It was around 1972 that studies started to come back showing that patients admitted to hospitals were at an increased risk of infection. It was about this time when the term nosocomial infections started to be used in reference to infections caused by the hospital.
By 2002, studies returned the following results as reported by the Centers for Disease Control and Prevention (CDC)/:
1. Urinary infections are the most common at 31%, and were linked to indwelling urinary catheters.
2. Pneumonia is the second most common at 27%, and was linked to intubation and ventilation
3. Blood stream infections were the third most common at 19%, and were linked to indwelling intravenous catheters
It was these statistics that inspired hospital orientated programs to investigate their causes and methods of their dissolution.