a-IPC Cheat Sheet | ExamFinch

Cheat sheet a-IPC Cheat Sheet Practice Questions Study Guide Print / Save PDF

Processes to Identify Infectious Diseases 16.5% of exam Chain of Infection Infection Status Terms Lab and Diagnostic Signals Antimicrobial Use Categories Host Risk Factors Alert Organisms

Surveillance and Epidemiologic Investigation 20% of exam Epidemiology Formulas Test Accuracy Metrics NHSN HAI Definitions Outbreak Investigation Steps Epidemic Curve Patterns Rate Picker

Preventing/Controlling the Transmission of Infectious Agents 16.5% of exam Standard Precautions Transmission-Based Precautions Hand Hygiene Rules Safe Injection Practices Antimicrobial Stewardship Precaution Picker

Employee/Occupational Health 8.2% of exam Bloodborne Exposure Facts OSHA Requirements Personnel Health Screening Respirator Rules

Management and Communication of the Infection Prevention Program 8.2% of exam Quality Improvement Tools Program Governance Blueprint Item Counts Reporting + Chain of Command

Education and Research 7.1% of exam Adult Learning + Evaluation Evidence Hierarchy Research Terms Feedback on Lapses

Environment of Care 11.8% of exam Environmental Cleaning Air and Water Systems ICRA and Construction Waste and Linen Disinfectant Picker

Cleaning, Disinfection, Sterilization of Devices 11.8% of exam Spaulding Classification Disinfection Levels Sterilization Parameters Sterilizer Monitoring Reprocessing Workflow

Quick Facts Exam a-IPC (CBIC) Items 100 total, 85 scored Pretest 15 unscored items Testing time 2 hours Appointment 2.5 hours total Pass 700 scaled (300-900) Score report Pass = no number Fee $335 USD Pass rate 63% (2025 testers) Navigation Forward-only, no review Delivery Prometric or ProProctor Eligibility None required Valid Five years Retake Once every six months Blueprint Effective May 2026

Colonization vs Infection ID

Colonization Organism present No tissue damage Usually not treated

Infection Tissue damage Clinical signs present Counted in surveillance Presence vs harm

Chain of Infection ID Infectious agent The pathogen itself Reservoir Where the agent lives Portal of exit How it leaves Mode of transmission How it travels Portal of entry How it enters Susceptible host Who it infects Break any link Transmission stops Rule Hand hygiene breaks Mode of transmission Vaccination breaks Susceptible host

Prophylactic vs Empiric ID

Prophylactic Before infection exists Preoperative dosing Prevention goal

Empiric Infection suspected Cultures pending Guided by antibiogram Prevent vs treat blind

Infection Status Terms ID Colonization Present, no tissue damage Infection Damage plus clinical response Contamination Organism on surface/specimen Pseudo-infection False positive, no disease Pseudo-outbreak Cluster of pseudo-infections Incubation period Exposure to symptom onset Communicable period When spread is possible Only infections count Colonization is excluded Trap

Lab and Diagnostic Signals ID Gram stain Minutes, presumptive only Culture + AST Days, gives susceptibility MALDI-TOF Rapid organism identification Multiplex PCR Hours, detects nucleic acid Whole genome sequencing Confirms outbreak relatedness Antibiogram Facility susceptibility summary Leukocytosis + left shift Suggests bacterial infection Fever threshold NHSN uses >38.0°C Read susceptibility panel Not organism name alone

Antimicrobial Use Categories ID Prophylactic Given before infection occurs Empiric Before cultures return Therapeutic/definitive Organism and susceptibility known Surgical prophylaxis timing Within 60 min before incision Vancomycin/fluoroquinolone window 120 minutes before incision After wound closure No additional doses De-escalation Narrow after culture results

Host Risk Factors ID Extremes of age Neonates and elderly Neutropenia Low neutrophil defense Transplant/chemotherapy Drug-induced immunosuppression Chronic corticosteroids Blunted inflammatory response Indwelling devices Bypass skin barrier Recent surgery Breached tissue planes Prior antimicrobials Selects resistant flora Travel + exposure history Shapes plausible pathogens

