In the span of four months, at least 94 children in 33 U.S. states have developed a devastating form of paralysis with symptoms similar to polio. Some require a ventilator to breathe. And some of the greatest government health minds in the country say they have no idea what’s causing it.

At the same time, during the past four months, at least 12 children have died after falling ill with a respiratory virus called Enterovirus D-68 (EV-D68). Again, federal health officials are at a loss to explain the origin of the epidemic.

Are the mysterious outbreaks linked?

The Centers for Disease Control (CDC) has given the perplexing paralysis cases a new name: acute flaccid myelitis (AFM). And although it has been the subject of a series of national alerts, it’s not been widely covered in the national news media.

Both the AFM paralysis and the EV-D68 respiratory virus infections occur primarily in children. CDC seemed to try to dispel the idea of a link between the two illnesses when asked about it last month stating,

What the CDC failed to mention was that its own published literature, intended for medical professionals, openly discusses a likely link.

In a November 7 alert to practitioners, the CDC noted, “the unusual clustering of acute limb weakness occurred against a background of a nationwide outbreak of severe respiratory illness among children due to enterovirus-D68 (EV-D68). Several of the patients in California and nearly half of the 11 cases identified in Colorado had tested positive for EV-D68 from nasopharyngeal (NP) swabs at the time of admission for their neurologic illness. This raised a possible association between these neurologic illnesses and the ongoing outbreak of respiratory disease due to EV-D68.”

Specialists in California where many of the paralyzed children were diagnosed suspected EV-D68 almost immediately. Two of the first five paralyzed patients were said to have tested positive for EV-D68.

Furthermore, Dr. Teri Schreiner of Children’s Hospital in Colorado recently referred to EV-D68 as “the suspected pathogen” in paralysis cases. And Dr. Benjamin Greenberg of University of Texas Southwestern said the theory of a link was “substantiated by significant evidence”—something CDC seemed reluctant to publicly acknowledge.

If the two are linked, it’s unclear why some children infected with EV-D68 respiratory virus go on to develop crippling paralysis. Since mid-August, the CDC has reported 1,149 serious cases of EV-D68 in 48 states. The actual count is likely higher since CDC doesn’t require states to report EV-D68 illnesses.

There are also more total AFM paralysis cases than the number CDC provided for this article. California alone reported an additional 23 cases through June of 2014, prior to the CDC count of 94 that began in August. That would mean a minimum of 117 AFM paralysis cases.

Link to Illegal Immigrant Children? Unknown.

CDC is unable to answer the widely-asked question as to whether the EV-D68 epidemic is connected to the tens of thousands of illegal immigrant children allowed to enter the U.S. from Central and South America in the last couple of years. EV-D68 is known to have circulated in El Salvador and Nicaragua.

But CDC appears to indicate a link is unlikely. When asked about it, CDC appeared to steer focus away by stating that EV-D68 strains prevalent in the U.S. are genetically related to “strains detected in previous years in the United States, Europe, and Asia”–not south of the U.S. border.

Yet, when asked again whether a possible link to Central and South America has been ruled out, CDC replied:

Another important question is whether the cause of the AFM paralysis is contagious. When asked, CDC did not answer the question. However, outside experts indicate it is a virus spread in the same way as the flu.

In an October question and answer session, Dr. Schreiner was asked how AFM paralysis can be prevented. She answered, “simple measures like washing your hands, coughing into your sleeve, and staying away from sick persons will help to prevent the spread of the virus.”

Good News

If there’s good news to be found among the mysteries, it’s that CDC believes the EV-D68 virus Peaked in September.

“CDC continues to receive and test specimens for EV-D68 from states…Over the past few weeks, there have been very few specimens testing positive for EV-D68,” said a spokesman.

Likewise, the trend of AFM paralysis cases seems to have slowed.

“Over the past few weeks, the number of new confirmed AFM reports has decreased significantly as reflected in our website updates,” says the CDC.

More Q-and-A with CDC

Below are CDC’s answers to a series of related questions for this article:

Question:
How concerned is CDC about the acute flaccid myelitis [AFM] outbreak?

CDC:
“Any unexplained severe illness is always a concern to us, especially when infants and children are affected. We continue to investigate the cases.”

Question:
Please provide the number of CDC verified reports of acute flaccid myelitis [AFM] that meets CDC’s case definition from Dec. 1, 2013 to date, broken down by month and state.

CDC:
“We do not have these data because AFM or other paralysis is not a nationally notifiable disease and our current investigation only covers the period from August 2014. [Reporter’s note: CDC does have specific information it is unaware of or chose not to provide here, including its own published information on case reports and totals from California.]”

Question:
Please provide the number of reports of unexplained paralysis (that may not meet CDC’s case definition) in children that CDC has received from Dec. 1, 2013 to date, broken down by month and state.

