HIV And Other Retroviruses
Question 1. HIV target binding site:
- Gp 120, gp 41
- Gp 120,p24
- Gp 36
- P24,p40
Answer. (1) (gp 120, gp41)
- Explanation: gp120 and gp41 are the binding sites for HIV.
Read And Learn More: Micro Biology And Immunology Multiple Choice Question And Answers
Question 2. Reverse transcriptase is encoded by:
- Gag gene
- Pol gene
- Env gene
- Tax gene
Answer. (2) (Pol gene)
Question 3. Not true about retroviruses:
- ss RNA
- ds RNA
- Reverse transcriptase
- Integrates with cell genome of a host cell with integrase
Answer. (2) (dsRNA)
- Retroviruses have two copies of ssRNA.
Question 4. The mean transformation to AIDS in HIV infection is:
- 5 years
- 7.5 years
- 10 years
- 30 years
Answer. (3) (10 years)
- The mean duration of transformation of HIV to AIDS is 10 years, ranging from a few months to 30 years.
- The incubation period of HIV is uncertain and ranges from a few months to 10 years or even more.
Question 5. Tropical spastic paraparesis is caused by:
- Epstein Barr Virus
- Human T-cell Lymphotropic Virus (HTLV)
- Human Immunodeficiency Virus
- Hepatitis B virus
Answer. (2) (Human T-cell Lymphotropic Virus ( HTLV)
- HTLV-I is associated with: (1)Tropical spastic paraparesis, (2)
- Adult T cell leukemia/lymphoma, (3) Cutaneous T-cell lymphoma, (4) Autoimmune manifestations such as uveitis and arthropathies
Question 6. Which of the following is/are true about HIV-2?
- HIV-2 was first detected in West Africa in 1986
- Donated blood is only screened for HIV-1, not HIV 2
- More virulent than HIV 1
- More closely related to simian immunodeficiency virus (SIV) than HIV 1
- Mode of transmission is like HIV 1
Answer. (1, 4,5) (HIV-2 was first detected in West Africa in 1986, More closely related to simian immunodeficiency virus (SIV) than HIV 1, Mode of transmission is like HIV 1)
- Characteristic Features of HIV-2
- HIV-2 was first reported in 1986 in West Africa and then in 1987 in the USA.
- Donated blood should be screened for both HIV-1 and HIV 2
- Less virulent: Compared to HIV-1 infection, HIV-2 infection is characterized by a longer asymptomatic stage, lower plasma HIV-2 RNA levels, and lower mortality; however, progression to
- AIDS does occur.
- HIV-2 was more similar to SIV strains than to HIV-1. HIV-1 is closely related to SIV found in chimpanzees, and HIV-2 to SIV found in sooty mangabeys
- HIV-2 has the same routes of transmission as HIV-1 but is less infectious than HIV-1.
- HIV-2 is far rarer than HIV-1, and geographically restricted to Africa.
- HIV-2 is intrinsically resistant to NNRTI and to Enfuvirtide.
Question 7. HIV infects which of the following cells?
- NK cells
- T-helper cells
- T suppressor cells
- Plasma cells
Answer. (2) (T-helper cells)
HIV infects CD4-positive cells, i.e. mainly T-helper cells and also on the surface of various other cells like monocytes, macrophages, Langerhans cells, astrocytes, keratinocytes, and glial cells.
Question 8. Resistance to HIV infection occurs due to mutation of:
- CCR 5
- CXCR4
- gp41
- CD4
- gp120
Answer. (1) (CCR5)
- CCR5-delta 32 mutation:
- CCR-5 molecules are the coreceptors for HIV, present in human macrophages, dendritic cells, and other immune cells.
- A genetic mutation of CCR-5 known as CCR5-delta 32 results in the blockade of HIV entry into the cells so that those lucky people having this mutation are resistant to HIV infection.
- It is observed among some European people:
- Homozygous: 1% of people from Northern Europeans, particularly Swedes are homozygous for CCR5-delta 32 genes and are immune to HIV infection
- Heterozygous: Another 10–15% of European people inherit one copy of the gene. It does not prevent infection, however reduces the carrier’s chances of infection and delays the progress of AIDS.
