DNA Viruses Flashcards
PARVOVIRIDAE
Virus
Transmission
Disease
Virus: Parvovirus B19
Transmission: Close contact, probably respiratory, transplacental, or from blood and blood products
Disease:
- Erythema infectiosum or fifth disease [“slapped cheek” rash],
only known human parvovirus (one serotype)
Parvovirus B19
ADENOVIRIDAE
Virus
❌Transmission
Site of latency
❌ Disease
- URT
- LRT
- GIT
- GUT
Diagnosis
Virus: Human Adenovirus
Transmission: Respiratory, fecal-oral, and direct contact (eye)
Site of latency: Replication in oropharynx
Disease :
URT: Pharyngitis, conjunctivitis, coryza (serotype 3, 7, 8, 19, 37)
LRT : bronchitis, atypical pneumonia (serotype 14):
GIT: acute gastroenteritis (infantile diarrhea) [serotype: 40, 41]
GUT: acute hemorrhagic cystitis (serotype: 7, 11,21)
Diagnosis: Cell culture (HEp-2) [Cowdry type B intranuclear basophilic inclusion bodies], EIA for gastroenteritis (40-41), PCR
HPV types 1 to 100+ (as determined by genotype; types defined by DNA homology, tissue tropism, and association with oncogenesis)
Papillomavirus
SV40, JC virus, BK virus, KI, WU, Merkel cell polyomavirus (MCPyV)
Polyomavirus
PAPILLOMAVIRUSES
Virus
Transmission
Site of latency
Disease
Diagnosis
Virus: Human Papilloma Virus
Transmission: Direct contact, sexual contact for genital warts
Site of latency: Epithelial tissue (Infect squamous cells and induce formation of cytoplasmic vacuole (koilocytes)
Disease: Skin and Genital warts, benign head and neck tumors, anogenital warts
Diagnosis: Cytology, DNA probes, HPV antigen
Types of HPV
Skin and plantar warts, verruca vulgaris
HPV 1, 2, 4, 7
Types of HPV
Genital warts (Condyloma acuminata)
Respiratory tract papillomas
Most common viral STD
HPV 6 and 11
Types of HPV
Carcinoma of the cervix, vulva, penis, anus
HPV 16, 18, 31, 33
POLYOMAVIRUSES
Virus
Site of latency
Disease
Diagnosis
Virus: Polyomavirus (BK and JC viruses infect humans)
Site of latency: kidney
Disease:
1. JCV: progressive multifocal leukoencephalopathy in patients with AIDS
2. BKV: hemorrhagic cystitis and nephropathy in patients with solid organ (kidney) and bone marrow transplants
Diagnosis: JC virus by PCR (CSF and urine) or EM (brain tissue); BK virus by PCR or cytology of urine (decoy cells)
Herpes Simplex Viruses (HSV)
Virus
Transmission
Site of latency
Disease
Diagnosis
Virus: Herpes simplex virus types 1 and 2 (HSV-1 and -2)
Transmission: Direct contact with infected secretions
HSV 1: saliva or direct.
HSV 2: sexual or transvaginal
Site of latency: Sensory nerve ganglia (neuron)
[HSV 1: Trigeminal ganglia]
[HSV 2: Lumbosacral ganglia]
Disease: Vesicle filled with virus particles and cell debris
Diagnosis: Tzanck smear (multinucleated giant cell), Cowdry type A, Cell culture (HDF, others), EIA, FA stain, PCR (CSF herpes encephalitis)
Varicella-Zoster Virus (VZV) / HHV-3
Virus
Site of latency:
Disease
Diagnosis❌
Prevention ❌
Virus: Varicella-Zoster virus (VZV)
Site of latency: Dorsal root ganglia
Disease: Chicken pox (varicella); shingles (herpes zoster); Ramsay Hunt syndrome (herpes zoster oticus), congenital varicella
Diagnosis: FA stain, cell culture (HDF), shell vial culture, PCR
Prevention: vaccine (VZIG and live attenuated (Oka strain))
Vesicular rash (‘dewdrop on a rose petal appearance’) that begins on trunk; spreads to face and extremities (centrifugal) with lesions of different stages
Varicella/Chicken Pox
Complications: Pneumonia, Encephalitis, Reye’s syndrome,
Cerebellar ataxia, secondary bacterial infection
Varicella/Chicken Pox
Unilateral painful vesicular eruption with a dermatomal distribution (thoracic and lumbar)
Herpes Zoster/Shingles
Debilitating pain (postherpetic neuralgia) ≥ most common complication
Herpes Zoster/Shingles
Reactivation of latent VZV residing within geniculate ganglion
RAMSAY-HUNT SYNDROME / HERPES ZOSTER OTICUS
A triad of ipsilateral facial paralysis, ear pain, and vesicles on the face, on the ear, or in the ear is the typical presentation.
