CDC warns of ‘unusually large’ cluster of 23 parechovirus cases in a month

CDC warns of ‘unusually large’ cluster of 23 cases of brain inflammation in children under three months old sparked by common virus that leads to cold-like illness in most but is more dangerous in infants

  • Infants were all diagnosed over a month-long period up to mid-May this year
  • Each suffered inflammation of the brain and brain lining due to the infection
  • Most recovered but one child may be left with life-long seizures, while a second could have permanent hearing loss
  • Parechovirus is a common infection, that usually sparks no symptoms
  • But it can be dangerous among children less than six months old causing fevers, seizures and brain inflammation. It could also prove fatal in rare cases 

An ‘unusually large’ cluster of 23 babies under three months old have suffered brain inflammation in Tennessee after being infected with parechovirus — and COVID-19 lockdowns could be to blame.

The Centers for Disease Control and Prevention (CDC) reports the infants were all diagnosed over a month-long period up to mid-May this year, and all but one were hospitalized. In 2018, only four cases were recorded a month in spring.

Parechovirus infections are common in children and usually pass without any symptoms, but among those under six months the disease can cause fevers, seizures and brain inflammations — and in rare cases be fatal. It is normally passed on via contact with siblings or parents.

Dr Lili Tao, the microbiologist at Vanderbilt University who led the paper, told the uptick may be due to ‘social distancing’ to stop Covid spreading also weakening immunity against this virus, sparking a surge of cases now.

The infants were all diagnosed over a month-long period up to mid-May this year, and all but one were hospitalized. (stock image)

The uptick in cases was revealed in the CDC’s Morbidity and Mortality Weekly Report (MMWR), the leading diseases publication in the United States.

It said the children were aged between five days to three months old with a median age of 24 days, and 13 were female while ten were male.

All of them suffered inflammation to the brain and lining of the brain because of the infection — medically termed human parechovirus meningoencephalitis. Several also had a fever, fussiness and poor eating.

What is parechovirus? 

Parechovirus is a common and normally harmless infection among children and adults.

Most cases cause few or no symptoms and quickly clear up on their own.

But the virus is much more dangerous in children less than six months old, where an infection can cause fevers, seizures and brain inflammation. In rare cases, it may also be fatal.

How do I catch parechovirus?

The disease can be caught by breathing in air from an infected person.

It may also be transmitted through the fecal-oral route, where someone touches a feces-contaminated surface and then their mouth.

What are the symptoms?

In many cases it may cause little or no symptoms.

But in more serious infections the virus can trigger fever, irritability, nausea and diarrhea.

Among children less than six months old it can also cause brain inflammation, seizures — and be fatal in rare cases.

Is there a treatment?

There is no specifically-designed treatment for the virus.

But sick newborns may be offered immunoglobins, an intravenous medication that boosts immunity.

They could also be given Pleconaril, an oral antiviral medication that fights infections.

Source: Cleveland Clinic.

All but one were admitted to hospital at the Monrow Carell Jr. Children’s hospital in Nashville.

Four of the children were moved to intensive care for treatment. 

Most of the children recovered from the illness, but one may be left with lasting seizures while a second could have permanent hearing loss.

The cases were diagnosed between April 12 and May 24 this year. 

It was not clear how they became infected, but the researchers noted 16 lived with siblings or were exposed to other children.

One also became infected while they were on the wards at a neonatal unit.

Asked how the infants became infected, Dr Tao said many of the patients came from homes where another member had symptoms of a respiratory virus — a tell-tale sign of parechovirus.

‘It suggests that it might be a household member in the family that had the infection and probably transmitted it to the very small babies,’ she said.

It also was not clear what treatment the babies had received. 

Cases of parechovirus usually rise about every two years over the spring and summer months in line with the warming conditions. 

But this normally goes largely undetected because the virus rarely causes severe infections in people.

Yet over 2020 — when the next surge was expected — none was detected as COVID-19 restrictions kept many at home and away from others.

Tao said the investigation was sparked after medics noticed more children being effected by parechovirus than normal.

Asked whether it could be driven by a drop in immunity due to restrictions stopping the virus circulating she said: ‘We cannot say for sure, but there is a fair chance that this is associated with social distancing.

‘We did not see any peak in the virus in 2020, that suggests it is associated with this.’

She could not say whether it was being driven by similar factors as the spate of hepatitis cases in children.

British scientists say it may be caused by lockdowns weakening children’s immunity, but in America health officials say there was no rise in hepatitis cases out of the normal.

There were 19 cases of parechovirus detected over five spring months in Tennessee in 2018, data shows. From 2019 to 2021 there were seven cases reported.