- This mutation has not been found in Africans, East Asians, or Amerindi Answer.
Question 9. The causative agent of AIDS was discovered in:
- 1983
- 1976
- 1994
- 1967
Answer. (1) (1983)
In 1983, Luc Montagnier and colleagues from the Pasteur Institute, Paris, isolated HIV from a West African patient with persistent generalized lymphadenopathy.
Question 10. WHO, AIDS-defining illness is/are:
- Herpes zoster
- Oropharyngeal candidiasis
- CMV retinitis
- Cryptococcal meningitis
- Primary brain lymphoma
Answer. All options (1, 2, 3, 4, 5)
Question 11. Which is a nonstructural gene of HIV?
- Gag
- Env
- Tat
- Pol
Answer. (3) (Tat)
- That is a nonstructural gene of HIV.
Question 12. In the absence of any intervention, the risk of HIV transmission from mother to baby in pregnancy, labor, delivery, and breastfeeding in the nonbreastfeeding population is:
- 5–10%
- 10–15%
- 15–30%
- 40–50%
Answer. (3) (15–30%)
- In the absence of prophylactic antiretroviral therapy to the mother during pregnancy, labor, and delivery, and to the fetus following birth, the probability of transmission of HIV from mother to infant/fetus ranges from 15% to 25% in industrialized countries and from 25% to 35% in developing countries.
- In the absence of any intervention, the rate of transmission of HIV from mother to infant/fetus ranges from 20% to 25%.
Question 13. What is p24?
- Envelop antigen in HIV
- Genome of HIV
- Core antigen in HIV
- Shell antigen
Answer. (3) (Core antigen in HIV)
- P24 is the Core antigen in HIV, coded by the gag gene.
Question 14. HTLV or HIV contains an extra gene that is not there in standard retrovirus:
- Gag
- Pol
- Env
- Tex
Answer. (4) (Tex)
- All retrovirus carries three genes for viral replication: Gag, pol, and env.
- Some retroviruses (trans-regulatory viruses) HTLV or HIV contain an extra gene that is not there in standard retrovirus – tex or tat.
Question 15. HIV can:
- Cross blood-brain barrier
- RNA virus
- Inhibited by 0.3% H2O2
- Thermostable
Answer. (1, 2, 3) (Cross blood-brain barrier, RNA virus, Inhibited by 0.3% H2O2)
- Option a: HIV crosses the blood-brain barrier and causes encephalopathy leading to loss of higher functions, progressing to dementia.
- Option b: HIV is a spherical, enveloped virus and its genome is composed of 2 identical single-stranded positive sense- RNA.
- Option c: HIV is inactivated by treatment with 50% ethanol, 35% isopropanol, 0.5% Lysol, 0.5% formaldehyde, 0.3% hydrogen peroxide, and 10% bleaching powder in 10 minutes.
- A 2% solution of glutaraldehyde is effective for disinfection of medical instruments.
- Option d: Incorrect:
- HIV is a thermolabile virus. It is readily inactivated at 60 °C in 10 minutes and at 100 °C in seconds.
Question 16. True about AIDS-defining cancer:
- Non-Hodgkin’s lymphoma
- Kaposi’s sarcoma
- Anal carcinoma
- Nasopharyngeal carcinoma
- Adipose tissue carcinoma
Answer. (1, 2) (Non-Hodgkins lymphoma, Kaposi’s sarcoma)
- AIDS-defining cancer includes Kaposi’s sarcoma, Invasive cervical cancer and
- Lymphoma (cerebral, B cell, and non-Hodgkin).
Question 17. The most common fungal eye infection in HIV infected patients:
- Cryptococcosis
- Aspergillosis
- Coccidioidomycosis
- Candidiasis
Answer. (4) (Candidiasis)
- Opportunistic Ocular Infection in HIV infected patient:
- Cytomegalovirus Retinitis: MC ocular infection in HIV
- HSV and VZV-induced acute retinal necrosis or progressive outer retinal necrosis
- Toxoplasma Retinochoroiditis
- Candida Endophthalmitis: MC fungal ocular infection in HIV
- Bacterial Retinitis
- Cryptococcus Chorioretinitis
- Pneumocystis Choroiditis
- Acute Retinal Necrosis
- Syphilis uveitis.
