Polio is an infectious disease caused by the poliovirus, which invades the nervous system and can lead to total paralysis in a short period of time. The virus mainly affects nerves in the spinal cord and brainstem, potentially causing paralysis, breathing difficulties, and, in some cases, death. It is highly contagious and spreads through person-to-person contact, as well as through contaminated water or food. The virus can easily spread if people do not practice proper hand hygiene or if water is contaminated with feces carrying the poliovirus. 

Recovering from polio varies depending on the severity of the infection. Most people with milder symptoms make a full recovery within 1-2 weeks. However, individuals with more severe symptoms can be weak or paralyzed for life, and some may even die. 

There is no cure for polio, only treatments to manage symptoms. For those who survive the acute phase of the disease, supportive treatments such as physical or occupational therapy can help with muscle weakness and paralysis caused by polio. 

Yes, polio is still around, but significant progress has been made in reducing its prevalence. 

Polio can cause various effects on the legs, depending on the severity of the infection. The virus primarily affects the nervous system and can lead to paralysis, particularly in the legs. This paralysis is often characterized by weakness and muscle wasting, leading to difficulties in walking and mobility. In some cases, polio can cause permanent paralysis of the legs or muscle weakness, which may emerge years after the initial infection as a condition known as post-polio syndrome.