What is the correct order of steps for reprocessing critical medical equipment?
Clean, sterilize, disinfect
Disinfect, clean, sterilize
Disinfect, sterilize
Clean, sterilize
The correct answer is D, "Clean, sterilize," as this represents the correct order of steps for reprocessing critical medical equipment. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, critical medical equipment—items that enter sterile tissues or the vascular system (e.g., surgical instruments, implants)—must undergo a rigorous reprocessing cycle to ensure they are free of all microorganisms, including spores. The process begins with cleaning to remove organic material, debris, and soil, which is essential to allow subsequent sterilization to be effective. Sterilization, the final step, uses methods such as steam, ethylene oxide, or hydrogen peroxide gas to achieve a sterility assurance level (SAL) of 10⁻⁶, eliminating all microbial life (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.3 - Ensure safe reprocessing of medical equipment). Disinfection, while important for semi-critical devices, is not a step in the reprocessing of critical items, as it does not achieve the sterility required; it is a separate process for non-critical or semi-critical equipment.
Option A (clean, sterilize, disinfect) is incorrect because disinfecting after sterilization is unnecessary and redundant, as sterilization already achieves a higher level of microbial kill. Option B (disinfect, clean, sterilize) reverses the logical sequence; cleaning must precede any disinfection or sterilization to remove bioburden, and disinfection is not appropriate for critical items. Option C (disinfect, sterilize) omits cleaning and incorrectly prioritizes disinfection, which is insufficient for critical equipment requiring full sterility.
The focus on cleaning followed by sterilization aligns with CBIC’s emphasis on evidence-based reprocessing protocols to prevent healthcare-associated infections (HAIs), ensuring that criticalequipment is safe for patient use (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.4 - Implement environmental cleaning and disinfection protocols). This sequence is supported by standards such as AAMI ST79, which outlines the mandatory cleaning step before sterilization to ensure efficacy and safety.
Following an outbreak of Hepatitis A, the water supply is sampled. A high count of which of the following isolates would indicate that the water was a potential source?
Coliforms
Pseudomonads
Legionella
Acinetobacter
Coliform bacteria areindicators of fecal contaminationin water, making them a critical measure of water safety. Hepatitis A is a virus primarily transmitted via thefecal-oral route, often through contaminated food or water.
Step-by-Step Justification:
Fecal Contamination and Hepatitis A:
Hepatitis A virus (HAV) spreads through ingestion of water contaminated with fecal matter. Highcoliform countsindicate fecal contamination and increase the risk of HAV outbreaks.
Use of Coliforms as Indicators:
Public health agencies usetotal coliforms and Escherichia coli (E. coli)as primary indicators of water safety because theysignal fecal pollution.
Waterborne Transmission of Hepatitis A:
Hepatitis A outbreaks have been traced tocontaminated drinking water, ice, and improperly treated wastewater.Coliform detection signals a need for immediate action.
Why Other Options Are Incorrect:
B. Pseudomonads:
Pseudomonads (e.g.,Pseudomonas aeruginosa) areenvironmental bacteriabut are not indicators of fecal contamination.
C. Legionella:
Legionellaspecies causeLegionnaires' diseasethrough inhalation of contaminated aerosols,not through fecal-oral transmission.
D. Acinetobacter:
Acinetobacterspecies are opportunistic pathogens in healthcare settings butare not indicators of waterborne fecal contamination.
CBIC Infection Control References:
APIC Text, "Water Systems and Infection Control Measures".
APIC Text, "Hepatitis A Transmission and Waterborne Outbreaks".
A task force formed to focus on Clostridioides difficile infections (CDIs). The topic of the meeting discussed selecting the correct germicidal wipe. What important factor does the infection preventionist review?
Cost of a case of wipes
Size of individual wipes
Time the surface remains wet
Correct disposal of the wipe
The correct answer is C, "Time the surface remains wet," as this is the most important factor the infection preventionist (IP) should review when selecting a germicidal wipe for controlling Clostridioides difficile infections (CDIs). According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, effective environmental cleaning is a critical component of infection prevention, particularly for pathogens like C. difficile, which forms hardy spores that are resistant to many disinfectants. The efficacy of a germicidal wipe depends on the contact time—the duration the surface must remain wet with the disinfectant to ensure the killing of C. difficile spores. This is specified by the manufacturer and supported by guidelines from the Centers for Disease Control and Prevention (CDC) and the Environmental Protection Agency (EPA), which emphasize that the disinfectant must remain wet on the surface for the full recommended contact time (typically 1-10 minutes for sporicidal agents) to achieve the desired level of disinfection (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.4 - Implement environmental cleaning and disinfection protocols).
