Jon* is a 16-year-old Vietnamese citizen who does well in school and dreams one day of being a doctor. Thom* is a charming and articulate 25-year-old Haitian who is starting his own import/export business. Jim* is 46 and a devoted father of three teenaged girls who is a former missionary and now teaches high school English in Arizona. Bob* is a 52-year-old fast-food franchise owner with three kids in college. Joe* is a 65-year-old banker who is thinking of retiring. Fred* is a 78-year-old golf course developer who loves to fox hunt.

What do these men have in common? Polio. They all contracted polio at some point in their lives, which dramatically and irrevocably changed them all, both physically and emotionally.

There has never been and never will be another disease quite like polio. An infectious disease caused by a virus, polio has been around for centuries. Some of the first references to polio are Biblical. There is an ancient Egyptian carving that appears to depict a man with classic polio findings who is leaning on his staff. Initially, polio was a rather unusual occurrence, which lulled the medical community and the public into a sense of complacency. And then during the first half of the 20th century, millions of people were devastated by polio as epidemics swept across the world. Polio's transformation from a sporadic disease to one of epidemic proportions in the early and mid-1900s was paradoxically due in large part to technological advances. Improvements in sanitation unpredictably allowed some diseases, including polio, to flourish because when water supplies consistently were contaminated with the polio virus (prior to improved sanitation), people would be exposed to polio in infancy during which time they had protection from the virus due to their mother's antibodies (from breast milk). With cleaner water, people were now exposed to polio at a later age when they were no longer protected by maternal antibodies. Thus, epidemics began and continued until the develpment of a vaccine in the mid-1950s. Blind to age, gender, and race, polio affects men, women, and children.

Polio's return

With the advent of the polio vaccines, America's polio plague ended. The vaccines were effective not only in eliminating the disease but also in erasing it from its place of prominence on political and health care agendas. In an amazingly short period of time, polio was so completely dismissed it was as if it never existed. Polio survivors moved on with their lives. The March of Dimes changed its mission and went on to fight birth defects, and politicians and celebrities promoted other causes. Even medical doctors learned about polio as merely an historical footnote, if they studied it at all.

However, polio's legacy was far from dead. First, polio continued, often occurring in poverty-stricken countries. Although polio will likely be the second disease eradicated worldwide (smallpox is the first), this has not happened yet. Also, after a long dormant period during which vaccines prevented new cases of acute polio in America and many other countries, in the late 1970s and early 1980s, the vestiges of a virus long gone returned to haunt the very people who had survived its initial onslaught.

With increasing frequency, polio survivors began reporting new problems that bore a remarkable resemblance to symptoms they had experienced at the onset of the disease decades ago. At first these odd complaints were attributed to a variety of other maladies, including malingering. But as more and more polio survivors described a nearly identical set of symptoms, clinicians realized that perhaps these new manifestations were somehow related to the original polio infection. These characteristic symptoms were described in various ways as post-polio sequelae, the late effects of polio, post-polio muscular atrophy, and post-polio syndrome (PPS).

PPS is characterized by new symptoms that occur in people with a history of paralytic polio after a long period of stability (generally at least 15-20 years) in which whatever strength they had remained unchanged. Frequently, the most prominent and alarming symptom is new weakness either in a limb that was known to be involved in the acute illness or in a limb that was not thought to have been affected by the initial polio. This new weakness often heralds a more pronounced level of disability in polio survivors who thought that the worst was over. Some survivors are so taken aback by these new symptoms that they do not seek treatment until years after they begin having manifestations of PPS. In some instances, individuals simply deny that they are having new problems until their condition becomes so pronounced that denial is no longer possible. For others, there is a lack of understanding that keeps them from seeking the medical care they need. Still other polio survivors, who are experts at managing adversity, may genuinely be unaware that anything out of the ordinary is occurring. In fact, sometimes the symptoms are so subtle that the only way to measure them is by taking a careful history that spans many years.

Sequelae

PPS is obviously a syndrome that, by definition, is a collection of symptoms that characteristically occur together. By definition, a syndrome does not have a single test that is able to identify it. Thus, a syndrome is attributed to someone only if they meet specific criteria established by the medical community and only after all other reasonable (and testable) conditions have been eliminated as possibilities. Therefore, in order to diagnose any syndrome, the following must occur: (1) an individual must present with specific symptoms, (2) all other possible causes for these symptoms must have been ruled out, and (3) the individual must meet the criteria established for the diagnosis of the syndrome.

Because syndromes do not have specific tests that can undeniably identify them, they are subject to interpretation and often their validity is challenged within the medical community. PPS is no exception. Although most physicians believe that PPS exists, there are a few who do not.

The symptoms of PPS are listed below.

1.It is important to note that one does not need to have all of the manifestations; however, if someone complains of symptoms that are not listed, other diagnoses should be considered. Some of the symptoms are weigted more heavily than others, and new weakness, the "sine qua non," is the most important criterion.

The symptoms consistent with the diagnosis of PPS include:
1. new weakness,
2. unaccustomed fatigue,
3. pain,
4. new swallowing problems,
5. new respiratory problems,
6. cold intolerance, and
7. new muscle atrophy.

Someone with new weakness may not specifically complain of it, but may report a history of recent trips or falls, difficulty lifting a gallon of milk, or needing to use two handrails on the stairs instead of one. New weakness may also present with respiratory or swallowing involvement with symptoms such as dyspnea on exertion or choking when eating.

Future Considerations

In May 2000, the March of Dimes in collaboration with the Roosevelt Warm Springs Institute for Rehabilitation held an international conference on PPS. The results of this conference were summarized in a report (available from the March of Dimes) that focused on "identifying best practices and care" for PPS.2 The report suggested that polio survivors be treated in a manner similar to how rehabilitation professionals routinely treat individuals with complex neurological and/or musculoskeletal conditions (including polio and PPS) with a multidisciplinary approach.

The polio treatment team may consist of physiatrists, pulmonologists, otolaryngologists, physical therapists, occupational therapists, speech and language pathologists, mental health professionals, orthotists, and many others. It is important to recognize that polio survivors, regardless of their age or whether they have been diagnosed with PPS, will likely need a comprehensive and multidisciplinary approach to their care.

Polio will be with us for at least another 100 years. It is not, and never has been, an historical footnote.

Julie K. Silver, MD, is an assistant professor at Harvard Medical School in the Department of Physical Medicine and Rehabilitation. She is the author of Post-Polio Syndrome: A Guide for Polio Survivors and Their Families (Yale University Press) and is the director of the International Rehabilitation Center for Polio at Spaulding Rehabilitation Hospital, Boston.

References
1. Silver J. Post-Polio Syndrome: A Guide for Polio Survivors and Their Families. New Haven, Conn: Yale University Press; 2001: 17.
2. Post-Polio Syndrome-Identifying Best Practices in Diagnosis and Care. White Plains, NY: The March of Dimes Birth Defects Foundation; 2001.
*Names and identifying characteristics have been changed to protect the privacy of individuals.