CBIC Updated CIC Exam Questions and Answers by natasha

Coliform bacteria are indicators of fecal contamination in water, making them a critical measure of water safety. Hepatitis A is a virus primarily transmitted via the fecal-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. High coliform counts indicate fecal contamination and increase the risk of HAV outbreaks​.

Use of Coliforms as Indicators:

Public health agencies use total coliforms and Escherichia coli (E. coli) as primary indicators of water safety because they signal fecal pollution​.

Waterborne Transmission of Hepatitis A:

Hepatitis A outbreaks have been traced to contaminated 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) are environmental bacteria but are not indicators of fecal contamination.

C. Legionella:

Legionella species cause Legionnaires' disease through inhalation of contaminated aerosols, not through fecal-oral transmission.

D. Acinetobacter:

Acinetobacter species are opportunistic pathogens in healthcare settings but are 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"​.

Multi-drug resistant (MDR) Klebsiella pneumoniae in a high-risk area like the ICU requires urgent investigation because:

It spreads rapidly via contaminated hands or equipment.

It poses a serious risk to immunocompromised patients.

An outbreak could lead to severe hospital-acquired infections (HAIs).

Why the Other Options Are Incorrect?

A. One blood isolate of Streptococcus agalactiae in the nursery – Single cases are not indicative of an outbreak.

B. Two isolates of Staphylococcus aureus in postoperative surgical sites – Common post-surgical pathogen; requires monitoring but not immediate outbreak investigation.

D. Two blood isolates of coagulase-negative staphylococci in the oncology unit – Common contaminants in blood cultures and not immediately alarming.

CBIC Infection Control Reference

APIC guidelines prioritize investigating MDR pathogens in high-risk units, such as ICU, to prevent transmission​.

The Certification Study Guide (6th edition) emphasizes that occupational health hazard prevention is based on risk assessment and targeted protection strategies, particularly for personnel with predictable, high-risk exposures. Providing pre-exposure vaccination against Neisseria meningitidis to laboratory personnel is a recognized best practice because laboratorians who routinely handle N. meningitidis isolates are at increased risk for aerosol or droplet exposure, which can result in rapidly progressive and potentially fatal disease.

The study guide highlights that pre-exposure immunization is preferred over post-exposure management when exposure risk is ongoing and well defined. This strategy aligns with evidence-based occupational health principles and recommendations from public health authorities, making it a proactive and preventive measure rather than a reactive one.

The other options are incorrect because they either reflect outdated practices or inappropriate control measures. Routine annual TB testing is no longer universally required and should be based on facility risk assessment. Post-vaccination varicella serologic testing is not recommended because commercial assays may not reliably detect vaccine-induced immunity. Excluding asymptomatic pertussis-exposed healthcare personnel from duty is not routinely recommended if appropriate prophylaxis is provided.

This question reflects a common CIC exam theme: best practices focus on targeted, evidence-based prevention, especially vaccination strategies for high-risk occupational groups.

The incidence rate is calculated using the formula:

Why the Other Options Are Incorrect?

B. (30 ÷ 150,000) × 100 = X – Incorrect multiplier (should be 100,000 for standard incidence rate).

C. (115 ÷ 150,000) × 100,000 = X – 115 represents total cases (prevalence), not incidence.

D. (115 ÷ 100,000) × 100 = X – Uses the wrong denominator and multiplier.

CBIC Infection Control Reference

APIC defines the incidence rate as the number of new cases per population unit, typically per 100,000 people​.