Viral Respiratory Tract Infection - Ghoul PDF

Viral Respiratory tract Infection By: Mustafa Abdul Nasir Ali Alkaseh Objective: 1. Discuss the general characteristics clinical symptom, preventions of coronavirus, and Hantavirus pulmonary syndrome. 2. Describe the properties, pathogenesis, clinical features, treatment and prevention of...

Viral Respiratory tract Infection By: Mustafa Abdul Nasir Ali Alkaseh Objective: 1. Discuss the general characteristics clinical symptom, preventions of coronavirus, and Hantavirus pulmonary syndrome. 2. Describe the properties, pathogenesis, clinical features, treatment and prevention of human influenza virus. 3. Discuss the general properties, pathogenesis and clinical findings of parainfluenza virus and respiratory syncytial virus. Table of contents 01 Coronavirus 02 Hantavirus 03 Influenza virus 04 Parainfluenza 05 Respiratory syncytial virus. 01 Coronavirus Characteristics of Coronavirus: Non-segmented, single-stranded, (+) polarity RNA. Enveloped with a helical nucleocapsid. E/M: Club-shaped spikes in the form of corona (halo). They use these Spikes to attach and enter host cells. Has 2 serotypes called 229E and OC43. Severe acute respiratory syndrome (SARS): is caused by a genome sequence of coronavirus that isn’t in the existing human strains. The receptor for the SARS on the host cell is angiotensin- converting enzyme 2. (ACE II) Middle East Respiratory Syndrome (MERS-CoV) is another severe pneumonia. C/F of Coronavirus: 1. Common cold characterized by - Coryza (rhinorrhea, runny nose) scratchy sore throat, and low-grade fever, Bronchitis. - lasts several days with no long-term sequelae. 2. SARS (severe atypical pneumonia) is characterized by: - fever (at least 38c), nonproductive cough, dyspnea. - hypoxia, chills, rigors, malaise, and headache. - Sore throat and rhinorrhea are uncommon. - Leukopenia and thrombocytopenia are seen. - CXR reveals interstitial ground glass infiltrates. 3. MERS has the same clinical manifestations as SARS. - Both Lasts for 2-10 days. Treatment and prevention: Treatment Prevention - No antiviral therapy or - COVID-19 vaccines: vaccine is available.. inactivated or weakened virus vaccines. 02 Hantavirus Characteristics of Hantavirus: Single-stranded, enveloped. Negative-sense RNA virus. Belongs to the bunyavirus family. It’s arbovirus (rodent-borne) unlike arboviruses that are arthropod-borne. Causes Korean hemorrhagic fever (KHF) in Asia and Europe. Hantavirus pulmonary syndrome (HPS): - caused by a hantavirus (Sin Nombre Virus). C/F of Hanta Virus: 1. Influenza-like symptoms followed rapidly by (ARF) 2. KHF is characterized by headaches, petechial hemorrhages, shock, and renal failure. 3. Transmitted by inhaling aerosols of rodent’s urine and feces. No person-to-person transmission. - Treatment and Prevention: A. No effective drug. B. No vaccine. C. Mortality rate is 10%. 03 Influenza.V Characteristics of Influenza.V: 1. Segmented (8-piece) single-stranded negative-sense RNA virus with Virion RNA polymerase (Ortho-myxo-virus family). 2. Lipoprotein envelope with helical nucleocapsid and 2 surface spikes (hemagglutinin & neuraminidase). 3. Influenza has group–specific (for A, B, C) and type-specific antigens (based on Hemagglutinin and neuraminidase): A.Influenza A: Pandemic, B. Influenza B: Outbreaks. C. Influenza C: mild RTI 4. Antibodies against hemagglutinin neutralize infectivity. Antibodies against neuraminidase reduce the spreading of the disease. 5. The determinant of Virulence is a nonstructural protein called NS-1 which inhibits the host cell's ability to produce interferon mRNA. Characteristics of Influenza.V: 1. Influenza A: shows changes in antigenicity by: A. Antigenic Shift (reassortment of genome segments) B. Antigenic Drift (mutation in the genome). (Antigenic Shift causes animal variants to infect humans) 2. Influenza A has 2 matrix proteins; A. M1 (for structural integrity). B. M2 (ion channel for uncoating of virion). 