Virology Questions on “Respiratory, Measles and Rubella Viruses”.
1. The reinfection from respiratory syncytial virus is called _____________
a) ART
b) URTI
c) MST
d) RTV
Answer: b
Clarification: The reinfection from the respiratory syncytial virus (RSV) is called upper respiratory tract infection (URTI). Among children and adults, the reinfections are common. It occurs during colder months and rainy season.
2. The RSV virus belongs to the genus __________
a) Pneumovirus
b) Karamvirus
c) Lilyvirus
d) Macanavirus
Answer: a
Clarification: The respiratory syncytial virus (RSV) belongs to the genera Pneumovirus. It is placed under the family Paramyxoviridae and subfamily Pneumovirinae. The RSV virus has no hemagglutinin or neuraminidase activity.
3. The RSV virus contains ___________ genome.
a) ssDNA
b) ssRNA
c) dsDNA
d) dsRNA
Answer: b
Clarification: The RSV virus possesses single-stranded negative-strand RNA as their genome that has a length of about 15 kilobases. The replication of the virus takes place in the cytoplasm of the infected-cells and infectious virions are released by budding through the cell membrane.
4. Which of the following receptor molecule is used by genus Morbilliviruses?
a) CD10
b) CD25
c) SLAM
d) ICAM
Answer: c
Clarification: The signaling lymphocyte activation molecule (SLAM) is used by the viruses of genus Morbilliviruses. The measles virus, rinderpest virus, etc. all enter cells through SLAM. The cellular distribution of SLAM overlaps the sensitivity of different cell types to wild type MV infection.
5. Which of the protein supports measle virus replication and transcription?
a) M
b) F
c) P
d) V
Answer: c
Clarification: The P protein is a protein whose main function is to support the replication and transcription of the virus and it is the essential component of the polymerase. The protein is phosphorylated and contains high intrinsic disorder, facilitating interactions with multiple viral and cellular proteins.
6. Which of the following protein counteract the innate response?
a) M
b) V
c) F
d) C
Answer: b
Clarification: The V protein is a protein whose main function is to counteract the innate immune response. It interferes with intracellular signaling pathways supporting the interferon response and sustain the virus spread in the host immune response.
7. Which of the following is the hallmark of MV infection?
a) Swelling of salivary glands
b) Depression of sperm production
c) Kidney failure
d) Multinucleated giant cells
Answer: d
Clarification: The formation of multinucleated giant cells is the histopathological hallmark of measles virus infection. It is also known as syncytia formation. MV viruses infect endodermal, ectodermal, and mesenchymal origin and syncytial cells.
8. Which of the following antibody initially responds to MV virus infection?
a) IgM
b) IgA
c) IgD
d) IgE
Answer: a
Clarification: IgM antibody initially responds to MV virus infection, followed by type I CD4 and CD8+ T-cell responses, and followed by the IgG antibody. These responses are completely effective in controlling viral replication and resolution of the infectious process.
9. Which of the following causes German measles?
a) HIV
b) Influenza
c) Corona
d) Rubella
Answer: d
Clarification: The rubella virus (RUBV) causes German measles. It is a benign disease which is also known as rubella. This can result in profound birth defects if contracted in utero. RUBV is a major teratogen.
10. Rubella virions are susceptible to aldehyde.
a) True
b) False
Answer: a
Clarification: Rubella virions are susceptible to aldehyde. Other commonly used inactivating agents are UV light and lipid solvents. They can be frozen at temperatures below -20°C without the loss of infectivity and are stable at physiological pH.
11. RT-PCR is used to detect rubella virus in saliva.
a) True
b) False
Answer: a
Clarification: The reverse-transcription-polymerase chain reaction (RT-PCR) is used to detect rubella virus in saliva, urine, or blood. It can be used to detect virus RNA in amniotic fluid or chorionic villi.