Mysterious paralysing illness hits record number of children in the US
Scientists are unsure what causes the illness, and suspect it may be caused by the EV-D68 virus. (AP: Cynthia S. Goldsmith, Yiting Zhang/CDC)
This year has seen a record number of cases of a mysterious paralysing illness in children, according to US health officials.
- The condition is called acute flaccid myelitis or AFM
- It has been likened to polio, but investigators have ruled out a connection to the disease
- The illness has unusually spiked every two years, with 158 cases in 2018
It is still not clear what is causing the kids to lose the ability to move their face, neck, back, arms or legs. The symptoms tend to occur about a week after the children had a fever and respiratory illness.
No-one has died from the rare disease this year, but it was blamed for one death last year and it may have caused others in the past.
What’s more, Centre for Disease Control and Prevention officials said many children had lasting paralysis and close to half those diagnosed with it this year were admitted to hospital intensive care units and hooked up to machines to help them breathe.
The condition has been likened to polio, a dreaded paralysing illness that once struck tens of thousands of US children a year before a vaccine was made available in the 1950s.
But investigators of the current outbreak have ruled out polio, finding no evidence of that virus re-emerging in recent cases.
The current mystery can be traced to 2012, when three cases of limb weakness were seen in California, but the first real wave of confirmed illnesses was seen in 2014, when 120 were reported.
Another, larger wave occurred in 2016, when there were 149 confirmed cases and so far this year there have been 158 confirmed cases.
In 2015 and 2017, the counts were far lower, and it’s not clear why.
The condition is called acute flaccid myelitis, or AFM.
Investigators have suspected it is caused by a virus called EV-D68.
The 2014 wave coincided with a lot of EV-D68 infections and the virus “remains the leading hypothesis,” said Dr Ruth Lynfield, a member of a 16-person AFM Task Force that the CDC established last month to offer advice to disease detectives.
But there is disagreement about how strong a suspect EV-D68 is.
Waves of AFM and that virus haven’t coincided in other years, and testing is not finding the virus in every case. CDC officials have been increasingly cautious about saying the virus triggered the illnesses in this outbreak.
Indeed, EV-D68 infections are not new in kids, and many Americans carry antibodies against it.
The CDC’s Dr Nancy Messonnier, who is overseeing the agency’s outbreak investigation, said the group was focused on understanding why the virus would cause paralysis.
Experts also said it was not clear why cases were surging in two-year cycles in the US, pointing to the fact more than 17 countries had reported scattered AFM cases, but none had seen large-scale cyclical surges like the US had.
When there has been a wave in the US, cases spiked in September and tailed off significantly by November.
Last week, CDC officials said the problem had peaked, but they warned the number of cases would go up as investigators evaluated — and decided whether to count — illnesses that occurred earlier.
As of Monday, there were 311 illness reports still being evaluated.
This year’s confirmed cases are spread among 36 states. The states with the most are Texas, with 21, and Colorado, 15.