Generalities Flashcards
A recent renal transplant recipient has fever, malaise, allograft dysfunction, and cells with “owl’s eye” inclusions. Diagnosis?
Cytomegalovirus infection
Not a retrovirus but has reverse transcriptase
Hepadnavirus
Largest DNA virus
Poxvirus
Longest virus
Ebola
Smallest DNA virus
Parvovirus
What is a pseudovirion?
The genetic material of one virus coated by the surface proteins of a different virus
Purified nucleic acids from which viruses are considered infectious?
Most double-stranded DNA viruses and positive-strand single-stranded RNA viruses
Why are negative-strand single-stranded RNA and double-stranded RNA viruses not infectious?
They require enzymes found in the complete virion to become infectious
Hepatitis B is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
DNA; enveloped
Herpesviruses are _____ (DNA/RNA) _____ (enveloped/nucleocapsid) viruses
DNA; enveloped
Smallpox is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
DNA; enveloped
Adenovirus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
DNA; nucleocapsid
Papillomavirus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
DNA; nucleocapsid
Parvovirus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
DNA; nucleocapsid
Influenza virus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
Parainfluenza is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
Respiratory syncytial virus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
Measles virus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
Rubella virus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
- Note:*
- It is a togavirus
- Memory aid:*
-
SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
-
Enveloped
- Togavirus
- Flavivirus
- Retrovirus
Mumps virus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
- Note:*
- It is a paramyxovirus
Rabies is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
Human T-lymphotropic virus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
- Note:*
- It is a retrovirus
- Memory aid:*
-
SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
-
Enveloped
- Togavirus
- Flavivirus
- Retrovirus
HIV is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; enveloped
Enteroviruses are _____ (DNA/RNA) _____ (enveloped/nucleocapsid) viruses
RNA; nucleocapsid
Rhinovirus is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; nucleocapsid
Note:
- It is a picornavirus
- Memory aid:*
-
SPIN Ca-He-Pi
- SS
- Positive
- Icosahedral
-
Naked
- Calicivirus
- Hepevirus
-
Picornavirus
- PERCH
Reovirus (rotavirus) is a _____ (DNA/RNA) _____ (enveloped/nucleocapsid) virus
RNA; nucleocapsid
Diagnosis and cause
Herpetic whitlow caused by HSV 1
Which DNA virus is associated with Kaposi sarcoma?
Human herpesvirus type 8 (Kaposi’s sarcoma-associated herpesvirus)
To what viral family does hepatitis B virus belong?
Hepadnavirus
Which enzyme does hepatitis B virus have in common with retrovirus?
Reverse transcriptase
JC virus is the causative agent of what condition in HIV-positive patients?
Progressive multifocal leukoencephalopathy
- See:*
- Neuro Dx – Progressive multifocal leukoencephalopathy
Vaccinia virus causes what condition?
Cowpox (“milkmaids blisters”)
Which is the only hepatitis-causing virus that is a DNA virus?
Hepatitis B virus
Which herpesvirus causes gingivostomatitis, keratoconjunctivitis, temporal lobe encephalitis, and herpes labialis?
Herpes simplex virus type 1
Herpes genitalis and neonatal herpes are most commonly caused by what herpes virus?
Herpes simplex virus type 2
What is the most likely etiology for a mononucleosis-like presentation that is monospot test negative?
Cytomegalovirus
- Note:*
- EBV causes Monospot positive mononucleosis
Human herpesvirus type 8 is primarily transmitted via what route?
Sexual contact
What is the Tzanck test?
A test to detect multinucleated giant cells in opened skin vesicles of herpes simplex virus type 1 and 2 and varicella zoster virus
Which herpesvirus is the most common cause of mononucleosis?
Epstein-Barr virus
A college student presents to the emergency department with fever, hepatosplenomegaly, pharyngitis and lymphadenopathy (especially posterior cervical nodes). Which viral infection should be suspected?
Epstein-Barr virus can cause mononucleosis, also known as the “kissing disease” because its peak incidence is 15-20 years old (peak “kissing years”); transmission is through saliva
Which two picornaviruses commonly cause aseptic meningitis?
Echovirus and coxsackievirus
Which two RNA viruses cause the common cold?
Which two RNA viruses cause the common cold?
Aseptic meningitis; myocarditis; herpangina; and hand, foot, and mouth disease are caused by which picornavirus?
Coxsackieviruses
Name a medically important calicivirus
Norwalk virus
Rotavirus belongs to which viral family?
