Vírus da Coriomeningite Linfocítica

Classificação

Características Gerais

Características básicas do vírus da coriomeningite linfocítica ( LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus)

• Com envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology
• Esférico
• Tamanho médio (diâmetro entre 60 e 300 nm)
• 2 glicoproteínas de superfície viral no envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology: G1 e G2
• Genoma do vírus:
  • Encapsulado por um nucleocapsídeo helicoidal
  • Segmentado com:
    • Uma cadeia simples grande (L) RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de sentido negativo
    • Um RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure pequeno (S) ambisense
  • Transporta RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure polimerase dependente de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure (RDRP, pela sigla em inglês)

Taxonomia:

• Família Arenaviridae Arenaviridae A family of RNA viruses naturally infecting rodents and consisting of one genus (arenavirus) with two groups: old world arenaviruses and new world arenaviruses. Infection in rodents is persistent and silent. Vertical transmission is through milk-, saliva-, or urine-borne routes. Horizontal transmission to humans, monkeys, and other animals is important. Lassa Virus
• Género Mammarenavirus Mammarenavirus Lassa Virus
• Os vírus contêm ribossomas hospedeiros, dando ao vírus uma aparência granular (arenosus é latim para “arenoso”)
• Outros arenavírus incluem:
  • Vírus Lassa (febre Lassa)
  • Vírus Junin (febre hemorrágica argentina)
  • Vírus Machupo (febre hemorrágica boliviana)
  • Vírus Guanarito (febre hemorrágica venezuelana)
  • Sabia (febre hemorrágica brasileira)
  • Chapare (febre hemorrágica de Chapare)
  • Lujo (febre hemorrágica de Lujo)

Epidemiologia

• Seroprevalência nos Estados Unidos: aproximadamente 5%
• Doença encontrada na:
  • América do Norte e do Sul
  • Europa
  • Austrália
  • Japão
• Sem predileção racial ou sexual
• Infeções mais MAIS Androgen Insensitivity Syndrome comuns em adultos jovens
• As infeções são mais MAIS Androgen Insensitivity Syndrome comuns no outono e inverno (quando os roedores procuram abrigo dentro de casa).

Patogénese

Reservatório

Arenavírus: causam infeções crónicas em roedores (rato doméstico, Mus musculus Mus musculus Lymphocytic Choriomeningitis Virus )

Transmissão

• Contacto direto com material contaminado por fezes/urina/ saliva Saliva The clear, viscous fluid secreted by the salivary glands and mucous glands of the mouth. It contains mucins, water, organic salts, and ptyalin. Salivary Glands: Anatomy de roedores infetados (através do olho, nariz, boca, ferimento na pele ou mordida de animal)
• Inalação de vírus aerossolizado
• Transmissão vertical da mãe para o feto
• Transplante de órgãos (destinatário do tecido de doador infetado)

Ciclo da vida

1. O vírus liga-se aos recetores do hospedeiro através de glicoproteínas do envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology.
2. O vírus é posteriormente endocitado, conseguindo assim entrar na célula.
3. Segue-se a fusão viral com um endossoma.
4. O vírus funde-se com a membrana do endossoma, permitindo a libertação do ribonucleocapsídeo viral no citoplasma.
5. O RDRP medeia a replicação e transcrição do gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics viral no citoplasma do hospedeiro.
6. Novos vírus agrupam-se e ligam-se, que leva à libertação do vírus para infetar outras células.

Fatores de risco do hospedeiro

• Donos de ratos de estimação ou hamsters
• Trabalhadores de laboratório

Processo da doença

O LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus não é citotóxico, mas enquanto a resposta imune do hospedeiro tenta eliminar o vírus, também se pode desencadear uma doença imunomediada. A resposta imune produz as diferentes manifestações da doença.

• Período de incubação: até 13 dias
• Segue-se viremia Viremia The presence of viruses in the blood. Erythema Infectiosum primária → disseminação para outros órgãos
• O vírus atinge o SNC ( meninges Meninges The brain and the spinal cord are enveloped by 3 overlapping layers of connective tissue called the meninges. The layers are, from the most external layer to the most internal layer, the dura mater, arachnoid mater, and pia mater. Between these layers are 3 potential spaces called the epidural, subdural, and subarachnoid spaces. Meninges: Anatomy, plexo coróide e revestimento ependimário ventricular), levando à infiltração de células inflamatórias.