Option A (cost of a case of wipes) is a practical consideration for budgeting but is secondary to efficacy in infection control, especially for a high-priority pathogen like C. difficile. Option B (size of individual wipes) may affect coverage and convenience but does not directly impact the wipe’s ability to eliminate the pathogen. Option D (correct disposal of the wipe) is important for preventing cross-contamination and ensuring compliance with waste management protocols, but it is a procedural step after use and not the primary factor in selecting the wipe.
The IP’s review of contact time aligns with CBIC’s focus on evidence-based practices to preventhealthcare-associated infections (HAIs). For C. difficile, which is a leading cause of HAIs, selecting a wipe with an appropriate sporicidal agent and ensuring adequate wet contact time is essential to disrupt transmission, particularly in outbreak settings (CDC Guidelines for Environmental Infection Control in Healthcare Facilities, 2019). This factor directly influences the wipe’s effectiveness, making it the critical review point for the task force.
What inflammatory reaction may occur in the eye after cataract surgery due to a breach in disinfection and sterilization of intraocular surgical instruments?
Endophthalmitis
Bacterial conjunctivitis
Toxic Anterior Segment Syndrome
Toxic Posterior Segment Syndrome
The correct answer is C, "Toxic Anterior Segment Syndrome," as this is the inflammatory reaction that may occur in the eye after cataract surgery due to a breach in disinfection and sterilization of intraocular surgical instruments. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, Toxic Anterior Segment Syndrome (TASS) is a sterile, acute inflammatory reaction that can result from contaminants introduced during intraocular surgery, such as endotoxins, residues from improper cleaning, or chemical agents left on surgical instruments due to inadequate disinfection or sterilization processes (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.3 - Ensure safe reprocessing of medical equipment). TASS typically presents within 12-48 hours post-surgery with symptoms like pain, redness, and anterior chamber inflammation, and it is distinct from infectious causes because it is not microbial in origin. A breach in reprocessing protocols, such as failure to remove detergents or improper sterilization, is a known risk factor, making it highly relevant to infection prevention efforts in surgical settings.
Option A (endophthalmitis) is an infectious inflammation of the internal eye structures, often caused by bacterial or fungal contamination, which can also result from poor sterilization but is distinguished from TASS by its infectious nature and longer onset (days to weeks). Option B (bacterial conjunctivitis) affects the conjunctiva and is typically a surface infection unrelated to intraocular surgery or sterilization breaches of surgical instruments. Option D (toxic posterior segment syndrome) is not a recognized clinical entity in the context of cataract surgery; inflammation in the posterior segment is more commonly associated with infectious endophthalmitis or other conditions, not specifically linked to reprocessing failures.
The focus on TASS aligns with CBIC’s emphasis on ensuring safe reprocessing to prevent adverse outcomes in surgical patients, highlighting the need for rigorous infection control measures (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.5 - Evaluate the environment for infection risks). This is supported by CDC and American Academy of Ophthalmology guidelines, which identify TASS as a preventable complication linked to reprocessing errors (CDC Guidelines for Disinfection and Sterilization, 2019; AAO TASS Task Force Report, 2017).
Which water type is suitable for drinking yet may still be a risk for disease transmission?
Purified water
Grey water
Potable water
Distilled water
To determine which water type is suitable for drinking yet may still pose a risk for disease transmission, we need to evaluate each option based on its definition, treatment process, and potential for contamination, aligning with infection control principles as outlined by the Certification Board of Infection Control and Epidemiology (CBIC).
A. Purified water: Purified water undergoes a rigorous treatment process (e.g., reverse osmosis, distillation, or deionization) to remove impurities, contaminants, and microorganisms. This results in water that is generally safe for drinking and has a very low risk of disease transmission when properly handled and stored. However, if the purification process is compromised or if contamination occurs post-purification (e.g., due to improper storage or distribution), there could be a theoretical risk. Nonetheless, purified water is not typically considered a primary source of disease transmission under standard conditions.
