Parvo Viruses

fackrel@Uwindsor.ca

Parvo Viruses

• Structure

• Classification

• Multiplication

• Clinical manifestations

• Epidemiology

• Diagnosis

• Control

Baron’s Web Site

Parvovirus Structure

• Small icosahedral

• non enveloped

• ssDNA + or - strand

Unable to grow Parvovirus in vitro cell culture

Parvovirinae 

• Genus Parvovirus
  • Type Species mice minute virus

• Genus Erythrovirus
  • Type Species B19 virus Web site

• Genus Dependovirus
  • Type Species adeno-associated virus 2

Classification

• Family Parvoviridae
  • Subfamily Parvovirinae
  • Subfamily Densovirinae

Densovirinae

• Genus Densovirus
  • Type Species Junonia coenia densovirus

• Genus Iteravirus
  • Type Species Bombyx mori densovirus

• Genus Contravirus
  • Type Species Aedes aegypti densovirus

Paroviridae Classification old

• Parvovirus
  • Parvo Virus Like Agent
  • Serum Parvo Like Virus

• Dependovirus
  • AKA Adeno Associated Virus

• Insect virus

B19 Genome

Parvovirus B19 Genome

VP1 Coding Region

VP2 Region

2444

3125

4787

Clinical manifestations

• Mild flu like illness

• Erythema infectosum

• Aplastic Crisis

• Stillbirth Web Site

Mild flu like illness

• Fever

• Headache

• Chills

• Myalgia,

• Malaise

• Sore throat

• hemoglobin conc down

Erythema infectosum

• Fifth Disease

• Rash on face that spreads to exposed skin eg arms and legs

• Subsides over 2 weeks

• Relapses frequent

• Arthritis of hands, wrists, knees and ankles

PPT Slide

Typical facial exanthem of erythema infectiosum. Note the sparing of the perioral areas, resulting in the typical "slapped cheek” appearance.

Web Site

PPT Slide

Lacy, reticular exanthem of the extremity in a child with erythema infectiosum.

Web site

Aplastic Crisis

• patients with Sickle cell anemia ie chronic hemolytic anemia

• Fever, malaise, myalgia, chills

• Maculopapular rash
  • arthritis & joint swelling, itching

• Decreased RBC formation
  • Life threatening

Web site

Stillbirth

• Parvovirus can cross the placenta

• no congenital abnormalities

Fifth Disease

• Droplets inhaled into upper respiratory tract

• local replication

• Viremia

• Replication in upper respiratory tract

• Rash and arthalgia

Aplastic Crisis

• Droplets inhaled into upper respiratory tract

• virus replicates in bone marrow

• Reticulocytosis

Clinical manifestation of B19

Web site

PPT Slide

Web site

Epidemiology

• Most infections before 40 years

• Erythema infectiosum 4-15 years

• 65% of adults have antibodies

Spread by respiratory droplets

• Spread by respiratory droplets

• less contagious than measles

Diagnosis

• Virus detected in serum or throat wash
  • Electron microscopy
  • EIA, RIA
  • DNA hybridization

• Anti viral IgM in serum
  • easier

Control

• No specific control

• patients with clinical erythema infectiosm not infectious
  • already transmitted the virus

DONE!!!