CDC:
CDC says it does not have and is not collecting this information.

Question:
If you have information on outcomes to date of the above cases, please send that.

CDC:
CDC says it does not have and is not collecting this information.

Question:
Has CDC determined the method of transmission of acute flaccid myelitis (i.e. airborne)? If so, what is it? If not, are you trying to figure that out and are there any clues?

CDC:
CDC did not answer this question.

Question:
Please provide lab test result numbers on EV-D68 specimens received from states from Aug. 1, 2014-today.

CDC:
“We do not have additional information about the test results from the state public health laboratories.”

Question:
But it’s my understanding that this information has been reported to CDC. Are you saying you haven’t received it? If you haven’t received it:
Are state numbers included in the total numbers you have provided?
Why haven’t you sought the information?
Please provide the list of states who you mentioned have the capability to conduct this testing.

CDC:
CDC would not answer this question.

Question:
CDC stated that EV-D68 was present in the U.S. in 2012 and 2013. Was 2012 the first date ever, or recently, that the virus was detected in the U.S.? What were the number of cases detected in 2012 and 2013?

CDC:
CDC did not provide this information.

Question:

CDC stated that there are “ongoing investigations” into possible linkage between EV-D68 and paralysis cases. Please detail what the investigations are (i.e. federal study? poll?)

CDC:
“CDC is pursuing a multi-pronged approach to further explore the potential association of acute flaccid myelitis (AFM) with EV-D68 and other etiologies as well as risk factors for AFM. We’re planning a case control study, and we’re also continuing to test specimens from AFM cases for a wide range of viruses that may be associated with this clinical presentation as well as testing to possibly detect previously unrecognized pathogens. The protocols have not been finalized for most of these activities. While we’re not able to share additional information at this time, we plan to submit a scientific paper for publication with more detailed findings in the near future. We continue to update information on the website each Thursday, specifically the number of confirmed reports.” For general information about EV-D68 and the 2014 outbreak, see http://www.cdc.gov/non-polio-enterovirus/about/EV-D68.html and http://www.cdc.gov/non-polio-enterovirus/outbreaks/EV-D68-outbreaks.html.

Question:
CDC stated that none of the CSF [cerebral spinal fluid] in the paralysis cases tested positive for EV-D68. Did any of the patients test positive for EV-D68 in any way—not through CSF, but other testing? If so, how many?

CDC:
CDC did not answer this question. [Reporter’s note: CDC chose not to include the published and known information about positive EV-D68 testing in paralysis cases as reported by a number of medical professionals investigating the cases.]

Question:
Why aren’t you encouraging states to send EV-D68 specimens to CDC for testing to get a complete picture of the mysterious epidemic?

CDC:
“Continued testing does not help with public health assessment of the current situation because of the significant decrease in activity of EV-D68 illness, and there is no systematic collection of specimens to use this testing to follow virus activity.”

Question:
Why haven’t you made EV-D68 a “nationally notifiable disease” so that you can more accurately measure prevalence and trends, as well as estimate total real cases?

CDC:
“This was considered and might have progressed in that direction if the outbreak had gotten worse. However, EV-D68 is not a disease, but merely one of many viruses that can cause severe respiratory disease. Therefore, it was not possible to increase the amount of information available to public health officials, since so few laboratories can identify EV-D68. Since the virus activity did decrease, there was no longer a public health reason for this action.”

Question:
Are there any clues as to why EV-D68 was so prevalent this year?

CDC:
“It’s not possible to discern any pattern as to why specific enteroviruses are common in some years and not others. Over the last several decades, there have been numerous U.S. outbreaks of other enterovirus types, similar in scope to this year’s EV-D68 outbreak. We do not have specific explanations for when large outbreaks occur for enteroviruses.”

Question:
Is it accurate to say EV-D68 is pretty much gone from the U.S. for the season?

CDC:
“Not exactly. Currently, there is significantly less activity of EV-D68 illness compared with activity during peak in September. The degree of reduced activity may be different from states to state. Since at least one of the strains of this virus has been in the United States for the last three years, it is safe to say that the virus is never really gone.”

Question:
Aren’t medical experts, including neurologists, assuming a linkage between the paralysis cases and EV-D68…please clarify whether you are claiming “no link” or have disproven all potential links.

CDC:
“We can’t comment on other experts’ conclusions since we do not know how they made their conclusions.” [Reporter’s note: CDC has chosen not to refer to published reports, including their own, that refer to a potential link and the reasons why one is suspected] “At this point, there’s no evidence for any conclusion and some of the evidence is conflicting, such as the absence of EV-D68 detected in cerebral spinal fluid, as you mention. As indicated above, we’re not claiming ‘no link,’ and we’re not saying we have ‘disproven all potential links,’ which is not possible.”