click below
click below
Normal Size Small Size show me how
RS Microbiology
Respiratory System Microbiology - Virology of LRTI
| Question | Answer |
|---|---|
| Important viral causes of LRTI: | Influenza Para-influenza Respiratory syncytial virus SARS MERS Human metapneumovirus (2001) common in comprised children and elderly persons |
| Para influenza Viruses cause: | Croup (Acute Laryngotracheobronchitis),pneumonia in children, and common cold – like disease in adults |
| 5 subtypes for Para Influenza viruses: | 1, 2, 3, 4a and 4b |
| Surface spikes on para influenza viruses consist of: | H, N and fusion proteins |
| Transmission of Parainfluenza via: | Respiratory droplets |
| Clinical findings of infection with parainfluenza: | Croup – Harsh cough – Inspiratory stridor – Hoarse voice Patients are usually afebrile. About 80% of patients exhibit runny nose |
| Which other viruses can induce croup? | Influenza viruses RSV Measles and chickenpox |
| Lab diagnosis: | Clinically for croup Cell culture isolation Immunoflurescence Antibody rising titre using HAI or ELISA |
| Treatment for parainfluenza: | Nursing in plastic tents supplied with cool, moistened oxygen Severe respiratory obstruction may require endotracheal intubation followed by a tracheotomy |
| RSV infections cause: | Pneumonia Bronchiolitis in infants |
| RSV is a major nosocomial pathogen in: | Pediatric wards |
| Transmission of RSV | Respiratory droplets and direct contact of contaminated hands with the nose or eye |
| Incubation period is: | 3-6 days |
| Syncytia form in which organ, in the case of RSV? | The lungs |
| RSV is the most common cause of: | Severe lower respiratory disease in young infants 50-90% bronchiolitis 5-40% pneumonias |
| In young children, RSV may cause: | Otitis media |
| In older children and adults, RSV may cause: | Common cold like disease |
| What is the effect of RSV infections in infants? | Febrile URTI Lower respiratory tract involvement Worsening cough Tachypnoea and dyspnoea Hyperinflation of lungs Cyanosis |
| Risk groups for RSV infections: | Infants with congenital heart disease Infants with pulmonary disease Immunocompromised infants Nephrotic syndrome and cystic fibrosis |
| Complications of RSV infections: | 1) Apnea 2) Alterations in pulmonary functions which may lead to chronic lung diseases later in life |
| Laboratory diagnosis of RSV infection is done with: | Immunoflurescence on smears of respiratory secretions ELISA for detection of RSV antigens Isolation in cell culture (multinucleated giant cells or syncytia) Rise of antibody titer |
| Characteristics of SARS-causing virus: | Enveloped virus, Replicates in cytoplasm of animal cells Single-strand 30 kb RNA genome First identified in Guangdong Province, China in 2002 Associated Coronavirus SARS-HCoV Replication in cytoplasm rather than nuclei |
| Symptoms for SARS: | Initially: High fever of 38оC or higher, head and body aches, and malaise. Week Later: dry cough, difficulty breathing and severe diarrhea. Recovery: after 5 to 6 days |
| Diagnostic tests for SARS: | Antivirals and steroids used for atypical pneumonia Lab tests: RT-PCR EIA ELISA |
| Prevention: | Isolation Sterilization of area 3 possible Vaccines (whole-killed, adenovirus vector, or recombination spike protein |
| What is MERS? | Middle East respiratory syndrome coronavirus |
| MERS was first reported in: | Saudi Arabia |
| Characteristics of MERS: | Positive-sense, single-stranded RNA virus of the genus Betacoronavirus |
| MERS-CoV is distinct from | SARS coronavirus Common-cold coronavirus Betacoronaviruses (HCoV-OC43 and HCoV-HKU1) |
| How does transmission of MERS occur? | Via respiratory secretions |
| Metapneumovirus was first isolated in: | Nasophargyngeal aspirates from 28 children over a 20 year period |