Herpesviruses Flashcards
properties of herpesviruses
- enveloped
- dsDNA
- linear viruses
Herpes simplex virus-1–route of transmission
- respiratory secretions
- saliva
Herpes simplex virus-1–clinical significance
- gingivostomatitis
- keratoconjunctivitis (A)
- herpes labialis (B)
- herpetic whitlow on finger
- temporal lobe encephalitis
Herpes simplex virus-1–notes
what is it the most common cause of?
how can it present?
- most common cause of sporadic encephalitis
- can present as altered mental status, seizures, and/or aphasia
Herpes simplex virus-2–route of transmission
- sexual contact
- perinatal
Herpes simplex virus-2–clinical significance
- herpes genitalis (C)
- neonatal herpes
Herpes simplex virus-2–notes
where is it latent?
what is more common with HSV2 than HSV1?
- latent in sacral ganglia
- viral meningitis more common with HSV-2 than HSV-1
Varicella Zoster virus (HHV-3)–route of transmission
- respiratory secretions
Varicella Zoster virus (HHV-3)–clinical significance
- varicella zoster (chickenpox (D), shingles (E))
- encephalitis
- pneumonia
what is the most common complication of shingles?
- post herpetic neuralgia
Varicella Zoster virus (HHV-3)–notes
where is it latent?
- latent in dorsal root or trigeminal ganglia
Epstein Barr virus (HHV-4)–route of transmission
- respiratory secretions
- saliva
- “aka kissing disease”–common in young adults, teens
Epstein Barr virus (HHV-4)–clinical significance
- mononucleosis
- fever
- hepatosplenomegaly
- pharyngitis
- lymphadenopathy (especially posterior cervical nodes (F))
- avoid contact sports until resolution due to risk of splenic rupture
- associated with lymphomas (ie. endemic Burkitt lymphoma)
- associated with nasopharyngeal carcinoma
Epstein Barr virus (HHV-4)–notes
which cells does it infect?
blood smear
+ Monospot test
- infects B cells thru CD21
- atypical lymphocytes on peripheral blood smear (G)
- not infected B cells but reactive cytotoxic T cells
- Monospot test
- heterophile antibodies detected by agglutination of sheep or horse RBCs
- Monospot test
cytomegalovirus (HHV-5)–route of transmission
- congenital transfusion
- sexual contact
- saliva
- urine
- transplant
cytomegalovirus (HHV-5)–clinical significance
- mononucleosis (- monospot) in immunocompetent patients
- infection in immunocompromised patients, especially pneumonia in transplant patients
- AIDS retinitis (“sightomegalovirus”): hemorrhage, cotton wool exudates, vision loss
- Congenital CMV
cytomegalovirus (HHV-5)–notes
what do the infected cells look like?
where is it latent?
- infected cells have characteristic “owl eye” inclusions (H)
- latent in mononuclear cells
human herpes viruses 6 and 7–route of transmission
- saliva
human herpes viruses 6 and 7–clinical significance
- roseola infantum (exanthem subitum)
- high fevers for several days that can cause seizures
- followed by diffuse macular rash (I)
what is a less common cause of roseola?
HHV-7
human herpesvirus-8–route of transmission
- sexual contact
human herpesvirus-8–clinical significance
- Kaposi sarcoma (neoplasm of endothelial cells)
- seen in HIV/AIDS and transplant patients
- dark/violaceous plaques or nodules (J) representing vvascular proliferations
- can also affect GI and lungs
HSV identification
- viral culture for skin/genitalia
- CSF PCR for herpes encephalitis
- Tzanck test
- a smear of an opened skin vesicle to detect multinucleated giant cells
- (A) commonly seen in HSV-1, HSV-2, and VZV infection
- “Tzanck heavens I do not have herpes”
- intranuclear inclusions also seen with HSV-1, HSV-2, and VZV
CMV–receptors
integrins (heparin sulfate)
