Further investigation called for to determine liver inflammation causes

An outbreak of sudden and severe cases of acute hepatitis has made at least 228 previously healthy children sick globally, and there have been five deaths in the United States.

The causes of the illness are still under investigation.

The US Centers for Disease Control and Prevention said on Friday that there had been 109 cases in 25 states and territories in the country in the past seven months.

"Sadly, this does include five reported deaths," said Jay Butler, deputy director for infectious disease at the CDC. More than 90 percent of the patients were admitted to hospital, 14 percent received liver transplants and more than half have a confirmed adenovirus infection.

World Health Organization officials believe that adenovirus, a common pathogen that has rebounded since the pandemic, is a possible underlying cause. It typically causes mild cold, flu-like symptoms, or stomach and intestinal problems.

By May 1, at least 228 cases had been reported in 20 countries, Philippa Easterbrook, a WHO infectious diseases physician and epidemiologist, said on Thursday.

The disease has made children aged between 1 month and 16 years ill, the WHO said. Cases have been reported in countries including the United Kingdom, Spain, the Netherlands, Belgium, and the US. The UK reported a significant increase of acute hepatitis cases among youth to the WHO on April 5.

Hepatitis is an inflammation of the liver. It could be caused by infection, autoimmune disorders, alcohol use, or medication. People infected with the disease could display a variety of symptoms, from vomiting, diarrhea, fever, and fatigue, to yellowing of the skin or eyes, known as jaundice.

It is also unknown what role other factors, such as environmental exposures, medications, or other possible infections of the patients, have played in the illness, Butler said.

Rohit Kohli, chief of the division of gastroenterology, hepatology and nutrition at Children's Hospital Los Angeles, told China Daily on Friday that doctors at the facility have treated seven hepatitis patients that "have met the CDC criteria".

"The jury is still out on what is causing this, but adenovirus is currently our highest suspicion," Kohli said, citing a recent report from the CDC that investigated hepatitis infection cases in Alabama that also showed an adenovirus viral infection. "More investigation is required," he said.

The CDC issued a nationwide health alert on April 21 after healthcare officials in Alabama identified nine cases of children with acute hepatitis between October and February. None of the children has died; two needed liver transplants.

Based on what healthcare authorities know now, no connection was found between the hepatitis cases and COVID-19, Kohli said. The data from the analysis of the initial US cases from Alabama showed no such link, he said.

Vigilance urged

Adenovirus has been found in at least 74 cases, with 18 patients contracting F type 41, a strain of adenovirus affecting the stomach that is commonly known to cause diarrhea and vomiting in children, the WHO reported.

There are more than 50 different types of adenovirus that could infect humans. While there are cases of children with weakened immune systems who developed hepatitis from adenovirus infections, F type 41 rarely causes hepatitis in healthy children, the WHO said.

Given that adenovirus primarily spread via the fecal-oral route, Kohli urged parents and children to use preventive measures such as hand hygiene to protect themselves.

"All children and adults should be washing hands with soap and water before and after eating/drinking and also before/after using the restroom. I believe vigilance and prevention are key."

Since the beginning of last month, Portugal has registered six suspected cases in the outbreak of acute hepatitis among children, the Portuguese Directorate-General of Health said on Friday.

Brunei has stepped up monitoring nationwide to detect cases of acute hepatitis of unknown origin among children, the health ministry said on Saturday.

Xinhua and agencies contributed to this story.