Answers to Multiple Choice Questions - Paper 3
Instructions for candidates
The examination consists of 30 multiple choice questions, each
divided into 5 different parts. Each part contains a statement
which could be true or false. Each question will have at least
one part which is true. For each part, you should indicate
whether you think it is true (T), false (F), or don’t know (DN).
You must fill in the relevant square with a black pen. One mark
will be given for each correct answer and one mark deducted for
each incorrect answer. You will not be marked for those questions
for which you have indicated "don’t know".
| 1. The following are DNA viruses | |
| False | Influenza A virus |
| False | Rubella Virus |
| True | Hepatitis B Virus |
| True | CMV Virus |
| True | Parvovirus |
| Influenza A virus and Rubella Virus are RNA viruses. CMV Virus and Hepatitis B Virus are double-stranded DNA viruses. Parvovirus is a single-stranded DNA virus | |
| 2. The following are negatively stranded RNA viruses | |
| False | Picornaviruses |
| True | Orthomyxoviruses |
| False | Coronaviruses |
| False | Flaviviruses |
| True | Rhabdoviruses |
| Picornaviruses, coronaviruses and flaviviruses are positively stranded RNA viruses | |
| 3. The following viruses have segmented genomes | |
| True | Orthomyxoviruses |
| False | Herpesviruses |
| False | Paramyxoviruses |
| True | Bunyaviruses |
| True | Rotaviruses |
| The genome of orthomyxoviruses consists of 7 or 8 single stranded RNA segments, bunyaviruses 3 single stranded RNA segments, and rotaviruses 11 double stranded RNA segments. | |
| 4. The following are enveloped viruses | |
| True | Herpesviruses |
| False | Adenoviruses |
| False | Rotaviruses |
| False | Parvoviruses |
| True | Orthomyxoviruses |
| 5. All viruses | |
| False | Contain DNA |
| False | Contain RNA |
| True | Contain protein |
| False | Are susceptible to lipid solvents |
| True | Are intracellular parasites |
| Viruses contain either DNA or RNA. All viruses contain protein. Only enveloped viruses are susceptible to lipid solvents. All viruses are intracellular parasites. |
| 6. The following viruses are associated with human cancers | |
| False | HSV-2 |
| True | EBV |
| True | HCV |
| False | Adenoviruses |
| True | HHV-8 |
| HSV-2 was associated with genital cancers at one time but this has now been disproved. EBV is associated with Burkitt's lymphoma, nasopharyngeal carcinoma, and large-cell lymphomas in immunocompromised individuals. Although adenoviruses may be oncogenic in vitro, there is no evidence that they are associated with human cancers. HHV-8 is associated with Kaposi's sarcoma. | |
| True | HSV-2 |
| True | Rubella |
| True | HIV |
| True | HBV |
| True | CMV |
| All the above viruses may cause congenital infection. Rubella and CMV are usually transmitted transplacentally in utero, whilst HIV, HBV and HSV-2 are usually transmitted perinatally during the birth process. | |
| 8. The following viruses have reverse transcriptase | |
| True | HIV |
| False | Parvovirus |
| True | HBV |
| False | CMV |
| True | HTLV-1 |
| HIV and HTLV-1 are retroviruses. HBV is a DNA virus whose replication depend on a reverse transcriptase | |
| 9. The following viruses replicate in the nucleus | |
| True | Herpseviruses |
| False | Poxviruses |
| False | Picornaviruses |
| True | Orthomyxoviruses |
| False | Paramyxoviruses |
| All DNA viruses, with the exception of poxviruses replicate in the nucleus. All RNA viruses, with the exception of orthomyxoviruses, replicate in the cytoplasm | |
| False | Rubella |
| True | Rabies |
| True | Hantaviruses |
| True | Lassa Fever |
| True | Japanese Encephalitis |
| Zoonoses are infections which are transmitted from a vertebrate animal to humans either directly, or indirectly through an arthropod vector. Rabies may be transmitted to human from various mammals. Hantaviruses and Lassa fever from rodents. The reservoir of Japanese encephalitis is in birds and pigs and it is transmitted to humans via culex mosquitoes |
| False | HSV-1 |
| False | HBV |
| False | HIV |
| True | Influenza A Virus |
| True | Rotaviruses |
| Reassortment of genes occur in influenza A and rotaviruses. It is thought to be responsible for large changes in antigenicity | |
| 12. The following statements are true of prions | |
| False | Readily inactivated by autoclave at 121oC |
| False | Contain |
| True | Have long incubation periods |
| False | Highly immunogenic |
| False | May be readily cultured |
| Prions required autoclaving at 134 oC in order to be effectively inactivated.They consist probably solely of protein: no DNA had ever had demonstrated. Prion diseases are characterised by long incubation periods. Being host-derived, prion proteins are not immunogenic. They may not be cultured readily. | |
| 13. The following are "slow virus" diseases | |
| False | Herpes Simplex Encephalitis |
| True | Creutzfeldt-Jacob disease |
| True | Subacute Scelerosing Panecephalitis (SSPE) |
| False | Rabies |
| True | Progressive multifocal leucoencephalopathy (PML) |
| "Slow virus infections" refer to viral or prion infections of the brain characterised by a long incubation period which is in terms of years. Human prion diseases, Subacute Scelerosing Panecephalitis (SSPE), and Progressive multifocal leucoencephalopathy (PML) are considered as slow virus infections. Herpes Simplex Encephalitis and rabies are not. | |
| 14. HSV-1 infection may result in | |
| True | Encephalitis |
| True | Gingivostomatitis |
| True | Genital Herpes |
| True | Corneal Ulcers |
| False | Shingles |
| HSV-1 infection may result in encephalitis, gingivostomatitis, genital herpes, and corneal ulcers. Shingles arise from a previous infection by VZV | |
| 15. The following viruses are associated with a vesicular rash | |
| False | Rubella Virus |
| False | Measles Virus |
| False | Parvovirus |
| True | HSV-1 |
| True | VZV |
| Rubella, measles, and parvoviruses cause a maculopapular rash |
| 16. Cytomegalovirus (CMV) | |
| True | Primary infection is usually asymptomatic |
| True | An infectious mononucleosis-like syndrome may occur during primary infection. |
| True | May cause severe infection in immunocompromised individuals |
| True | May cause congenital infection |
| True | Reactivate from time to time |
| All the above | |
| 17. Epstein-Barr Virus (EBV) is associated with | |
| True | Infectious Mononucleosis |
| False | Kaposi's Sarcoma |
| True | Burkitt's lymphoma |
| True | Nasopharyngeal carcinoma |
| False | Adult T-cell lymphoma |
| HHV-8 is associated with Kaposi's sarcoma, HTLV-1 is associated with Adult T-cell lymphoma | |
| False | Fifth disease |
| False | Roseala Infantum |
| True | Kaposi's Sarcoma |
| False | Nasopharyngeal Carcinoma |
| False | Oral leukoplakia |
| Parvovirus is associated with fifth disease, HHV-6 with Roseala Infantum, EBV with Nasopharyngeal Carcinoma and oral leukoplakia | |
| 19. The following viruses are thought to cause gastroenteritis | |
| False | Enteroviruses |
| True | Caliciviruses |
| True | Norwalk-like viruses |
| True | Astroviruses |
| False | Paramyxoviruses |
| Although enteroviruses may be found in the faeces, they are not associated with gastroenteritis. Paramyxoviruses are not associated with gastroenteritis | |
| 20. The following statements are true | |
| True | Human polyoma virus JC is associated with progressive multifocal leucoencephalopathy (PML) |
| False | Human polyoma virus JC is associated with warts |
| False | HPV-6 and HPV-11 are associated with genital cancers |
| True | HPV-6 and HPV-11 are associated with Juvenile laryngeal papillomatosis |
| True | Patients with Epidermodysplasia verruciformis are susceptible to widespread warts caused by HPV |
| Human papillomaviruses (HPV) are associated with warts. HPV-16 and 18 are associated with genital cancers. Patients with Epidermodysplasia verruciformis are susceptible to widespread warts caused by a variety of HPV types. These lesions may become cancerous later on in life. |
| 21. The following statements are true | |
| True | Influenza A may undergo antigenic shift |
| False | Influenza B may undergo antigenic shift |
| True | Influenza A may undergo antigenic drift |
| True | Influenza B may undergo antigenic drift |
| False | Influenza B may respond to amantidine |
| Only influenza A is known to undergo antigenic shift. Both influenza A and influenza B may undergo antigenic drift. Only influenza A respond to amantidine | |
| 22. Respiratory Syncytial Virus | |
| False | Cause disease mainly in adults |
| True | May cause bronchiolitis |
| False | May be prevented by vaccination |
| False | May be treated by amantidine |
| False | May cause latent infections |
| RSV mainly causes disease in infants. It is the main cause of bronchiolitis. There is no vaccine available. It will not respond to amantidine but will respond to ribavirin. It is not known to cause latent infections, | |
| 23. HIV may respond to | |
| True | Nucleoside analogues |
| True | Protease inhibitors |
| False | Neuraminidase inhibitors |
| True | Reverse transcriptase inhibitors |
| True | Acyclovir |
| HIV may respond to reverse transcriptase inhibitors, many of which are nucleoside analogues. It may also respond to HIV protease inhibitors which are the most potent agents to date. Neuraminidase inhibitors are used for the treatment of influenza virus infections whilst acyclovir is used for herpesvirus infections. | |
| 24. During the incubation period of HIV infection, there is | |
| False | Little HIV replication |
| False | HIV is mainly integrated into the genome of long-lived cell populations |
| True | High turnover of CD4 cells |
| True | The viral load has a direct bearing on the prognosis |
| False | Little antibody against the HIV envelope |
| During the incubation period, there is a huge amount of viral replication and consequently a high turnover of CD4 cells. Only a very small proportion of HIV is integrated into the genome of long-lived cell populations. The viral load has a direct bearing on the prognosis. HIV envelope antibody remains at a high level throughout the incubation period. | |
| 25. Hepatitis A infection | |
| False | May result in chronic infection |
| True | May be prevented by immunoglobulin |
| True | May be prevented by vaccination |
| False | Is highly infectious during the jaundice phase |
| False | May result in cirrhosis |
| HAV infection does not result in chronic infection and therefore cirrhosis. It may be prevented by the administration of human normal immunoglobulin (HNIG), and active vaccination by an inactivated vaccine. By the time jaundice appears, there is little viral excretion and thus infectivity. |
| True | May result in chronic infection |
| True | May result in cirrhosis of the liver |
| True | May result in hepatocellular carcinoma |
| True | Is highly infectious when positive for HBeAg |
| True | May respond to interferon therapy |
| HBV infection may result in chronic infection, cirrhosis of the liver and hepatocellular carcinoma. The presence of HbeAg indicates viral replication and thus infectivity. Chronic HBV infection may respond to interferon therapy. | |
| 27. The following statements are true of hepatitis B core escape mutants | |
| True | Associated with fulminant hepatitis |
| False | HbeAg positive |
| True | anti-HbeAg antibody positive |
| True | HBV-DNA positive |
| False | Anti-HbsAg antibody positive |
| Hepatitis B core escape mutants are associated with acute fulminant hepatitis. They are anti-HbeAg antibody positive and HBV-DNA positive. HbsAg is present and therefore they should be no anti-HbsAg antibody. | |
| 28. Hepatitis C virus | |
| True | May be transmitted by blood |
| True | Is associated with hepatocellular carcinoma |
| True | May respond to interferon therapy |
| False | Has one stable genotype only |
| False | May cause chronic infection |
| HCV is mainly transmitted by blood. It may cause chronic infection and is associated with hepatocellular carcinoma. It may respond to interferon therapy. There are a number of HCV genotypes. | |
| 29. The following statements are true | |
| True | Dengue virus infection result from bites by Aedes mosquitoes |
| True | Cases of dengue haemorrhagic fever usually result from reinfection by a different serotype of dengue virus |
| False | Pigs act as the reservoir for dengue virus |
| False | Yellow fever is prevalent throughout Asia |
| True | Yellow fever may be prevented by vaccination |
| Dengue virus infection result from bites by Aedes mosquitoes. Cases of dengue haemorrhagic fever usually result from reinfection by a different serotype of dengue virus: an immunopathological mechanism is thought to be involved. No animal reservoir is involved in the vast majority of dengue cases: transmission arise from a man-mosquito-man cycle. Yellow fever is not found in Asia, it is prevalent in some West African and Central and South American countries. It can be prevented by vaccination with a live attenuated vaccine. | |
| 30. Measles virus | |
| True | Infection may result in pneumonia |
| True | Infection may result in encephalitis |
| False | Undergo antigenic drift |
| False | May respond to acyclovir |
| True | May be prevented by vaccination |
| Measles virus infection may result in pneumonia and encephalitis. There is one stable serotype. Measles will not respond to acyclovir but can be prevented by vaccination. |