Apresentação Clínica

Infeção pelo vírus da coriomeningite linfocítica adquirida

A infeção com LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus resulta em doença bifásica.

Início dos sintomas:

• Ocorre 8-13 dias após a exposição
• Os primeiros sintomas podem durar entre 5 a 7 dias.
• 33% são assintomáticos.
• 50% têm doença febril sem envolvimento neurológico.

Sintomas da 1ª fase:

• Febre
• Falta de apetite
• Cefaleia
• Dores musculares
• Mal-estar
• Náuseas e/ou vómitos
• Linfadenopatia
• Rash Rash Rocky Mountain Spotted Fever cutânea maculopapular Maculopapular Dermatologic Examination

Sintomas da 2ª fase:

Após alguns dias de recuperação, os sintomas da 2ª fase podem começar, e incluem sintomas neurológicos (típicos de meningite e/ou encefalite).

• Aumento da cefaleia, fotofobia
• Rigidez da nuca
• Mudança no estado de consciência (letargia, coma Coma Coma is defined as a deep state of unarousable unresponsiveness, characterized by a score of 3 points on the GCS. A comatose state can be caused by a multitude of conditions, making the precise epidemiology and prognosis of coma difficult to determine. Coma)

Outros achados menos frequentes:

• Orquite
• Miocardite
• Artrite
• Parotidite
• Pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia

Infeção pelo vírus da coriomeningite linfocítica congénita

As mulheres infetadas com LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus durante a gravidez podem transmitir a infeção para o feto.

• As infeções que ocorrem durante o 1º trimestre podem resultar em morte fetal ou aborto espontâneo.
• Infeções no 2º e 3º trimestres podem resultar em defeitos congénitos, incluindo:
  • Cegueira: A coriorretinite é um achado comum em crianças.
  • Atraso no desenvolvimento
  • Hidrocefalia
  • Epilepsia

Infeção pelo vírus da coriomeningite linfocítica do transplante de órgãos

A imunossupressão significativa em doentes recetores de transplante desempenha um papel no desenvolvimento da doença:

• Encefalopatia
• Insuficiência respiratória
• Insuficiência renal/hepática
• Disfunção do enxerto
• Coagulopatia
• Trombocitopenia
• Febre

Diagnóstico

Meios complementares de diagnóstico

• Os testes Testes Gonadal Hormones de confirmação para o LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus incluem:
  • Deteção de anticorpos IgM IgM A class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin. Immunoglobulins: Types and Functions e IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis no LCR e soro
  • RT-PCR RT-PCR A variation of the pcr technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard pcr protocols. Polymerase Chain Reaction (PCR)
  • Cultura viral do LCR
• Para a infeção congénita por LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus, como os bebés podem não ter mais MAIS Androgen Insensitivity Syndrome o vírus, são usados os níveis de IgM IgM A class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin. Immunoglobulins: Types and Functions e IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis.
• Achados comuns no LCR incluem:
  • Aumento dos níveis de proteína
  • Pleocitose linfocítica
  • Diminuição dos níveis de glicose

Achados adicionais

Durante a 1ª fase da doença, as anomalias laboratoriais mais MAIS Androgen Insensitivity Syndrome comuns são

• Hemograma:
  • Leucopenia
  • Trombocitopenia
• Enzimas hepáticas elevadas

Tratamento

• Doentes com meningite assética, encefalite ou meningoencefalite requerem:
  • Hospitalização
  • Tratamento de suporte com base na gravidade
• A recuperação geralmente dura até 3 semanas.
• Taxa de mortalidade:
  • Infeção adquirida por LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus: aproximadamente 1%
  • Infeção congénita por LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus: pode chegar a 35% dependendo das doenças associadas

Comparação de Espécies

Os arenavírus podem causar doenças neurológicas ( LCMV LCMV Lymphocytic choriomeningitis virus (LCMV) is a single-stranded RNA virus transmitted to humans via rodents, the primary reservoir. Viral infections can occur through direct contact (such as through a break in the skin) with rodent urine, saliva, or droppings or via inhalation of aerosolized virus. The disease typically results in a self-limited, febrile, biphasic disease. Lymphocytic Choriomeningitis Virus) e/ou febres hemorrágicas, para as quais uma das principais etiologias é o vírus Lassa.

