Name Clinical/Diagnosis Pathogenesis




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Name

Clinical/Diagnosis

Pathogenesis

Treatment/Vaccine




Herpesviridae

©2009 Mark Tuttle

Latent, persistent, and lytic infections. Alter normal host immune response. Contains tegument

HSV-1 + 2

Herpesviridae
α HHV-1 + 2




Oral/Genital herpes

Painful, itchy sores on shaft of penis and sore throat.



Other diseases

  • Herpes pharyngitis

  • Herpetic keratitis (eyes)

  • Herpetic whitlow (fingers)

  • Herpes gladiotorum (skin)

Labs




  • Initial infection involves epithelial cells and fibroblasts.
    1: above waist, 2: below
    HSV-2 is more likely to induce viremia and flu-like symptoms

  • Infects neurons but is latent in ganglia.

  • In recurrent episodes, the virus returns to the site of the initial infection where it can produce vesicular lesions or not. Recurrent episodes can be stimulated by stress or immunosuppression.

  • Disease is controlled mainly by CTLs but Abs contribute

Complications

  • Can result in meningitis

  • Encephalitis is rare but accounts for 95% of sporadic enceph.

    • Occurs when virus spreads from trigem. gang to brain




No vaccine

Acyclovir works because it is an α group HHV and has a thymidine kinase.

Other drugs work if they prove to be resistant




Varicella-Zoster Virus (VZV)

Herpesviridae
α HHV-3

  • Thymidine kinase

  • Latent in neurons




Intense, burning pain, blisters restricted to a particular dermatome -> Band-like

Primary infection – Varicella (Chickenpox)

  • 2 week incubation period

  • Fever, maculopapular rash

  • Vesicle  pustule

  • Worse in adults since it can result in immune-mediated interstitial pneumonia

Recurrent infection – Zoster (Shingles)

  • Band pattern or painful rash

Labs

  • Cytopathic effect on cells (CPE)

  • ELISA for Ab/Ag

  • PCR

  • Portal of entry is the respiratory system

  • Two periods of active viral replication:

    • From respiratory system to lymph nodes (Primary viremia)

    • From lymph nodes to liver and spleen (Secondary viremia)

  • Transmission is cell-to-cell except in the skin lesions

  • BOTH cell mediated and antibody-mediated immunity are important

  • Clinical features are largely due to the host immune response

    • Adult infection is more severe

Complications

  • Can be fatal in immonocompromised people. The virus gets disseminated into multiple organs, including lungs, brain and liver.

  • Older patients: postherpetic neuralgia -> chronic pain

Vaccine

Live-attenuated vaccine

Same schedule as MMR

85-90% efficacy

Treatment

Acyclovir since VZV has thymidine kinase

Passive immunization with Ig


Herpes virus B

Herpesviridae
α Herpesvirus –
not a human herpesvirus


Can be unapparent or result in vesicular lesions

Complications

  • Fatal encephalomyelitis






Name

Clinical/Diagnosis

Pathogenesis

Treatment/Vaccine

Cytomegalovirus (CMV)

Herpesviridae
β HHV-5

  • Latent in T-cells




  • High fever, dry cough, shortness of breath

  • Often inapparent

  • **Disease of immunocompromised

  • Bad congenital disease (TORCH)

Labs

  • Owl eye” inclusions

  • ELISA for IgM (in utero) or IgG

  • PCR




Congenital (1% infected, 10% of those show symptoms)

  • Small size, thrombocytopenia, microcephaly, intracerebral calcification, hepatosplenomegaly, rash (cytomegalic inclusion disease)

Perinatal: During birth. Usually asymptomatic.

Complications

  • Mononucleosis, similar to EBV but less severe

  • Immunocompromised: pneumonia, retinitis, colitis, renal transplant failure

  • Encephalitis is rare but accounts for 95% of sporadic enceph.

    • Occurs when virus spreads from trigem. gang to brain




Vaccine is only for those post renal transplant

Maternal antibodies confer no protection



Ganciclovir acts on CMV-kinase


HHV 6 + 7

Herpesviridae
β HHV-6+7

  • Latent in T-cells

90% of people are carriers

Patients generally fully recover

HHV 6

  • Childhood rash (6th disease)
    Exanthem subitom / Roseolla

  • High fever

  • Rash in 30%

HHV 7

  • Mononucleosus

  • Lymphadenopathy

Epstein-Barr Virus

Herpesviridae
γ HHV 4

Infectious Mononucleosis

  • Swollen cervical lymph nodes, fatigue, splenomegaly, fever,exudative pharyngitis

Labs

  • Downey cells (atypical lymphocytes)

  • Heterophile antibodies (nonspecifics Abs)
    (Test doesn’t work in children)

  • EBNA, EA, VCA

Lymphoproliferative diseases

  • African Burkitt Lymphoma

  • Hodgekin’s Lymphoma

  • Nasopharyngeal carcinoma

  • Hairy oral leukoplakia -> mouth lesions

  • Two types: A + B, different geographical distributions

  • Immortalize B cells cells – yield the atypical Downey cells

    • No longer respond to cell cycle signals

    • Start producing non-specific heterophile antibodies to the Paul-Bunnell Ag which is on RBCs of other animals

    • Become 10-80% of WBCs

    • Can lead to cancers

  • Disease results from a misdirected immune response since the virus produces an IL-10 analogue. (Worse in adults!)

  • Anti-VCA (Viral Capsid Antigen) IgM indicates an acute infection

  • Anti-EBNA (Epstein-Barr Nuclear Antigen) indicates latent

Complications:

No vaccine

No treatment



Kaposi sarcoma-associated herpesvirus
γ HHV 8

  • Latent in B-cells

HIV/immunocompromised

  • Primary infection usually asymptomatic, disease results from reactivation

  • Elderly men of Mediterranean and Eastern Europeans

  • Sexually transmitted, other routes poss.

Labs

  • Clinical presentation, PCR, serology

Kaposi Sarcoma

  • Muscocutaneous lesions, breathlessness, cough, fever, wheezing, immunoglobinemia, lung lesions as a result of endothelial immortalization

Also





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