Alert Organisms ID MRSA Methicillin-resistant Staphylococcus aureus VRE Vancomycin-resistant Enterococcus CRE Carbapenem-resistant Enterobacterales C. difficile Spore-forming, toxin-mediated colitis Candida auris Multidrug-resistant, environmentally persistent yeast M. tuberculosis Airborne, requires AIIR Legionella pneumophila Water system pathogen Aspergillus fumigatus Construction dust mold Norovirus Alcohol-resistant, explosive gastroenteritis

Incidence vs Prevalence SU

Incidence New cases only Measures risk Needs a period

Prevalence New plus existing Measures burden Point in time Risk vs burden

Rate Picker SU New cases over period → Incidence All cases at once → Prevalence Outbreak among exposed → Attack rate ( Times 100 ) Comparing device infections → Rate per 1,000 device-days Comparing surgical infections → Rate per 100 procedures Measuring device exposure → Device utilization ratio Comparing to national baseline → SIR ( Risk-adjusted ) Predicted below 1.0 → Rates instead ( No SIR calculated )

Epidemiology Formulas SU Incidence New cases / population at risk Prevalence All cases / population, point Attack rate Ill / at risk x 100 Device-associated rate Infections / device-days x 1,000 SSI rate SSIs / procedures x 100 DUR Device-days / patient-days SIR Observed / predicted infections SUR Observed / predicted device-days SIR floor rule Not calculated below 1.0 predicted NHSN SIR under 1.0 Fewer infections than predicted

Rate vs SIR SU

Rate Per 1,000 device-days Not risk-adjusted Good for trending

SIR Observed / predicted Risk-adjusted Needs 1.0 predicted Local trend vs benchmark

Test Accuracy Metrics SU Sensitivity TP / (TP + FN) Specificity TN / (TN + FP) PPV TP / (TP + FP) NPV TN / (TN + FN) Sensitivity finds cases Few missed infections PPV depends on prevalence Falls in low-prevalence populations Trap Mean, median, mode Measures of central tendency Standard deviation Spread around the mean

Sensitivity vs PPV SU

Sensitivity TP / (TP + FN) Property of the test Prevalence independent

PPV TP / (TP + FP) Depends on prevalence Answers: is it real Test property vs result meaning

NHSN HAI Definitions SU CLABSI line rule In place >2 consecutive days CLABSI eligibility starts Central line day 3 Central line Ends at/near the heart CAUTI catheter rule IUC >2 consecutive days CAUTI removal rule In place or removed yesterday CAUTI culture threshold 100,000 CFU/ml, max 2 species SSI default window 30 days post-procedure SSI 90-day list Implant-heavy procedure categories Superficial incisional SSI Always 30 days VAC baseline >=2 days stable oxygenation VAC worsening PEEP +3 or FiO2 +20 Secondary BSI Not counted as CLABSI

SSI 90-Day Categories SU BRST Breast surgery CARD / CBGB / CBGC Cardiac and bypass procedures CRAN Craniotomy FUSN Spinal fusion FX Open fracture reduction HER Herniorrhaphy HPRO / KPRO Hip and knee prosthesis PACE Pacemaker surgery PVBY Peripheral vascular bypass VSHN Ventricular shunt

Outbreak Investigation Steps SU Verify the diagnosis Confirm laboratory results first Confirm the outbreak Compare against baseline rate Notify stakeholders Leadership, providers, public health Write case definition Clinical criteria plus time/place/person Conduct case finding Apply definition uniformly Describe by epidemiology Time, place, and person Form hypothesis Source and transmission mode Implement control measures Do not wait Priority Test hypothesis Case-control or cohort study Evaluate and report Confirm rates returned to baseline

Epidemic Curve Patterns SU Point source One sharp peak Continuous common source Plateau while exposure persists Intermittent common source Irregular repeated peaks Propagated Successive person-to-person peaks Peak spacing Roughly one incubation period X axis Onset date or time Y axis Number of cases

Surveillance Design Terms SU Targeted surveillance Selected units or procedures Housewide surveillance Whole facility, resource heavy Process measure Was the practice done Outcome measure Did infection occur Numerator Cases meeting the definition Denominator Population or device-days Risk assessment Drives the annual plan Validation Re-review records for accuracy Benchmark rule Same definitions and risk adjustment

WHO 5 Moments TR Before patient | Before aseptic | After fluids | After patient | After surroundings 1 and 2 protect patient 3, 4, 5 protect worker Applies to gloves too

