infection control

Infection Control Overview

• Infection: Invasion and multiplication of microorganisms in the body, causing localized cellular injury.

  • Can be local (restricted) or systemic (entire body).

  • Body's natural resistance can be lowered by age, nutrition, stress, fatigue, medications, general health, and disease.

• Cycle of Infection: Pathogen finds environment to grow, then moves through host, portal of entry, method of transmission, and portal of exit.

  • Carriers: Harbor disease without symptoms but can transmit pathogens.

  • Portals of Exit/Entry: Respiratory, gastrointestinal, urinary, reproductive tracts; breaks in the skin; blood.

  • Breaking the Chain: The only way to stop infection spread is to break this cycle using aseptic techniques.

Standard Precautions

• Minimum standards by CDC for infection control in healthcare settings.

• Apply to blood, all body fluids, secretions, excretions, nonintact skin, and mucous membranes.

• Handwashing: Essential after gloves, between patient contact, and when contaminated.

• Gloves: Worn when touching blood/body fluids, nonintact skin, mucous membranes, or contaminated items.

• Masks, Eye Protection, Face Shields: Worn if splashes/sprays of blood/body fluid are possible.

• Gowns: Worn if soiling of clothing is likely.

• Equipment: Cleaned, reprocessed; single-use items discarded.

• Linen: Contaminated linen placed in leak-proof bags.

• Sharps: Discarded in puncture-resistant containers (uncapped or with mechanical recapping).

• Barrier Devices: Gloves, gowns, eyeglasses, face shields, masks protect healthcare workers.

Hospital-Acquired Infections (HAIs) / Nosocomial Infections

• Infections acquired during hospitalization, not present on admission.

• Often preventable and a threat to patient safety.

• Statistics: $722,000$ HAIs in U.S. hospitals (2011), $75,000$ deaths; costs ~$10 billion/year.

• Frequency: $1$ in $25$ patients acquire an HAI.

• Causes: Typically human error and equipment failures.

• Spread: Healthcare workers can spread infections from patient to patient.

• Prevention: Proper handwashing techniques are the best way to stop the spread.

  • Viruses (e.g., Clostridium difficile, norovirus) are harder to remove; aggressive handwashing and good rinsing are critical.

  • Hand sanitizers kill most microorganisms but handwashing is still needed for visible soil.

Proper Hand Hygiene

How to Properly Wash Your Hands with Soap and Water (CDC Method)

• Wet hands with clean running water (warm or cold); apply soap.

• Lather hands, rubbing backs of hands, between fingers, and under nails.

• Scrub for at least 20 seconds.

• Rinse well under clean, running water.

• Dry hands using a clean towel or air dry them.

How to Properly Use Hand Sanitizers

• Apply proper amount per manufacturer's instructions.

• Rub hands together, covering all surfaces of hands and fingers until dry.

Common Infections

• ** *Clostridium difficile ** ( *C. diff **)

  • Bacterial infection living 70-90 days outside the body (sheets, rails, doorknobs, transducers).

  • Symptoms: Diarrhea and fever (2-3 days post-exposure).

  • Spread: Fecal-oral route, usually from unwashed hands; entry point is mouth. Transducer contamination can lead to patient infection.

  • Growth: Can grow out of control when antibiotics destroy healthy bacteria.

  • Antibiotics that can lead to C. diff: Cipro, Cefotan, penicillin, clindamycin.

  • Defense: Soap and water handwashing (alcohol-based sanitizers are ineffective); use of gloves, proper disinfection with chlorine bleach-based products for contaminated surfaces.

• **Methicillin-Resistant *Staphylococcus aureus ** (MRSA)

  • Antibiotic-resistant infection, difficult to treat.

  • Survival: Can survive on surfaces for months; spread by contact.

  • Diagnosis: Nasal swab (colonizes in nostrils).

  • Symptoms: Swollen, painful red bump (pimple/spider bite-like), warm, pus/drainage, fever; can lead to deep abscesses or life-threatening infections in bones, joints, bloodstream, etc.

  • Spread: Direct skin contact or touching contaminated objects; poor hand hygiene among healthcare workers.

  • Precautions for Sonographers: Wear appropriate PPE, follow hand hygiene, disinfect transducers and unit after examination (usually portable exams in patient rooms).

