Virology and Infections Quiz

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Questions and Answers

What is the most common method of transmission for Norovirus?

Airborne transmission

Direct contact with infected individuals

Fecal-oral route through contaminated food or water (correct)

Vector-borne transmission by insects

Which of the following symptoms is NOT commonly associated with acute 2019-nCoV infections?

Cough

Nausea (correct)

Hemoptysis

Shortness of breath

What is a significant characteristic of the Orthomyxovirus family?

They cannot mutate or reassort their genes.

Their genomes are single-stranded (+) RNA.

They have a segmented (-) RNA genome. (correct)

They are resistant to detergents and drying.

What is the estimated percentage of gastrointestinal outbreaks in the USA caused by Norovirus?

50% Signup and view all the answers

Which complications indicate the need for urgent medical attention in acute 2019-nCoV cases?

Difficulty breathing, chest pain, loss of speech or movement Signup and view all the answers

Which of the following polyomaviruses is known to cause progressive multifocal leukoencephalopathy (PML) in immunocompromised hosts?

JC Signup and view all the answers

What is the primary mode of transmission for polyomaviruses?

Respiratory route Signup and view all the answers

Which clinical syndrome is NOT typically associated with adenoviruses?

Progressive multifocal leukoencephalopathy Signup and view all the answers

Which of the following statements about adenoviruses is true?

They were first isolated from human adenoid cell culture. Signup and view all the answers

What is the average lifespan of patients diagnosed with progressive multifocal leukoencephalopathy (PML)?

1 to 4 months Signup and view all the answers

Which of the following herpesviruses belongs to the gammaherpesviruses subfamily?

HHV4 Signup and view all the answers

What prevention strategy can help control adenovirus infections?

Handwashing Signup and view all the answers

What type of infections are herpesviruses known to establish after primary infection?

Latent or persistent infections Signup and view all the answers

What additional symptoms are commonly seen in children with acute influenza infection compared to adults?

Higher fever Signup and view all the answers

Which of the following is NOT a complication associated with acute influenza infection?

Croup Signup and view all the answers

What is the primary action of amantadine and rimantadine in influenza treatment?

Inhibit viral uncoating Signup and view all the answers

Which virus is associated with the maculopapular rash seen in measles?

Measles virus Signup and view all the answers

What complication can result from measles infection that affects the brain?

Meningoencephalitis Signup and view all the answers

Which of the following vaccinations protects against measles, mumps, and rubella?

MMR vaccine Signup and view all the answers

What is one of the most notable features of atypical measles?

More intense rash with petechia Signup and view all the answers

Which of the following viruses is a respiratory pathogen that can lead to multinucleated giant cells?

Parainfluenza virus Signup and view all the answers

What is a common opportunistic infection in patients with a CD4 lymphocyte count between 50 and 200 per microliter?

Pneumonia by Pneumocystis jiroveci Signup and view all the answers

Which of the following is true regarding Hepatitis B?

It can cause chronic infection. Signup and view all the answers

Which treatment option is classified as a protease inhibitor?

Saquinavir Signup and view all the answers

What is a significant challenge in developing a vaccine for HIV?

It hides from the immune system during latency. Signup and view all the answers

Which of these conditions occurs at a CD4 lymphocyte count of less than 50 per microliter?

HIV dementia Signup and view all the answers

Which type of viral structure does Hepatitis C have?

RNA with an enveloped structure Signup and view all the answers

What is the mode of transmission for Hepatitis D?

Parenteral and sexual transmission Signup and view all the answers

What is a characteristic of Moraxella catarrhalis?

It's primarily involved in pneumonia. Signup and view all the answers

What is a significant outcome of respiratory syncytial virus infection in infants?

Formation of mucus plugs leading to airway obstruction Signup and view all the answers

Which statement accurately describes rabies progression?

Hydrophobia is a symptom during the neurologic phase Signup and view all the answers

What is true about the prevention of rabies?

Postexposure prophylaxis includes wound cleaning and vaccinations Signup and view all the answers

Which of the following is NOT true about filoviruses?

They cause chronic respiratory conditions Signup and view all the answers

What is the primary type of animal in which Ebola virus is endemic?

Bats and monkeys Signup and view all the answers

What clinical syndrome is associated with respiratory syncytial virus in children?

Febrile rhinitis Signup and view all the answers

Which is a potential consequence of vaccination against rabies?

Decreased spread of the virus in wildlife Signup and view all the answers

How do filoviruses primarily replicate within the body?

In monocytes and macrophages Signup and view all the answers

What is the primary cause of diarrhea in children attributed to reovirus?

Virus affects epithelial cells in the small intestine Signup and view all the answers

Which symptom is NOT commonly associated with hemorrhagic fever?

Erythema Signup and view all the answers

What is a significant characteristic of togaviruses and flaviviruses?

Positive, single-stranded RNA Signup and view all the answers

In rotavirus infection, which mechanism leads to the loss of electrolytes and water?

