Parvovirus Infection in Children
Introduction
Parvovirus infection in children, also known as erythema infectiosum or "fifth disease," is a common viral illness caused by human parvovirus B19. It primarily affects children but can also occur in adults. The infection is generally mild and self-limiting, characterized by a distinctive "slapped cheek" rash and sometimes accompanied by flu-like symptoms.
Etiology
Human parvovirus B19, a small, non-enveloped DNA virus belonging to the Parvoviridae family, is the causative agent of erythema infectiosum. The virus targets erythroid progenitor cells in the bone marrow, leading to temporary suppression of erythropoiesis.
Epidemiology
- Prevalence: Parvovirus B19 infection is common worldwide, with seroprevalence increasing with age.
- Age distribution: Most cases occur in children aged 5-15 years.
- Seasonality: Outbreaks are more common in late winter to early spring.
- Transmission: Primarily through respiratory droplets and close personal contact.
- Incubation period: 4-14 days, but can be as long as 21 days.
Clinical Manifestations
The clinical presentation of parvovirus infection in children typically progresses through three stages:
- Prodromal phase (2-3 days):
- Low-grade fever
- Malaise
- Headache
- Mild respiratory symptoms
- Erythematous phase (7-10 days):
- "Slapped cheek" appearance: bright red rash on the cheeks
- Lace-like, erythematous rash on the trunk and extremities
- Rash may be pruritic and can fluctuate in intensity
- Recovery phase:
- Gradual resolution of symptoms
- Rash may recur with exposure to heat, sunlight, or stress
Note: Some children may be asymptomatic or experience only mild symptoms.
Diagnosis
Diagnosis of parvovirus infection in children is primarily clinical, based on the characteristic rash and associated symptoms. Laboratory tests can be used for confirmation:
- Serology:
- IgM antibodies: indicate recent infection (detectable 7-10 days after exposure)
- IgG antibodies: indicate past infection or immunity
- PCR: Detection of viral DNA in blood or tissue samples
- Complete blood count (CBC): May show transient anemia or reticulocytopenia
Treatment
Treatment for parvovirus infection in children is generally supportive, as the illness is usually self-limiting:
- Rest and adequate hydration
- Antipyretics and analgesics (e.g., acetaminophen) for fever and discomfort
- Antihistamines for pruritus, if necessary
- In severe cases or immunocompromised patients:
- Intravenous immunoglobulin (IVIG) may be considered
- Blood transfusions for severe anemia
Complications
While most cases of parvovirus infection in children are mild, complications can occur, especially in certain high-risk groups:
- Transient aplastic crisis: In patients with underlying hemolytic disorders (e.g., sickle cell disease, thalassemia)
- Chronic anemia: In immunocompromised patients
- Myocarditis: Rare but potentially severe
- Arthropathy: More common in adults but can occur in children
- Fetal complications: Hydrops fetalis and fetal loss in pregnant women infected during the first 20 weeks of gestation
Prevention
There is no vaccine available for parvovirus B19. Prevention measures include:
- Good hand hygiene
- Proper respiratory etiquette (covering mouth and nose when coughing or sneezing)
- Avoiding close contact with infected individuals
- Exclusion of symptomatic children from school or daycare until the rash appears (as they are no longer infectious at this stage)
2. Parvovirus Infection in Children
- What is the scientific name for the human parvovirus that commonly infects children?
Parvovirus B19 - What is the common name for parvovirus B19 infection in children?
Fifth disease or erythema infectiosum - What age group is most commonly affected by parvovirus B19?
Children aged 5-15 years - What is the primary mode of transmission for parvovirus B19?
Respiratory droplets - What is the incubation period for parvovirus B19 infection?
4-14 days, but can be up to 21 days - What is the characteristic rash associated with fifth disease called?
"Slapped cheek" rash - How long does the typical parvovirus B19 rash last?
1-3 weeks - What percentage of adults have antibodies against parvovirus B19?
50-80% - Which blood cell type does parvovirus B19 primarily infect?
Erythroid progenitor cells - What is the most serious complication of parvovirus B19 infection in pregnant women?
Hydrops fetalis - How is parvovirus B19 infection typically diagnosed?
Serological testing for IgM and IgG antibodies - What treatment is usually recommended for uncomplicated parvovirus B19 infection in children?
Symptomatic treatment (no specific antiviral therapy) - Can parvovirus B19 infection cause arthritis in children?
Yes, but it's more common in adults - What is the risk of parvovirus B19 infection to individuals with sickle cell disease?
Transient aplastic crisis - How long can an infected person spread parvovirus B19?
Before the onset of the rash, typically 5-10 days after infection - What is the structure of the parvovirus B19 capsid?
Icosahedral - What type of genetic material does parvovirus B19 contain?
Single-stranded DNA - Can parvovirus B19 infection be prevented by vaccination?
No, there is currently no vaccine available - What is the approximate size of a parvovirus B19 particle?
18-26 nanometers - Which season has the highest incidence of parvovirus B19 infections?
Late winter to early spring - What is the risk of parvovirus B19 infection to immunocompromised individuals?
Chronic anemia - How does parvovirus B19 enter host cells?
By binding to the P antigen (globoside) receptor - What is the name of the major structural protein of parvovirus B19?
VP2 (Viral Protein 2) - Can parvovirus B19 infection cause fever in children?
Yes, but it's usually low-grade and not present in all cases - What is the typical duration of viremia in parvovirus B19 infection?
5-7 days - Can a person get parvovirus B19 infection more than once?
Generally no, infection confers lifelong immunity - What is the risk of parvovirus B19 infection to fetuses in the first trimester of pregnancy?
Less than 10% risk of fetal loss - How long can parvovirus B19 persist in the environment?
It can remain infectious for several weeks - What is the role of intravenous immunoglobulin in treating parvovirus B19 infection?
Used in severe cases, particularly in immunocompromised patients - Which parvovirus B19 protein is responsible for the cytotoxicity to erythroid progenitor cells?
NS1 (Non-structural protein 1)
