Week 5 DMS 206- Infection Control

Infection

• An infection is a condition that results when microorganisms cause injury to a susceptible host.

  • A parasite can also cause disease.

• Infectious diseases are spread from one person to another.

• Some microorganisms are helpful.

• The pathogenicity of a certain microorganism can depend upon many factors.

  • These include number and location of the microorganism.

  • Some microorganisms are helpful.

Categories of Disease Caused by Pathogens

• Infectious diseases result when a pathogen colonizes (inhabits) the body and subsequently causes disease such as MRSA or gas gangrene

• Microbial intoxications result when a person ingests a toxin (poisonous substance) that has been produced by a pathogen in vitro (outside the body) such as staph food poisoning and foodborne botulism

Conditions That Favor the Growth of Pathogens

• Most microorganisms require a certain amount of moisture or water to survive.

• Some, like bacteria, produce spores.

  • These spores are resistant to many attempted forms of destruction and thus remain dormant for a long period of time until optimal growth situations arise.

All microorganisms require:

• Nourishment: This may be found on contaminated organic matter.

• The right temperature: Many require normal body temperature to survive.

• