[an error occurred while processing this directive]

Answers to Mulitple Choice Questions - Paper 1

 

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. Viruses
False Contain both DNA and RNA
True May have an envelope
False Have their own metabolism
True May contain enzymes for replication
False Cell wall
 Comments  Viruses contain either DNA or RNA but not both. Some may have an envelope. Unlike bacteria, they do not have a cell wall or their own metabolism. They may contain enzymes for replication.
   
  2. The following are DNA viruses
True  Herpesviruses
False Orthomyxoviruses
False Enteroviruses
True  Hepadnaviruses
True  Parvoviruses
 Comments  Herpesvirus and Hepadnaviruses are double stranded DNA viruses. Parvovirus is a single stranded DNA virus. Orthomyxoviruses and enteroviruses are singles stranded RNA viruses.
   
  3. The following are RNA viruses
True  Picornaviruses
False Adenoviruses
False Papillomaviruses
True  Rhabdoviruses
True  Rotaviruses
 Comments Adenoviruses and papillomaviruses are double standed DNA viruses. Picornaviruses and rhabdoviruses are single stranded RNA viruses. Rotaviruses are double stranded RNA viruses.
   
  4. Live attenuated vaccines are available against the following viruses
False Influenza A Virus
False Hepatitis B Virus
True Rubella Virus
True Yellow Fever Virus 
True Varicella-Zoster Virus
 Comments  Live attenuated vaccines are available against rubella, yellow fever, and varicella-zoster viruses. Influenza A viral vaccines are either inactivated split or subunit vaccines. The vaccines in current use against hepatitis B are recombinant subunit vaccines.
   
  5. The following antiviral agents is active against the following virus
True Lamivudine and HIV
True Lamivudine and HBV
False Amantidine and influenza B virus
True Ribavirin and RSV
True Acyclovir and HSV
Comments Lamivudine is a reverse transcriptase inhibitor active against both HIV and HBV. Amantidine is active against influenza A only. Ribavirin is active against RSV and acyclovir against HSV


 
 

  6. Herpes Simplex Encephalitis
True Commonly affect the temporal lobe
False Is usually diagnosed by culture of the CSF
True May be diagnosed by PCR of the CSF
False Should be treated with IV ganciclovir
True May be diagnosed by the finding of specific antibody in the CSF
Comments   Herpes Simplex Encephalitis commonly affect the temporal lobe. Culture of the CSF is usually unsuccessful. PCR of the CSF is a much better choice. A diagnosis can also be made by the detection of HSV-specific antibodies in the CSF. Herpes Simplex Encephalitis should be treated with IV acyclovir.
   
 
  • 7. The following statements are true of Varicella-Zoster Virus
  • False Causes a maculopapular rash
    False Respond to AZT therapy
    True Remains latent in sensory ganglia following primary infection
    False Recurrent episodes of Shingles usually occur
    False Patients with shingles are not infectious
     Comments  VZV causes a vesicular rash. It does not respond to AZT as it does not possess reverse transcriptase. It remains latent in sensory ganglia following primary infection. It is rare for more than one episode of shingles to occur. Patients with shingles are infectious.
       
      8. Cytomegalovirus (CMV)
    True Primary infection is usually symptomatic
    True An infectious mononucleosis-like syndrome may occur during primary infection.
    True May cause severe infection in immunocompromised individuals
    False Is teratogenic
    False Causes Kawasaki's Disease
    Comments  Primary CMV infection is usually asymptomatic. Occasionally, an infectious mononucleosis-like syndrome may occur during primary infection. CMV is well known to cause severe disease in immunocompromised individuals, notably transplant recipients and patients with AIDS. Although it may cause severe congenital infection, it is not teratogenic. It attacks already formed fetal organs. It is not associated with Kawaski's disease.
       
