Parvoviridae Flashcards
The virus to know, and the only one to cause disease in humans
Human Parvovirus B19
Genome of Human parvovirus B19
- positive or negative
- single stranded
- DNA
Capsid structure
Icosahedral
Is it enveloped?
no
Cells that B19 prefers to infect
- mitotically active cells
- cells of erythroid lineage
Transcription, replication, assembly occurs where
Nucleus
B19 binds to?
erythrocyte blood group P antigen(globoside)
Process of replication
- bind to cell
- internalized
- virion uncoated, DNA delivered to nucleus
- single stranded DNA converted to ds DNA by host cell
- transcription, replication, assembly occurs
- released by cell lysis
Clinical presentation of B19
Children: febrile infection, maculopapular rash(slapped)
Early Phase(highly contagious): sore throat, fever, upset stomach, headache, fatigue, itching
Late Phase: Rash => erythematous maculopapular rash on truck and limbs => changes to rash
Adult: joint soreness hands, wrists, knee, ankles
Dangers of B19 during pregnancy
- infection during pregnancy not associated with malformation
- infection during pregnancy associated with increased fetal loss(attacks reticulocytes => anemia in fetus)
Description of fetal hydrous fetalis
- anaemic heart failure
- pleural effusion
- hepatoslenomegaly
- ascites
Parovirus and anemia - Aplastic crisis
- patients with chronic hemolytic anemia
- abnormal decrease in reticulocytes
- cessation of erythrocyte production
- pale think skin, shortness of breath, headache, fever, fainting, fast heartbeat
Transmission of B19
- Aerosol of respiratory and oral secretions
- transplacental
Location of infections by B19
-erythroid precursor cells in bone marrow
Description of biphasic disease that results from B19
- initially phase related to viremia: flulike symptoms, viral shedding
- related to immune response: circulating immune complexes of antibodies
