Investigators with the Centers for Disease Control and Prevention continue to look into a nationwide outbreak of hepatitis infections among children. The cause of the infections remains unknown.

As of May 18, there have been 180 patients identified, an increase of 71 from the most recent report on May 5, according to the CDC. Reports of the illnesses of unknown origin date back to October 2021. There are patients in 36 states, but the CDC is not reporting how many cases per state because of patient confidentiality considerations.

“(M)ost of these numbers involve patients that are just now being reported, rather than new cases of hepatitis – so not all are recent, and some may ultimately wind up not being linked to this current investigation,” the CDC reported. 

“Additionally, there have been no reported deaths since February 2022, and the proportion of patients requiring liver transplants has gone down from 15 percent to 9 percent since May 5.”

Although hepatitis viruses can be transmitted via foods and beverages, the CDC has not indicated that these are infection routes for this outbreak.

“CDC continues to examine possible causes, including testing for and ruling out some of the viruses that commonly cause hepatitis — hepatitis A, B, C, D, and E. Adenovirus has been detected in nearly half of the children and continues to be a strong lead,” the CDC reports.

The public health agency has contacted doctors and clinicians across the country and is encouraging them to check for hepatitis infections, especially in children younger than 10 years old.

“It’s important to note that severe hepatitis in children remains rare. However, we encourage parents and caregivers to be aware of the symptoms of hepatitis – particularly jaundice, which is a yellowing of the skin or eyes – and to contact their child’s healthcare provider with any concern,” the CDC says.

CDC will begin posting regular online updates specific to the number of patients under investigation on a weekly basis.

Person under investigation (PUI) does not mean this person is a confirmed case. The states and CDC are looking broadly — including hepatitis cases of unknown origin in children under 10 years of age, since October, 2021 — so the number  of PUIs may go up or down as CDC and states review medical charts and learn more.