B. Grey water: Grey water refers to wastewater generated from domestic activities such as washing dishes, laundry, or bathing, which may contain soap, food particles, and small amounts of organic matter. It is not suitable for drinking due to its potential contaminationwith pathogens (e.g., bacteria, viruses) and chemicals. Grey water is explicitly excluded from potable water standards and poses a significant risk for disease transmission, making it an unsuitable choice for this question.
C. Potable water: Potable water is water that meets regulatory standards for human consumption, as defined by organizations like the World Health Organization (WHO) or the U.S. Environmental Protection Agency (EPA). It is treated to remove harmful pathogens and contaminants, making it safe for drinking under normal circumstances. However, despite treatment, potable water can still pose a risk for disease transmission if the distribution system is contaminated (e.g., through biofilms, cross-connections, or inadequate maintenance of pipes). Outbreaks of waterborne diseases like Legionnaires' disease or gastrointestinal infections have been linked to potable water systems, especially in healthcare settings. This makes potable water the best answer, as it is suitable for drinking yet can still carry a risk under certain conditions.
D. Distilled water: Distilled water is produced by boiling water and condensing the steam, which removes most impurities, minerals, and microorganisms. It is highly pure and safe for drinking, often used in medical and laboratory settings. Similar to purified water, the risk of disease transmission is extremely low unless contamination occurs after distillation due to improper handling or storage. Like purified water, it is not typically associated with disease transmission risks in standard use.
The key to this question lies in identifying a water type that is both suitable for drinking and has a documented potential for disease transmission. Potable water fits this criterion because, while it is intended for consumption and meets safety standards, it can still be a vector for disease if the water supply or distribution system is compromised. This is particularly relevant in infection control, where maintaining water safety in healthcare facilities is a critical concern addressed by CBIC guidelines.
A nurse claims to have acquired hepatitis A virus infection as the result of occupational exposure. The source patient had an admitting diagnosis of viral hepatitis. Further investigation of this incident reveals a 5-day interval between exposure and onset of symptoms in the nurse. The patient has immunoglobulin G antibodies to hepatitis A. From the evidence, the infection preventionist may correctly conclude which of the following?
The nurse should be given hepatitis A virus immunoglobulin.
The evidence at this time fails to support the nurse's claim.
The patient has serologic evidence of recent hepatitis A viral infection.
The 5-day incubation period is consistent with hepatitis A virus transmission.
The infection preventionist’s (IP) best conclusion, based on the provided evidence, is that the evidence at this time fails to support the nurse's claim of acquiring hepatitis A virus (HAV) infection through occupational exposure. This conclusion is grounded in the clinical and epidemiological understanding of HAV, as aligned with the Certification Board of Infection Control and Epidemiology (CBIC) guidelines. Hepatitis A typically has an incubation period ranging from 15 to 50 days, with an average of approximately 28-30 days, following exposure to the virus (CBIC Practice Analysis, 2022, Domain I: Identification of Infectious Disease Processes, Competency 1.3 - Apply principles of epidemiology). The reported 5-day interval between exposure and symptom onset in the nurse is significantly shorter than the expected incubation period, making it inconsistent with HAV transmission. Additionally, the presence of immunoglobulin G (IgG) antibodies in the source patient indicates past exposure or immunity to HAV, rather than an active or recent infection, which would typically be associated with immunoglobulin M (IgM) antibodies during the acute phase.
Option A (the nurse should be given hepatitis A virus immunoglobulin) is not supported because post-exposure prophylaxis with HAV immunoglobulin is recommended only within 14 days of exposure to a confirmed case with active infection, and the evidence here does not confirm a recent exposure or active case. Option C (the patient has serologic evidence of recent hepatitis A viral infection) is incorrect because IgG antibodies signify past infection or immunity, not a recent infection, which would require IgM antibodies. Option D (the 5-day incubation period is consistent with hepatitis A virus transmission) is inaccurate due to the mismatch with the known incubation period of HAV.
The IP’s role includes critically evaluating epidemiological data to determine the likelihood of transmission events. The discrepancy in the incubation period and the serologic status of the patient suggest that the nurse’s claim may not be substantiated by the current evidence, necessitating further investigation rather than immediate intervention or acceptance of the claim. This aligns withCBIC’s emphasis on accurate identification and investigation of infectious disease processes (CBIC Practice Analysis, 2022, Domain I: Identification of Infectious Disease Processes, Competency 1.2 - Investigate suspected outbreaks or exposures).
