Epidemiology 227 Mid-term Examination May 1, 2013

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1 Epidemiology 227 Mid-term Examination May 1, 2013 Select the best answer from the multiple choice questions. There are 78 questions and 12 pages on the examination. Notify your instructor if your examination does not have 12 pages. Clearly indicate on the scan form the one best answer to each question among the answers provided. Be sure that you have entered your name and identification number on the scan form and filled out the bubbles in the columns for the letters of your name and numbers of your identification number correctly Use a #2 pencil and fill all circles completely 1. The highest incidence of HIV/AIDS is in: a. Southeast Asia b. United States c. Brazil d. Sub-Saharan Africa e. Australasia 2. The p24 molecule is a component of which part of the HIV. a. Core b. Envelope c. Reverse transcriptase d. Fusion domain e. Nucleus 3. The highest proportion of infected HIV persons is in which of the following age groups? a years b years c years d years e. The active elderly 4. More men than women are HIV-infected in every region EXCEPT: a. Asia b. South Asia c. Sub-Saharan Africa d. North America e. Latin America 5. What proportion of HIV-infected persons globally do not know that they are infected? a. 10% b. 25% c. 50% d. 75% e. 99%

2 6. The prevalence of HIV-infected individuals is highest in which region of the United States? a. West b. Northwest c. Southeast d. Mid-west e. New England 7. The incidence of HIV infection is increasing in which of the following areas? a. Central Asia b. Southeast Asia c. Sub-Saharan Africa d. The Caribbean 8. Which country of Southeast Asia has the lowest share of care funded by international agencies. a. Vietnam b. India c. Cambodia d. Myanmar e. Timor-Leste 9. The incidence of new diagnoses of HIV-infection in the United States is highest in which of the following groups. a. European Americans b. Hispanic Americans c. African Americans d. Asian Americans 10. The prevalence of HIV-infected persons in the United States is highest in: a. California b. North Dakota c. New York d. Washington, D.C. e. Miami 11. As of 2009 the rate of HIV-diagnoses in the United States is increasing only in which risk group? a. Injection drug users b. Men who have sex with men c. Heterosexuals d. Health care workers e. Epidemiology students

3 12. The highest number of AIDS cases in California is in: a. Stockton b. Los Angeles/Long Beach c. San Francisco d. Sacramento e. Fresno 13. The highest proportion of HIV/AIDS cases in Los Angeles is among: a. African Americans b. Hispanic Americans c. Asian Americans d. European Americans e. South Pacific Islanders 14. The highest risk of acquiring HIV infection is to the: a. Women in vaginal intercourse b. The receptive partner in anal intercourse c. The male partner in vaginal intercourse d. The male partner in oral intercourse e. The receptive partner in oral[-genital intercourse 15. Which of the following groups is at the lowest risk of acquiring HIV infection? a. Men who have sex with men b. Women who have sex with women c. Injection drug users d. Health care workers e. Children of ART-treated HIV-infected mothers 16. The risk of an HIV-infected person transmitting his/her infection is highest during: a. Early infection b. Mid-infection c. After the diagnosis of AIDS d. a. and c. e. b. and c. 17. The average incubation period to a diagnosis of AIDS is usually: a. 1 year b. 5 years c. 10 years d. 15 years e. 20 years 18. Pooling of 10 blood specimens for diagnosis of HIV-infection is cost effective when the prevalence of HIV is: a. <1%