  • Community-Associated MRSA: Found in gyms, schools, daycare, jails; spread via toys, towels, clothes, equipment.

• Vancomycin-Resistant Enterococci (VRE)

  • Bacteria resistant to many antibiotics, especially vancomycin.

  • Origin: Live in intestines and on skin without problems until resistant.

  • Infections: Can occur anywhere, especially intestines, urinary tract, wounds.

  • Spread: Hands of healthcare workers, environmental surfaces, medical equipment (including transducers); usually not airborne.

  • Symptoms: Depend on location (red/tender skin, burning urination, diarrhea, fever/chills).

  • Diagnosis: Samples of blood, wound, urine, or stool.

  • Prevention: Keep hands clean (soap/water or alcohol-based sanitizer); healthcare providers must wash before and after every patient. Sonographers wear PPE (gown/gloves) for portable exams, disinfect equipment, and wash hands.

• Tuberculosis (TB)

  • Transmission: Generally low in U.S., but increased risk in healthcare facilities with high rates of HIV, persons from TB-endemic countries, or high TB prevalence.

  • Cause of spread in facilities: Incomplete implementation of CDC infection control measures.

  • Precautions: Patients in special isolation units; sonographers wear appropriate respiratory protective equipment for portable ultrasound exams. Annual TB screening may be required.

• Human Papillomavirus (HPV)

  • Group of more than 150 related viruses; some cause cervical, anal, vaginal, penile, and oropharynx cancers.

  • Transmission: Intimate skin-to-skin contact.

  • Survival: Can remain infectious on surfaces for days.

  • Ultrasound Transducers: Potential source of infection; 3-7% of transvaginal transducers remain contaminated after routine disinfection.

  • Resistance: Highly resistant to Cidex OPA.

  • Effective Disinfection: Sonicated 35% hydrogen peroxide solution is most effective.

  • Prevention: Cover transducers with approved sheath/condom; use effective disinfection solutions.

Disinfection Levels (Spaulding's Criteria)

• Critical Level: Requires sterilization (destruction of all viable microorganisms).

• Semicritical Level: Requires high-level disinfection (destruction of all viable microorganisms except bacterial spores). Required for intracavitary/transesophageal transducers, and those for biopsies/invasive procedures.

• Noncritical Level: Requires intermediate or low-level disinfection (destruction of most vegetative bacteria and viruses). Used for surface transducers (touch only skin).

• Recommendation: High-level disinfection for all transducers, including surface transducers, to truly break the chain of infection.

• New Product: Trophon device uses sonicated 35% hydrogen peroxide for high-level disinfection of transducers in 7 minutes, effective against HPV.

Sonographer Responsibilities & Precautions

• Personal Practices: Keep fingernails short/clean, avoid chipped nail polish/artificial nails, wash hands after every patient contact (even with gloves), wear clean uniform/lab coat daily, avoid costume jewelry (some places ban wedding rings), do not work when ill, cover mouth/nose when coughing/sneezing.

• Equipment & Environment: Regularly schedule cleaning/disinfection of ultrasound console, tables, transducer holders, gel bottle warmers, and transducers.

• Transducer Storage: Only necessary transducers on unit; others stored in enclosed cabinets marked as clean.

• Gel Bottles: Single-use gel packets encouraged; many places ban refilling bottles due to bacterial growth risk.

• Manufacturer Guidelines: Determine appropriate cleaning products for specific ultrasound units and transducers to prevent damage.

• Protocols: Collaborate with infection control and safety officers to develop, document, and train staff on reprocessing protocols; noncompliance leads to HAIs.

• Patient Trust: Disinfect transducers to prevent infection, maintain high standards, patient safety, and sonography's reputation.

Isolation Techniques

• Goal: Prevent spread of communicable diseases and microorganisms.

• General Guidelines:

  • Organize supplies before entering isolation area.

  • Wash hands before and after each patient contact, even with gloves.

  • Discard gloves in appropriate container before leaving isolation.

  • Discard gowns in designated hamper before leaving isolation.

  • Masks cover nose/mouth, put on before entry, remove/discard before leaving; change when moist.

  • Use masks only once; never lower and reuse.

  • Clean ultrasound equipment before entering; consider sterile transducer cover.

  • Properly disinfect all equipment after use before leaving the area.