Toxin-like action of the virus Signup and view all the answers

Which of the following is a prevention method for yellow fever?

Live vaccine Signup and view all the answers

What is the estimated mortality rate associated with hemorrhagic fever?

90% Signup and view all the answers

Which clinical syndrome is commonly linked to Chikungunya virus?

Arthritis Signup and view all the answers

Which of the following diseases is NOT included in the classic childhood exanthems?

Mumps Signup and view all the answers

Which symptom is particularly severe in infants infected with rotavirus?

Diarrhea and vomiting Signup and view all the answers

How is the Zika virus primarily transmitted?

Mosquito bites Signup and view all the answers

Study Notes

Clinical Virology

Focuses on various viruses and their clinical implications.
Covers different virus types (DNA, RNA, etc.) and their associated diseases.
Includes information on pathogenesis, clinical syndromes, treatment, prevention, and control.

DNA Virus: Papillomavirus

At least 100 types identified.
Naked double-stranded DNA virus.
Can be cutaneous or mucosal.
A group associated with mucosal HPV is linked to cervical cancer.
HPV genome is circular and has approximately 8,000 base pairs.
HPV DNA encodes early genes (E1 to E8) and late/structural genes (L1 and L2).
Viral pathogenesis includes inoculation, local multiplication, wart formation, and potential cell transformation.
Clinical syndromes include warts (benign, self-limited skin proliferations), oral papillomas (benign epithelial oral tumors), and laryngeal papillomas (common benign epithelial head and neck tumors).
Anogenital warts (condylomata acuminata) are almost exclusively on the squamous epithelium of the external genitalia and perianal regions, caused by HPV 6 and 11.
Cervical dysplasia/neoplasia associated with high-risk HPV types (HPV 16 and 18) can cause cervical neoplasia and cancer.
Mild dysplasia often spontaneously regresses (approximately 40-70%).

DNA Virus: Polyomavirus

Includes BK, JC, and SV40 viruses.
Acquired by respiratory route, is typically asymptomatic.
Establishes latent and persistent infections.
Reactivates in immunosuppressed hosts and can cause progressive multifocal leukoencephalopathy (PML).
Viral pathogenesis involves inoculation, multiplication in the respiratory tract, potential multiplication in kidney, possible viruria, and reactivation within the CNS.
Primary infection is usually asymptomatic.
Activation in immunocompromised patients, indicated by virus detection in urine, as in up to 40% of patients
PML is a growing concern due to increasing AIDS cases.
PML causes multiple neurological symptoms, eventually followed by paralysis, and typically results in death within 2 years.

DNA Virus: Adenovirus

First isolated in human adenoid cell culture.
Naked double-stranded DNA viruses.
Spread through aerosols, close contact, or fecal-oral routes.
Can cause lytic infections (mucoepithelial cells), latent infections (lymphoid and adenoid cells), and transforming infections (animal cells only).
Clinical syndromes include undifferentiated upper respiratory tract infections, pharyngoconjunctival fever, acute respiratory disease, pertussis-like syndrome, pneumonia, acute hemorrhagic cystitis, epidemic keratoconjunctivitis, gastroenteritis, hepatitis and meningoencephalitis in infants and children.

DNA Virus: Herpesviruses

Enveloped double-stranded DNA viruses.
Three subfamilies: alphaherpesviruses (HHV1, 2, and 3), betaherpesviruses (HHV5, 6, and 7), and gammaherpesviruses (HHV4 and 8).
Establish latent or persistent infections.
Reactivation is more likely during immunosuppression.
Table summarizing different Herpes virus types, target cells, sites of latency, and transmission routes.

DNA Virus: Herpes Simplex Virus 1 and 2

Disease initiated by direct contact on infected tissue.
Establishes latency in neurons.
Reactivated by stress.
HSV-1 commonly causes oral infections.
HSV-2 typically associated with sexual infections.
Clinical presentations include acute gingivostomatitis, herpes labialis (cold sores), ocular herpes, genital herpes, and other forms of cutaneous herpes.

DNA Virus: Varicella-Zoster Virus (HHV-3)

Transmitted via respiratory droplets.
Infects epithelial cells, fibroblasts, T cells, and neurons.
Causes lifelong latent infection in neurons.
Manifest as chickenpox (varicella) in initial infection.
Reactivation as shingles (herpes zoster), affecting the sensory dermatomes.

DNA Virus: Epstein-Barr Virus (HHV-4)

Initiates infection by saliva contact and spreads to B cells.
Establishes latency in B cells.
Clinical manifestations include infectious mononucleosis, Burkitt's lymphoma, and nasopharyngeal carcinoma in China.

DNA Virus: Cytomegalovirus (CMV)(HHV-5)

Acquired by blood, body fluids, or vertical transmission.
Infects epithelial and other cells.
Establishes latency in T cells, macrophages, and other cells.
Clinical manifestations include cytomegalic inclusion disease (congenital), usually asymptomatic perinatal or postnatal infections.
Can cause infections in immunocompromised hosts: pneumonia, retinitis, colitis, and encephalopathy.

