Polio: history and prevention

Poliomyelitis, commonly shortened to polio, is a highly infectious disease caused by the poliovirus. The virus is found in the gut and is spread through the faeces of an infected person. The virus may also be spread due to poor hand washing or water contamination. The virus may also be found in the throat of an infected person and can be spread through saliva. The virus has an affinity for nervous tissue, and can cause paralysis if it reaches the central nervous system. Polio can also paralyse the breathing and swallowing muscles, leading to death.  

This disease was endemic globally from antiquity to the 19th century. From the 19th century until vaccine development in the mid-1950s the disease was rife globally, with regular outbreaks occurring. Polio only became a notifiable disease in Ireland in 1941. The first epidemic occurred in 1942 and continued into the following year with further epidemic waves in 1947, 1950 and 1953. Cork, the home of this project, experienced its most significant outbreak in 1956. This outbreak resulted in school closures, the closure of the open-air lee baths at Victoria cross, a drop in cinema and dance hall attendance and the postponing of both football and hurling All Ireland finals to limit transmission from Cork to Dublin.   

There is no cure for polio and treatments only alleviate symptoms. Throughout the 1900s, prior to the development of the polio vaccine, a common treatment was to encase the majority of a patient’s body in a negative pressure ventilator or ‘iron lung’.  It functioned to assist a person’s breathing when muscle control of breathing was lost or the workload of breathing was too much. Use of iron lung has now been made redundant due in part to the development of better breathing therapies, but primarily due to the development of the polio vaccine. Polio is a vaccine-preventable disease. Polio vaccine is given to all children as part of the 6 in 1 vaccine at 2, 4 and 6 months of age. A booster vaccine dose is given at 4-5 years of age. The polio vaccine was introduced in Ireland in 1957 and the last recorded case was in 1984. As of 2017, the virus remains in circulation in only three countries in the world – Afghanistan, Pakistan and Nigeria – and it is hoped that the disease will soon be eradicated globally.