CDC: Rising parvovirus B19 cases

The CDC's Health Alert issued on August 15, 2024, highlights an increase in human parvovirus B19 activity in the United States. This virus, typically a seasonal respiratory pathogen, has shown an unusual rise in cases, following similar trends observed earlier in 2024 across 14 European countries.¹

CDC reports indicate a notable surge in cases, with rising test positivity rates and increased antibody prevalence in clinical specimens and plasma samples. Specifically, the proportion of individuals with IgM antibodies, which indicate recent infection, increased from less than 3% in 2022–2024 to 10% by June 2024. Among children aged 5–9 years, infection rates surged from 15% to 40% in the same period. Additionally, among plasma donors, the prevalence of parvovirus B19 DNA increased from 1.5% in December 2023 to 19.9% in June 2024. There have also been anecdotal reports of severe outcomes, such as fetal anemia and increased aplastic anemia in individuals with sickle cell disease.²

"Parvovirus B19 is the cause Fifth Disease (Erythema infectiosum) that has the classic “slapped cheek” rash," Tina Tan, MD, FAAP, FIDSA, FPIDS, editor in chief, Contemporary Pediatrics, professor of pediatrics, Feinberg School of Medicine, Northwestern University, pediatric infectious diseases attending, Ann & Robert H. Lurie Children's Hospital of Chicago, told Contemporary Pediatrics.

"Most of the time disease is mild, however, may be more serious in patients that are immunocompromised," added Tan. "In addition to the rash, it may also cause arthralgia and flu-like symptoms, especially in older children and adults. Keep Parvovirus B19 in differential when patient presents with some of these symptoms."

While the FDA recommends testing plasma-derived products for parvovirus B19, whole blood is not routinely screened in the US. Healthcare providers are advised to maintain heightened suspicion of parvovirus B19 in individuals presenting with symptoms, particularly those at high risk. Preventive measures should be implemented, and counseling provided to at-risk groups. Providers should follow established guidelines for testing and managing parvovirus B19 cases. Health departments are urged to inform healthcare providers about the increase in parvovirus B19 activity and promote respiratory illness prevention strategies. They should also communicate with daycare and school providers about parvovirus B19 risks and return-to-school guidelines.²

"With children headed back to school this fall we may continue to see a rise in cases of parvovirus B19," said Rana Hamdy, MD, in a statement to Contemporay Pediatrics. Hamdy is an assistant professor of pediatrics, George Washington University School of Medicine and Health Sciences; pediatric infectious diseases attending, director, Antimicrobial Stewardship Program, associate director, Fellowship Training Program, Children’s National Hospital, Washington, DC.

"It’s important to keep in mind that the virus can manifest differently in different patient populations," Hamdy added. "The more commonly recognized childhood illness manifests as an often febrile illness with myalgias and arthralgias preceding the classic “slapped cheek” exanthem and “lacy” macular rash in immunocompetent children. Once the rash appears they are no longer contagious. In immunocompetent adolescents and young adults it can present as a febrile illness with a purpuric rash on the extremities, termed the 'papular-purpuric gloves-and-socks syndrome (PPGSS)', while in immunocompromised hosts, it can lead to a chronic infection resulting in red cell aplasia. Rarely, acute infection in pregnancy can lead to hydrops fetalis or fetal loss."

For the public, it is important to be aware of parvovirus B19 symptoms and seek medical care if pregnant, immunocompromised, or have a chronic hemolytic disorder with signs of the virus.²

^"Transmission of the virus can be decreased through standard infection control precautions like hand hygiene," said Hamdy.

What is Parvovirus B19?

The international spread suggests a potential shift in the virus's transmission or behavior. This is particularly significant as parvovirus B19 can cause various illnesses, including erythema infectiosum (fifth disease) in children, and more severe complications in adults, particularly pregnant women and individuals with weakened immune systems.¹

While the infection is usually not serious, it can cause complications in people with certain blood disorders, weakened immune systems, or during pregnancy, where it may lead to anemia or increase the risk of miscarriage. Most people recover without needing special treatment, though supportive care may be necessary for those with complications.³

This alert is important because there is no routine surveillance for parvovirus B19 in the US, the true extent of the outbreak may be underreported. By targeting clinical laboratory professionals, the CDC is urging increased vigilance, testing, and reporting to manage this potential public health threat effectively. This advisory underscores the need for awareness and preparedness to mitigate the virus's impact.¹

"For patients with aplastic crisis, they may require transfusions of blood products," said Tan. "In immunodeficient patients, intravenous immune globulin is effective and should be used for the treatment of parvovirus B19 infection in immunodeficient patients."

This article was initially published by our sister publication, Contagion.

References:

1. 08/15/2024: Lab Advisory: CDC Issues Alert for Increase in Human Parvovirus B19 Activity in the United States. CDC. August 15, 2024. Accessed August 22, 2024. https://www.cdc.gov/locs/2024/08-15-2024-Lab-Advisory_CDC_Issues_Alert_Increase_Human_Parvovirus_B19_Activity_United_States.html
2. Increase in Human Parvovirus B19 Activity in the United States. CDC. August 21, 2024. Accessed August 22, 2024. https://emergency.cdc.gov/han/2024/han00514.asp
3. About Parvovirus B19. CDC. August 13, 2024. Accessed August 22, 2024. https://www.cdc.gov/parvovirus-b19/about/index.html