Standard vs Transmission-Based TR

Standard All patients always Diagnosis irrelevant PPE by task

Transmission-Based Known or suspected pathogen Added on top Contact, droplet, airborne Universal vs pathogen-specific

Precaution Picker TR Every patient, always → Standard Precautions ( Baseline ) Pulmonary tuberculosis → Airborne ( AIIR plus N95 ) Measles or varicella → Airborne ( Immune staff preferred ) Suspected disseminated zoster → Airborne plus contact Influenza or pertussis → Droplet ( Surgical mask ) Neisseria meningitidis → Droplet ( Until 24 hours therapy ) MRSA, VRE, CRE → Contact ( Gown and gloves ) C. difficile → Contact ( Soap, sporicidal cleaning ) Candida auris → Contact ( EPA List P ) RSV or rotavirus → Contact ( Pediatric units ) Severely immunocompromised transplant → Protective environment ( Positive pressure )

Standard Precautions TR Applies to Every patient, every time Rule Hand hygiene Core component PPE by task Anticipated exposure decides Respiratory hygiene Cough etiquette, source masking Safe injection practices One needle, one syringe Safe equipment handling Clean between patients Sharps safety No recapping, use containers Environmental cleaning High-touch surfaces prioritized Lumbar puncture mask Worn for spinal procedures

Contact vs Droplet TR

Contact Gown and gloves Touch transmission MRSA, VRE, C. difficile

Droplet Surgical mask Large respiratory particles 3-foot separation Touch vs respiratory spray

Hand Hygiene Picker TR Hands visibly soiled → Soap and water C. difficile care → Soap and water ( Spores survive alcohol ) Norovirus care → Soap and water After restroom use → Soap and water Hands not soiled → Alcohol-based hand rub ( Preferred default ) Before aseptic procedure → Alcohol-based hand rub Before surgery → Surgical hand antisepsis

Transmission-Based Precautions TR Layered on Always added to Standard Contact PPE Gown and gloves Contact examples MRSA, VRE, C. difficile Droplet PPE Surgical mask on entry Droplet separation At least 3 feet Droplet examples Influenza, pertussis, meningococcus Airborne PPE N95 or higher respirator Airborne examples TB, measles, varicella Patient transport Mask the patient, notify receiver Cohorting Same organism, shared room

Alcohol Rub vs Soap TR

Alcohol rub Faster and preferred Kinder to skin No sporicidal activity

Soap and water Visibly soiled hands C. difficile, norovirus Physically removes spores Kill vs physical removal

Hand Hygiene Rules TR Alcohol rub is default Faster, better skin tolerance Alcohol concentration At least 60% alcohol Soap and water when Hands visibly soiled Also soap and water C. difficile and norovirus Also after restroom And before eating Wash duration At least 15 seconds Alcohol fails against Bacterial spores Best compliance measure Direct observation Artificial nails Prohibited in high-risk care

Safe Injection Practices TR One needle, one syringe One patient, one time Syringe reuse Never, even with new needle Single-dose vial One patient only Multi-dose vial Disinfect septum every entry Preparation area Clean, away from contamination Bags and tubing One patient, then discard Point-of-care devices Dedicate or disinfect glucometers

Antimicrobial Stewardship TR Leadership commitment Dedicated funding and staffing Accountability Named program leader Pharmacy expertise Pharmacist co-leader Action Prospective audit and feedback Tracking Use and resistance data Reporting Share with prescribers Education Teach clinicians and patients Preauthorization Approval before restricted agent Antibiotic time-out Reassess at 48-72 hours IV to oral Convert when tolerating enterally

Emergency Preparedness TR Mitigation Reduce risk before events Preparedness Plan, train, stockpile Response Execute during the event Recovery Restore normal operations Syndromic surveillance Symptom patterns before diagnosis Surge PPE planning Burn rate and reserves Category A agents Anthrax, plague, smallpox, tularemia

Bloodborne Exposure Facts OC Hepatitis B risk 22-31% if HBeAg-positive Hepatitis C risk About 0.2% percutaneous HIV risk About 0.3% percutaneous Only vaccine-preventable Hepatitis B Trap First action Wash site, report immediately HIV PEP timing Start within hours HIV PEP duration 28 days HBV post-exposure HBIG plus vaccine, status-driven HCV post-exposure No PEP, test and treat

