Skip to main content

Notes from the Field: #Parvovirus B19 #Activity — #USA, January 2024–May 2025 (MMWR)

Image
By G.M.



Summary

-- What is already known about this topic?

- Parvovirus B19 (B19) is a respiratory virus that can cause adverse fetal outcomes in pregnant women and persons who are immunocompromised or have chronic hemolytic blood disorders. After relatively low rates during the COVID-19 pandemic years of 2021–2023, B19 activity in 2024 exceeded that of prepandemic years.

-- What is added by this report?

- Data from the National Syndromic Surveillance Program indicated that the proportion of sera specimens positive for B19 antibodies during January–May 10, 2025, was higher than during the same period in 2024, suggesting a sustained increase in B19 transmission.

-- What are the implications for public health practice?

- Health care providers should have a heightened suspicion of and consider providing testing for B19 infection among groups at high risk for severe outcomes, including pregnant women with compatible symptoms or exposure to B19. Among pregnant women, health care providers should remain vigilant for fetal complications related to B19 infection. Pregnant women and persons at increased risk for complications from B19 infection might consider using additional prevention strategies (e.g., wearing a mask around other persons).


Abstract

Parvovirus B19 (B19) is a respiratory virus primarily transmitted through the air by persons with symptomatic or asymptomatic infection. B19 infection causes mild illness in most persons but can result in adverse fetal outcomes in pregnant women or severe disease in persons who are immunocompromised or have chronic hemolytic blood disorders. No antiviral medication exists to treat B19 infection. B19 activity typically peaks in the second quarter of the year (April–June). After low rates during the COVID-19 pandemic (2021–2023), B19 activity in 2024 exceeded prepandemic years, and CDC released a Health Advisory in August 2024 (1,2).

Source: US Centers for Disease Control and Prevention, http://dx.doi.org/10.15585/mmwr.mm7423a3

____

Labels:

Comments

Post a Comment

Popular posts from this blog

#Neuroinvasive #Oropouche virus in a patient with #HIV from extra-Amazonian #Brazil

By G.M.
{Excerpt} A novel reassortant Oropouche virus (OROV) lineage (with medium [M], large [L], and small [S] RNA segments : M1L2S2) has driven Brazil's largest and most geographically widespread OROV epidemic , expanding beyond the endemic Amazon basin to establish local transmission across multiple Brazilian states and other previously unaffected Latin American countries . The rapid spread of this lineage underscores its evolutionary potential and reinforces its significance as a public health threat .1 Similar to chikungunya and Zika viruses, expanding arboviruses can exhibit unexpected clinical and epidemiological shifts , including vertical transmissions , neuroinvasive effects, and potentially fatal outcomes.2–4 Although OROV typically causes self-limited febrile illness, accumulating clinical and experimental evidence suggests neurotropic potential .5 This Correspondence describes the first confirmed case of neuroinvasive OROV infection caused by the emergent M1L2S2 lineage in ext...
Post a Comment
Read more »

No evidence of immune #exhaustion after repeated #SARS-CoV-2 #vaccination in vulnerable and healthy populations

By G.M.
Abstract Frequent SARS-CoV-2 vaccination in vulnerable populations has raised concerns that this may contribute to T cell exhaustion , which could negatively affect the quality of immune protection. Herein, we examined the impact of repeated SARS-CoV-2 vaccination on T cell phenotypic and functional exhaustion in frail older adults in long-term care (n = 23), individuals on immunosuppressive drugs (n = 10), and healthy adults (n = 43), in Canada . Spike-specific CD4+ and CD8+ T cell levels did not decline in any cohort following repeated SARS-CoV-2 vaccination, nor did the expression of exhaustion markers on spike-specific or total T cells increase. T cell production of multiple cytokines (i.e. polyfunctionality) in response to the spike protein of SARS-CoV-2 did not decline in any cohort following repeated vaccination. None of the cohorts displayed elevated levels of terminally differentiated T cells following multiple SARS-CoV-2 vaccinations. Thus, repeated SARS-CoV-2 vaccination was...
Post a Comment
Read more »

Chimeric #hemagglutinin and #M2 #mRNA #vaccine for broad #influenza subtype protection

By G.M.
Abstract Since multiple and unpredicted influenza viruses cause seasonal epidemics and even high-risk pandemics , developing a universal influenza vaccine is essential to provide broad protection against various influenza subtypes. Combined with the mRNA lipid nanoparticle-encapsulated (mRNA-LNP) vaccine platform and chimeric immunogen strategy , we developed a novel cocktail mRNA vaccine encoding chimeric HAs (cH5/1-BV, cH7/3) and intact M2 (termed Fluaxe), which confers broad protection against major circulating IAVs and IBVs , as well as highly pathogenic avian influenza . Two-dose intramuscular immunization of Fluaxe in mice elicited cross-reactive neutralizing antibodies , T cell responses, and long-lived immunity, resulting in robust protection against multiple lethal influenza virus infections and severe acute lung injuries . In particular, intramuscular administration stimulated systemic immunity together with a prominent lung tropism of memory cells . Moreover, Fluaxe immuniza...
Post a Comment
Read more »