* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download ORTHOMYXOVIRUS PARAMYXOVIRUS
Survey
Document related concepts
2015–16 Zika virus epidemic wikipedia , lookup
Hepatitis C wikipedia , lookup
Swine influenza wikipedia , lookup
Human cytomegalovirus wikipedia , lookup
Ebola virus disease wikipedia , lookup
West Nile fever wikipedia , lookup
Orthohantavirus wikipedia , lookup
Middle East respiratory syndrome wikipedia , lookup
Marburg virus disease wikipedia , lookup
Hepatitis B wikipedia , lookup
Antiviral drug wikipedia , lookup
Lymphocytic choriomeningitis wikipedia , lookup
Henipavirus wikipedia , lookup
Transcript
ORTHOMYXOVIRUS PARAMYXOVIRUS Ma. Rosario L. Lacandula, MD, MPH Department of Microbiology & Parasitology College of Medicine Our Lady of Fatima University Orthomyxovirus Influenza virus Influenza A- pandemics and epidemics; humans and animals Influenza B- epidemics; human virus Influenza C- mild respiratory tract infection Morphology: Segmented, ss genome,helical nucleocapsid with outer lipoprotein envelope Envelope contain 2 spikes Hemagglutinin Binds to cell surface receptors( neuraminic acid/sialic acid Neuramidase Enzymatic activity Internal antigens- M1 & NP proteins- type specific, shows cross reactivity Antigenic Variations Antigenic shift Undergoes reassortment Results in changes of the H and N antigen Pandemics and epidemics Occurs with influenza A only Antigenic drift Change in the amino acid sequence of the H ag Occur both in A & B MOT: airborne respiratory droplets ( less than 10 um) Survive for short period on surfaces I.P. 18-72 hours Virus concentration in nasal and tracheal secretions remains high for 24 to 48 hours Site of infection- epithelial cells of the respiratory tract Recovery- interferons and CMI Humoral Immunity- ( IgG & IgA)protection against reinfection, antibody against HA is important Symptoms and complications 1. Uncomplicated influenza Fever ( 38-40 C) Myalgias, headache Ocular symptoms- photophobia, tears, ache Dry cough, nasal d/c 2. Pulmonary complications/sequelae Croup( acute larygotracheobronchitis) Primary influenza pneumonia Secondary bacterial infection 3 Non pulmonary complications Myositis Cardiac complications Encephalopathy Reyes syndrome Guillen-Barre syndrome Diagnosis 1. virus isolation Monkey kidney cell etc. No CPE 2.serology Hemadsorption PCR Chemotherapy Rimantadine and amantadine Zanamavir and oseltamivir Rest, liquids and anti febrile agents PROPERTIES OF ORTHOMYXOVIRUS AND PARAMYXOVIRUS Property orthomyxovirus paramyxovirus viruses Influenza A,B,C Measles,mumps, RSV,& parainfluenza genome Segmented Non segmented Virion RNA polymerase yes yes Capsid helical helical Envelope yes yes size Smaller(110 nm) Larger( 150 nm) Surface spikes H&N diff. spikes H&N same spikes Giant cell formation no yes Envelope spikes Virus H N Fusion protein Measles virus + - + mumps + + + RSV - - + Parainfluenza + + + Paramyxovirus Non segmented, ss genome; helical capsid with outer lipoprotein envelope Envelope spikes: H & N and fusion protein MEASLES VIRUS Single serotype H- target of neutralizing Ab Humans are the natural host Pathogenesis Receptor: CD46 on surface of macrophages Rash-cytotoxic T cells attacking the virus infected vascular endothelial cells in the skin CMI- neutralizing the virus during viremic phase MOT: droplet inhalation Hematogenous transplacental Clinical IP 7-13 days Prodrome- high fever, 3C & P- infectious Koplick’s spots- buccal mucosa across the molars- grains of salt surrounded by red halo Rashes appears-starts below the ears and spread throughout the body undergoes brawny desquamation Complications Encephalitis Bacterial pneumonia Giant cell pneumonia- defective CMI Atypical measles- older inactivated mealses SSPE-subacute sclerosing panencephalitis Mumps virus H and N + fusion protein on envelope spikes Internal nucleocapsid protein- S Antigendetected in complement fixation test Humans are the natural host thermolabile Mumps Nasal or URT epithelial cells- bloodsalivary glands, testes,ovaries, pancreas, meninges and kidneys Shed in the saliva 2 days before to 9 days after the onset of salivary gland swelling (+) virus in urine up to 14 days after onset of symptoms Clinical 1/3 of patients subclinical 50% with swelling of the salivary glands Pain and anorexia Complications Orchitis-postpubertal-unilateral, bilateral-sterility aseptic meningitis Oophoritis-5% Pancreatitis- 4% Immunity Ab vs HN glycoprotein- correlate with immunity Ab vs S Ag- appear earliest, gone w/in 6 months Passive immunity from mother to offspringprotection during 1st 6 months of life Diagnosis 1. cell culture Specimen-saliva, spinal fluid or urine Monkey kidney cell CPE- cell rounding and giant syncytia formation 2. serology- 4 fold rise in Ab titer in HI or CF Ab vs S antigen- current infection Ab Vs V antigen- past infection Prevention: vaccine, attenuated vaccine Respiratory Syncytical Virus Most important cause of pneumonia and bronchiolitis in infants Fusion proteins- syncytia formation Humans and chimpanzees- natural host 2 serotype: A & B MOT: respiratory droplet Clinical 1. infants- bronchiolitis, pneumonia 2. young children- otitis media 3. older children and adults- common cold Diagnosis: immunofluorescence Isolation in cell culture- + CPE serology Treatment Aerosolized Ribavirin Ribavirin + hyperimmune globulins Prevention NO VACCINE Palivizumab-prophylaxis, monoclonal ab vs. fusion protein Parainfluenza Virus Surface spikes: H & N same spike, fusion on different spike Both humans and animals infected Four serotypes: 1, 2, 3 & 4 MOT: respiratory droplet No viremia Clinical: 1&2- major cause of croup; children < 6 y/o Laryngitis Pneumonia Common cold- 4 Pharyngitis Otitis media