Childhood Diseases: The Polio Panic

The Polio Panic

On a warm August evening in 1921, after spending a relaxing vacation in Campobello Island, New Brunswick, 39-year-old Franklin Delano Roosevelt felt a mild flu coming on. By the morning, FDR had a fever of 102 degrees and had lost strength in his aching legs. As night approached, the pain spread to his neck and back, and soon he couldn't move his legs at all.

The future president of the United States didn't have a case of the flu; he had contracted poliomyelitis, more commonly known as polio, a crippling viral disease that would leave him paralyzed from the waist down for the rest of his life.

Polio has caused sporadic paralysis and death for much of human history. In the twentieth century, epidemics of polio occurred regularly in cities during the summer, leaving large numbers of healthy children and adults crippled or dead due to paralysis of their breathing muscles. The image of polio-stricken individuals confined to an “iron lung,” a large metal cylinder that operated like a pair of bellows to allow them to breath, was a frightening reminder of the disease's devastation.

Generally known as “infantile paralysis,” polio infected 27,363 persons in 1916, with more than 7,000 deaths. Each year, the “summer plague” left its mark on a scared public only to vanish with the first frost.

Soon after the introduction of effective vaccines in the late 1950s and early 1960s, polio was brought under control and was largely eliminated as a public health problem in industrialized countries. Today, the disease has been eradicated from large parts of the world. Outbreaks have occurred in Eastern Europe, but the only main remaining major reservoirs of virus transmission are in South Asia and sub-Saharan Africa.

Picking Polio Out from the Crowd

Polio is caused by a virus that enters the body through the mouth and multiplies inside the throat and intestines. The incubation period is usually 6 to 20 days, although it may range from 3 to 35 days. The initial symptoms include fever, fatigue, headaches, diarrhea, vomiting, constipation, stiffness in the neck, and pain in the limbs. The virus persists in the throat for about a week, and it may be excreted—still infectious—in the feces for many weeks.

In 95 percent of people, the infection causes no symptoms. However, in some cases, the virus enters the central nervous system. As it multiplies, the virus destroys nerve cells that activate muscles. The muscles of the legs are affected more often than the arm muscles. In the most severe cases, poliovirus attacks the motor neurons of the brain stem, reducing breathing capacity and causing difficulty in swallowing and speaking. Without life support, death ensues.

Children Are Targets

Polio can strike at any age, but affects mainly children under three. Patients are most infectious from 7 to 10 days before and after the onset of symptoms, but remain contagious as long as the virus is present in the throat and feces.

Unfortunately, there are no effective drugs to treat polio. Typically, the disease is treated by applying moist heat, coupled with physical therapy to stimulate the muscles.

A Most Welcome Vaccine

In the late 1950s, Albert Sabin and Jonas Salk developed effective vaccines against the virus. The Salk vaccine is an injection of chemically killed virus, which primes the immune system to recognize the virus and eliminate it. This vaccine confers lasting, but not always lifelong, immunity. The Sabin vaccine is given orally and contains attenuated, live viruses. The attenuated, or weakened, virus is not strong enough to cause paralysis. It multiplies in the intestinal tract and induces immunity.

Widespread immunization campaigns rapidly brought polio under control in developed countries. A global campaign to eradicate polio, rivaling smallpox, has a real chance for success.