Parvovirus
| Categorization | |
|---|---|
| Genome: DNA Virus, ssDNA Virus | Structure: Nonenveloped Virus, Icosahedral Virus |
| Overview |
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- Parvoviruses are a family of related viruses which are characterized by their small physical size and single stranded DNA (ssDNA) genome. Parvovirus subtype B19 is the only subtype which has definitively been shown to infect humans and is discussed here. Infection with Parvovirus B19 is highly common and most individuals are infected during childhood.
| Pathogenesis |
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- Parvovirus B19 replicates in erythrocyte progenitors and in doing so can transiently arrest erythropoiesis. In most healthy individuals, development of an effective humoral immune response eliminates the virus and erythrocyte production resumes without any clinical evidence of anemia. However, in individuals who are dependent on high levels of erythropoiesis, such as those with hemolytic anemia, arrest of erythropoiesis can lead to a transient aplastic anemia.
| Clinical Consequences |
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- Erythema Infectiosum (AKA: Fifth Disease)
- This is the manifestation of B19 infection in normal individuals and usually occurs during childhood. The disease is heralded by a fever along with a characteristic erythematous skin rash which gives a "slapped-cheek" appearance. Disease is self-limited but may be accompanied by arthralgia.
- Transient Aplastic Crisis
- This may be the manifestation of B19 infection in those with Hemolytic Anemia as well as those with Sickle Cell Disease, Thalassemia, or Autoimmune Hemolytic Anemia. Investigation of the bone marrow will reveal an absence of erythroid precursors.