Of all illnesses, infections are among the most common cause of death in U.S. hospitals.  Hospital acquired infections are now recognized as a major cause of sickness and death. 

Infectious diseases are the third leading cause of death in the U.S.; hospital-acquired infections are the fourth, translating to 100,000 deaths every year. All together, about two million patients – or about one in 20 – contract an infection after they're admitted to a hospital.  A surviving patient with a very serious infection can end up enduring weeks, months or years of treatment and rehabilitation.  And, organisms acquired in the hospital can be transmitted throughout the community through discharged patients, visitors and staff.

Healthcare professionals don't really have a handle on whether hospital-acquired infections are on the rise or are being conquered.  In a 2007 report, the Centers for Disease Prevention and Control (CDC) cited declines in rates of centralline associated bloodstream infections and surgical site infections observed among certain hospitals from about 1992 to 2004 as a positive trend.  However, a number of factors point to a potential for the problem to worsen before it gets better.  Numbers have been notoriously underreported, and as data gathering and submission improves for more hospitals, the numbers will rise.  As microbes develop new survival tactics to resist drug treatments, they are becoming more virulent.  Finally, we are constantly coming into contact with newly identified microbes – just since 1976, scientists have identified approximately 30 new pathogens. In either event, reporting will never account for all cases.  It's a time-consuming process that's becoming more difficult with today's shorter hospital stays and no standard procedure for tracking patients after discharge.

About Infections
When a microbe – such as a virus, bacterium, fungus, or parasite – enters your body, it can remain dormant, be quickly killed by your immune system or multiply and produce an acute infection.   If you're otherwise healthy and get an acute infection, your immune system may still claim victory or medical treatment may be needed.  If not, one of two things can happen – a state of balance may be achieved producing a chronic infection or the microbes can continue to multiply and overwhelm your body's defenses. 

Infections can be localized (limited to a specific part of the body) or generalized (one that enters the bloodstream and causes systemic symptoms).  Localized infections can result in serious tissue damage, but the real danger occurs when an infection moves from a localized area into the bloodstream and turns into a systemic infection.  A systemic infection can be life-threatening, affecting the lungs, bones, joints, heart, and central nervous system.

The CDC lists the 4 most common hospital-acquired infections as:

• Urinary tract infections (UTI) 32%
• Surgical wound infections 22%
• Pneumonia (lung infections)15%
• Bloodstream infections 14% 

About Superbugs
Bacteria that cause the most troublesome hospital infections are those that have become resistant to the broad-spectrum antibiotics long used to treat them.  One of the faults lies with our heavy – and often inappropriate – use of antibiotics.  When you take an antibiotic, the drug kills susceptible bacteria and can leave behind those that can resist it. The survivors multiply, creating a new bacterial strain that the old antibiotic can't kill.

Studies have shown contamination rates of MRSA on surfaces in hospitals from 10 percent to much higher.  MRSA is a potent antibiotic-resistant bacterium that causes some 94,000 invasive infections in the U.S. each year, resulting in almost 19,000 deaths. Get more information about superbugs by reading the Second Opinion episode on Antibiotic Use.

Common Risk Factors

Factors that contribute to hospital-acquired infection include:

• The condition of a patient upon admission.  Those who are already in a poor state of health can become infected more easily.
  
  
• Patients who bring infections with them.  This is especially likely for patients who are transferred among various health care institutions or from among different rooms within a hospital.
  
  
• The number of procedures performed:
• Surgical procedures:  Microbes can enter the incision at the time of surgery, usually from bacteria already in or on the patient. Also, major surgery can stress a patient's body and lower their natural resistance to infection.
• Procedures involving invasive devices:  Iintubation tubes, catheters, surgical drains and tracheostomy tubes all bypass the body's natural lines of defense against pathogens and provide an easy route for infection.
  
  
• Length of hospital stay. The longer the hospital stay the higher risk there is of contracting an infection.
  
  
• Treatments that leave patients vulnerable to infection:
• Immunosuppression and antacid treatment undermine the body's defenses.
• Antimicrobial therapy may remove competitive flora and leave resistant organisms.
• The prolonged use of antibiotics may reduce the effectiveness of a patient's own immune system.
  
  
• Contamination in hospital environmental systems such as air-conditioning and water systems.
  
  
• Multi-bed rooms where patients and visitors come in close contact with one another. 
  
  
• Understaffed units.  Studies have shown that in busy units, even basic hand-washing can get lost in the rush to treat patients.
  
  
• Insufficient knowledge of or resistance by healthcare providers to practice the most effective ways to prevent infection.  (See Key Point #2  for more information on what healthcare providers can do to reduce infections risks.)

Learn more about Hospital Acquired Infection:

Key Point 2:  Hand washing by hospital staff, patients and visitors is an effective way to prevent hospital acquired infections.  Screening and environmental cleaning are very important but are not effective without hand washing. 

Key Point 3: While the burden of decreasing the number of hospital acquired infection cases lies with the healthcare system, patients can also take steps to protect themselves.