Ask the Doctors

Dear Doctor: I've been reading about a new illness that's a lot like polio and is making children in parts of the country very sick. What is it, and should my family and I be worried?

Dear Reader: You're referring to acute flaccid myelitis, also known as AFM, a rare neurological disease that affects the spinal cord. The symptoms mimic those of polio, which has helped to push AFM into the headlines.

Before we get into specifics, we want to stress that AFM is quite rare. Despite the sudden spate of alarming news reports that have, quite understandably, caused you concern, the rate of infection is extremely low -- one person per million. As of last November, there were 120 confirmed cases of AFM in the United States in 2016.

So what exactly is AFM?

It's a syndrome that can cause the muscles and reflexes in the body to stop working normally. Symptoms often arise quickly. What begins as a fever or respiratory illness gives way to weakness in the limbs, including a possible loss of muscle tone.

In several reported cases, the first symptom in a child diagnosed with AFM was a sudden limp. Some patients have slurred speech or facial drooping. In the most serious cases, acute weakness in the muscles that control breathing has led to respiratory difficulties.

At this time, the causes of AFM are not fully understood. Officials at the Centers for Disease Control and Prevention suspect a range of viruses may be involved. These include West Nile virus, enteroviruses that enter the body through the intestines, and adenoviruses, which can cause coldlike symptoms, including sore throat, bronchitis, pneumonia, diarrhea and pink eye.

Research into the causes of AFM, which affects children in greater numbers than adults, is a national priority. At the CDC, scientists and public health specialists are gathering blood samples as well as fluid specimens from the nose, respiratory tract and spinal cord of affected patients for testing. Results are collected into a database for study and analysis.

The symptoms of AFM are similar to several other conditions that are far more common. This has increased the challenge of arriving at an accurate diagnosis. However, awareness of the disease among health care providers is growing rapidly, which means that diagnosis and reporting are become more accurate.

If you believe you or your child has symptoms that correspond with those of AFM, call your family doctor. The findings from a careful examination of the nervous system, with accurate mapping of the muscles and reflexes affected, and diagnostic tests such as an MRI and analysis of the cerebrospinal fluid, will allow a correct diagnosis.

Several germs are suspected in AFM, so the CDC recommends that your family is up-to-date on polio and all other recommended vaccinations, and that you protect yourself and your family from mosquito-borne viruses by using insect repellents.

The good news is that increased awareness of AFM is leading to an ever-larger volume of reliable data for researchers to work with. That means more information about what causes the disease, and more avenues in which to seek and find a cure.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

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