When visiting a hospital, it is not uncommon to see a variety of different methods to keep the disease of one patient from spreading to another. Between hand washing, rubber gloves and face masks, physicians are usually very careful that not only themselves, but the instruments they use are sterile. Unfortunately, due to general negligence, and increasingly resistant strains of of certain types of diseases, the efforts to keep hospitals clean can be futile.
Who does this happen to? Well most people who are admitted to a hospital are there because the severity of the malady has forced them outside their own home. So not only do we have an environment filled with people who, by their own admission to the hospital show that their health has been somewhat comprimised, we have a breeding ground for a variety of different bacteria.
It is ironic that a place where individuals go to receive medical attention and feel better would also act as an ideal environment for the spreading of infections....CDC experts estimate that approximately 2 million US citizens were diagnosed with some form of nosocomial illness last year, 90,000 of which resulted in fatality. Hospital infections kill more people than homicides and car accidents combined every year.
Generally, deadly diseases such as AIDS and herpes aren't exactly the kinds prevalent illnesses floating around the hospital environment. But that doesn't mean that the ones that are are anything to be taken lightly. Common pathogens include the staphylococcus bacteria. Staph can result in lung, bone, blood, or a variety of different types of infections that are increasingly becoming harder to deal with due to their resistance of anti-microbial agents. E-Coli, and other bacteria can cause intestinal disorders, and pneumonia and TB, and urinary tract infectinos can also be contracted as well.
Direct contact, including surface to body surface contact is one method of transmission, ie touching a handle of a bathroom, a keyboard, etc. Dust or evaportaed water droplets, usually entering the environment via sneezing, coughing, that contain the pathogen can remain airborne and also serve as a method of transmission.
Thankfully, technology is coming to the rescue, but many fear its not happening quite swiftly enough. A variety of companies are beginning to research methods of computer activated and controlled ventilation and ionizing units in hope of decontaminating airbone pathogens and residue. This is beginning to replace the ventilating of formaldehyde to decontaminte certain areas. With the help of sensors and detectors, the machines being produced will take periodic air quality samples and can be remotely or automatically activated to produce disinfecting vapors (hydrogen peroxide tends to be a favorite).
References:
Nosocomial Infections on Wikipedia
BioQuell Decomtamination Solutions
NewScientist Article on Ionisers
CBS Report on Hospital Infections