Patients admitted to hospitals in the United States during 2010 were twice as likely to have a potentially life-threatening bacterial infection than those admitted 10 years earlier, according to a recent study at University of Texas at Austin.
The university’s College of Pharmacy study found that the incidence of Clostridium difficile infection (CDI), a highly contagious gastrointestinal disease often linked to the overprescribing of antibiotics, nearly doubled between 2001 and 2010. It also determined there were no improvements in patient health outcomes, including mortality or hospital length of stay, over the study period.
Dr. Kelly Reveles, assistant professor of pharmacotherapy, is primary author of the study that looked at 2.2 million cases of CDI from 2001 through 2010. Data were drawn from the U.S. National Hospital Discharge Surveys. Results of her work were published in the October issue of the American Journal of Infection Control under the title, “The rise of Clostridium difficile infection incidence among hospitalized adults in the United States: 2001 to 2010.”
According to the Centers for Disease Control and Prevention, CDI is one of the most common healthcare-associated infections. The UT Austin study found that CDI patients are most likely to be female (59 percent), white (86 perfect), and older than 65 years of age (70 percent). Of the 2.2 million cases, about 7.1 percent, or 154,184 patients died during the study period. The proportion of patients with CDI who died in the hospital increased slightly, from 6.6 percent in 2001 to 7.2 percent in 2010.
“Overuse of antibiotics is the primary risk factor for this disease,” said Reveles, adding that “up to 50 percent of all antibiotic use is unnecessary.”
Antibiotics are effective in combatting bacterial infections, but do nothing to fight viruses. Reveles said that when patients do not feel well, they often believe an antibiotic is needed and will ask their provider for a prescription. Most common respiratory illnesses are due to viruses though, and the use of antibiotics for these infections can lead to unnecessary side effects or the eventual inability of antibiotics to kill certain bacteria in the future.
Reveles said patients entering the hospital with a suspected infection are often given multiple antibiotics, known as “empiric therapy” to combat the suspected infection while healthcare workers attempt to identify the bacteria causing the infection. Once a diagnosis is made, hospitals sometimes are slow to pull back on the higher levels of antibiotics. Reveles said this is an area where pharmacists can play a big role as part of the health care team, by helping physicians choose appropriate antibiotics while limiting unnecessary use.
In a follow-up study presented as a platform presentation at the 2014 Interscience Conference on Antimicrobial Agents and Chemotherapy, Reveles found that the incidence of CDI is highest in the northeast portion of the country and lowest in the western region. This might be due to differences in antibiotic prescribing patterns or population characteristics, although Reveles said additional studies are needed to pinpoint reasons for the regional differences.
The human body uses what is known as “good bacteria” to function properly, the researcher explained. For instance, good bacteria reside in the digestive tract to help break down food. Antibiotics can kill these bacteria and allow C. difficile to multiply in the gut. C. difficile can then cause severe diarrhea often accompanied by fever, as well as abdominal swelling and cramping.
The highest incidence of CDI occurred in 2008, while CDI slightly declined for the last years that were reviewed, Reveles said.
“The leveling off of CDI incidence toward the end of our study period may be the result of increased antibiotic stewardship programs and improved infection control measures such as use of contact precautions, cleaning and disinfection of equipment and environment, and hand hygiene.”
Hospitalized patients, their family members, and their caregivers can help avoid CDI by washing their hands upon entering a patient’s room. Reveles said patients also should understand that antibiotics are not always needed to fight many illnesses such as the common cold.
Reveles conducted the study as part of her Ph.D. program in translational sciences. She completed the program in August under the guidance of Dr. Chris Frei, head of the College of Pharmacy’s Pharmacotherapy Division, and joined the faculty as an assistant professor shortly after completing her studies.
“Dr. Reveles has been an exceptional trainee and treasured asset for the four institutions involved in the new Translational Science PhD program,” said Frei. “She is a strong researcher and prolific writer, and her work holds great potential to transform the care for patients with healthcare associated infections, including Clostridium difficile infection. The faculty and leaders of the TS PhD program are very proud of her and her many accomplishments.”