OSHA Requirements OC Bloodborne standard 29 CFR 1910.1030 Exposure control plan Written, reviewed annually Hepatitis B vaccine Free, within 10 working days PPE cost Employer pays, always Sharps injury log Required record of injuries Engineering controls Safety devices, sharps containers Respiratory standard 29 CFR 1910.134 Fit test frequency Before use, then annually Seal check Every single donning Facial hair Invalidates a tight seal

Personnel Health Screening OC Core HCP vaccines HepB, MMR, varicella, Tdap, influenza HBV response check Anti-HBs 1-2 months after Non-responder Repeat series, then evaluate TB baseline Screening on hire Work restriction driver Transmission risk to patients Exposed susceptible staff May need furlough Product sensitivity Offer latex-free alternatives

Blueprint Weights MA Surveillance 20 is the biggest slice Identify + transmission = 16.5 each Environment + devices = 11.8 each Education 7.1 smallest

Quality Improvement Tools MA PDSA Plan, Do, Study, Act Fishbone diagram Groups possible causes Pareto chart Ranks the vital few Flow chart Maps the actual process SWOT Strengths, weaknesses, opportunities, threats Gap analysis Current versus required practice Root cause analysis Retrospective, after sentinel event Run chart Data plotted over time

Program Governance MA Annual risk assessment Foundation of the plan Risk ranking Probability times potential impact IP plan contents Goals, surveillance priorities, resources Chain of command Read the organizational chart Media inquiries Route to communications leadership Notifiable disease authority State or local, not CDC Urgent reporting Some conditions within 24 hours Business case Cost of infections avoided Accreditation Joint Commission, CMS conditions

Blueprint Item Counts MA Identify diseases 14 items (16.5%) Surveillance + investigation 17 items (20%) Preventing transmission 14 items (16.5%) Occupational health 7 items (8.2%) Management + communication 7 items (8.2%) Education + research 6 items (7.1%) Environment of care 10 items (11.8%) Device reprocessing 10 items (11.8%) Scored total 85 items Sum CBIC publishes Item counts, not percentages

PDSA Cycle ED Plan | Do | Study | Act Small rapid tests Predict before you do Adopt, adapt, abandon

Adult Learning + Evaluation ED Adults learn best Job-relevant and immediately applicable Build on experience Respect existing knowledge Return demonstration Best proof of skill Teach-back For patients and families Attendance is not learning Measure behavior instead Trap Process measure Observed compliance rates Outcome measure Infection rates over time Immediate feedback Correct lapses privately, now

Evidence Hierarchy ED Systematic review Highest, synthesizes trials Randomized controlled trial Strongest single study Cohort study Follows exposed and unexposed Case-control study Starts from outcome backwards Case series/report Descriptive, no comparison group Expert opinion Lowest level of evidence Check publication date Guidelines are superseded Peer review Preferred over vendor literature

AIIR vs Protective Environment EN

AIIR Negative pressure Protects others TB, measles, varicella

Protective environment Positive pressure Protects the patient HEPA supply air Contain vs shield

Disinfectant Picker EN C. difficile room → EPA List K ( Sporicidal ) Candida auris room → EPA List P Norovirus outbreak → EPA List G Routine MRSA room → Hospital-grade disinfectant Blood spill present → Clean, then tuberculocidal product Surface still soiled → Clean before disinfecting

Environmental Cleaning EN Clean before disinfect Soil inactivates disinfectants Rule Wet contact time Follow the product label Surface dries early Reapply the disinfectant Clean to dirty Directional workflow High to low Work downward in room High-touch surfaces Rails, buttons, doorknobs, tables Terminal cleaning After discharge or transfer Cleaning verification ATP, fluorescent marker, culture

Cleaning vs Disinfection EN

Cleaning Physically removes soil Always comes first Mechanical action

Disinfection Kills remaining organisms Needs wet contact time Inactivated by soil Remove then kill

EPA Product Lists EN List K Sporicidal, C. difficile List P Candida auris List G Norovirus List N SARS-CoV-2 Quats Low-level, not sporicidal Sodium hypochlorite Common sporicidal choice Sporicidal contact times Usually longer than routine