4 b. 10% c. 15% d. 20% e. 25% 19. The most sensitive test for detection of the HIV currently commonly used is: a. Elisa for p24 antigen b. Polymerase chain reaction (PCR) c. Virus culture d. Elisa for p17 antigen 20. Circumcised males are at higher risk of acquiring HIV infection. 21. The use of condoms with every intercourse guarantees 100% protection against HIV infection. 22. The single most important factor in confronting the HIV-epidemic in a country is: a. Availability of anti-retroviral drugs b. Political commitment from the top levels of government c. A low prevalence of injection drug users d. Incarceration of sex workers e. Incarceration of men who have sex with men 23. The biggest single barrier to control of HIV globally is: a. Availability of treatment b. Stigmatizing attitudes c. Inadequate supply of condoms d. The limited number of methadone clinics e. The limited number of needle exchange programs 24. A small proportion of individuals can resist infection by HIV because they lack the: a. CCR 5 receptor b. CXCR 4 receptor c. The fusion domain d. The GP41 receptor e. The CD4 receptor 25. Protease inhibitors block: a. Entry of HIV b. Transcription of HIV RNA to HIV DNA c. Integration of HIV DNA into the host DNA

5 d. Packaging of the progeny HIV e. All of the above 26. Infection by HIV stimulates the production of CD4 cells 27. HIV infection of the gut causes: a. Death of gut mucosal cells b. Increased permeability of the gut lining c. Entry of commensal bacteria into the blood stream e. a. and c. above 28. Infected bloods are most likely to be antibody test NEGATIVE in: a. The first several weeks after infection b. The first six months after infection c. The two months before an AIDS diagnosis d. Two months after an AIDS diagnosis 29. Pathogen translocation following ingestion of HIV increases activation of CD4 cells. 30. Partial reconstitution of the immune system occurs with successful treatment. 31. Multidrug regimens have reduced the incidence of HIV-infected infants born to HIV-infected mothers to: a. 8% b. 5% c. < 2 % d. No reduction 32. The majority of HIV infection of women globally is due to: a. Heterosexual activity b. Injection drug use c. Homosexual activity d. Circuit parties e. Non-injection drug use 33. The highest risk of transmission from an HIV-infected mother to her infant occurs: a. In utero b. During the birth process

6 c. Through breast feeding d. Equal risk at each stage 34. Most HIV-infected babies can be identified shortly after birth by testing them for antibodies to HIV. 35. The most important predictor of the probability of a mother passing her HIV infection to her infant is the mother s: a. Level of HIV anti bodies b. Level of CD4 cells c. Level of viral RNA d. Level of vitamin A e. Level of vitamin C 36. Breast-fed infants of HIV-infected mothers in poor, unsanitary countries should: a. Be exclusively breast fed for 6 months b. Have breast feeding supplemented by solid food as early as possible. c. Be exclusively formula fed 37. To prevent infection of the infant through breast milk treatment of an HIV-infected mother is more important during breast feeding than treatment of the infant. 38. Elective C-section for delivery of babies of HIV-infected mothers should be accompanied by ART treatment of the mother. 39. Pregnant women need to only be tested for HIV at their first antenatal visit. 40. Distribution of free condoms is: a. A behavioral intervention b. A structural intervention c. Behavioral modification d. An evidence-based policy modification e. A targeted behavioral intervention 41. The 100% condom program implemented in Thailand is an example of a: a. Community-led structural intervention b. Top-down intervention

7 c. Biomedical intervention d. Failed intervention 42. Evidence-based interventions typically use: a. A manual of operations b. Ad hoc methods c. A flexible approach d. Adaptions for the particular situation 43. The popular opinion leader model for community targeted interventions focuses on: a. Innovators b. Early adopters c. Middle adopters d. Late adopters 44. Lowering of the community viral load is based on the concept of treatment as prevention 45. Task shifting for health programs places program responsibility on: a. Physicians b. Policy makers c. Community health workers d. Security personnel e. Village leaders 46. Promoting condom use as being a responsible individual is an example of: a. Framing to motivate change b. Health behavior jargon c. A way to sell more condoms d. A strategy to humiliate non-condom users 47. Fidelity is a key element of evidence-based intervention programs. 48. Mobile phones are used in intervention programs to: a. Inform b. Train c. Monitor 49. Smart phones can eliminate the need for paper implementation and monitoring of

