Hospital-acquired infections are those infections that patients get during their hospital stay, rather than because of a pre-existing condition before admission. The Centers for Disease Control and Prevention estimates that these infections are associated with 99,000 deaths per year in the U.S. What makes the problem especially challenging is that these infections are becoming increasingly difficult to treat because they are typically caused by microbes that are resistant to antibiotics.

A new study published this month in the Archives of Internal Medicine focused on two specific types of hospital-acquired infections: sepsis and pneumonia. Sepsis is a potentially lethal systemic response to infection, while pneumonia is an infection of the lungs and respiratory tract. Patients typically develop these infections after surgery because of inadequate sterile techniques during the operation.

The analyses are based on 69 million discharges from hospitals in 40 U.S. states between 1998 and 2006. The results are alarming: In one year, sepsis and pneumonia killed 48,000 people and increased health care costs by $8.1 billion.

Patients who acquired sepsis after surgery had to stay in the hospital for an additional 11 days, with an associated increased cost of $33,000 per patient. Around 20% of those patients died as a result of the infection.

For patients who acquired pneumonia after surgery, the additional stay at the hospital was 14 days, while the additional cost was $46,000 per patient. Around 11% of those patients died as a result of the infection.

According to study author Dr. Ramanan Laxminarayan: “In many cases, these conditions could have been avoided with better infection control in hospitals.” He adds that “infections that are acquired during the course of a hospital stay cost the United States a staggering amount in terms of lives lost and health care costs. Hospitals and other health care providers must act now to protect patients from this growing menace.”

Anup Malani, a study co-author, warns that “in some cases, relatively healthy people check into the hospital for routine surgery. They develop sepsis because of a lapse in infection control—and they can die.” He suggests that “the nation urgently needs a comprehensive approach to reduce the risk posed by these deadly infections. Improving infection control is a clear way to both improve patient outcomes and lower health care costs.”

For more information on hospital-acquired infections and antibiotic resistance, please visit Extending the Cure.