Microbiology
Summary
Parvovirus B19 is a naked, single-stranded DNA virus, setting it apart from most other DNA viruses, which are double-stranded. Additionally, it's one of the smallest DNA viruses, with "parvo" actually translating to "small". Generally, parvovirus is transmitted through respiratory droplets or vertically from a mother to her baby in utero.
Most commonly, parvovirus causes fifth disease, also known as erythema infectiosum, which manifests in a low-grade fever and a "slapped cheek" rash, progressing to a lacy reticular pattern down the body. Other clinical findings may include joint pain and arthritis, especially in adults, and transient aplastic anemia particularly in people with sickle cell disease. In extreme cases, prenatal exposure to the parvovirus can result in hydrops fetalis, a severe fetal anemia causing fetal demise.
Lesson Outline
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FAQs
Parvovirus B19, a member of the Parvoviridae family, is one of the smallest DNA viruses. Additionally, it is unique in that it is a single-stranded DNA virus, distinguishing it from most other DNA viruses, which are double-stranded. Parvovirus B19 predominantly causes erythema infectiosum, also known as fifth disease and slapped cheek disease due to the characteristic "slapped cheek" rash.
Parvovirus B19 spreads primarily through respiratory droplets when an infected person coughs or sneezes. However, it can also be transmitted through blood products, and there is a risk of transmission from mother to fetus during pregnancy. Good hygiene practices, like washing hands regularly and avoiding close contact with infected individuals, can reduce transmission risk.
Parvovirus B19 causes fifth disease, also known as erythema infectiosum. The name "fifth disease" came about because it was the fifth condition to be added to a list of rash-associated diseases commonly contracted by children. Patients initially present with symptoms like mild fever, headache, and runny nose, but the notable feature is a bright red rash on the cheeks, often referred to as "slapped cheek rash".
While parvovirus B19 generally causes mild disease like fifth disease, it can occasionally lead to more severe complications. These include transient aplastic anemia, especially in individuals with weakened immune systems or in those with pre-existing conditions that render them anemic. Notably, in pregnant women, infection can cause hydrops fetalis, a severe condition in which abnormal amounts of fluid accumulate in the tissues and cavities of a developing fetus.
