Free Virology MCQs with Answers

• A. HBCAg
• B. HBeAg
• C. Anti-HBC
• D. Anti-HBS

Explanation: HBeAg is a marker of active hepatitis B replication and therefore correlates with high infectivity.

• A. HBs Ag
• B. IgM anti - HBc
• C. Anti HBs
• D. None of the above

Explanation: During the hepatitis B window period, HBsAg has disappeared but anti-HBs has not yet appeared; IgM anti-HBc remains the key evidence of…

• A. Give inmunoglobulins for passive immunity
• B. Give ARV
• C. Immediately stitch wound under antibiotic coverage
• D. Immediately wash wound with soap and water

Explanation: A category III dog bite requires immediate washing, rabies vaccine, and rabies immunoglobulin infiltrated around the wound.

• A. Measles virus
• B. Herpes Virus
• C. Papavo virus
• D. Adeno virus

Explanation: Measles virus is an enveloped, single-stranded negative-sense RNA virus.

• A. Immunodeficiency virus
• B. Influenza
• C. Polio virus
• D. Hepatitis virus

Explanation: HIV is a retrovirus because it carries RNA and uses reverse transcriptase to make a DNA copy inside the host cell.

• A. Type 6,12,18
• B. 16,18,31
• C. 6,8,11
• D. 3,10,19

Explanation: HPV types 16, 18 and 31 are high-risk oncogenic types strongly associated with cervical carcinoma.

• A. Interferon production
• B. Toxin production
• C. Lymphocytes production
• D. Neutrophils production

Explanation: Viral infection stimulates interferon production, an important antiviral host response that helps distinguish it from typical bacterial…

• A. RNA -DNA-RNA
• B. RNA-DNA
• C. DNA-RNA
• D. DNA-RNA-DNA

Explanation: A retrovirus follows the sequence RNA to DNA to RNA: reverse transcriptase makes DNA from the viral RNA, and the integrated DNA is later…

• A. 2 weeks
• B. 4 weeks
• C. 9 weeks
• D. 12 weeks

Explanation: HIV seroconversion commonly occurs about 2 to 8 weeks after infection, with many patients becoming antibody-positive around 4 weeks.

• A. ELISA
• B. Western blot
• C. P24 antigen
• D. Lymph node biopsy

Explanation: At three weeks after exposure, the patient may be in acute HIV infection before antibodies become reliably detectable, so p24 antigen is…

• A. HBV
• B. HCV
• C. HDV
• D. HEV

Explanation: HEV infection is usually acute and self-limited and does not commonly progress to chronic hepatitis, except rarely in immunosuppressed…

• A. Measles
• B. Mumps
• C. Rubella
• D. Hepatitis B

Explanation: The hepatitis B vaccine is a subunit or cell-fraction vaccine containing purified hepatitis B surface antigen, produced by recombinant…

• A. Flavi virus
• B. Togaviridae
• C. Reoviridae
• D. Rhabdoviridae

Explanation: Dengue virus is a member of the genus Flavivirus in the family Flaviviridae.

• A. It can be detected during the window period
• B. Free P24 antigen disappears after the appearance of IgM response to it:
• C. Virus load parallel P24 titre
• D. It remains during asymptomatic phase

Explanation: Free p24 antigen is detectable before antibodies appear and usually falls after seroconversion, so it is not continuously present during…

• A. Herpes Simplex
• B. Mumps
• C. Rubella
• D. Papilloma

Explanation: Rubella virus crosses the placenta and can cause congenital rubella syndrome, including cataracts, deafness and cardiac defects.

• A. Chicken pox
• B. Rabies
• C. Small pox
• D. Measles

Explanation: Measles produces both intranuclear and intracytoplasmic inclusion bodies, particularly in giant cells.

• A. Ribonuclease
• B. Reverse transcriptase
• C. DNA polymerase
• D. Restriction endonuclease

Explanation: Retroviruses carry reverse transcriptase, which copies their RNA genome into DNA after entry into the host cell.

• A. Virus
• B. Bacteria
• C. Parasite
• D. Bacteria superadded on virus

Explanation: Dengue haemorrhagic fever is a severe form of dengue virus infection, associated with increased vascular permeability and bleeding.

• A. Protein synthesis
• B. DNA/RNA replication
• C. When virus enters the cell
• D. Uncoating of the virus proteins capsule

Explanation: Interferon induces antiviral proteins that chiefly inhibit viral protein synthesis, especially translation, and also affect viral…

• A. Echo virus
• B. Hepatitis C
• C. HIV
• D. Orthomyxovirus

Explanation: HIV, hepatitis C virus and some enteroviruses can be associated with salivary-gland infection or dysfunction.