Poliomyelitis or polio is a acute viral infectious disease. It is spread through crowding, unclean conditions, and improper sanitation of waste fluids. During the early 20th century, this disease devastated many populations around the world; thanks to vaccines developed in the middle of the century, it is rare in first world countries. Unfortunately, lack of thorough vaccination in developing nations makes polio a recurring problem in these areas of the world.
The infection is caused by the poliovirus, a virus that attacks the digestive tract in human beings. There are three classes of the disease, and the most mild, type three, represents the bulk of infections. The patient may experience a general feeling of malaise and flu-like symptoms, but he or she may not even realize that these symptoms are the result of a polio infection. In more severe cases, the virus gets into the bloodstream and starts to rapidly multiply, causing more serious health problems.
A more aggressive form of polio is focused on the spinal cord. It causes a condition known as aseptic meningitis, which can be very serious. The patient experiences the classic symptoms of meningitis, such as a fever and stiff neck, but the symptoms are caused by the virus instead of the bacteria and viruses more commonly associated with meningococcal disease. It can be treated by keeping the patient hydrated and rested, on a firm bed.
The most serious type of polio is associated with paralysis. About 1% of cases will result in a condition called flaccid paralysis, in which the virus interrupts muscle signals, causing muscles to grow slack and weak. In some cases, the body can naturally recover, growing fresh nerve cells to replace the damaged ones. In other instances, permanent paralysis or disfigurement may result. If the polio reaches the brain or lungs, it can be fatal, as it will cause the patient to stop breathing. More aggressive therapy, such as putting the patient on a ventilator, may be required for survival.
When a polio outbreak is occurring, proper hygiene is crucial. The disease has a three to 12 day incubation period, so members of a household may already have it. To prevent the spread of the disease, water should be boiled before drinking, and the house should be kept scrupulously clean. Once a patient has been diagnosed with the virus, he or she may face a lengthy period of physical therapy, if the infection takes a paralytic form.
In 1955, Jonas Salk developed a vaccine for polio, using deactivated virus. Albert Sabin followed in 1963 with an easy to administer oral active vaccine, which is also highly effective. Routine vaccination this disease is standard in many countries as a result.