Question 18. Features of stage III HIV infection is/are:
- Fever > 38.5 °C
- Oral hairy leukoplakia
- Candidiasis
- Diarrhea of > 20-day duration
- > 26% CD4 count in adults
Answer. (1, 2, 3, 4) (Fever, Oral hairy leukoplakia, Candidiasis, Diarrhea of > 20 day duration)
Question 19. A 25-year-old male presents with 2 2-month history of loose stools and weight loss. Laboratory diagnostic tests are positive for HIV. Presence of which of the following disease is most likely in diagnosing HIV/AIDS:
- Lyme disease
- Glandular fever-like syndrome
- Oropharyngeal candidiasis
- Pulmonary MTB
Answer. (2) (Glandular fever-like syndrome)
- The Acute HIV Syndrome presents as acute infectious mononucleosis (glandular fever)
like syndrome and characterized by:- General: Fever, pharyngitis, lymphadenopathy, headache, arthralgia/myalgia, weight loss, and vomiting/diarrhea
- Neurologic: Meningitis, encephalitis, peripheral neuropathy and myelopathy
- Dermatologic: Rash and mucocutaneous ulceration
- Lyme disease is not associated with HIV
- Diarrhea in HIV patients is associated with fungal infections such as Histoplasmosis,
coccidioidomycosis, and penicilliosis but not Oropharyngeal candidiasis - Diarrhea in HIV patients is associated with MAC infection; but not Pulmonary MTB
- Also remember the causes of Diarrhea in HIV-infected patients: Salmonella, Shigella, and Campylobacter,
- Clostridium difficile and MAC
- Parasitic: Cryptosporidium, microsporidia, and Isospora belli
- Fungal: Histoplasmosis, coccidioidomycosis, and penicilliosis
- Viral: CMV colitis
- AIDS enteropathy (chronic diarrheal syndrome for which no etiologic agent).
Question 20. Parotid enlargement in an HIV-infected child is characterized in which stage of AIDS, according to WHO?
- Stage 1
- Stage 2
- Stage 3
- Stage 4
Answer. (2) (Stage 2)
- Unexplained persistent parotid enlargement is seen in WHO Clinical Staging 2 for children with confirmed HIV infection.
Question 21. Common CNS lesions in HIV is caused by:
- Cryptococcus
- Toxoplasma
- Neurocysticercosis
- Mucormycosis
- Lymphoma
Answer. (1, 2, 5) (Cryptococcosis, Toxoplasma, and Lymphoma)
- Neurologic Diseases in Patients with HIV are Extrapulmonary cryptococcosis (meningitis), Toxoplasma encephalitis,
- Lymphoma (cerebral, B cell, and non-Hodgkin) and HIV encephalopathy.
Question 22. Fungal infection in AIDS:
- Mucormycosis
- Aspergillosis
- Disseminated candidiasis
- Mucocutaneous candidiasis
- Pneumocytis jiroveci
Answer. (3, 4, 5) (Disseminated candidiasis, Mucocutaneous candidiasis, Pneumocystis jiroveci)
- Fungal opportunistic infections in HIV-infected patients:
- Pneumocystis jirovecii pneumonia
- Esophageal candidiasis
- Extrapulmonary cryptococcosis (meningitis)
- Disseminated mycoses (histoplasmosis and coccidioidomycoses)
Question 23. The most common organism amongst the following that causes acute meningitis in AIDS patients is:
- Streptococcus pneumoniae
- Streptococcus agalactiae
- Cryptococcus neoformans
- Listeria monocytogenes
Answer. (3) (Cryptococcus neoformans)
- Cryptococcus neoformans is the leading infectious cause of meningitis in patients with AIDS.
- It is the initial AIDS-defining illness in ~2% of patients and generally occurs in patients with CD4+ T-cell counts < 100/µL.
- But bacterial pathogens predominate in pediatric AIDS as the most common cause of meningitis.
