An outbreak of acute flaccid myelitis, a disease closely resembling polio, has infected at least 50 people, including children, across 24 U.S. states and it is expected to worsen.
The Centers for Disease Control and Prevention reported an outbreak of AFM, which directly affects the patient’s nervous tissues, causing paralysis and nerve tissue degeneration. Currently, there is no vaccine to treat acute flaccid myelitis. Poliomyelitis, or polio, was eradicated from the U.S. in 1979. The disease can often cause muscle weakness which renders the patient unable to move.
Polio is making a comeback
Although patients might be able to recover, this is not always the case. The primary cause of polio infection is the ingestion of infected fecal matter, but thanks to the polio vaccine, the U.S. was able to completely eradicate the virus. It is now a disease bound to developing countries with suboptimal sanitary conditions such as Nigeria and Pakistan.
The cause behind AFM is currently unknown, although the best candidate is enterovirus 68, which is closely related to the viral family that causes polio. This categorizes AFM as a potentially viral disease. It can also be linked to the Guillain-Barré syndrome and other environmental toxins. Some suggest that the West Nile virus is a cause of AFM, as the mosquito carries viruses which are in the same family as enterovirus 68.
What we know so far about acute flaccid myelitis
According to the CDC, symptoms of AFM include facial drooping, drooping eyelids, difficulty when swallowing and talking, and most importantly, limb weakness. The disease was spotted back in 2013 when a pattern in Texas showed that most of the infected were younger than 21 years old and displayed severe spinal cord lesions. The most severe cases of AFM lead up to respiratory failure that requires the application of ventilator support.
To diagnose AFM, doctors must examine the patient’s reflexes, the condition of their muscle tone, if they feel weakness on their body, analyze the cerebrospinal fluid, or performing an MRI, although most of the times more than one procedure will take place to correctly assess the disease.
“It you lift the arm up, it literally drops. Sensation is usually intact. There might be slightly decreased sensation in the other arm, but these are younger kids, so they’re not always so cooperative in giving you a good sensory exam,” said Dr. Dan Hurley to Neurology News back in 2014.
Since 2014, the CDC has confirmed a total of 1,153 cases of “enterovirus 68” infection in 43 states, although not every case displayed acute flaccid myelitis. In 2014 there were 120 infections of AFM, in 2015 there were 21, and in 2016 the number raised to 50.
The CDC states that currently, there is no specific treatment for AFM, but a specialist may recommend interventions for particular cases, which can be helpful for dealing with the disease. The only way to prevent the disease is to be vaccinated against polio, which would help to rule out any off-chance that one may become infected with polio instead of AFM.
Protection from mosquitoes can also be helpful as the West Nile virus is one of the contestants for being the cause behind AFM. Doctors advise using mosquito repellent, getting rid of containers with stagnant water and stop being outdoors at sunrise and sunset, when mosquitoes are most likely to bite.
The same measures to prevent polio apply to protecting oneself against AFM. This includes washing one’s hands with soap and water, using disinfectant, making sure that food and anything that you or your child puts on its mouth is clean and disinfected, and finally, avoiding contact with infected people. It is also advisable to care for wounds extensively to prevent infection from the environment, and always washing hands after touching an animal.
CDC pediatrician Dr. Manisha Patel said the institution is investigating each case while also guiding nationwide health departments to find the cause and to subsequently find a cure. Patel acknowledged that limb weakness is a sign of illness alongside a loss of reflexes and muscle tone.
“Until we better understand this, we are asking parents to remain vigilant, practicing hand washing procedures with soap and water,” stated Dr. Patel to CBS News.
Researchers have already studied 25 children diagnosed with partial paralysis due to AFM. The results suggest that most of the kids were not able to completely recover from their limb weakness. The study yielded more evidence pointing out to enterovirus 68 as the responsible for causing AFM.
Doctors are still not sure why some cases show muscle paralysis and others do not. It also appears that enterovirus outbreaks are common in late summer and during the first weeks of fall, but are expected to drop as winter arrives. This will allow epidemiologists to understand if the virus is affected by seasonal events or if the cause of the epidemic is somewhere else to be found.
Parents are advised to get their children to an emergency room if they have trouble breathing or muscle weakness. In 2015, doctors recognized that that year’s AFM outbreak would not be the last. Cases of acute flaccid myelitis have increased significantly during the 2016 outbreak, putting nationwide virology specialists on red alert.