Air and Water Systems EN AIIR pressure Negative, at least 2.5 Pa AIIR in inches 0.01 inch water gauge AIIR air changes 12 new, 6 existing AIIR exhaust Outdoors or HEPA-filtered AIIR door Kept closed, monitored daily Protective environment Positive pressure, HEPA supply PE air changes At least 12 hourly PE patients Allogeneic stem cell transplant Legionella program ASHRAE 188, CMS required Legionella growth drivers Stagnation, biofilm, scale, temperature Legionella growth range 77-113°F (25-45°C) Hot water storage At least 140°F (60°C)

ICRA and Construction EN ICRA inputs Activity type plus patient risk Done when Before work begins Timing Primary hazard Aspergillus in construction dust Highest-risk patients Neutropenic and transplant recipients Rigid barriers Required for Class III/IV Work zone pressure Negative to patient areas HEPA exhaust Filters construction air Tacky mats Capture dust at exit Daily monitoring Verify barriers and pressure

Waste and Linen EN Regulated medical waste Would release blood if compressed Also regulated Caked dried blood Always regulated Sharps, pathological, microbiological waste Most room trash Not regulated waste Trap Soiled linen handling Minimal agitation, bag at use Clean linen Covered transport and storage Sharps containers Puncture-resistant, closable, upright

Spaulding Ladder RE Sterile tissue | Mucous membrane | Intact skin Critical = sterilize Semicritical = high-level Noncritical = low-level Use decides, not name

HLD vs Sterilization RE

High-level disinfection Kills all but spores Semicritical items Liquid chemical, timed

Sterilization Kills spores too Critical items Steam, EtO, plasma Mucous membranes vs sterile tissue

Reprocessing Picker RE Enters sterile tissue → Sterilization ( Critical item ) Enters vascular system → Sterilization ( Critical item ) Touches mucous membranes → High-level disinfection ( Semicritical ) Touches non-intact skin → High-level disinfection ( Semicritical ) Touches intact skin only → Low-level disinfection ( Noncritical ) Heat-sensitive critical device → Low-temperature sterilization ( EtO or plasma ) Instrument still soiled → Clean again first ( Never skip ) Manufacturer conflicts with policy → Follow the IFU

Spaulding Classification RE Critical Enters sterile tissue/vascular system Critical requires Sterilization Semicritical Contacts mucous membranes Semicritical requires High-level disinfection minimum Noncritical Touches intact skin only Noncritical requires Low-level disinfection Category driver Intended use, not name Rule Examples critical Implants, surgical instruments, catheters Examples semicritical Endoscopes, laryngoscope blades

Monitoring Triad RE Physical | Chemical | Biological Physical = gauges Chemical = exposure Biological = kill proof

Chemical vs Biological Indicator RE

Chemical indicator Proves exposure only Every package Read immediately

Biological indicator Proves spore kill Weekly plus implants Requires incubation Exposed vs actually killed

Disinfection Levels RE Sterilization Destroys all microbes, spores included High-level All except many spores Intermediate-level Kills mycobacteria, tuberculocidal claim Low-level Vegetative bacteria, enveloped viruses OPA 0.55% 12 minutes at 20°C Glutaraldehyde 2% 20 minutes at 20°C Other HLD agents Follow FDA-cleared label Alcohol limitation Not sporicidal, evaporates fast

Sterilization Parameters RE Gravity displacement 121°C for 30 minutes Prevacuum wrapped 132°C for 4 minutes IUSS unwrapped 132°C for 3 minutes Four steam requirements Time, temperature, steam, contact Air is the enemy Blocks steam penetration Ethylene oxide Heat-sensitive devices, long aeration Hydrogen peroxide plasma Low temperature, no cellulose Dry heat Oils, powders, anhydrous materials IUSS restriction Not routine; avoid implants

Sterilizer Monitoring RE Physical monitors Gauges, printouts, cycle charts Chemical indicator Shows exposure, not sterility Trap Internal CI Inside every package External CI When internal is hidden Biological indicator Only true kill proof Steam and plasma BI Geobacillus stearothermophilus EtO and dry heat Bacillus atrophaeus BI frequency At least weekly, daily preferred Implant loads Every load, hold until negative Bowie-Dick test Daily, empty prevacuum chamber Bowie-Dick timing Before first processed load Positive BI Quarantine sterilizer, recall loads