Question 24. In a patient having HIV infections, oral ulcer is most commonly due to:
- Candida
- Cryptococcosis
- Histoplasma
- Trichophyton
Answer. (1) (Candida)
- Oral lesions in HIV-infected patients oral thrush, hairy leukoplakia, and aphthous ulcers
- Oral thrush/oral ulcers occur commonly due to Candida infection, and oral hairy leukoplakia is due to EBV generally occur in patients with CD4+ T-cell counts of < 300/µL.
- Sometimes, palatal, glossal, or gingival ulcers may result from Cryptococcal disease or histoplasmosis.
Question 25. The tissue of origin of the Kaposi’s sarcoma is:
- Lymphoid
- Vascular
- Neural
- Muscular
Answer. (2) (Vascular)
- Kaposi’s sarcoma is a vascular tumor of endothelial origin
- It appears in skin, mucous membranes, lymph nodes and visceral organs.
- Other tumors commonly seen in AIDS patients:
- Hodgkin’s and non-Hodgkin’s lymphomas
- Cervical cancer
- Anogenital cancer
- Burkitt’s lymphoma.
2Question 6. An HIV patient complains of visual disturbances. Fundal examination shows bilateral retinal exudates and perivascular hemorrhages. Which of the following viruses are most likely to be responsible for this retinitis?
- Herpes simplex
- Varicella zoster
- Cytomegalovirus
- EBV
Answer. (3) (Cytomegalovirus)
The history provided gives clearly clue that patient is suffering from CMV retinitis.
- CMV retinitis
- The majority of cases of CMV retinitis occur in patients with a CD4+ T cell-count <50/µL.
- CMV reactivation syndrome seen in 25–30% of patients with AIDS.
- CMV retinitis presents as a bilateral painless, progressive loss of vision, blurring of vision, ‘floaters,’ and scintillations.
- There is characteristic perivascular hemorrhage and exudates of retina.
- Therapy for CMV retinitis consists of oral valganciclovir, IV ganciclovir, or IV foscarnet, with cidofovir as an alternative.
- HSV and varicella zoster viruses
- Cause a rapidly progressing, bilateral necrotizing retinitis referred to as the acute retinal necrosis syndrome, or progressive outer retinal necrosis .
- This syndrome, in contrast to CMV retinitis, is associated with pain, keratitis, and iritis.
- It is often associated with orolabial HSV or trigeminal zoster.
- Ophthalmologic examination reveals widespread pale gray peripheral lesions.
- This condition is often complicated by retinal detachment.
Question 27. Persistent diarrhea in AIDS is caused by A/E:
- Microspora
- Cryptosporidia
- Cryptococcus
- Isospora belli
- Giardia lamblia
Answer. (3, 5) (Cryptococcus, Giardia lamblia)
Question 28. Multifocal tumor of vascular origin in a patient of AIDS:
- Kaposi sarcoma
- Astrocytoma
- Gastric carcinoma
- Primary CNS lymphoma
Answer. (1) (Kaposi sarcoma)
- Kaposi’s sarcoma is a multifocal vascular tumor of endothelial origin
- It appears in skin, mucous membranes, lymph nodes, and visceral organs.
Question 29. In India most common cause of TB in HIV:
- Myco. tuberculosis
- Myco. avium intracellulare
- M. bovis
- M. scrofulaceum
Answer. (1) (M. tuberculosis)
- In developing countries like India, the most important pathogen is M. tuberculosis, with many strains being multidrug-resistant.
Question 30. WHO stage IV includes all except:
- Toxoplasma
- Pneumocystis
- HIV wasting syndrome
- Oral thrush
Answer. (4) (Oral thrush)
- Oral thrush belongs to WHO clinical stage 3
Question 31. MC opportunistic infection in HIV positive patients in India is:
- M. tuberculosis
- Cryptococcus
- Candida
- Cryptosporidiosis
Answer. (1) (M. tuberculosis)
- MC opportunistic infection in HIV positive patients in India is Tuberculosis
- MC opportunistic infection in HIV positive patients in the world is Tuberculosis
Question 32. HIV in a 5-month-old child is confirmed by:
- p24 Antigen assay
- HIV ELISA
- HIV DNA PCR
- Viral culture
Answer. (3, 5) (HIV DNA PCR, NAT)
- HIV in children <18 months is best diagnosed by HIV DNA PCR, which is a type of nucleic acid amplification test. Other methods include HIV RNA detection and p24 antigen detection.
