<p>Thirty-three countries have reported 920 probable cases of severe acute hepatitis in children so far, a jump of 270 from May, the World Health Organization (WHO) said on Friday.</p>.<p>The WHO said that the European Region accounted for half the probable cases, including 267 from the United Kingdom, while a third of the probable cases were from the United States.</p>.<p>Health authorities globally have been investigating the mysterious rise in severe cases of hepatitis - or liver inflammation – in young children. The outbreak was first reported in April in Britain and has since then hit dozens of other countries.</p>.<p>US health officials say infection with adenovirus, a common childhood virus, is the leading hypothesis for the cases.</p>.<p>The latest WHO data was as of June 22 and excluded four countries with reported cases yet to be classified.</p>.<p>Of the 422 cases in which gender and age-related information is available, close to half occurred in males, with most of them under 6 years of age, according to the report.</p>.<p>The WHO said 45 children with acute hepatitis have required liver transplants, and there have been 18 deaths, most of them occurring in the Americas region.</p>
<p>Thirty-three countries have reported 920 probable cases of severe acute hepatitis in children so far, a jump of 270 from May, the World Health Organization (WHO) said on Friday.</p>.<p>The WHO said that the European Region accounted for half the probable cases, including 267 from the United Kingdom, while a third of the probable cases were from the United States.</p>.<p>Health authorities globally have been investigating the mysterious rise in severe cases of hepatitis - or liver inflammation – in young children. The outbreak was first reported in April in Britain and has since then hit dozens of other countries.</p>.<p>US health officials say infection with adenovirus, a common childhood virus, is the leading hypothesis for the cases.</p>.<p>The latest WHO data was as of June 22 and excluded four countries with reported cases yet to be classified.</p>.<p>Of the 422 cases in which gender and age-related information is available, close to half occurred in males, with most of them under 6 years of age, according to the report.</p>.<p>The WHO said 45 children with acute hepatitis have required liver transplants, and there have been 18 deaths, most of them occurring in the Americas region.</p>