Two common conditions caused by hospital-associated infections killed 48,000 people and ramped up health care costs by $8.1 billion in 2006 alone, according to a study published in the Archives of Internal Medicine.

This is the largest nationally representative study to date of the toll taken by sepsis and pneumonia, two conditions often caused by deadly microbes, including Methicillin-resistant Staphylococcus aureus. Such infections can lead to longer hospital stays, serious complications and even death.

Researchers analyzed 69 million discharge records from hospitals in 40 states and identified two conditions caused by health care-associated infections: sepsis, a potentially lethal systemic response to infection, and pneumonia, an infection of the lungs and respiratory tract.

The researchers looked at infections that developed after hospitalization. They zeroed in on infections that are often preventable, like a serious bloodstream infection that occurs because of a lapse in sterile technique during surgery, and discovered that the cost of such infections can be quite high. For example, people who developed sepsis after surgery stayed in the hospital 11 days longer, and the infections cost an extra $33,000 to treat per person. Even worse, the team found that nearly 20 percent of people who developed sepsis after surgery died as a result of the infection.

The team also looked at pneumonia, an infection that can set in if a disease-causing microbe gets into the lungs—in some cases when a dirty ventilator tube is used. They found that people who developed pneumonia after surgery, which is also thought to be preventable, stayed in the hospital an extra 14 days. Such cases cost an extra $46,000 per person to treat. In 11 percent of the cases, the patient died as a result of the pneumonia infection.

According to the authors, health care-associated infections frequently are caused by microbes that defy treatment with common antibiotics, also known as superbugs. In 2002, the Centers for Disease Control and Prevention estimated that all health care-associated infections were associated with 99,000 deaths per year. Based on their research, study authors were able to estimate the annual number of deaths and health care costs due to sepsis and pneumonia that is actually preventable.

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