An unusual spate of infant deaths linked to a new strain of a normally harmless virus has raised alarm in France.
According to a warning from the World Health Organization (WHO), seven babies are known to have died after being infected with Echovirus-11, and two more are in hospital.
Echovirus-11 belongs to the family of pathogens called enteroviruseswhile it normally only causes cold or flu-like symptoms in adults, it can be dangerous for young children.
Health authorities are particularly concerned about the current cluster of cases because of their rapid onset of serious illness and the high mortality rate that is unusual.
British experts said it’s possible Covid lockdowns could be partly to blame, as mothers who lack immunity to common insects can pass this vulnerability on to their babies.
Enteroviruses usually cause only mild illness, but tend to affect newborns and young children more severely than older children. They can cause symptoms such as fever, runny nose, sneezing, cough, rash, and muscle aches
The warning from France comes after the UK raised the alarm last month about an unusual cluster of enterovirus, caused by a different strain, that left one baby dead and eight in intensive care.
French health authorities detected a total of nine cases of Echovirus-11 in newborns in three unnamed regions between July 2022 and April this year.
The babies, eight of whom were born prematurely, experienced severe sepsis and multi-organ failure after infection, resulting in seven deaths.
Three of the cases were recorded in 2023, the rest occurred in 2022.
The newborns are believed to have contracted the virus from their mothers by accidentally swallowing infected bodily fluids during childbirth, the WHO said.
Genetic analysis of the Echovirus-11 strain behind the deaths suggests it is a new version of the virus that has not previously been registered by global health authorities.
The WHO report said that while the possibility that the new strain could be more deadly could not be ruled out, further research was needed.
Although higher pathogenicity of this new line cannot be ruled out, the severity of infections can also be explained by young age, preterm birth and the absence of maternal immunity.
“Further analyzes are warranted to delineate the characteristics of this recombinant virus.”
However, the WHO added that, although based on the “limited” information, the risk to the public from the cluster of cases is still considered low.
It also highlighted that since many countries do not routinely report enterovirus infections, some cases may have gone under the radar.
WHO alert said echovirus 11 strain behind France’s newborn deaths appears to be new, with no previous data anywhere in the world
Enterovirus question and answer
What’s the situation?
More than a dozen young children in the UK have developed myocarditis (inflammation of the heart) in addition to an enterovirus infection.
How many cases have been detected?
Between June 2022 and March 2023, ten cases have been reported in South Wales and five in South West England.
How many children have been hospitalized?
Eight youths were treated in intensive care, where they were intubated, ventilated and given blood flow support.
Details of six cases are unclear, so the number may be higher.
Have any children died?
One child died before being transferred to tertiary care, part of a hospital that provides highly specialized treatment.
However, a South Wales couple has shared details of the death of their son Elijah, who died in similar circumstances.
As this death occurred in March 2022, outside the nine month period defined by Public Health Wales, it is not being investigated as part of the official cluster.
What’s behind the outbreak?
Experts don’t know.
But health chiefs from Public Health Wales are investigating the reasons for the cluster of cases and looking for other cases to be reported in the coming weeks.
What is the situation in France?
Health chiefs have identified a cluster of newborn cases caused by a different type of enterovirus than the UK outbreak.
As of June 2022, seven babies have died as a result of the infection, with two still in hospital.
The World Health Organization says a new pathogen called Echovirus-11 is responsible.
No specific antiviral therapy is available for enteroviruses, so treatment is aimed at preventing complications.
French authorities have urged doctors to monitor newborns whose mothers may be sick with an enterovirus in response to the recent cases.
MailOnline understands that there are currently no signs of a similar cluster of Echovirus-11 infections in the UK.
However, UK health authorities have observed a series of unusual cases of another enterovirus during the same period, which they are still investigating.
As of June 2022, a total of 15 newborns in Wales and the South West of England have been affected by severe myocarditis ? inflammation of the heart.
PCR testing of nine of the children confirmed they had coxsackie B3 or B4 – types of enterovirus.
One of the affected babies died. Eight were treated in intensive care, where they were intubated, placed on a ventilator and given circulatory support.
Details on the remaining six cases have not yet been published.
Myocarditis usually occurs after a virus. It is caused by the body’s immune system overreacting to infection and causing inflammation, which can remain in the heart even after the virus has cleared.
Although some patients have no symptoms, it can cause chest pain, palpitations, and shortness of breath.
The sick children in the UK also showed sepsis – which can kill within hours unless treated quickly. They were also less interested in eating and drinking.
Health authorities consider the two clusters of enterovirus clusters in the UK and France to be unrelated.
Previous unusual outbreaks of infectious diseases in children, including Strep A last winter, have been blamed on lockdowns that may have weakened immunity against the usually harmless bugs.
Professor Ian Jones, a virologist at the University of Reading, told MailOnline that a possible explanation for a recent increase in the severity of enterovirus cases could be that mothers are not exposed to common bugs during lockdown.
“Neonates are protected by maternal antibodies for the first three months of life, so I think one could speculate that lower rates of enterovirus infection due to lockdowns have resulted in less protective antibody being passed on to the newborn,” he said.
However, he noted that there is currently no evidence of this.
Professor Jones added another factor to consider is that because enteroviruses are such a large group of viruses, it is easy for them to recombine and spawn new variants.
“The current cases in France appear to be caused by such a recombinant, not a previously circulating virus,” he said.
But he added: “While the cases are remarkable, the absolute numbers are small and I don’t think they represent a global threat.”
Dr. Simon Clarke, an infectious disease expert in Reading, said the cases in France and the UK, although caused by the same broad group of pathogens, are not linked.
“The two WHO warnings are caused by different enteroviruses in babies in different countries, so they are not linked,” he said.
He added that given that people can be infected with enteroviruses without knowing it, it could be helpful for clinicians to screen pregnant women for possible infection.
“Since they can be worn without causing disease, the message here is that it may be helpful to screen pregnant women for the presence of certain pathogens that can cause serious infection in a newborn,” he said,
Even if an infection cannot be cured, screening can identify potential problems before they arise.’
FRANCE warns of newborn deaths from usually-harmless infection after string of similar cases in UK