May 6 (UPI) -- The Centers for Disease Control and Prevention announced Friday that it's investigating more than 100 cases of unexplained hepatitis in children, five of which have resulted in death.
The agency said in a press briefing that the infections across 25 states and territories may be connected to a global outbreak of the disease that's killed multiple children. Worldwide, there have been 228 cases in 20 countries, according to the World Health Organization.
Dr. Jay Butler, the CDC's deputy director for infectious diseases, said that of the 109 cases the agency's investigating, more than 90% of the children had to be hospitalized and 14% needed liver transplants. He said, though, that the CDC is "casting a wide net" in its investigation and not all of the cases may be linked to the same cause.
"Investigators both here and across the globe are hard at work to determine the cause," Butler said.
The CDC issued a health advisory in response to the cluster of mysterious hepatitis cases in April. At that time, the agency was investigating a much smaller cluster of cases in Alabama involving nine children.
Hepatitis is inflammation of the liver that can be caused by viral infections, alcohol use, toxins, medications and certain other medical conditions. In the United States, the most common causes of hepatitis are hepatitis A, B and C viruses.
Symptoms of hepatitis include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored stools, joint pain, and jaundice.