Reoviruses
Note:
-
Reoviruses include:
- Rotavirus
- Coltivirus
Togaviruses cause what four diseases?
- Rubella (German measles)
- Eastern equine encephalitis
- Western equine encephalitis
- Chikungunya
- Memory aid:*
- Chik Rubi on a Horse has toga!
Name two RNA viruses that have reverse transcriptase
HIV (a retrovirus), and human T-lymphotropic virus
Human T-lymphotropic virus causes what disease?
T-lymphocyte leukemia
Which medically important RNA virus belongs to the orthomyxovirus family?
Influenza
What disease does respiratory syncytial virus cause in babies?
Bronchiolitis
Arenaviruses are the causative agents of what diseases?
- LCMV—lymphocytic choriomeningitis virus
- Lassa fever encephalitis
Bunyaviruses are the causative agents of what four diseases?
- California encephalitis
- Sandfly/Rift Valley fevers
- Crimean-Congo hemorrhagic fever
- Hantavirus
Hepatitis D virus belongs to which viral family?
Delta virus
What must a negative-stranded DNA virus do to replicate within a human cell?
Transcribe its negative strand to a positive strand; it does this by carrying an RNA-dependent RNA polymerase
Picornaviruses (except rhinovirus and hepatitis A virus) can cause what condition in humans?
Aseptic meningitis
Picornaviruses are (small/large) _____, (RNA/DNA) _____ viruses
Small, RNA
- Remember:*
- PicoRNAvirus = RNA virus
Yellow fever is caused by a virus that belongs to what viral family?
Flavivirus, which is an arbovirus (flavi = yellow)
- Memory aid:*
- What’s the flavor? West Nile JC-SYDZ
A 30-year-old man presents to the emergency room with a high fever, black vomitus, and a yellow discoloration to his skin. What is the most likely etiology?
Yellow fever
Globally, what is the most important cause of infantile gastroenteritis?
Rotavirus
Influenza virus is _____ (enveloped/nonenveloped), with _____-_____ (single-stranded/double-stranded), _____ (segmented/nonsegmented) RNA
Enveloped; single-stranded; segmented
The recombination of human flu A virus with swine flu A virus is an example of what?
Genetic shift, the reassortment of viral genome, which can cause worldwide pandemics
An unvaccinated 4-year-old boy presents with fever, lymphadenopathy, arthralgias and a fine truncal rash. The rash persists for only 3 days. Which viral infection should be suspected?
Rubella
Arboviruses include members of which viral families?
Flavivirus, Togavirus, and Bunyavirus
- Remember:*
- Fever Transmitted by Bites
Viruses with ease to invade our machinery hence can cause infection right away
- ssDNA virus: Parvoviridae
- dsRNA virus: Reoviridae
Gold standard in viral diagnosis
Presence of viral DNA or RNA
Oncogenic viruses and diseases caused
- HTLV 1
- T-cell leukemia
- HTLV 2
- Hairy cell leukemia
- HBV, HCV
- Hepatocellular carcinoma
- HPV
- Cervical cancer, anogenital cancer, skin cancer
- EBV
- Burkitt’s lymphoma, NPCA, immunoblastic lymphoma
- HHV-8
- Kaposi sarcoma, Castleman’s disease
Most common cause of sporadic encephalitis
HSV 1
- Note:*
- Temporal lobe encephalitis
The most common teratogen in utero
CMV
The most common opportunistic pathogen in HIV
CMV
Viral causes of diarrhea
- Rotavirus
- Norovirus
- Adenovirus
Most common cause of conjunctivitis
Adenovirus
Most common viral STD
HPV (serotype 6 and 11)
Most common viral cause of myocarditis and pericarditis
Coxsackie B
Most common cause of epidemic encephalitis
Japanese B virus
Most common cause of nonbacterial diarrhea in adults
Norwalk virus (Norovirus)
Most common microbial cause of congenital abnormalities
CMV
Memory aid:
- _C_ongenital
- _C_MV
The most common cause of erythema multiforme
HSV 1
Only vaccine that is routinely used post-exposure
Rabies virus
Most common cause of aseptic meningitis
Coxsackievirus
A patient presents with ulcerating painful lesions on her genitals similar to the image shown here. What is the diagnosis?
Herpes genitalis
Only virus with fiber
Adenovirus
Causes of mononucleosis
- Heterophil-positive
- Epstein-Barr Virus
- Heterophil-negative
- Cytomegalovirus
- Toxoplasma