3. Influenza B: cannot undergo Antigenic Shifts. but it undergoes Antigenic Drift enough to have to create a new version of the vaccine yearly. 4. Humans influenza, there are 3 types of hemagglutinin (H1, H2, H3) and 2 types of neuraminidase (N1, N2) Pathogenesis Influenza Virus: Forth Immunity depends on Third secretory IgA and Viremia rarely occurs, cytotoxic T cells. IgG is Second but due to circulating less protective Infection is limited to cytokines in the blood, First the respiratory tract there is severe After inhalation of the because of the myalgia. Necrosis of virus, neuraminidase protease that cleaves the superficial layers of degrades protective the hemagglutinin. respiratory epithelium. mucus, allowing the virus access to cells of the respiratory tract. C/F of Influenza Virus: 1. After 24-48 hours, fever, severe myalgias, headache, sore throat, and cough develop suddenly. 2. Vomiting and diarrhea are rare. 3. Symptoms resolve spontaneously after 4-7 days but influenzal or bacterial pneumonia (s.aureus) complicates the course. 4. Reye’s syndrome: characterized by encephalopathy and liver degeneration is rare but life-threatening in children. Usually follows viral infections such as influenza B and chickenpox. (Aspirin given for fever) Treatment & Prevention & Diagnosis: 1. PCR & Antibody titers & ELISA. Diagnosis 2. FLU-OID test, and FSTAT-FLU test. 1. Neuraminidase inhibitors: Oseltamivir and Treatment Zanamivir are Used for both Influenza A and B. 2. Amantadine: effective for influenza A only 1. Killed Vaccine (works for 6-months only). Prevention 2. Live-attenuated Vaccine. 04 Parainfluenza Characteristics of Parainfluenza: 1. Enveloped non segmented, single-stranded RNA of negative polarity. Has virion RNA polymerase and a helical nucleocapsid. 2. Surface spikes: consist of hemagglutinin and neuraminidase on the same spike, and fusion protein on a separate spike. Forms multinucleated giant cells. 3. Has 4 types based on antigenicity, cytopathic effect, & pathogenicity. Pathogenesis: ❖ Causes upper and lower respiratory tract diseases without viremia. ❖ Type 1 & 2: major causes of croup. ❖ Type 3: MC in children with lower RTI. ❖ Type 4: rarely causes disease, except common cold. C/F of Parainfluenza : 1. Main cause of croup in children below 5 years. Characterized by harsh cough and hoarseness. 2. Cause common cold, pharyngitis, laryngitis, otitis media, bronchitis, and pneumonia.  Respiratory 05 syncytial virus. Characteristics of RSV: 1. Enveloped non-segmented, single-stranded RNA of negative polarity. Has virion RNA polymerase and a helical nucleocapsid. 2. Surface spikes: are fusion proteins that cause cells to fuse forming multinucleated giant cells (syncytia). 3. Humans are natural hosts of RSV. It has 2 serotypes (A and B). Pathogenesis: 1. More severe in infants, involving the (LRT). No Viremia. 2. In infants: have an immunopathogenic mechanism due to maternal antibodies forming immune complexes that damage respiratory cells. 3. Most individuals get multiple infections but the reason is unknown (not antigenic variation) C/F of Respiratory syncytial virus.: 1. In infants: - bronchiolitis and pneumonia (lower respiratory tract). 2. In young children: - otitis media. 3. Older children and healthy adults: - common cold and bronchitis. 4. In the elderly (65+) and adults: - Chronic cardiopulmonary diseases, severe lower respiratory tract disease including pneumonia.  Thanks Bofa Ghoul Was Here. ‫َوﻣَﺂ أ ُوﺗِﯾﺗُم ﻣﱢنَ ٱ ْﻟ ِﻌﻠْمِ إ ﱠِﻻ َﻗﻠ ًِﯾﻼ‬ CREDITS: This presentation template was created by Slidesgo, and includes icons by Flaticon and infographics & images by Freepik