Rare Polio-Like Disease in California

UPDATE (April 29): UCSF and Stanford physicians and researchers report on five cases of polio-like illness in California at the annual meeting of the American Academy of Neurology in Philadelphia on April 29, 2014 from 3:00-6:30 p.m. EST. View details.

Over the past 18 months, physicians in California have observed on rare occasions what may be a new disease, one in which patients, usually children, quickly and permanently lose muscle function in an arm or leg.

In some cases, patients have had infectious respiratory symptoms before the paralysis begins. The illness shares some features with polio, but it is not the same disease.

The cause of the disease is still unknown, but a strong possibility is that it is caused by a virus known as enterovirus-68, which was detected in two of five cases that Emmanuelle Waubant, MD, PhD, of UCSF Benioff Children’s Hospital, and Keith Van Haren, MD, of Stanford University's Lucile Packard Children’s Hospital, will present in detail at the annual meeting of the American Academy of Neurology this spring.

A similar type of rare paralysis caused by a virus related to enterovirus-68 has been reported for many years in Asia and Australia.

The current illness is extremely rare, and does not represent an epidemic. Only about 25 suspected cases have been identified in the U.S., all in California, a state with a population of 38.3 million people, of whom 9.3 million are under age 18, according to the U.S. Census Bureau. No "clustering" of these cases within a small geographic area has been observed, nor are there any apparent connections between the children affected.

The polio vaccine does not appear to protect against this possibly new disease, but the UCSF and Stanford physicians are advising that children continue to receive the polio vaccine to protect against polio. They also urge that any child who shows symptoms of paralysis be seen immediately by his or her primary care physician.

Waubant and Van Haren are actively working with the California Department of Public Health (CDPH) to identify and track cases, with the goal of learning the cause of the disease.

The CDPH is taking all reports of this illness very seriously, and Waubant and Van Haren hope their combined efforts will help lead to prevention and treatment strategies in the future.

Updated April 29, 2014. Original version published February 26, 2014.