With an increase in the number of mystery cases, the CDC is seeking help to resolve the case

TThe Centers for Disease Control and Prevention Tuesday urged doctors to report suspected cases of mysterious illness affecting young children quickly, pointing out that delays in identifying possible cases of acute flaccid myelitis, or AFM, are hampering research. of the cause.

Every two years since 2014, an increasing number of polio-like illnesses have affected many young children across the country, leaving them weakened. Efforts to find the cause of the phenomenon have highlighted viral infections as a possible culprit, but to date, no virus has been clearly implicated.

Dr. Tom Clark, deputy director of the CDC's Viral Disease Division, said the agency needed to hear about these cases during their hospital investigation, not after the fact. Sometimes cases are not reported for months, he said.

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"The kid may have gone home [from hospital] even before we are notified. It's not ideal for us, "Clark told STAT. "This delay in reporting hamstring problems is a testament to our efforts to consistently perform the appropriate laboratory tests."

The delay may affect the types of samples taken from the children. Instead of getting quality samples with enough material to test, sometimes the CDC ends up with "leftover samples," Clark said.

"When we try to apprehend new approaches, new ways of trying to reach the cause of the AFM, you sort of go away with this amalgam of specimens," he said. "So we're really trying to argue that it's a quick recognition and reporting that will help us systematically collect the best specimens early enough so that we can better understand the cause of the AFM."

On Tuesday, the CDC also released an update of its investigation of MFA cases identified during the 2018 season, the third wave of cases that the country has experienced.

Although these cases may occur at any time and year, there appears to be an increase in cases every two years in late summer and early fall. By 2018, the largest wave to date, there were 232 confirmed cases of AD and 26 probable cases. An additional 109 cases reported to the CDC were ultimately excluded as not being MAP cases. None of the 2018 cases have died, according to the report.

Children affected by the disease – the median age of cases is about 5 years old – usually suffer from a respiratory or diarrheal disease shortly before experiencing muscle weakness. Muscle weakness often starts quickly, with some children waking up and unable to move one or more limbs. The condition often affects the arms.

Most of the affected children end up being hospitalized and about 60% of them are admitted to intensive care. about a quarter of confirmed cases are placed in a ventilator to help them breathe for a while.

The first wave observed, occurring in 2014, coincided with a major outbreak of enterovirus infections called EV-D68, similar to the wave 2018. The polio virus also belongs to the family of enteroviruses. Over the years, several cases of AFM have shown signs of recent infection with another enterovirus, EV-A71, or with rhinoviruses, which cause colds.

Efforts to search for viral culprits in cerebrospinal fluid cases have also sometimes led to positive results, but rarely. According to the CDC report, only two of the 2018 cases for which cephalic fluid was tested were positive for an enterovirus.

Clark explained that the tests may have been too late and that the damage caused by the infection had already occurred at the time of nostril sampling or cerebrospinal fluid sampling for viruses.

"The real key is that when you look in the cerebrospinal fluid, case after case, you almost never find anything," he said. "If you continue to search for enterovirus or other viruses in the cerebrospinal fluid using the same methods, you will probably continue to not find it very often. And it's because it's not there … or it was there, but now it's gone. So you have to find new ways to look. "

One of the recent ways in STAT is to look for antibodies to enterovirus and other pathogens in the cerebrospinal fluid. It is a bit like recognizing that if the horse has already left the barn, proof of his previous presence may be the way to answer the question.

But this approach, among other things, requires clinicians caring for children suspected of suffering from AFD to alert public health officials from the first moments of their admission to hospital. Clark noted that these children are likely to be treated by neurologists, who may not be used to informing public health authorities in the same way as infectious disease physicians.

"They do the right things. They admit children, place them in the ICU, do MRIs, give back patches. [But] Pick up the phone and call the health department is not one of their many activities, "he said. "We want to make it one of the things that they do."

Dr. John Williams, head of the Division of Pediatric Infectious Diseases at UPMC Children's Hospital Pittsburgh, said another contributing factor to the delay in reporting could be that many children in the country are managed in community hospitals, where they might not be seen by pediatric neurologists or pediatric infectious disease specialists. In these cases, doctors may not be aware of the recent unusual pattern of MFA cases, Williams said.

"We are all waiting to see what happens this summer and next summer. And I think that in 2020, many doctors of all specialties who will see children – neurologists, general practitioners, family physicians, pediatricians, family doctors – will all think about it, "said Williams, whose name suggests that he will not be able to do so. The hospital is part of the CDC's collaboration in the surveillance of respiratory and intestinal diseases. He added that the AFM was being added to the conditions sought by the network.

The CDC also wants to ensure that the medical community does not assume that the number of MFA cases will decrease this fall due to the large number of cases in 2018.

"The message is that we are ready for another outbreak season, should that happen," Clark said. "And we are preparing a bit as if 2019 could be a season of epidemics, but if the trend continues, it will not be."