Reprocessing Workflow RE Point-of-use treatment Keep soil moist Transport Closed, leak-proof container Clean The step everything depends on Rinse and dry Before disinfection or packaging Inspect Check function and residual soil Package and sterilize Or high-level disinfect Storage Controlled, dry, event-related sterility Workflow direction Dirty to clean to sterile Biofilm Defeats sterilization if left IFU Manufacturer instructions govern

Common Traps

Colonization vs infection Colonization is not counted ≠ Infection meets surveillance criteria

Incidence vs prevalence Incidence counts new cases ≠ Prevalence counts all cases

Alcohol rub vs spores Alcohol kills vegetative bacteria ≠ Soap removes C. difficile spores

Chemical vs biological indicator Chemical proves exposure only ≠ Biological proves spores died

Cleaning vs disinfection Cleaning removes the soil ≠ Disinfection kills what remains

Device name vs use Spaulding follows intended use ≠ Not the device label

Rate vs SIR Rates are not risk-adjusted ≠ SIR compares to prediction

AIIR vs protective environment AIIR is negative pressure ≠ PE is positive pressure

Total vs scored items Exam has 100 items ≠ Only 85 are scored

Attendance vs learning Sign-in sheets prove attendance ≠ Observation proves behavior change

Regulated vs routine waste Most room trash is routine ≠ Saturated, sharps, pathological only

Reporting authority States set notifiable lists ≠ CDC does not mandate

Last Minute 1 . 100 items, only 85 scored 2 . Pass = 700 scaled; range 300-900 3 . Passing candidates get no number 4 . Forward-only: no skipping, no going back 5 . Surveillance 20% is the heaviest area 6 . Chain of infection has six links 7 . Standard Precautions = every patient always 8 . Airborne = N95 + negative-pressure room 9 . Droplet = surgical mask, 3 feet 10 . Contact = gown + gloves on entry 11 . C. difficile = soap + EPA List K 12 . Candida auris = EPA List P 13 . Device rate = infections / device-days x 1,000 14 . Attack rate = ill / at-risk x 100 15 . SIR = observed / predicted infections 16 . No SIR when predicted below 1.0 17 . CLABSI and CAUTI: line >2 days 18 . SSI = 30 days; some 90 19 . Critical = sterilize; semicritical = high-level 20 . Gravity = 121°C for 30 min 21 . Prevacuum = 132°C for 4 min 22 . Biological indicator = only kill proof 23 . Bowie-Dick daily in empty chamber 24 . Clean first; disinfectants need wet time 25 . HepB vaccine within 10 working days

CBIC a-IPC Associate Infection Prevention and Control Practice Questions 105 questions Study Guide 47 topics Cheat Sheet 328 facts Flashcards 50 cards Shorts 1 short Videos 1 video Blogs 1 blog Free CE Podcast

Third-party resources · We may earn a commission from purchases.

CBIC a-IPC Updated Practice Test Prep: The Complete Associate Infection Prevention Study Guide with 3,000 Practice Questions and Detailed Explanations By Ashley, Martin McDonough $35.99 · Buy on Amazon

Same family resources Explore More CBIC Infection Prevention Certifications Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

CBIC Cheat Sheet 176 facts Practice Questions 231 questions Study Guide 33 topics Flashcards 50 cards Shorts 2 short s Free CE

More From This Family Videos and articles for deeper review. Video FREE a-IPC Exam Guide 2026: CBIC Associate Prep This exam Article FREE a-IPC Exam Guide 2026: CBIC Associate Prep 10 min read

Independent exam preparation notice OpenExamPrep is an independent education provider, not affiliated with or endorsed by the exam sponsors named on this site. Exam and certification names identify what our resources help you study for; they do not imply sponsorship, approval, or review of our materials. Unless a resource expressly identifies authorized public material, our practice questions are independently developed simulations, not actual, recalled, or sponsor-provided exam items. We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor. Updated 2026-09-04 . Official exam sources checked Effective May 2026 (CBIC content outline) . This is a study aid only and is not for use during the exam. CBIC a-IPC certification overview CBIC a-IPC test specifications (2025 analysis) CBIC Candidate Handbook CDC Guideline for Isolation Precautions CDC Disinfection and Sterilization Guideline NHSN CLABSI protocol NHSN CAUTI protocol NHSN SIR guide