Clostridium difficile infection following outpatient cancer surgery

Although most Clostridium difficile infections (CDI) are healthcare-associated, <25% occur during hospitalization.¹ Increasingly, onset occurs in the community among patients who recently received medical treatment in inpatient or outpatient settings.² The changing epidemiology of C. difficile from a hospital- to a community-onset infection coincides with, and may be driven by, trends toward shorter inpatient stays and more options for outpatient medical and surgical care.³

Patients undergoing outpatient surgery may be at risk for postoperative CDI due to preoperative healthcare exposures, pre- and postoperative antibiotics, or contact with contaminated fomites or colonized patients in the perioperative environment.⁴ The purpose of this study was to determine the incidence of CDI following outpatient cancer surgery, to describe characteristics of patients who developed postoperative CDI, and to identify possible C. difficile transmission events in an outpatient cancer surgery center.

Methods

Sample and setting

We conducted a retrospective cohort study at a freestanding outpatient surgical facility (12 operating rooms and 28 private recovery rooms) within a National Cancer Institute-designated cancer center in New York that includes an acute-care hospital and regional outpatient clinics. The outpatient facility performs ~6,000 procedures annually related to the diagnosis, treatment, and management of cancer. All patients aged ≥18 years who underwent a procedure at the facility from January 2016 through May 2018 were included.

Data collection

Patient characteristics (age, sex, type of surgery, International Classification of Disease, Ninth or Tenth Revision documentation of Crohn’s disease or ulcerative colitis) and treatment information (prophylactic antibiotics, cancer therapy) were extracted from existing hospital databases following institutional review board approval. The CDI cases were obtained from the institution’s infection control surveillance database, which includes CDI diagnoses occurring in any inpatient or outpatient facility affiliated with the cancer center (~600 annually) and CDI diagnoses in cancer center patients reported by outside facilities. CDI testing across all affiliated sites is performed on a single-step polymerase chain reaction (PCR) platform (GeneXpert, Cepheid, Sunnyvale, CA) with subsequent molecular fingerprinting by multilocus sequence typing.⁵ Only diarrheal stool samples are tested.

Data analysis

We calculated the incidence of postoperative CDI (CDI within 90 days of surgery) for all procedures performed during the study period, excluding surgeries in which the patient had a known history of CDI. We then compared molecular typing for all C. difficile isolates from patients who had a history of CDI prior to surgery or acquired postoperative CDI to determine whether transmission may have occurred within the facility.

Results

The facility performed 16,597 procedures on 13,755 unique patients during the study period (Table 1). Excluding surgeries in which the patient had a history of CDI (n = 31), postoperative CDI was detected following 11 procedures (0.66 per 1,000 procedures). The cases were diagnosed in the cancer center’s urgent care clinic (n = 5), outpatient office practices (n = 5), and intensive care unit (n = 1). Time from surgery to CDI onset ranged from 5 to 87 days (median, 33; interquartile range, 56).

Table 1.

Characteristics of Patients Undergoing Procedures at an Outpatient Cancer Surgery Center^a

Characteristic	All Surgeries	Surgeries in Patients Who Developed Postoperative CDI
No.	16,597	11
Age, y	55 (12.9)	53 (13.5)
Sex, female	14,040 (85)	11 (100)
History of Crohn’s disease or ulcerative colitis	282 (2)	0 (0)
Procedure type
Breast	8,291 (50)	11 (100)
Plastics	2,822 (17)	0 (0)
Gynecology	2,260 (14)	0 (0)
Urology	1,924 (12)	0 (0)
Head and neck	1,030 (6)	0 (0)
Other	270 (2)	0 (0)

Note. CDI, Clostridium difficile infection.

^aData are mean (standard deviation) for age and frequency (percent) for all other variables.

Prophylactic antibiotics included single-dose cefazolin 1 g IV (n = 5), cefazolin 1 g followed by 500 mg oral cephalexin (n = 3), and clindamycin 900 mg IV (n = 3). Oral antibiotics for preoperative gut decontamination were not used prior to any surgeries. Molecular typing was available for 8 of the 11 postoperative CDI cases. Of these isolates, 3 strains had been identified in patients who had previously undergone procedures at the facility. The time between surgeries for patient pairs with identical strain type were 9 days, 70 days, and 9 months.

Discussion

To our knowledge, this is the first study to report CDI incidence following outpatient surgery, perhaps because such data are difficult to track for outpatients who return to the community immediately following surgery. Until now, understanding of CDI following outpatient procedures has been limited to associational data. For example, a recent case-control study using national population-based surveillance data found that patients who developed community-onset CDI were significantly more likely to report having had a recent outpatient surgical procedure compared with uninfected community controls.⁶ In the setting of a comprehensive cancer center in which nearly all patients continue a treatment and surveillance relationship following outpatient surgery, we were able to estimate the incidence of CDI in this population.

The incidence of postoperative CDI in this study was lower than reported for inpatient surgical procedures overall and was comparable to those reported for lower-risk surgeries such as gynecological procedures.⁷ In our study, all patients who developed postoperative CDI had undergone breast surgery, though only 50% of procedures performed at the facility were breast surgeries. This may represent a higher risk due to adjuvant or neoadjuvant treatment, prosthetic reconstruction for patients with breast cancer, or provider practices (eg, continuing prophylactic antibiotics postoperatively).

This study has several limitations. Due to the specialized setting, these findings may not be generalizable to stand-alone outpatient surgery centers or noncancer surgery. For example, we identified only 3 cases in which patients developed CDI with an isolate identical to that of a patient who had previously undergone a procedure at the facility, and only 2 cases occurred within the time frame that C. difficile is known to survive on fomites.⁸ Opportunities for transmission may be higher at facilities with different populations or cleaning practices.

Outpatient surgery is increasingly common, including for patients with cancer and other comorbidities who are at high risk of CDI.^3,9,10 Although the risk of CDI following outpatient surgery is relatively low, the impact of exposure to outpatient surgery on community-onset CDI should be considered as this patient population continues to grow. Breast surgery may be an important target for CDI prevention efforts.