Skip to Main Content

++

I. DEFINITION

++

Human parvovirus B19 (PB19) is a small, single-stranded, nonenveloped DNA virus.

++

II. INCIDENCE

++

Infection with PB19 is common worldwide. Infection occurs mostly among school-aged children where the major manifestation is erythema infectiosum (fifth disease). The prevalence of immunoglobulin G (IgG) antibodies directed against PB19 ranges from 15 to 60% in children 6–19 years old. About 35–45% of women of childbearing age do not possess protective IgG antibodies against PB19 and therefore are susceptible to primary infection. The incidence of acute PB19 infection in pregnancy is 3.3–3.8%. Annual seroconversion rates in pregnant women in the United States range from 1 to 1.5%.

++

III. PATHOPHYSIOLOGY

++

The only known natural host cell of PB19 is the human erythroid progenitor cell. PB19 is a potent inhibitor of hematopoiesis. The cellular receptor for PB19 is globoside or P-antigen, which is found on erythrocyte progenitor cells, synovium, placental tissue, fetal myocardium, and endothelial cells. The B19-associated red blood cell aplasia is related to caspase-10–mediated apoptosis of erythrocyte precursors. Infection with PB19 is usually acquired through respiratory droplets, but the virus can also be transmitted by blood or blood products and vertically from mother to fetus. In children and adults, viremia develops 2 days after exposure and reaches its peak at ∼1 week. During the phase of viral replication and shedding, the patient is generally asymptomatic. When the typical rash (characterized by a “slapped cheek” appearance on the face and a “lace-like” erythematous rash on the trunk and extremities) or arthralgias develop, the patient is no longer infectious to others. Symptoms during pregnancy are nonspecific and include a flulike syndrome with a low-grade fever, sore throat, generalized malaise, and headache. Pregnant women rarely develop the characteristic “slapped cheek.” The fetus may become infected during the maternal viremic stage. Because of active erythropoiesis in the fetus with a shortened red-cell life span, marked fetal anemia, high-output cardiac failure, and fetal hydrops may develop. Myocarditis, and less often fetal hepatic infection, may contribute to fetal cardiac failure. Teratogenicity from PB19 has been described in case reports; also, one recent study found high prevalence of trisomy in pregnancy loss ascribable to PB19/erythrovirus infection. Despite that, PB19 is considered nonteratogenic based on large epidemiologic studies.

++

IV. RISK FACTORS

++

The risk of acquiring PB19 infection during pregnancy is highest in schoolteachers, day care workers, and women who have school-aged children at home.

++

V. CLINICAL PRESENTATION

++

  1. During pregnancy. The mother may report a history of exposure to a child with erythema infectiosum. More commonly, the mother does not recall such exposure and the diagnosis is made based on ultrasound findings. Fortunately, most maternal infections are associated with normal pregnancy outcomes. The overall risk of adverse outcomes after primary infection is probably <10% despite transplacental transmission rate of 33–50%. Adverse outcomes include the following:

    1. Fetal death. Infection in the first trimester may result in fetal loss or miscarriage. ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessPediatrics Full Site: One-Year Subscription

Connect to the full suite of AccessPediatrics content and resources including 20+ textbooks such as Rudolph’s Pediatrics and The Pediatric Practice series, high-quality procedural videos, images, and animations, interactive board review, an integrated pediatric drug database, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessPediatrics

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.