Via SFGate.com, a long report: Doctors hunting rare polio-like illness getting tripped up. Excerpt:
(03-19) 20:56 PDT SAN FRANCISCO -- Stanford University and UCSF neurologists leading the investigation into a rare polio-like paralysis that's affected at least two dozen children in California are still hunting for the source of the illness, and they're finding themselves hampered by delays in reporting cases and questions about how to even describe the disease.
The California Department of Public Health last week released the first geographic data on 20 cases it has investigated. Of those 20, five are in the Bay Area and six are in other parts of Northern California. The two Bay Area doctors heading the state investigation say an additional four or five cases in California are being investigated, including a child from Los Angeles who became sick in January. The first patients got sick in September 2012. Cases have been scattered throughout the state, and one involved a child who was hospitalized in California but lives in another state.
In almost every case, the patients - mostly children, although there have been one or two adults with milder illnesses - weren't tested for a possible viral cause of their paralysis until long after any pathogen may have left their bodies. That has made it challenging for investigators to identify the cause of the illness, although they believe it's probably a virus.
What exactly is it?
Investigators also have had a hard time simply defining the disease, which further complicates finding and reporting new cases. With so few cases for comparison, it can be difficult to develop a list of diagnostic criteria that will help doctors sort out which cases they should look at and which to ignore.
"The state's job is to cast a wide enough net that (investigators) can pick up on important diseases, but my role is to try to help them narrow it so they're not looking at every single patient with weakness in California," said Dr. Keith Van Haren, a pediatric neurologist at Stanford's Lucile Packard Children's Hospital who studied the first cases.
Van Haren and Dr. Emmanuelle Waubant, a UCSF neurologist, are leading the state investigation, and part of their focus is putting together a diagnostic list that pediatricians and other front-line doctors can use to find new cases. The most notable symptom of the mystery illness is sudden paralysis in one or more limbs. Patients have what's known as flaccid paralysis, which means the muscles become weak or limp. Children who have the polio-like syndrome can't move the affected limbs, although they often retain sensation.
Sudden paralysis is unusual in the United States, hitting about 1 in 100,000 children younger than 15 each year, according to the Centers for Disease Control and Prevention. The cause is often never determined, but it can be due to a variety of factors such as a stroke or other brain injury, or inflammation from a nervous system infection.
It's rarer, according to the CDC, for sudden flaccid paralysis to be caused by a virus. And those cases are notoriously difficult to investigate.