Health officials are investigating whether dogs are behind a rise in cases of hepatitis in children, it has emerged.
The UK Health Security Agency (UKHSA) said on Friday that the number of sudden onset hepatitis cases has jumped by 18 since last week to 163, including 11 children who have had liver transplants after their organs were badly damaged.
Unexplained hepatitis – or liver inflammation – is rare in children, and the cases have sparked alarm across the globe.
Health officials said that adenovirus, a usually mild viral infection that causes the common cold, remained the main theory. But the report added that “relatively high numbers” of affected children – 70 per cent of 93 survey respondents – either came from families with dogs, or had some other “exposure” to the pets before falling ill.
“The significance of this finding is being explored,” officials wrote.
But they noted that having a dog was “common in the UK” and there was “limited data on background rates of pet ownership in families of young children”, making it difficult to assess the importance of the data.
The Telegraph understands that health officials are not convinced that the link is strong, but felt that it was too soon to discard any potential hypothesis given the results of the survey.
‘No sensitive link between pets and hepatitis’
Prof Francois Balloux, director of the University College London Genetics Institute, added that he could not think of “any sensible explanation” for a link between exposure to dogs and hepatitis in children.
“Dogs carry their own adenoviruses, including CAV-1, a dog liver pathogen, but there’s no prior evidence at all for CAV-1 being able to infect humans,” he told The Telegraph.
Dr Meaghan Kall, an epidemiologist at the UKHSA, said on Twitter that the theory seemed “far-fetched”.
The report comes after the World Health Organization said that roughly 300 cases had now been reported in at least 20 countries.
While most are in Europe, small numbers have been identified in the Americas, western Pacific and southeast Asia – including three deaths this week in Indonesia, bringing total fatalities to four.
Currently, the leading theory is that the cases are linked to an adenovirus, with 72 per cent of children who were tested for the pathogen in the UK returning a positive result.
Lockdowns could be a factor
But the UKHSA said it was likely that other factors may be amplifying the infection.
One theory is that Covid-19 lockdowns may have weakened children’s immunity, because they were less exposed to common pathogens while in isolation, or that the virus is acting in tandem with another infection.
This could include Sars-Cov-2. So far, 14 per cent of children affected across Britain have recently tested positive for Covid, and scientists have not ruled out the possibility that the hepatitis cases are a consequence of an infection.
Another is that there is an “exceptionally large wave of normal adenovirus infections”, meaning very rare complications are presenting possibility more frequently, or that this is a new adenovirus variant.
Dr Meera Chand, director of clinical and emerging infections at UKHSA, on Friday urged parents to look out for symptoms of hepatitis. The most common symptom – found in more than 70 per cent of children – is jaundice, while vomiting and pale stools were also prevalent.
“It’s important that parents know the likelihood of their child developing hepatitis is extremely low,” she said. “However, we continue to remind everyone to be alert to the signs of hepatitis – particularly jaundice, look for a yellow tinge in the whites of the eyes – and contact your doctor if you are concerned.”
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