Question 33. Most sensitive test for HIV infection:
- Western blot
- ELISA
- Agglutination test
- CFT
Answer. (2) (ELISA)
- ELISA is considered as the most sensitive test for the diagnosis of HIV.
Question 34. In HIV window period indicates:
- Time between infection and onset of first symptoms
- Time period between infection and detection of antibodies against HIV
- Time period between infection and minimum multiplication of the organism
- Time period between infection and maximum multiplication of the organism
Answer. (2) (Time between infection and detection of antibodies against HIV)
- It takes 2–8 weeks to months for antibodies to appear in HIV infection—this period is called the window period or seronegative infective stage.
- During this period, individuals may be highly infectious.
- HIV infection can be detected during this period by p24 antigen assay and PCR.
35. HIV can be detected and confirmed by:
- Polymerase Chain Reaction (PCR)
- Reverse transcriptase PCR
- Real-time PCR
- Mimic PCR
Answer. (2) (Reverse transcriptase PCR)
- NACO Guidelines to prevent neonatal HIV:
- RT-PCR is done to detect HIV RNA.
- Real-time RT-PCR is done to quantify HIV RNA load.
36. Antenatal maternal HIV diagnosis is of importance in:
- To prevent vertical transmission
- To terminate
- To discharge
- To isolate the patient
Answer. (1) (To prevent vertical transmission)
- HIV infection can be transmitted from an infected mother to her fetus during pregnancy, during delivery, or by breast-feeding.
- The relative proportions of mother-to-child transmissions were 23–30% before birth, 50–65% during birth, and 12–20% via breastfeeding.
- Treatment of an HIV-infected mother with nevirapine during pregnancy and the infant during the first weeks following birth has proved very effective in dramatically decreasing mother-to-child transmission of HIV.
37. All of the following methods are used for the diagnosis of HIV infection in a 2-month-old child except:
- DNA-PCR
- Viral culture
- HIV ELISA
Answer. (3) (HIV ELISA)
- Anti-HIV antibody detection by ELISA or any other method is done only after 18 months of birth when all maternal antibodies would have disappeared.
- HIV diagnosis <18 months: (1) HIV DNA detection (best), (2) p-24 antigen, (3) HIV RNA detection, (4) virus isolation
38. How to manage pregnant women who are discovered to be HIV positive?
- Start ART in the second trimester and give it till pregnancy
- Start ART in the second trimester and continue lifelong
- Start ART immediately and give it till pregnancy
- Start ART immediately and continue lifelong
Answer. (4) (Start ART immediately and continue lifelong)
- Pregnant women who are found to be HIV reactive are initiated on lifelong ART (TLE regimen); their newborn (HIV exposed) babies are initiated on 6 weeks of Syrup
- Nevirapine immediately after birth.
- Regimen (TLE): Single daily dose of tenofovir (300 mg) plus lamivudine (300 mg) plus efavirenz (600 mg) is given for 28 days.
39. Common drugs for hepatitis B & HIV are all except:
- Emtricitabine
- Lamivudine
- Zidovudine
- Tenofovir
Answer. (3) (Zidovudine)
- Emtricitabine, lamivudine, and tenofovir have activity against both HIV and HBV, Hence an
- ART regimen for patients with both HIV and HBV should be included in the antiretroviral (ARV) regimen if the patient is coinfected with HBV.
40. Which of the following is used to prevent HIV transmission from an HIV-positive pregnant mother to a child?
- Lamivudine
- Stavudine
- Nevirapine
- Didanosine
Answer. (3) (Nevirapine)
41. Which of the following is an opportunistic organism in AIDS?
- Ascaris
- Strongyloidiasis
- Hookworm
- Enterobius
Answer. (2) (Strongyloidiasis)
Transmission And Pathogenicity
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