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Rabies virus Shape: bullet Genome: -ssRNA enveloped virus CPE: Negri body Structure of Rabies Virus 抵抗力不强,60C 30min或100C 2min可灭活。可被强酸、强碱、乙醇、 乙醚、肥皂水、去垢剂等灭活。 在脑组织中室温或4C可持续1-2周。 甘油中可保存数月。 Reservoir Urban forms: Dogs and cats Sylvatic forms: Bats, foxes, raccoons莞熊, wolves, skunks臭鼬, coyotes丛林狼, mongooses猫鼬, and biting animals Transmission By bite or scratch Via saliva Airborne ( bats) BAT armadillo Cat raccoon fox dog Rabies or hydrophobia Fever Dysphagia咽下困难 Altered mental status Excitement, agitation Paralysis麻痹 Hydrophobia恐水 Hypersalivation 多涎 Nausea, vomiting恶心;作 呕 Headache malaise不适 Laboratory diagnosis Diseased dog: viral antigen and Negri body in brain tissue. Patient: IF assay, PCR. Prevention and treatment Prevention and treatment Bite Geographical area, type of animal, severity and site of bite. Animal Live - observe in cage: If survives > 8 days, then NOT rabies. Dead - brain - Negri bodies - IFA - virus isolation Prevention and treatment Man Live - difficult diagnosis - clinical picture, skin biopsy, corneal impression (antibodies only appear very late) Dead - brain sent to Onderstepoort "Negri bodies" in cytoplasm of brain cells; immunofluorescence virus isolation . Human papillomavirus (HPV) Biological properties naked dsDNA virus with 9 ORF belongs to Papovaviridae more than 60 types artificial cultivation unsuccessful. Transmission contact infection sexual infection congenital infection. Pathogenesis Host-specific Tissue-specific. Disease Cutaneous warts Epidermodysplasia verruciformis Mucosal HPV infections Cervical cancer and other cancers: A significant proportion of cancers is associated with HPV infection: 11% of all cancers in women and 2% of all cancers in men. LIFE CYCLE OF HUMAN PAPILLOMAVIRUS Laboratory diagnosis - Cytology - Histology - Colposcopy in the case of genital HPV infections. - Electron microscopy. - Immunocytochemistry can detect major capsid protein but are generally group specific not type specific - DNA detection techniques. This is the only way to type HPVs.PCR PARVOVIRUSES Human parvovirus B19 DISTINCTIVE PROPERTIES Are small, naked viruses with icosahedral nucleocapsids. Contain single-stranded DNA and replicate in the nucleus. Include human parvovirus (B19) and adenoassociated virus, a defective virus of the dependovirus genus that requires adenovirus to replicate. Human pathogen, B19, has tropism for red blood cell progenitors Human diseases associated with B19 parvovirus Syndrome Host or condition Clinical features Fifth diseases Children Adilts Cutaneous rash Arthralgiaarthrtis Transient aplastic crisis Pure red cell aplasia Underlying Severe acute hemolysis anemia Immunodeficienci Chronic anemia es Hydrops fetails Fetus Fatal anemia EPIDEMIOLOGY These organisms are widely distributed in nature. Enters the body through: The respiratory tract Blood transfusions Vertically from mother. DIAGNOSIS PARVOVIRUS B-19 SEROLOGY Serology Direct detection of the viral DNA may be achieved by PCR Interpretation IgGIgM- No past infection Patients susceptible to infection IgG+ IgM- There has been a past infection Patient probably immune IgG + or – IgM equivocal Current or recent infection Patient should be retested in a few weeks IgG+ IgM+ Ongoing or recent infection Fetus may be at risk if patient pregnant IgG- (or equivocal) IgM+ Current infection Patient should be retested in a few weeks Prevention and Treatment Immunological: no vaccines are available Treatment: Commercial immunoglobulin preparations contain parvo B19 antibodies can successfully eliminate the infection in immunocompromised patients