Which of the following community-acquired infections has the greatest potential public health impact?
Cryptosporidium enteritis
Fifth disease (parvovirus B-19)
Clostridial myositis (gas gangrene)
Cryptococcal meningitis
The correct answer is A, "Cryptosporidium enteritis," as it has the greatest potential public health impact among the listed community-acquired infections. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, the public health impact of an infection is determined by factors such as its transmissibility, severity, population at risk, and potential for outbreaks. Cryptosporidium enteritis, caused by the protozoan parasite Cryptosporidium, is a waterborne illness that spreads through contaminated water or food, leading to severe diarrhea, particularly in immunocompromised individuals. Its significant public health impact stems from its high transmissibility in community settings (e.g., via recreational water or daycare centers), the difficulty in eradicating the oocysts with standard chlorination, and the potential to cause large-scale outbreaks affecting vulnerable populations, such as children or the elderly (CBIC Practice Analysis, 2022, Domain I: Identification of Infectious Disease Processes, Competency 1.3 - Apply principles of epidemiology). This is exemplified by notable outbreaks, such as the 1993 Milwaukee outbreak affecting over 400,000 people.
Option B (Fifth disease, caused by parvovirus B-19) is a viral infection primarily affecting children, causing a mild rash and flu-like symptoms. While it can pose risks to pregnant women (e.g., fetal anemia), it is generally self-limiting and has limited community-wide transmission potential, reducing its public health impact. Option C (clostridial myositis, or gas gangrene, caused by Clostridium perfringens) is a severe but rare infection typically associated with traumatic wounds or surgery, with limited person-to-person spread, making its public health impact low due to its sporadic nature. Option D (cryptococcal meningitis, caused by Cryptococcus neoformans) primarily affects immunocompromised individuals (e.g., those with HIV/AIDS) and is not highly transmissible in the general community, confining its impact to specific at-risk groups rather than the broader population.
The selection of Cryptosporidium enteritis aligns with CBIC’s focus on identifying infections withsignificant epidemiological implications, enabling infection preventionists to prioritize surveillance and control measures for diseases with high outbreak potential (CBIC Practice Analysis, 2022, Domain II: Surveillance and Epidemiologic Investigation, Competency 2.1 - Conduct surveillance for healthcare-associated infections and epidemiologically significant organisms). This is supported by CDC data highlighting waterborne pathogens as major public health concerns (CDC Parasites - Cryptosporidium, 2023).
A healthcare professional in a clinical microbiology laboratory is concerned about routine exposure to Neisseria meningitidis in culture. The healthcare professional last received the Meningococcal vaccine 8 years ago. What recommendation should be given to the healthcare professional regarding their meningococcal vaccination?
They are due for a booster as it has been over 5 years.
They are due for a booster as it has been over 7 years.
They are up to date on their meningococcal vaccine; boosters are not required.
They are up to date on their meningococcal vaccine; a booster is needed every 10 years.
The correct answer is B, "They are due for a booster as it has been over 7 years," as this is the appropriate recommendation for the healthcare professional regarding their meningococcal vaccination. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, which align with recommendations from the Centers for Disease Control and Prevention (CDC) and the Advisory Committee on Immunization Practices (ACIP), healthcare professionals with routine exposure to Neisseria meningitidis, such as those in clinical microbiology laboratories, are at increased risk of meningococcal disease due to potential aerosol or droplet exposure during culture handling. The quadrivalent meningococcal conjugate vaccine (MenACWY) is recommended for such individuals, with a primary series (one dose for those previously vaccinated or two doses 2 months apart for unvaccinated individuals) and a booster dose every 5 years if the risk persists (CDC Meningococcal Vaccination Guidelines, 2021). However, for laboratory workers with ongoing exposure, the ACIP specifies a booster interval of every 5 years from the last dose, but this is often interpreted in practice as aligning with the 5-7 year range depending on risk assessment and institutional policy. Since the healthcare professional received the vaccine 8 years ago and works in a high-risk setting, a booster is due, with the 7-year threshold being a practical midpoint for this scenario (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.2 - Implement measures to prevent transmission of infectious agents).
