CBIC Updated CIC Exam Questions and Answers by aadhya

The CBIC Certified Infection Control Exam Study Guide (6th edition) explains that the effectiveness of disinfection depends on multiple physical, chemical, and biologic factors, but virulence of the organism is not one of them. Virulence refers to an organism’s ability to cause disease in a host, which is a clinical characteristic, not a determinant of susceptibility to disinfectants.

Disinfection efficacy is influenced by factors such as the type and number of microorganisms, particularly their intrinsic resistance (for example, spores are more resistant than vegetative bacteria), making option C a true determinant. The amount of organic material present (option B) is also critical, as organic matter can inactivate disinfectants or shield microorganisms from exposure. Likewise, the length of exposure (contact time) to the chemical agent (option D) is essential to achieving the desired level of microbial kill and is specified in manufacturer instructions for use.

Virulence does not affect how easily an organism is destroyed by a disinfectant. For example, a highly virulent organism may be easily killed by a low-level disinfectant, while a less virulent organism such as a bacterial spore may be highly resistant. Therefore, virulence plays no role in determining disinfection effectiveness.

For CIC® exam preparation, it is important to distinguish between clinical severity and microbial resistance. Disinfection effectiveness is based on resistance characteristics and process variables—not on how dangerous the organism is to humans.

The scenario describes a cluster of five out of 35 residents in a long-term care facility developing high fever, nasal discharge, and a dry cough, suggesting a potential respiratory infection outbreak. The Certification Board of Infection Control and Epidemiology (CBIC) emphasizes the "Identification of Infectious Disease Processes" and "Surveillance and Epidemiologic Investigation" domains, which require selecting the most appropriate diagnostic tool to identify the causative agent promptly. The Centers for Disease Control and Prevention (CDC) provides guidance on diagnostic approaches for respiratory infections, particularly in congregate settings like long-term care facilities.

Option C, "Nasopharyngeal swab," is the best diagnostic tool in this context. The symptoms—high fever, nasal discharge, and a dry cough—are characteristic of upper respiratory infections, such as influenza, respiratory syncytial virus (RSV), or other viral pathogens common in congregate settings. A nasopharyngeal swab is the gold standard for detecting these agents, as it collects samples from the nasopharynx, where many respiratory viruses replicate. The CDC recommends nasopharyngeal swabs for molecular testing (e.g., PCR) to identify viruses like influenza, RSV, or SARS-CoV-2, especially during outbreak investigations in healthcare facilities. The dry cough and nasal discharge align with upper respiratory involvement, making this sample type more targeted than alternatives. Given the potential for rapid spread among vulnerable residents, early identification via nasopharyngeal swab is critical to guide infection control measures.

Option A, "Blood culture," is less appropriate as the best initial tool. Blood cultures are used to detect systemic bacterial infections (e.g., bacteremia or sepsis), but the symptoms described are more suggestive of a primary respiratory infection rather than a bloodstream infection. While secondary bacteremia could occur, blood cultures are not the first-line diagnostic for this presentation and are more relevant if systemic signs (e.g., hypotension) worsen. Option B, "Sputum culture," is useful for lower respiratory infections, such as pneumonia, where productive cough and sputum production are prominent. However, the dry cough and nasal discharge indicate an upper respiratory focus, and sputum may be difficult to obtain from elderly residents, reducing its utility here. Option D, "Legionella serology," is specific for diagnosing Legionella pneumophila, which causes Legionnaires’ disease, typically presenting with fever, cough, and sometimes gastrointestinal symptoms, often in association with water sources. While possible, the lack of mention of pneumonia or water exposure, combined with the upper respiratory symptoms, makes Legionella serology less likely as the best initial test. Serology also requires time for antibody development, delaying diagnosis compared to direct sampling.

The CBIC Practice Analysis (2022) and CDC guidelines for outbreak management in long-term care facilities (e.g., "Prevention Strategies for Seasonal Influenza in Healthcare Settings," 2018) prioritize rapid respiratory pathogen identification, with nasopharyngeal swabs being the preferred method for viral detection. Given the symptom profile and outbreak context, Option C is the most effective and immediate diagnostic tool to determine the causative agent.

The scenario describes a potential outbreak of multidrug-resistant Enterococcus faecium in an extended-care facility (ECF) wing, indicated by four positive cultures (including the current case and three prior cases from urine and a draining wound) within a month. The organism exhibits resistance to ampicillin, vancomycin, and penicillin, but sensitivity to linezolid, suggesting a possible vancomycin-resistant Enterococcus (VRE) strain, which is a significant concern in healthcare settings. The Certification Board of Infection Control and Epidemiology (CBIC) emphasizes the importance of rapid outbreak detection and response in the "Surveillance and Epidemiologic Investigation" domain, aligning with Centers for Disease Control and Prevention (CDC) guidelines for managing multidrug-resistant organisms (MDROs).

Option A, "Notify the medical director of the outbreak," is the most immediate and critical action. Identifying an outbreak—defined by the CDC as two or more cases of a similar illness linked by time and place—requires prompt notification to the facility’s leadership (e.g., medical director) to initiate a coordinated response. The presence of four Enterococcus cases, including a multidrug-resistant strain, within a single ECF wing over a month suggests a potential cluster, necessitating urgent action to assess the scope, implement control measures, and allocate resources. The CDC’s "Management of Multidrug-Resistant Organisms in Healthcare Settings" (2006) recommends immediate reporting to facility leadership as the first step to activate an outbreak investigation team, making this the priority.

Option B, "Compare the four culture reports and sensitivity patterns," is an important subsequent step in outbreak investigation. Analyzing the antibiotic susceptibility profiles and culture sources can confirm whether the cases are epidemiologically linked (e.g., clonal spread of VRE) and guide treatment and control strategies. However, this is a detailed analysis that follows initial notification and should not delay alerting the medical director. Option C, "Conduct surveillance cultures for this organism in all residents," is a proactive measure to determine the prevalence of Enterococcus faecium, especially VRE, within the wing. The CDC recommends targeted surveillance during outbreaks, but this requires prior authorization and planning by the outbreak team, making it a secondary action after notification. Option D, "Notify the nursing administrator to close the wing to new admissions," may be a control measure to prevent further spread, as suggested by the CDC for MDRO outbreaks. However, closing a unit is a significant decision that should be guided by the medical director and infection control team after assessing the situation, not an immediate independent action by the IP.

The CBIC Practice Analysis (2022) and CDC guidelines prioritize rapid communication with leadership to initiate a structured outbreak response, including resource allocation and policy adjustments. Given the multidrug-resistant nature and cluster pattern, notifying the medical director (Option A) is the most immediate and appropriate action to ensure a comprehensive response.

Maintaining hot water at 140°F (60°C) prevents Legionella growth and is the most effective control strategy​.

Flushing water (A) alone is not sufficient.

Carbon filters (C) do not remove Legionella.

Routine testing (D) is not always necessary unless an outbreak occurs.

CBIC Infection Control References:

APIC Text, "Waterborne Pathogens and Infection Control," Chapter 9​.