Incidence and characteristics of nosocomial infections

The majority of bacterial infections are community acquired; however, the incidence of nosocomial (hospital-acquired) infections has been increasing. Nosocomial infections can occur in any healthcare facility, including hospitals, surgical centers, ambulatory clinics and long-term care facilities. According to the Centers for Disease Control and Prevention (CDC), almost 2 million individuals contract nosocomial infections each year in the U.S., and 99,000 of them die as a result.1

In the U.S., the majority of nosocomial infections are caused by Gram-positive bacteria. However, significantly more Gram-negative bacterial infections are contracted in the ICU. According to the National Healthcare Safety Network at the CDC, more than 30.0% of nosocomial infections and approximately 70.0% of those contracted in the ICU can be attributed to Gram-negative bacteria.2

Moreover, the rates of resistance to nosocomial pathogens have also been increasing, putting an additional burden on the healthcare system. An analysis of the direct medical costs attributable to nosocomial infections was conducted by the CDC in 2009. Estimates of the costs of treating nosocomial infections were found to vary dramatically, but range from $6.8 billion – $45.0 billion USD annually.3


Increasing sales of antibiotics worldwide

The global antibiotic market generated an estimated $42 billion USD in sales in 2009. With an average annual growth rate of 4%, antibiotic sales could reach $60 billion USD by 2015.4

In part because of the broad utility of β‑lactam antibiotics in the treatment of either Gram-negative or Gram-positive bacteria, a majority of antibiotics sold worldwide are in the β‑lactam class. It is estimated that 65% of the antibiotics sold worldwide are in the β‑lactam family.5




1 CDC at Work – Preventing Healthcare-Associated Infections. Accessed August 15, 2012.

2 Hidron AI, Edwards JR, Patel J, Horan TC, Sievert DM, Pollock DA, Fridkin SK. NHSN annual update: antimicrobial-resistant pathogens associated with healthcare-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006–2007. Infect control hosp epidemiol. 2008;29(11):996–1011. doi: 10.1086/591861.

3 Scott RD. The direct medical costs of healthcare-associated infections in U.S. hospitals and the benefits of prevention. Atlanta, GA: Centers for Disease Control and Prevention; 2009. Accessed August 15, 2012 at

4 Hamad, B., 2010. The antibiotics market. Nat. Rev. Drug Discov. 9, 675–676.

5 Elander RP. Industrial production of beta-lactam antibiotics. Appl Microbiol Biotechnol 2003;61:385–92