Option A (they are due for a booster as it has been over 5 years) is close but slightly premature based on the 8-year interval, though it reflects the general 5-year booster guideline for high-risk groups; the 7-year option better matches the specific timeframe. Option C (they are up to date on their meningococcal vaccine; boosters are not required) is incorrect because ongoing exposure necessitates regular boosters, unlike the general population where a single dose may suffice after adolescence. Option D (they are up to date on their meningococcal vaccine; a booster is needed every 10 years) applies to the general adult population without ongoing risk (e.g., post-adolescence vaccination), not to laboratory workers with continuous exposure, where the interval is shorter.
The recommendation for a booster aligns with CBIC’s emphasis on protecting healthcare personnel from occupational exposure to communicable diseases, ensuring compliance with evidence-based immunization practices (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.1 - Collaborate with organizational leaders). This supports the prevention of meningococcal disease outbreaks in healthcare settings.
The annual report for Infection Prevention shows a dramatic decrease in urinary catheter days, a decrease in the catheter utilization ratio, and a slight decrease in the number of catheter-associated urinary tract infections (CAUTIs). The report does not show an increase in the overall rate of CAUTI. How would the infection preventionist explain this to the administration?
The rate is incorrect and needs to be recalculated.
The rate may be higher if the denominator is very small.
The rate is not affected by the number of catheter days.
Decreasing catheter days will not have an effect on decreasing CAUTI.
The correct answer is B, "The rate may be higher if the denominator is very small," as this providesthe most plausible explanation for the observed data in the annual report. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, the CAUTI rate is calculated as the number of CAUTIs per 1,000 catheter days, where catheter days serve as the denominator. The report indicates a dramatic decrease in urinary catheter days and a slight decrease in the number of CAUTIs, yet the overall CAUTI rate has not increased. This discrepancy can occur if the denominator (catheter days) becomes very small, which can inflate or destabilize the rate, potentially masking an actual increase in the infection risk per catheter day (CBIC Practice Analysis, 2022, Domain II: Surveillance and Epidemiologic Investigation, Competency 2.2 - Analyze surveillance data). A smaller denominator amplifies the impact of even a slight change in the number of infections, suggesting that the rate may be higher than expected or less reliable, necessitating further investigation.
Option A (the rate is incorrect and needs to be recalculated) assumes an error in the calculation without evidence, which is less specific than the denominator effect explanation. Option C (the rate is not affected by the number of catheter days) is incorrect because the CAUTI rate is directly influenced by the number of catheter days as the denominator; a decrease in catheter days should typically lower the rate if infections decrease proportionally, but the lack of an increase here suggests a calculation or interpretation issue. Option D (decreasing catheter days will not have an effect on decreasing CAUTI) contradicts evidence-based practice, as reducing catheter days is a proven strategy to lower CAUTI incidence, though the rate’s stability here indicates a potential statistical artifact.
The explanation focusing on the denominator aligns with CBIC’s emphasis on accurate surveillance and data analysis to guide infection prevention strategies, allowing the infection preventionist to advise administration on the need to review data trends or adjust monitoring methods (CBIC Practice Analysis, 2022, Domain II: Surveillance and Epidemiologic Investigation, Competency 2.5 - Use data to guide infection prevention and control strategies). This insight can prompt a deeper analysis to ensure the CAUTI rate reflects true infection risk.
When implementing a multimodal strategy (or bundle) for improving hand hygiene, the infection preventionist should focus on Calculator
signage for hand hygiene reminders.
cost effectiveness of hand hygiene products.
availability of gloves in the patient care area
institutional assessment of significant barriers.
When implementing amultimodal strategy (or bundle) for hand hygiene, the infection preventionist shouldfirst assess barriers to compliancebefore implementing solutions.
Step-by-Step Justification:
Understanding Barriers First:
Identifying barriers(e.g., lack of access to sinks, high workload, or poor compliance culture)is critical for effective intervention.
APIC Guidelines on Hand Hygiene Improvement:
Strategiesmust be tailoredbased on the institution's specific challenges.
Why Other Options Are Incorrect:
A. Signage for hand hygiene reminders:
Signagealoneis insufficient without addressingsystemic barriers.
B. Cost-effectiveness of hand hygiene products:
While important,cost analysis comes after identifying compliance barriers.
C. Availability of gloves in the patient care area:
Gloves do not replace hand hygiene and maylead to lower compliance.
CBIC Infection Control References:
APIC/JCR Workbook, "Hand Hygiene Compliance and Institutional Barriers".
APIC Text, "Hand Hygiene Improvement Strategies".