8 intervention programs. 50. The humoral immune system: a. Produces antibodies b. Generates B cells c. Generates T cells 51. In order to be activated a T cell requires: a. CD3 b. CD28 c. CD HIV requires which of the following in order to replicate itself intracellularly? a. VPR b. VPU c. TAT d. REV e. Tat and REV 53. CD 8 cells can be infected by HIV if they have: a. A CD4 receptor b. The CD28 molecule on their surface c. The CD38 molecule on their surface d. A nef gene e. The CD28 and CD38 molecule on their surface 54. The majority of immune cells are located in: a. The gut b. Peripheral blood c. The liver d. The kidney e. The rectum 55. Normal mice cannot be infected with HIV. 56. Mutation of HIV is responsible for: a. Drug resistance

9 b. Escape from the immune system c. Increased replication potential 57. Memory cells survive an average of: a. One week b. One month c. Six months d. One year e. Decades 58. Immature T cells can be infected. 59. HIV infects: a. Neurons b. Microglial cells c. Macrophages e. b. and c. above 60. The most common opportunistic infection of the central nervous system is: a. Papova virus b. Toxoplasmosis c. Cryptococcus d. Tuberculosis e. Pneumocystis 61. PML primarily involves the: a. Subcortical white matter of the brain b. Cortical areas of the brain c. The neurons d. The CD4 cells of the brain e. The CD8 cells of the brain 62. Kaposi s sarcoma is a common opportunistic malignancy affecting the brain. 63. Which virus is mostly commonly associated with primary central nervous system lympohoma? a. CMV b. HSV

10 c. EBV d. Dengue e. Japanese encephalitis 64. Opportunistic infections of the central nervous system typically occur when the CD4 level is: a. <1000 b. <500 c. <200 d. <100 e. < What proportion of AIDS patients have neuropathologic abnormalities at death? a % b % c % d. 100% 66. The most characteristic sign of HIV-associated neurocognitive disorder is: a. Alzheimer s like loss of cognitive ability b. Memory loss c. Slowing and lost precision in motor and mentation control d. Language disturbances 67. HIV-associated neurocognitive disorder usually characterized by: a. Changes in normal activities of daily living b. Change in mood or normal social relationships c. Mania and psychosis 68. Changes in the Trail-making Part B test usually first occur: a. Within one year of HIV seroconversion (infection) b. Concurrent with the diagnosis of AIDS c months prior to the diagnosis of AIDS d. When the CD4 level declines to 200 or less e. When the CD8 level declines to 200 or less 69. In HIV infection neuropsychological tests are used to: a. Identify specific patterns of cognitive impairment b. Identify different subtypes of HIV dementia c. Track the progression of cognitive changes e. a. and c. above

11 70. Cognitive impairment is usually completely reversed by treatment even in long-standing HIV infection. 71. An epitope is: a. A portion of a peptide b. A 9-12 sequence of amino acids c. A glycoprotein 72. The major role of the immune system is to protect the individuals from non-self. 73. The major component of the acquired immune system are: a. B-cells b. NK cells c. T cells d. All of the aove e. a. and c. above 74. CD8 cytotoxic cells kill: a. Cells containing HIV b. HIV in the serum c. Antibody producing B cells 75. Antibodies act by: a. Clearance of antigens b. Neutralization of viruses c. Direct killing of viruses 76. MHC molecules present which of the following to T cells: a. Viral peptides b. HIV c. HLA antigens e. a. and c. above 77. Cells of the immune system communicate through:

12 a. Gene interactions b. Cytokines c. Chemokines e. b. and c. above 78. Antibodies fail to neutralize HIV because a. GP120 proteins are highly glycosylated b. Binding sites are masked by the looping of the GP120 glycoprotein c. GP120 proteins can not stimulate antibody production

5. Over the last ten years, the proportion of HIV-infected persons who are women has: a. Increased b. Decreased c. Remained about the same 1

5. Over the last ten years, the proportion of HIV-infected persons who are women has: a. Increased b. Decreased c. Remained about the same 1 Epidemiology 227 April 24, 2009 MID-TERM EXAMINATION Select the best answer for the multiple choice questions. There are 60 questions and 9 pages on the examination. Each question will count one point.