal epithelium. In contrast to other works, we observed that after 24 h, amebas invaded the epithelium, without evidence of the disruption of the nasal mucosa. In addition some trophozoites invading through the respiratory epithelium were observed, suggesting an additional invasion route. The inflammatory response detected was scarce until 30 h post-inoculation. After 96 h, the inflammatory response was severe in the olfactory bulb and brain, and the tissue damage great. Consequently, an inflammatory reaction may enhance tissue damage but apparently does not destroy amebas which seem to proliferate in the olfactory bulb.
Assuntos
Amebíase/fisiopatologia , Amebíase/parasitologia , Meningoencefalite/fisiopatologia , Meningoencefalite/parasitologia , Naegleria fowleri/patogenicidade , Amebíase/imunologia , Animais , Encéfalo/imunologia , Encéfalo/parasitologia , Encéfalo/patologia , Imuno-Histoquímica , Inflamação/imunologia , Inflamação/parasitologia , Inflamação/fisiopatologia , Masculino , Meningoencefalite/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Naegleria fowleri/crescimento & desenvolvimento , Bulbo Olfatório/imunologia , Bulbo Olfatório/parasitologia , Bulbo Olfatório/patologia , VirulênciaAssuntos
Ceftriaxona/uso terapêutico , Cefalosporinas/uso terapêutico , Meningoencefalite/tratamento farmacológico , Neurossífilis/tratamento farmacológico , Adulto , Humanos , Masculino , Meningoencefalite/diagnóstico , Meningoencefalite/fisiopatologia , Neurossífilis/diagnóstico , Neurossífilis/fisiopatologiaRESUMO
As meningoencefalites por vírus determinam um padrao de hipercelularidade liquórica tipo linfomonocitário e seus agentes etiológicos sao pouco conhecidos no Brasil. Aspectos da patogenia das viroses que acometem o sistema nervoso central sao analisados desde o momento da infecçao. Os mecanismos de defesa antiviral do hospedeiro, a chegada dos vírus ao sistema nervoso central, suas distintas formas de invasao do tecido nervoso, bem como o acometimento deste tecido e a imunidade a nível local, sao abordados neste trabalho de revisao.
Assuntos
Humanos , Doenças do Sistema Nervoso Central/virologia , Meningoencefalite/virologia , Doenças do Sistema Nervoso Central/fisiopatologia , Doenças do Sistema Nervoso Central/imunologia , Meningoencefalite/imunologia , Meningoencefalite/fisiopatologia , Vírus/patogenicidadeRESUMO
Clinical approach has been made in eight patients with histoplasmosis of the central nervous system. All patients had no evidence of immunodepression. Time disease at diagnosis ranged from 6 to 108 months (median 36 months). Main signs and symptoms were: intracranial hypertension in 6 patients; impairment of memory in 4; confusion in 4; seizures in 2; urinary incontinence in 2; sexual impotency in 1. Meningo-encephalitic form was present in 6 patients, while the granulomatous form was found in 2. Diagnostic confirmation was based on: biopsy, in 1 case; necropsy, in 2 cases; cerebrospinal fluid (CSF) sediment culture, in 1; detection of antibodies against Histoplasma capsulatum in the CSF, in 5 cases. There was, in all patients, an expressive difference between CSF alterations (intense, merging acute and chronic phase elements) and clinical symptomatology (patients in general oligosymptomatic).
Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Histoplasmose/diagnóstico , Adolescente , Adulto , Doenças do Sistema Nervoso Central/fisiopatologia , Criança , Feminino , Histoplasmose/fisiopatologia , Humanos , Masculino , Meningoencefalite/diagnóstico , Meningoencefalite/fisiopatologia , Pessoa de Meia-IdadeRESUMO
Las meningitis bacterianas son un importante problema de salud pública en la población pediátrica. En este capítulo se tratarán conjuntamente a dos de los más relevantes agentes etiológicos, Haemophilus influenzae del serotipo b y Neisseria meningitidis, debido a que los cuadros clínicos que provocan son prácticamente indistinguibles y a que además tienen varias características en común: a) forman parte de la flora normal de la faringe de individuos sanos; b) se transmiten de persona a persona a través de objetos; c) presentan reactividad cruzada con antígenos de otras especies bacterianas; d) poseen una cápsula prominente de naturaleza polisacarídica; e) tienen una membrana externa formada por varias clases de proteínas; y f) cuentan con la capacidad de elaborar protesas extracelulares contra inmunoglobulina. En México las enfermedades invasivas causadas por H. influenzae no han recibido la atención que requieren y el conocimiento que se tiene es insuficiente para poder evaluar su impacto real como problema de salud. Hasta la fecha en México, se han hecho un gran número de estudios en relación con estos padecimientos, aunque la mayoría se han basado en su diagnóstico clínico o bacteriológico, el reconocimiento de sus complicaciones tales como las secuelas neurológicas en el caso de la meningitis y su tratamiento con medicamentos antimicrobianos. Con base a estos estudios sólo se cuenta con datos sobre la frecuencia de casos de meningitis purulenta en la población infantil, los que indican que H. influenzae es el agente causal más frecuente, encontrándose aproximadamente en el 25 por ciento de los casos, seguido por Streptococcus pneumoniae. H. influenzae también es la causa bacteriana principal de secuelas neurológicas graves hasta en el 50 por ciento de los pacientes que sobrevivien a la infección meníngea