“Fifth disease” alert in France. “An epidemic of Parvovirus B19 infections is currently affecting France,” indicates Public health France in a report released Monday evening. The epidemic, which “started in May 2023, affects all age categories and in particular children”, continues the health agency, which observes that it has recently accelerated.
Most of the time not serious, Parvovirus infection can in certain cases give rise to serious complications, and has caused the death of five babies in 2024. What is this disease? What are its symptoms and who can be affected? 20 minutes takes stock of what we know about this virus.
A generally benign “fifth disease”
The infection is contracted “through droplets, such as saliva or nasal mucus, details the American CDC, Centers for Disease Control and Prevention. But also via blood or blood products [en cas de transfusion], and during pregnancy, from mother to baby.” And “the disease is transmitted especially before the appearance of skin rashes in people for whom this is the only manifestation, and probably cannot be transmitted subsequently due to the disappearance of viremia”, adds the Public Health Agency of Canadawhich states that the incubation period is “4 to 14 days, but can last up to 21 days.”
Human Parvovirus B19 infection, its full name, “is most often asymptomatic or associated with fever or flu-like syndrome”, specifies the French Society of Microbiology (SFM). But it can cause “infectious erythema, or fifth disease, a benign childhood infection”, specifies Public Health France.
Among the names for this viral condition, Parvovirus is also called “slapped cheek disease” because of the bright red rash it can cause on the cheeks. It can also spread throughout the body, similar to measles. Why is it also nicknamed “fifth disease”? Because it is the fifth viral infection responsible for a rash in children after measles, chickenpox, rubella and roseola.
Serious complications possible
Most often benign, this disease is not subject to surveillance or any specific prevention measures in France. Excluding affected children from school is not even recommended since when symptoms appear, the sick are no longer contagious.
However, it is “recommended to inform subjects at risk when cluster cases or community cases occur in order to avoid contact,” insists Public Health France. Because this virus can be dangerous for some people. “Primary infection can cause severe manifestations in people with chronic hemolytic anemia, in immunocompromised people and in pregnant women, in whom it can be responsible for miscarriages and fetal-placental hydrops,” a disease severe fetal, warns the health agency. In some cases, “myocarditis or encephalitis may be observed.”
And since the start of the year, five deaths have been recorded, all of infants, four of them after an infection of their mother during pregnancy. Figures at levels higher than before the Covid-19 pandemic, when the number of annual deaths was generally less than two.
The epidemic peak has not yet been reached
Generally, “small epidemics occur every three to four years, at the end of winter and the beginning of spring,” notes the SFM. But since the start of the epidemic a year ago, “its intensity increased in the last quarter of 2023 and it continues its rise in 2024 with a peak which has not yet been reached in March”, specifies Public Health France.
This epidemic, also observed in other European countries such as Denmark and the Netherlands, is part of a broader context of an increase in several infections. Public Health France recently reported a rebound in whooping cough cases. Similar observations have been made with measles or meningococcal infections.
These upsurges are generally explained as a consequence of health restrictions taken during the Covid-19 crisis, then their lifting. These measures have, in effect, reduced people’s exposure to many pathogens, such as bronchiolitis, thus temporarily reducing the opportunity to build immune responses to them. The health agency, which monitors the evolution of the virus in the territory, will update its epidemiological bulletin in May.