RAMSAY-HUNT SYNDROME / HERPES ZOSTER OTICUS
Fetuses infected at 6-12 weeks’ AOG: maximal interruption with limb development (short and malformed limbs covered with cicatrix - skin lesion with zigzag scarring associated with atrophy of the affected limb)
Fetuses infected at 16-20 weeks’ AOG: eye and brain involvement
CONGENITAL VARICELLA
Cytomegalovirus (CMV)
Transmission
Site of latency
Disease
Diagnosis
Transmission: close contact with infected secretions, blood transfusion (WBCs), organ transplants, transplacental
Site of latency: WBCs, endothelial cells, cells in a variety of organs
Disease: asymptomatic infections, congenital disease of newborn, systemic infection of immunocompromised host, and heterophile negative IM
Diagnosis: Cell culture (HDF), shell vial culture, CMV antigenemia, FA stain, PCR, negative heterophil test, Giant cells with “owl’s-eye” nuclear inclusion
Epstein-Barr Virus (EBV) / HHV-4
Transmission
Site of latency
Disease
Oncogenic
Diagnosis
Transmission: close contact with infected saliva
Site of latency: B lymphocytes (C3d complement)
Disease: Infectious mononucleosis (IM) [“Kissing disease”], progressive lymphoreticular disease, oral hairy leukoplakia in HIV-infected patients .
Oncogenic: Burkitt’s Lymphoma, nasopharyngeal carcinoma
Diagnosis: Serology, PCR, Hematologic reports (Downey cells)
Heterophil-Positive:
Epstein-Barr Virus
Heterophil-Negative
Cytomegalovirus
Human Herpesvirus 6 and 7 (HHV-6 and HHV 7)
Transmission
Site of latency
Disease
Transmission: close contact via respiratory route (saliva); almost all children infected by age 2-3 years
Site of latency: T lymphocytes (CD4 cells)
Disease: Roseola (roseola infantum/exanthem subitum/6th disease)
Human herpesvirus type 8 (HHV-8)
Site of latency:
Disease
Site of latency: viral genome found in Kaposi’s sarcoma tumor cells, endothelial cells, and tumor- infiltrating leukocytes
Disease: Kaposi’s sarcoma
POXVIRIDAE
Virus:
Characteristics
Transmission
Disease
Virus: Smallpox (variola) and molluscum contagiosum
Characteristics: largest and most complex of all viruses; brick- shaped virion
Transmission: Respiratory droplets (smallpox); direct contact (molluscum)
,Disease: all diseases of the skin ; smallpox and molluscum contagiosum
is generalized infection with pustular rash
smallpox
manifest benign nodules of skin.
molluscum contagiosum
Only disease that has been eradicated from the face of the earth
SMALLPOX
Prodome of fever and malaise followed by centrifugal rash
SMALLPOX
HP of Smallpox
Guarnieri bodies: intracytoplasmic eosinophilic inclusions
flesh-colored dome-shaped papules with central umbilication
MOLLUSCUM CONTAGIOSUM
HP of MOLLUSCUM CONTAGIOSUM
Henderson-Patterson bodies: intracytoplasmic eosinophilic inclusions