      9. Epstein-Barr Virus (EBV) is associated with
    True Infectious Mononucleosis
    True Hepatitis
    True Burkitt's lymphoma
    True Nasopharyngeal carcinoma
    True Oral leukoplakia 
     Comments  All the above
       
     
  • 10. HHV-6 is associated with
  • False Fifth disease (erythema infectiosum)
    True Roseala Infantum
    False Kaposi's Sarcoma
    True Infectious Mononucleosis-like illness
    False Oral leukoplakia
    Comments Parvovirus is associated with Fifth disease (erythema infectiosum). HHV-6 is associated with Sixth disease (Roseala Infantum) HHV-8 is associated with Kaposi's sarcoma. Rarely, in adults, primary HHV-6 infection may result in an infectious mononucleosis-like illness. EBV is associated with oral leukoplakia


     
     

     
  • 11. Adenoviruses
  • False Are associated with genital cancers
    True May cause gastroenteritis
    True May cause conjunctivitis
    True May cause pneumonia
    False May cause warts
     Comments  Human papillomaviruses are associated with genital cancers. Adenoviruses type 40 and 41 are associated with gastroenteritis. Adenoviruses may also cause conjunctivitis and pneumonia. Human papillomaviruses are associated with warts.
       
      12. Human Papillomaviruses
    False HPV-6 and HPV-11 are associated with genital cancers
    True HPV-16 and HPV-18 are associated with genital cancers
    True Warts caused by papillomaviruses may respond to interferon therapy
    False Papillomavirus infection is commonly diagnosed by viral culture
    False Are associated with progressive multifocal leucoencephalopathy (PML)
     Comments  HPV-16 and HPV-18 are associated with genital cancers. Warts caused by papillomaviruses may respond to interferon therapy although it is rarely used. Huamn Papillomaviruses cannot be grown in cell culture. Polyomavirus JC is associated with PML.
       
      13. Coxsackie B Virus is associated with the following
    True Paralytic illness
    True Myocarditis
    True Bornholm's disease
    True Severe congenital infection
    True Meningitis
     Comments  All the above
       
      14. Influenza A Virus
    True May undergo antigenic shift and antigenic drift
    True May cause pandemics
    True Respond to rimantidine
    True Respond to neuraminidase inhibitors
    False Vaccination confers lifelong protection
     Comments  Influenza A Virus may undergo antigenic shift and antigenic drift. Antigenic shifts result in pandemics. Influenza A virus will respond to rimantidine, which is a similar compound to amantidine. It will also respond to newly available neuraminidase inhibitors. Because of constant antigenic changes, vaccination will not confer lifelong immunity; it will last for one year only.
       
      15. Paramyxoviruses may cause
    True Croup
    False Maculopapular rash
    True Pneumonia
    True Bronchiolitis
    False Diarrhoea
    Comments   Paramyxoviruses most commonly cause croup. They may occasionally cause bronchiolitis and pneumonia. 


     
     

      16. Respiratory Syncytial Virus (RSV)
    False Respond to Amantidine
    True May cause bronchiolitis 
    True May cause croup
    True May cause pneumonia
    False May be prevented by vaccination
     Comments  RSV will not respond to amantidine. It most commonly cause bronchiolitis and pneumonia. Occasionally, it may cause croup. There is no vaccine available.
       
      17. Parvoviruses
    False Causes Roseola Infantum
    True Causes Erythema Infectiousum
    False Is teratogenic
    True May cause abortion
    True May cause aplastic crisis in persons with haemolytic anaemias
     Comments Parvovirus causes erythema infectiousum. Although it may cause abortion and stillbirths, it is not teratogenic. It causes  aplastic crisis in persons with haemolytic anaemias
       
     
  • 18. Measles Virus Infection
  • False Causes a vesicular rash
    True May cause encephalitis
    False May respond to acyclovir
    True May be prevented by HNIG
    True May be prevented by vaccination
     Comments  Measles causes a maculopapular rash. It may cause encephalitis. It does not respond to acyclovir. Susceptible individuals may be protected by HNIG. A live attenuated vaccine is now given as part of universal vaccination in many countries.
       
      19. Rubella Virus
    True The rash of rubella is similar to that caused by parvo and enteroviruses
    True Is teratogenic
    True Congenital rubella is charaterised by eye, ear and heart defects
    True Congenital rubella is diagnosed by the finding of rubella-specific antibody in the cord blood of infants
    True Infants with congenital rubella poses a great infectious risk.
     Comments  The rash of rubella is similar to that caused by parvo and enteroviruses. It is teratogenic, the classical triad of congenital rubella consists of eye, ear and heart defects. Congenital rubella can be diagnosed by the finding of rubella-specific antibody in the cord blood of infants.Infants with congenital rubella poses a great infectious risk since they may excrete the virus for up to 1 year.
       
