The Centers for Disease Control and Prevention (CDC) released a health advisory alerting healthcare providers and the public about a rise in parvovirus B19 cases in the United States. Here’s what you need to know.
What is parvovirus B19?
Parvovirus B19, discovered in 1974, is the only member of the Parvoviridae family known to cause disease in humans. The virus targets erythroid progenitor cells, which are responsible for developing red blood cells in the bone marrow.
While typically mild, the virus can cause conditions like erythema infectiosum (Fifth Disease) or joint pain in adults. However, complications such as anemia can occur in people with blood disorders, weakened immune systems, and pregnant individuals.
Moreover, parvovirus B19 can cause severe complications in certain groups. Pregnant individuals face a 5% to 10% risk of complications such as fetal anemia or miscarriage, especially if infected between the 9th and 20th weeks of gestation. People with blood disorders or weakened immune systems may develop severe anemia, requiring treatments such as red blood cell transfusions or immunoglobulin therapy.
Who is most at risk for parvovirus B19?
Parvovirus B19 is highly contagious, spreading through respiratory droplets. Outbreaks are common in schools, and daycare staff and teachers are at a higher risk due to close contact with children. About 50% of adults have immunity by age 20, increasing to 70% by age 40. The virus can also be passed from mother to baby during pregnancy, although transmission through blood transfusions is rare. There is no vaccine or specific treatment, but most cases resolve with supportive care.
Symptoms of parvovirus B19 to watch for
Infections can be asymptomatic, but when symptoms do occur, they typically follow a two-phase pattern. The first phase includes flu-like symptoms such as fever and muscle aches and is the most contagious period. The second phase, occurring 7 to 10 days later, may involve a red “slapped cheek” rash in children or joint pain in adults. Symptoms usually resolve within one to three weeks but may persist longer.
How to prevent parvovirus B19 infection
Good hygiene practices, including handwashing and covering coughs, can reduce the risk of transmission. Pregnant individuals and those with weakened immune systems should avoid contact with symptomatic individuals during the contagious phase of illness.
Diagnosis and treatment
Most cases do not require specific testing or treatment, though blood tests may be used in special situations, such as pregnancy or chronic health conditions. Treatment focuses on managing symptoms like fever and joint pain, while more severe cases, such as anemia, may require blood transfusions. Medical guidance should be sought for those at higher risk of complications.
Where is parvovirus B19 spreading?
According to the CDC, which cited reports from the European Centre for Disease Prevention and Control, officials in 14 European countries have seen an unusual rise in cases. The agency says “there is no routine surveillance for parvovirus B19” in the United States, but that various data is indicating a rise in activity stateside.
“Data includes increased test positivity for parvovirus B19 in clinical specimens and pooled plasma from a large commercial laboratory, and reports of clusters of parvovirus B19-associated complications among pregnant people and people with sickle cell disease,” the CDC wrote.