Question & Answer Session Sandra Hamilton-Titus MBA, MSN, RN, CMSRN Lenox Hill Hospital Northwell Health 01/17/2018

Which of the following statements regarding Clostridium difficile spores is NOT true? A. Hand washing is the most effective method to prevent C. difficile transmission. B. Spores are noninfectious forms of the organism. C. Ingestion triggers spore activation to their disease-causing form. D. Spores can be recovered from computer keyboards and window coverings.

A: In a manner similar to the spores of Bacillus anthracis, an outermost layer of Clostridium difficile spores called the exosporium renders these microbes sticky, which enables them to adhere to health care workers' hands or environmental surfaces, such as computer keyboards, window coverings, and telephones, used by clinical staff. The most effective prevention strategy is barrier protection, as in rigorous adherence to glove use, which should always be followed by thorough hand washing. Although many commercial products claim to rid hands of spores, their success rates are less than that of barrier methods. Spores are the noninfectious forms of the organisms, which are activated following ingestion to their disease-causing form.

2. Identify the TRUE statement regarding enterococcal infections in the United States: A. Most human enterococcal infections are due to Enterococcus avium. B. Enterococci are normal inhabitants of the gastrointestinal tract. C. Enterococci rarely show resistance to vancomycin. D. Gram stain typically reveals gram-negative diplococci in short chains.

2. B: The ubiquity and increasing antimicrobial resistance patterns among Enterococcus spp. is an infection control challenge for health care facilities worldwide. Vancomycin-resistant strains are frequently reported in the United States. These enteric, facultative gram-positive cocci grow in short chains. They are normal inhabitants of the gastrointestinal tract (large bowel) and female genitourinary tract. While E. faecalis causes the majority of infections and shows emerging resistance to many antibiotics, E. faecium isolates demonstrate a high degree of vancomycin resistance. Because many nosocomial enterococcal infections are transmitted by contact, these organisms are also found on skin and wounds, often as a result of hand carriage by health care workers.

3. Which of the following pathogens is the LEAST likely to be associated with nosocomial wound infections? A. Escherichia coli B. Staphylococcus aureus C. Coagulase-negative staphylococci D. Bacteroides fragilis

3. D: The bacterial species most commonly responsible for surgical site infections (SSI) is Staphylococcus aureus. In one study, this species accounted for 20% of all SSI. Given this microbe's increasing rates of antimicrobial resistance, as in methicillin-resistant S. aureus (MRSA), these infections represent a formidable foe in terms of mortality, morbidity, and increasing health care costs. Following S. aureus in frequency are those infections caused by coagulase-negative staphylococci (14%), as in S. epidermidis, frequently found on skin and mucous membranes as normal bacterial flora. These organisms are often associated with infections related to indwelling devices and catheters, and in endocarditis. Following staphylococci in frequency are wound infections involving enterococcus (12%) and E. coli (8%). Although infections involving anaerobic Bacteroides fragilis are worrisome, these organisms accounted for only 2% of all SSI in the study noted, following other more frequently occurring infections related to pathogens such as Pseudomonas, Klebsiella, Proteus, and Enterobacter species.

4. An intensive care unit (ICU) patient in a metropolitan hospital is diagnosed with culture-positive non- acid-fast multidrug resistant bacteria (MDR). This occurs 1 week after admission to the same ICU of a homeless 46-year-old man with pneumonia and underlying COPD who was also diagnosed with MDR. Infection control surveillance should include all of the following EXCEPT: Masks for patient and all caregivers B. Strict hand washing precautions C. Decontamination procedures for all portable chest radiography D. Surface culture samples of shared diagnostic or invasive equipment

4. A: Cross-contamination or cross-colonization may occur even with strict infection control precautions in place. Laxity in adhering to IC guidelines increases the likelihood of breaching IC standards, which may be especially hazardous with multidrug resistant organisms, particularly those that require long periods of complex antimicrobial therapy, as in multidrug-resistant tuberculosis (MDR-TB). With isolation of a non-acid-fast organism, contact transmission appears more likely than airborne transmission that would indicate mask precautions for patient and caregivers. Surface cultures of shared equipment may help isolate the infectious culprit while rigorous decontamination procedures may halt the spread of infection to new unit admissions. As in any outbreak occurrence, increased vigilance to hand washing techniques should be enforced because suboptimal compliance by health care workers in multiple settings is frequently reported.

5. A hospital's IP reported postsurgical wound infections by classification in a group of patients. Which was classified correctly as clean-contaminated (class II)? A. Closed reduction of Colles fracture in 74-year-old woman B. Emergency appendectomy and abscess evacuation in febrile 18-year-old man C. Elective thoracotomy with right upper lobectomy in 52-year-old smoker D. Stab wound to abdomen with intestinal perforation in 25-year-old man

5. C: Clean-contaminated or class II surgical wounds may involve entry into parts of the body that normally contain flora, such as the respiratory or urinary tracts; however, in order to qualify as class II, such procedures must be elective and not violate aseptic technique nor show evidence of an infectious process. By definition, the closed wrist fracture reduction does not involve a break in skin and would be a class I procedure. The emergency appendectomy with evidence of abscess implicates perforation and infection, and is thus a class IV wound. The elective thoracotomy with right upper lobe resection involves the respiratory tract, a potential source of contamination. However, surgery was elective and did not note infection or break in technique, so it is correctly classified as clean-contaminated.

6. What percentage of nosocomial infections is believed to be caused by bacterial contamination carried by hands of caregivers and health care workers? 50% B. 33% C. 25% D. 15%

6. D: Many studies attribute about 15% of nosocomial infections to contamination caused by hand carriage of pathogens by health care workers. These incidents may occur via direct patient-to-patient contact or with intermediary static objects that may be contact-contaminated, from computer keyboards, pens, or even radiologic equipment. The latter is a common occurrence in ICU settings where portable radiography is employed. Many health care workers erroneously believe (or become complacent through years of clinical practice) that the use of gloves trumps the need for meticulous hand hygiene, or do not understand or follow the need for proper hand washing even after gloves are removed. Particularly in settings where gloved health care workers come into contact with potentially devastating pathogens (e.g., C. difficile, antibiotic-resistant strains, MRSA), it is imperative that hand washing and other infection-control strategies be ingrained in staff, with appropriate reminders, surveillance, and continuing education as necessary.

Thank You!