      20. Human T-lymphotropic virus 1 (HTLV-1) is associated with
    False Burkitt's lymphoma
    True Adult T-cell lymphoma
    True Tropical Spastic Paraparesis
    False Multiple Sclerosis
    False Hodgkin's lymphoma
     Comments  Human T-lymphotropic virus 1 (HTLV-1) is associated with Adult T-cell lymphoma and Tropical Spastic Paraparesis


     
     

      21. HIV Infection may lead to
    True Dementia
    True Chronic Diarrhoea
    True CMV retinitis
    True Oesophageal candidiasis
    True Non-Hodgkin's lymphoma
     Comments  All the above
       
     
  • 22. The following may be useful for prognostic purposes in HIV-infected individuals 
  • False HIV envelope antibody level
    True HIV-p24 antigen
    True CD4 count
    False HIV pro-viral DNA in leucocytes
    True HIV plasma RNA
     Comments  HIV envelope antibody remains high at a constant level throughout the period of infection and is thus of no use as a prognostic marker. HIV-p24 antigen had been widely used as a prognostic marker in the past but has now been supplanted by HIV plasma RNA (viral load). The CD4 count provides important information on the stage of the disease.
       
      23. A chronic carrier state may occur in the following:
    False Hantavirus Infection
    False Hepatitis A
    True Hepatitis B
    True Hepatitis C
    False Smallpox Infection
     Comments A chronic carrier state may occur with HBV and HCV infection.
       
     
  • 24. The following markers are usually present in a hepatitis B carrier with chronic active hepatitis
  • True HbeAg
    True Anti-HBc IgG
    False Anti-HBc IgM
    True HBV-DNA
    True HbsAg
     Comments In patients with chronic active hepatitis, HBV replication is present and hence HBV-DNA and HbeAg. HbsAg is present. Anti-HbcIgM is normally absent although it may occasionally be detected during periods of exacerbations. Anti-HBc IgG is present.
       
      25. The following statements are true
    True Chronic HBV infection may respond to interferon therapy
    True Chronic HCV infection may respond to interferon therapy
    True Chronic HCV infection may respond to ribavirin therapy
    True Hepatitis Delta infection may be prevented by vaccination against HBV
    False Hepatitis E Infection may be prevented by vaccination
    Comments Chronic HBV and HCV infection may respond to interferon therapy. Chronic HCV infection may respond to ribavirin therapy; however ribavirin is usually given with interferon. Hepatitis Delta infection may be prevented by vaccination against HBV. There is no vaccine available against HEV.


     
     

      26. The following viruses can be transmitted by blood
    True Hepatitis A
    True HIV
    True HTLV-1
    True HBV
    True HCV
     Comments  All the above viruses may be transmitted by blood
       
      27. Regarding viral infection of the central nervous system (CNS)
    True Meningitis may occur together with encephalitis
    True Enteroviruses are one of the commonest causes of CNS infections in childhood
    False HSV encephalitis is a postinfectious encephalomyelitis
    True Measles encephalitis is a postinfectious encephalomyelitis
    True The detection of antibody in the CSF is a useful diagnostic marker
     Comments  Meningitis usually occurs with encephalitis. Enteroviruses are one of the commonest causes of CNS infections in childhood. HSV encephalitis result from invasion of the virus rather than an allergic postinfectious event as in the case of measles. The detection of antibody in the CSF is a useful diagnostic marker
       
      28. The following viruses are associated with gastroenteritis
    True Astroviruses
    True Norwalk-like viruses
    False Picornviruses
    True Adenoviruses
    True Rotaviruses
     Comments  Although enteroviruses may be found in faeces, they are not associated with gastroenteritis
       
      29. The following viruses are transmitted from animals to humans
    True Rabies Virus
    False Polioviruses
    False CMV
    True Hantaviruses
    True Lassa Fever Virus
     Comments  Rabies may be transmitted to humans from a variety of mammals. Hantaviruses and Lassa Fever Virus may be transmitted to humans by rodents.
       
      30. The following is true of rabies virus
    False  The majority of cases world-wide result from bat bites
    True Infection may be prevented by active and passive immunisation
    False Human Rabies vaccine is a live attenuated vaccine
    True The animal reservoir differ from country to country
    True May be diagnosed by serology
    Comments The majority of human rabies cases world-wide result from dog bites. Infection may be prevented by active and passive immunisation. Although live attenuated vaccines are available for vaccinating animals, inactivated vaccines are used in humans for safety reasons. May be diagnosed by serology.

    [an error occurred while processing this directive]