Diagnóstico Diferencial

Os seguintes vírus selecionados de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure também podem levar à infeção do SNC.

• Vírus da encefalite transmitida por carraça: devido a um vírus de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de cadeia simples do género Flavivirus Flavivirus A genus of flaviviridae containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is yellow fever virus. Tick-borne Encephalitis Virus. A transmissão ocorre principalmente através de carraças Ixodes encontradas na Europa, Rússia e Ásia. A maioria dos doentes está assintomática, mas os indivíduos sintomáticos podem apresentar uma doença bifásica. Os doentes podem desenvolver manifestações neurológicas, como meningite, encefalite ou meningoencefalite. A serologia ou PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR) podem confirmar o diagnóstico. Não há terapia antiviral Antiviral Antivirals for Hepatitis B eficaz para infeções por vírus da encefalite transmitida por carraça, portanto, o tratamento é de suporte
• Vírus da encefalite equina: arbovírus transmitidos por mosquitos (pertencentes a Togaviridae Togaviridae A family of RNA viruses, mainly arboviruses, consisting of two genera: alphavirus (group A arboviruses), and rubivirus. Virions are spherical, 60-70 nm in diameter, with a lipoprotein envelope tightly applied to the icosahedral nucleocapsid. Rubella Virus , género Alphavirus Alphavirus A genus of togaviridae, also known as group a arboviruses, serologically related to each other but not to other togaviridae. The viruses are transmitted by mosquitoes. The type species is the sindbis virus. Equine Encephalitis Viruses) que podem causar doenças virais menores e, em casos graves, encefalite em humanos. O vírus é um RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de cadeia simples de sentido positivo. O vírus da encefalite equina oriental é o mais MAIS Androgen Insensitivity Syndrome clinicamente relevante nos Estados Unidos. O vírus é mantido num ciclo entre mosquitos e hospedeiros aviários, mas espalha-se para humanos através de vetores-ponte. Os sintomas incluem febre, dor de cabeça e vómitos, com recuperação da maioria dos doentes. A doença pode progredir para encefalite grave. O diagnóstico é feito por estudos do LCR, com serologia e deteção de antigénio viral ou sequência genómica. Não há tratamento específico e a terapia é maioritariamente de suporte.
• Vírus do Nilo Ocidental: pode causar doença neuroinvasiva, incluindo meningite, encefalite e paralisia flácida aguda. É um vírus de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de cadeia simples, de sentido positivo, com envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology do género Flavivirus Flavivirus A genus of flaviviridae containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is yellow fever virus. Tick-borne Encephalitis Virus. Os hospedeiros primários são as aves, e a doença é mais MAIS Androgen Insensitivity Syndrome frequentemente transmitida por mosquitos Culex. A maioria das pessoas infetadas com o vírus está assintomática. Alguns doentes terão uma doença febril autolimitada, denominada febre do Nilo Ocidental. O diagnóstico é confirmado com serologia ou serologia do LCR, ou RT-PCR RT-PCR A variation of the pcr technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard pcr protocols. Polymerase Chain Reaction (PCR). O tratamento é geralmente de suporte. A prevenção visa o controlo local do mosquito e a proteção contra picadas de mosquito.
• Vírus da encefalite de Saint Louis: vírus de RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure de cadeia simples, de sentido positivo, com envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology, pertencente ao género Flavivirus Flavivirus A genus of flaviviridae containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is yellow fever virus. Tick-borne Encephalitis Virus e causador da encefalite de St. Louis. A transmissão é por espécies de mosquito Culex. A maioria das infeções é assintomática. Indivíduos sintomáticos podem apresentar sintomas semelhantes aos da gripe, meningite assética, encefalite ou meningoencefalite. O diagnóstico é confirmado com serologia. Não há tratamento antiviral Antiviral Antivirals for Hepatitis B eficaz, portanto, o tratamento é de suporte. A prevenção visa o controlo local do mosquito e a proteção individual com repelente de insetos e roupas de proteção.