Antibiotic Resistance—an Alarming Health Care Issue - Statistical Data Included

AORN Journal, July, 2000 by Carolyn Twomey

When antibiotics were introduced in the medical arena in the 1940s, many believed they were the definitive answer to infectious disease. Within a few years, however, microbes had begun to exhibit their resistance to antibiotics. At one time, Walt Kelly's comic strip character, Pogo, described pollution, saying, "We have met the enemy and he is us." Today, however, he could have been describing the alarming medical threat of bacterial infections that are resistant to all known antibiotics.

Every year, 17 million people die of infectious diseases. Emerging highly infectious viral agents, resurgent diseases, and mutating bacteria have combined to create a global health care crisis.(1) Despite major strides in prevention and control, infectious diseases continue to take a significant and economic toll on society. The cost to the health care system is enormous. One report estimated the annual cost of antibiotic resistance to a single pathogen, Staphylococcus aureus, was $122 million.(2) In 1995, the annual cost was estimated to be at least $1.5 billion.(3) Organisms that once displayed uniform susceptibility now exhibit resistance to specific antibiotics.

The problem has created a serious concern for patients with prolonged hospital stays. Since the 1980s, the number of reported nosocomial infections, particularly bacterial infections, has increased drastically. The US Centers for Disease Control and Prevention (CDC) estimates that the annual cost of treating patients who acquire nosocomial infections in acute care facilities in the United States is $3.5 billion.(4) The incidence of nosocomial gram-positive infections has continued to rise, and available antimicrobials have become useless against resistant strains (Figure 1). Coagulase-negative staphylococci (CNS), S. aureus, and enterococci now are the three most common nosocomial isolates, comprising 67% of all nosocomial bacteremias.(5) For the preponderance of CNS and S. aureus strains, vancomycin remains the appropriate therapeutic option, it now has been documented, however, that 17% of all enterococci isolates are vancomycin resistant.

[Figure 1 ILLUSTRATION OMITTED]

A SIGNIFICANT PROBLEM

A national surveillance project involving several hundred tertiary care medical centers between 1980 and 1989 revealed a 754% increase in CNS blood infections.(6) This project also revealed a 120% increase in enterococcal infections and a 176% increase in S. aureus infections. A more recent survey examined nosocomial bacteremic infections in more than 4,500 patients between 1995 and 1996 and found

* 67% of infections were caused by gram-positive bacteria,

* 79% of infections were methicillin-resistant CNS,

* 28% were methicillin-resistant S. aureus (MRSA), and

* 17% were vancomycin-resistant enterococci (VRE).

In cases in which pathogens were susceptible to multiple medications, pathogens rapidly were becoming susceptible to vancomycin only or completely nonsusceptible.(7)

NOSOCOMIAL INFECTIONS

Antibiotic resistance can be found in all organisms, including bacteria, fungi, viruses, and parasites. Among these, bacteria are the greatest concern because of their prevalence in both hospital and community settings. Bacterial resistance to antibiotics can result in patients having

* increased severity of illnesses,

* more debilitating diseases,

* longer hospital stays,

* adverse long-term sequelae, and

* higher mortality rates.

Collectively, these factors create great costs for the health care system.

Losing ground. According to the CDC, each year approximately two million people acquire infections while being hospitalized.(8) Microbes that have developed antibiotic or multimedication resistance typically are the primary cause for infections and complicate treatment. Although resistance is possible in all microbes (ie, bacteria, fungi, viruses), bacteria cause the majority of medication-resistant problems. It currently is estimated that 70% of bacteria causing these infections are resistant to at least one of the more commonly used antibiotics.(9) More alarming is that 60% of patient deaths that are attributed to infections are caused by bacteria that now are resistant to at least one antibiotic.(10)

Data collected in 1999 show antibiotics losing ground to certain pathogens. This study of selected antimicrobial-resistant pathogens associated with nosocomial infections in patients in intensive care units revealed an increased resistance in VRE (43%), MRSA (37%), imipenem-resistant Pseudomonas aeruginosa (56%), and quinolone-resistant P. aeruginosa (50%), as compared to data collected between 1994 and 1998.(11) This resistance is driving health care workers to use experimental and potentially toxic medications to combat infection.

Impact of contemporary medicine. Patients' shortened hospital stays and the trend toward outpatient treatment and surgery have contributed to bacterial resistance. It was estimated that 75% of all surgical procedures will be performed in ambulatory, same-day, or outpatient ORs by the turn of this century.(12) As a result, it is critical that health care professionals make no distinction involving infection control and sterile technique between surgical care delivered in conventional inpatient arenas and in outpatient facilities.