Respiratory Syncytial Virus Questions With 100% Correct Answers.

How was RSV first discovered? - 1. First isolated in a group of chimpanzees 2. First named "chimpanzee coryza agent" 3. Later it was discovered that the chimps contracted the virus from a lab worker 4. Robert Chanock and his colleagues were able to isolate and characterize the virus in 1963 What are the general characteristics of RSV? - 1. Belonging to genus Pneumovirus 2. Medium sized non-segmented negative sense single-stranded RNA enveloped virus 3. 2 subtypes: A and B, with A being the symptomatic and more severe viral version 4. Three structural protein groups: nucleocapsid protein, phosphoprotein, and viral polymerase What are the growth and culture requirements of RSV? - 1. Low temperatures are optimal for growth 2. The incubation period for RSV is 2-8 days in humans 3. In a research study it showed that RSV was best cultured and isolated in human lung fibroblast and primary rhesus monkey kidney cells. How does RSV effect humans? - 1. Common respiratory virus that is more severe in infants and older adults 2. Infects lungs and all breathing passages 3. Most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lung) 4. 87% of infants have developed antibodies to RSV by 18 months old 5. By 3 years old, nearly all children have been infected 6. Symptoms -Barking cough -Difficulty breathing -Difficulty drinking -Lethargy-Nasal congestion -Wheezing -Cyanosis -Apnea What is RSV's infection mechanism? - 1. G Protein creates attachment of virus to epithelial cell (normally nasal epithelial) 2. Virus enters cytoplasm after F protein is cleaved (if this step does not occur, infection does not occur) 3. RSV replicates within host, and buds out when mature enough 4. Continued infection causes the destruction of the upper respiratory tract's epithelial cells 5. G protein is a major virulence factor - helping shield RSV from being neutralized by antibodies What is the adaptive and innate immunity to RSV? - 1. Humoral -some level of maternal antibody should be present, but very variable by age 2. Cell Mediated -Cytototoxic lymphocytes and T helper cells come into play for those affected with weaker or more compromised immune systems 3. F protein activates innate immune response via CD14 & TLR4 receptors (toll-like receptors) 5. Pulmonary surfactant is the first line of lung defense 6. Very quick neutrophil recruitment - and cytotoxic effect depends on its ability to stick to the virus 7. Monocyte production of IL-12 (antiviral cytokine) 8. In most cases, the body is not able to properly recruit eosinophils