DNA Virus: Herpes Viruses 6 and 7

Transmitted in saliva.
Cause roseola in children (rash and fever).
In immunocompromised individuals can lead to mononucleosis syndrome and HIV co-factor.

DNA Virus: Herpes Virus 8

HHV-8 found in almost 100% of Kaposi's sarcoma cases.
Tumor of blood vessels (Kaposi's sarcoma).

RNA Virus: Poxvirus

Large, complex viruses.
Linear double-stranded DNA genome with fused ends.
Includes variola virus (smallpox), molluscum contagiosum, and other zoonotic viruses.
Smallpox has been eradicated.

RNA Virus: Parvovirus

Smallest DNA virus.
Naked icosahedral capsid.
Single-stranded (plus or minus) DNA strand.
Transmitted via respiratory droplets.
Infects mitotically active erythroid precursor cells in bone marrow.
Only B19 can cause disease in humans

RNA Virus: Picornavirus

Small RNA viruses.
Naked icosahedral capsid.
Includes enteroviruses (poliovirus, coxsackie A & B, echovirus, enterovirus, rhinovirus 1-100+, cardiovirus, aphthovirus, and hepatitis A virus).

RNA Virus: Coronavirus

Are named for the solar corona-like appearance.
Single-stranded (+) RNA.
Spreads via respiratory droplets, but also found in sweat, urine, and feces.
Four subfamilies: alpha, beta, gamma, and delta.
Primarily from mammals (alpha and beta) and other animals (gamma and delta).
Clinical syndromes include mild-moderate common colds, and severe forms like SARS (severe acute respiratory syndrome), MERS (Middle East respiratory syndrome), and COVID-19.

RNA Virus: Norovirus

Positive (+) RNA viruses.
Resistant to detergents, drying, and acid.
Transmitted through fecal-oral routes in contaminated food or water.
Causes 50% of gastrointestinal outbreaks in the USA.
Clinical manifestations consist of diarrhea, nausea, and vomiting.

RNA Virus: Orthomyxovirus (Influenza)

Enveloped viruses with segmented (-) RNA genomes.
Three types: Influenza A, B, and C (only A and B cause disease in humans).
Segmented genome facilitates new strains through mutation (drift) and reassortments (shift).
Spanish flu pandemic (1918-1919) was highly lethal.

RNA Virus: Paramxyovirus

Large virion particles with negative-sense single-stranded RNA genomes.
Transmitted through respiratory droplets and initiate infection in the respiratory tract.
Cause cell-cell fusion, resulting in multinucleated giant cells.
Includes measles, parainfluenza, mumps, and respiratory syncytial viruses (RSV).

RNA Virus: Filovirus

Filamentous, enveloped, single-stranded (-) RNA viruses.
Cause hemorrhagic fever.
Includes Ebola and Marburg viruses.
Ebola endemic in some parts of Africa.

RNA Virus: Reovirus

Non-enveloped viruses.
Double-layered protein capsid and double-stranded RNA.
Rotavirus is the main pathogen, causing diarrhea in children.

RNA Virus: Togavirus and Flavivirus

Enveloped viruses with positive-sense single-stranded RNA genomes.
Transmitted by arthropods (arboviruses).
Togaviridae and Flaviviridae are significant for diseases like Chikungunya, Dengue, Yellow Fever, Japanese Encephalitis, Zika virus, and Hepatitis C.

RNA Virus: Bunyaviridae

More than 200 viruses, enveloped viruses with segmented (-) RNA.
Transmitted by arthropods or ticks (mosquitoes, etc.).
Clinical manifestations include flu-like syndromes, encephalitis, and hemorrhagic fever.

RNA Virus: Arenaviridae

Enveloped viruses with two circular, (-) RNA genome segments.
Infections are zoonoses with a rodent reservoir.
Includes Lymphocytic choriomeningitis (LCM) and hemorrhagic fever viruses (Lassa, Junin, Machupo).

Retrovirus

Enveloped (+)-sense single-stranded RNA viruses.
Replication through a DNA intermediate.
HIV (Human Immunodeficiency Virus) is a lentivirus associated with AIDS.
Composition: lipid envelope, glycoprotein (gp120 and gp41), nucleocapsid (protein p24), and RNA with enzymes supporting replication.
Genetic Diversity: HIV has high genetic diversity, necessitating combination therapy.
Clinical Manifestations: Acute (retroviral syndrome), Chronic, and Final/Crisis (severe immunosuppression).

Hepatitis Viruses

Table summarizing Hepatitis A, B, C, D, and E virus characteristics.

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Description

Test your knowledge on various viruses, their transmission methods, associated symptoms, and prevention strategies. This quiz covers important aspects of viruses like Norovirus, adenoviruses, and polyomaviruses. Enhance your understanding of viral infections and their clinical implications.