• Types of Isolation:

  • Strict Isolation: Protects others from highly contagious/virulent diseases spread by air or contact. Requires private room, gowns, gloves, masks. Hands washed after leaving; contaminated articles disinfected/disposed.

  • Respiratory Isolation: Protects others from germs in patient's nose, mouth, throat, lungs (droplet spread). Requires private room. Masks needed for close contact; gowns only if soiling likely. Hands washed after removing gloves. Patients may travel with mask on.

  • Enteric Isolation: Prevents infections from direct/indirect contact with feces (e.g., diarrheal viruses, hepatitis A, enteroviruses, C. difficile). Requires private room. Handwashing, gowns, gloves for direct contact. Masks not needed. Dispose of contaminated articles in special bags. For C. difficile, strict soap/water handwashing.

  • Reverse Isolation: Protects immunocompromised patients (e.g., neutropenia, chemotherapy, steroid therapy). Wash/disinfect hands before entry. Wear gloves, gowns, masks, and discard properly after patient contact. Clean ultrasound equipment/transducer before scanning if patient comes to department.

Protective Measures

• Gloves:

  • Protection for patient and sonographer. Must not be damaged.

  • Hands must be dry before putting on.

  • Discard and replace if punctured, torn, or cut.

  • Should cover wrists (and gown cuffs if wearing gown).

  • Used only once, discard after use.

  • New pair for blood/bodily fluids/secretions/excretions.

  • When removing, turn inside out (inside is clean). Wash hands immediately after removal.

• Gowns:

  • Long and large enough to completely cover clothing.

  • Wet gowns are contaminated and should be replaced.

  • Inside/neck are clean; outside/waist ties are contaminated.

  • Remove watches/jewelry, roll up long sleeves before gowning.

  • Wear overlapped at back, tied snugly at neck/back.

  • Put on gloves after gowning.

  • Remove gloves first, then undo gown ties. Pull from shoulders, turning inside out, roll away from body. Wash hands.

• Masks:

  • Used for airborne particle and droplet protection. Put on before gowning.

  • Contaminated if moist/wet; discard and replace.

  • Wash hands before putting on. Do not touch part touching face.

  • Tie upper strings over ears, toward top of head. Fit snugly over nose (under glasses if worn).

  • Wash hands again before patient contact.

  • Remove gloves first, then untie bottom, then top strings. Hold top strings, remove, fold inside together. Discard and wash hands.

• Eye Protectors and Face Shields:

  • Protect mucous membranes of eyes from pathogens. Worn with facemask.

  • Discard disposable eyewear; clean reusable eyewear with soap, water, disinfectant.

  • Personal glasses may suffice or goggles may be needed over them.

Preparing a Sterile Field

• For biopsy or invasive procedures.

• Obtain proper sterile pack/tray.

• Should be prepared just before procedure begins.

• Steps:

  • Select clean, dry, above-waist-level flat work surface.

  • Wash hands thoroughly.

  • Place sterile linen-wrapped pack on surface.

  • Remove tape seal, unwrap both layers. Wrapper can be used as sterile field.

  • Open outermost flap away from yourself, keeping arm outstretched.

  • Grasp adjacent corner, hold straight up, over work surface, away from body.

  • Position bottom half over work surface first, then top half.

  • Add sterile items directly to field or with sterile forceps.

  • Wear sterile gloves. Nonsterile person opens outside wrapper; sterile person removes contents.

  • Nonsterile person shows numbing agent name/expiration, tears cap, rubs alcohol, offers to sterile person for drawing up (care to avoid needle stick).

Sonographer Injury and Exposure Precautions

• Needle stick or other sharp injury:

  • Immediately wash affected area with soap and water.

  • Gently squeeze to induce bleeding (if possible).

  • Notify supervisor and report to Health Services Department.

• Splash of blood/body fluids to mucosa (eyes, nose, mouth):

  • Immediately flush affected area with water or saline.

  • Notify supervisor and report to Health Services Department.

• Splash of blood/body fluids onto nonintact skin:

  • Immediately wash affected area with soap and water.

  • Notify supervisor and report to Health Services Department.

• Splash of blood/body fluids onto intact skin:

  • Immediately wash affected area with soap and water.

  • If contact is prolonged or extensive, notify supervisor and report to Health Services Department.

Learn your facility's procedures for reporting and care.