病原生物学：呼吸道病毒.ppt

呼吸道病毒,教学大纲,1171 掌握人流感病毒及禽流感病毒的生物学性状和变异以及致病性、微生物检查方法、免疫性和防治原则 1172 熟悉麻疹病毒致病性、免疫性和防治原则 1173 熟悉腮腺炎病毒、风疹病毒的致病性及防治原则 1174 熟悉冠状病毒的生物学性状以及致病性 1175 了解腺病毒的生物学性状和致病性 1176 了解新现呼吸道病毒的防控原则A group of viruses caused respiratory Infection or can invade host through respiratory tract.,Including,Orthomyxoviridae (正粘病毒科) : Influenza virus Paramyxoviridae (副粘病毒科): Respiratory syncytial virus(RSV),Measles virus, Mumps virus. Other viruses Rhinovirus, Adenovirus, Coronavirus,Principles of Virology, ASM Press,Respiratory viral infections,Upper respiratory tract diseases,Upper respiratory tract diseases,Sneezing, sore throat and runny nose with little fever Leading cause of doctor visits 22 million lost school days account for 40% of the time lost from jobs Major causes of common colds: 30-50% - Rhinoviruses (Picorna-) 10-30% - Coronaviruses 10-15% - Adenoviruses Enterovirus, Parainfluenza virus, Respiratory syncytial virus,Belonging to the family Picornaviridae More than 100 serotypes These viruses are the most frequent cause of the common cold. Infections are self-limited and do not cause serious disease,Rhinoviruses,Principles of Virology, ASM Press,Nature Reviews Microbiology 9, 254-264,Rhinoviruses,Spread by contaminated objects) and aerosols,Grow optimally at 33C -limited to upper respiratory tract No anti-rhino drug, No vaccine 100 types,Coronaviruses,(+) RNA genome Enveloped Virions have a corona-like appearance. SARS (2002-2003) - severe acute respiratory syndrome MERS (2012, first found in Saudi Arabia) - middle east respiratory syndrome,Nature Reviews Microbiology 9, 254-264,Coronaviruses,Spread by aerosols,33-35C, limited to upper respiratory ract enteric tract diarrhea (occasional, mostly infants 12 mo) No anti-rhino drug, No vaccine,SARS,Severe acute respiratory syndrome (SARS) (uncommon) An outbreak of this very lethal disease started in China in 2002. In March 2003, a novel coronavirus (SARS-CoV) was discovered in association with the outbreak of severe acute respiratory syndrome (SARS) Unlike typical human coronaviruses, SARS infection involves lower respiratory tract. The virus jumped to man from animals (masked-palm civets) fatality rate (due to respiratory stress) much benign course in children 60-year, 40%,MERS,N Engl J Med 2012; 367:1814-1820,A novel coronavirus isolated from a 60-year-old Saudi man died from pneumonia (Jeddah, Saudi Arabia, June, 2012),Confirmed cases (as 8/2/2013): 94 cases, 46 deaths Cases have been reported in Jordan, Qatar, United Arab Emirates, Saudi Arabia, France, Germany, Italy, the UK, and Tunisia. All cases detected outside the Arabian peninsula were linked to one of the Middle Eastern countries, either as a result of travel to those countries or through transmission from a person thought to have acquired the infection there.,However, unlike SARS, the virus is still limited to the Middle East and shows no sign of spreading easily between people,Origin of SARS and MERS/2012,Coronaviruses highly similar to SARS and MERS could be found in bats,Theory:,other animals,Camels (for MERS?),humans,- Genetic changes on viruses - Environmental or agricultural changes,Animal reservoir: bats,Adenoviruses,dsDNA genome non-enveloped Naked, icosadeltahedral capsid that has fibers extending from the vertices. 50 types No anti-adeno drugs,1. How is adenovirus transmitted?,The predominant route : aerosols Also transmitted by: contact : fecal-oral route.,2. What diseases can adenoviruses cause?,swimming pool conjunctivitis,Lower respiratory tract diseases,most caused by bacteria,Paramyxoviruses,Paramyxoviruses,Envelope glycoproteins Fusion protein syncytia Nucleocapsid Genome: -ssRNA,not segmented. with: nucleocapsid large polymerase Phophoprotein,Parainfluenza virus,Asymptomatic in most cases Mild-cold like symptoms (upper respiratory tract) - older children and adults Serious respiratory tract disease - bronchitis/bronchiolitis in young children - 1st cause for Croup (laryngotracheobronchitis) swelling at the voice box, “barking” cough No antiviral drug/No vaccine Reinfections occur throughout life, indicating that immunity is short-lived, but partial immunity,Respiratory syncytial virus (RSV),Milder symptoms in older children and adults Serious respiratory tract disease Bronchiolitis/bronchitis in young children (2-3%) 1st cause for Infantile bronchiolitis/pneumonia global annual infection rates of 64 million and mortality of 160,000. Incidence is seasonal (Winter) No vaccine is currently available for RSV prophylaxis.,Respiratory syncytial virus (RSV), Antiviral drugs Ribavirin used only in persons at high risk for severe disease (premature and immunocompromised infants) Prevention (high risk groups) RespiGam pooled human serum containing anti-RSV antibody Synagis antibody against F protein of RSV,Orthomyxoviridae,Influenza virus,Three types: A (mammals and birds) B (mammals) C (mammals),Influenza Pandemics,Occur 11 to 42 years apart 19181919 (2050 million people died),1918-19 Pandemic,Spani。