24 Questions
What is the characteristic symptom of the rash that appears on the cheeks of children infected with parvovirus B19?
Slapped cheek appearance
What is the common symptom experienced by adults infected with parvovirus B19?
Polyarthritis with or without a rash
What is the serious complication of parvovirus infection in people with chronic hemolytic anemia?
Aplastic crisis
What is the effect of parvovirus infection on hemoglobin levels during the prodromal period?
Slight decrease
What is the duration of reticulocytopenia in patients with chronic hemolytic anemia infected with parvovirus B19?
7 to 10 days
What is the risk of fetal death in a pregnant seronegative mother infected with parvovirus B19?
Significantly increased risk
What is the effect of parvovirus infection on erythropoiesis in the bone marrow of patients with chronic hemolytic anemia?
Transient reduction
What is the characteristic symptom of parvovirus infection in immunocompromised individuals?
Chronic disease
What was the appearance of the daughter's face?
As if it had been slapped
What symptom did the mother report having more of than usual?
Joint pain
When was the child contagious?
During the initial disease signs and symptoms
What causes the initial nonspecific disease signs?
Interferon and other innate responses to the infection
What causes the rash?
Antibody and virion immune complexes
Why are individuals with chronic hemolytic anemia at increased risk for serious disease after B19 infection?
Because B19 replicates in erythrocyte precursors and prevents development of new erythrocytes or shortens their lifetime
Why is quarantine a poor means of limiting the spread of B19 parvovirus?
Because the virus is spread before the onset of the classic disease signs and symptoms of erythema infectiosum
What is a risk factor for serious disease after B19 infection in pregnant women?
Hydrops fetalis and loss of the fetus
What is a notable symptom of Parvovirus B19 infection?
Slapped-face rash
What is a symptom of Parvovirus B19 infection in adults?
Arthralgia
What is the typical course of Parvovirus B19 infection?
Biphasic disease
What is the characteristic rash of Parvovirus B19 infection?
Slapped-face rash
What is the time frame during which a child with Parvovirus B19 infection is contagious?
Before the onset of symptoms
What is the underlying condition that increases the risk of serious disease after Parvovirus B19 infection?
Anemia
What is the reason why quarantine is a poor means of limiting the spread of Parvovirus B19?
The child is contagious before the onset of symptoms
What is the diagnostic method used to detect Parvovirus B19 DNA in clinical samples?
PCR
Study Notes
Phases of Parvovirus B19 Infection
- Large numbers of viruses are released in oral and respiratory secretions during the first phase, making the person contagious.
- The second phase is immune-mediated, characterized by arthralgia and rash, which occur when specific antibodies react with B19 and form immunocomplexes that deposit and cause tissue injury.
Effects of Parvovirus B19 Infection
- In children, B19 virus causes erythema infectiosum (fifth disease), characterized by a distinctive rash on the cheeks, which appears as if they have been slapped.
- In adults, B19 infection causes polyarthritis (with or without a rash) that can last for weeks.
- In patients with chronic hemolytic anemia (e.g., sickle cell anemia), serious complications can occur, including aplastic crisis, characterized by a transient reduction of erythropoiesis in the bone marrow, leading to reticulocytopenia, decreased hemoglobin levels, and systemic manifestations of fever, rash, and arthralgia.
Diagnosis and Treatment
- Diagnosis is usually based on clinical picture, but definitive diagnosis can be made using serological techniques (ELISA for B19 IgM and IgG) and molecular techniques (PCR for detecting B19 DNA in clinical samples).
- No specific antiviral treatment or human vaccine is available.
Case Study
- The symptoms of the mother and daughter are related, as they are both caused by the presence of antibody, formation of immune complexes, and hypersensitivity reactions.
- The biphasic nature of the disease and the slapped-face rash are notable symptoms of parvovirus B19 etiology.
- Quarantine is a poor means of limiting the spread of B19 parvovirus because the virus is spread before the onset of the classic disease signs and symptoms of erythema infectiosum (fifth disease).
This quiz covers the two phases of a viral infection, including the contagious phase and the immune-mediated phase, and its symptoms such as rash and joint pain. Learn about the effects of the virus on children and normal individuals.
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