Paramyxoviruses Lecture Notes PDF

Respiratory system module microbiology Prof. azza labeeb Professor and head of microbiology and immunology department  Paramyxovirus virus viral upper respiratory infection *By the end of this lecture, students should be able to: 1.Recognize and classify differe...

Respiratory system module microbiology Prof. azza labeeb Professor and head of microbiology and immunology department  Paramyxovirus virus viral upper respiratory infection *By the end of this lecture, students should be able to: 1.Recognize and classify different types and sites of respiratory tract infection. 2.Identify the most important micro-organisms causing Upper and lower respiratory tract infections. 3.Classify paramyxovirus family 4-interpret the different clinical syndrome produced from paramyxovirus family  Respiratory tract infection classification Upper respiratory tract Lower respiratory tract Site infection Site infection Sinus Sinusitis Trachea Tracheitis Middle ear Otitis media Pharynx Pharyngitis Bronchi Bronchitis Tonsils Tonsillitis Epiglottis Epiglottitis Larynx laryngitis Lung Pneumonia  Common respiratory infection classification I- Viral Upper respiratory tract infections and bronchitis II- bacterial Upper respiratory tract infections and bronchitis III- Lower respiratory tract infection The lungs (pneumonia) IV-Pulmonary TB I- Viral Upper respiratory tract infections and bronchitis Clinical disease causes I- influenza and common cold Orthomyxovirus =influenza virus Rhino virus = common cold II- upper respiratory disease paramyxovirus parainfluenza virus-RSV III- Coronavirus Covid-19 IV-prodromal stage of upper respiratory infection paramyxo virus =mump and measles  RNA enveloped Important viruses Important character Orthomyxoviruses Influenza A,B and C Segmented RNA virus Cause influenza Paramyxoviruses RSV-parainfluneza Main cause of respiratory disease and croups in infant Measles Cause Measles Mumps Cause Mumps  Paramyxoviruses 4 members 1- Parainfluenza 2- Mumps 3- Measles airborne 4- Respiratory syncytial virus (RSV)  Important properties Fusion protein (F) Antigenically stable 14 multinucleated giant cell (Syncytium) Dr.T.V.Rao MD 15   Important properties of Paramyxoviruses 1-SS RNA-non segemented 2-Envelope 3-F spikes (F fusion ) that mediate virus fusion with cell and cell to cell fusion and form multinucleated giant cell (Syncytium) 4-Antigenically stable. No mutation- No reassortment N.B also have HA NA  Parainfleunza  Disease 1-Upper respiratory infection 2-the first cause of croups in infant , young children under one year age Correct in the book please Transmission: Respiratory droplet  Parainfleunza CROUP Laryngotracheitis, laryngotracheobronchitis AFFECTION OF larynx, trachea, and may be bronchi =swelling of larynx and upper air way obstruction Laryngotracheitis, laryngotracheobronchitis lead to inspiratory stridor and barking cough (dog voice –seal voice).  Respiratory syncytial virus (RSV) Pathogenesis All have fusion spikes (F) that mediate virus fusion with cell and cell to cell fusion and form multinucleated giant cell (Syncytium).  Respiratory syncytial virus (RSV) DISEASE 1-The first cause of lower respiratory disease (bronchiolitis and pneumonia) in neonates, infant -in infant difficult to breath -also cause croup 2-common cold in adult Immune Escape in RSV F protein variation This alteration in conformation can lead to immune evasion, potentially impacting disease severity, outbreaks, and reinfections. DISEASE spread by droplet and contact  RSV Vaccine  Infection typically starting during the fall and peaking in the winter RSV typically peaks between December and February. It is important that babies have protection before RSV season peaks.  In May 2023, the US Food and Drug Administration (FDA) approved the first RSV vaccines,  Arexvy (developed by GSK plc) contains recombinant RSV glycoprotein F  Abrysvo (Pfizer). contains recombinant RSV glycoprotein F  An RSV antibody (nirsevimab) MONOCLONAL antibody Who get both vaccines? 1-old age above 60 2-patient with immunosuppressed condition 3-not approved for children only antibody for children 4- Only Pfizer Abrysvo approved for mothers during pregnancy to protect child 32 through 36 1-An RSV maternal vaccine (Pfizer Abrysvo) is also available for pregnant mothers at weeks 32-36 of pregnancy to pass on protection to their baby. 2-Infants and young children To prevent severe RSV disease in infants, CDC recommends either maternal RSV vaccination or infant immunization with RSV monoclonal antibodies. Most infants will not need both. Monoclonal antibody vaccine An RSV antibody (nirsevimab) is available for babies and some young children to protect them from severe RSV. The final vaccine type developed for use against the respiratory syncytial virus involves using a monoclonal antibody to attack the surfaces on the virus’ F protein in infants at birth.  Mumps Virus Disease: Mumps enlargement of parotid gland Spread by droplet  Mumps Virus Complications: 1. Orchitis in post-pubertal males  may lead to sterility if bilateral 2. Meningitis – usually benign, self-limited, and without sequelae  Mumps Virus Prophylaxis: Vaccination by Living attenuated vaccine MMR vaccine.measles mump rubella vaccine. S.C injection: 2 doses first at 15 month second at school entry (4-6 years) as it gives immunity for 10 years  Measles virus  This virus causes Measles = Rubeola. a) fever, respiratory symptoms b) red eye-Kopliks spots in prodromal stage c) then maculopapular skin rash starts on head→ to trunk Transmission: airborne transmition Prevention: Living attenuated vaccine MMR vaccine Measles mumps rubella  Rubella or German measles=3 day measles Disease characterized by rash –fever - children mainly affected It's caused by rubella virus which is togavirus -ssRNA –enveloped Mode of transmission 1-postnatal Rubella→ by droplet 2-Congenital rubella→ transplacental  Clinical picture 1- Rubella(German measles) Affect children and adult by droplets  maculopapular rash  Rash starts on Face Extremities  enlargement of subocciptal LNs- enlargement of cervical LNs 2-Congenital Rubella syndrome (teratogenic virus) It's caused by rubella virus If infection occur in pregnant female dangerous due to congenital anomaly –Transplacental transmission occur. Effect Danger if in first trimester leads to leads to congenital anomalies: 1-mental retardation 2-deafness 3- blindness  Prevention: Living attenuated vaccine given in combination against Mumps, Measles and Rubella called MMR Single rubella vaccine recommended for girls before marriage if not immune Vaccine should avoided in pregnant and in immunosupperesed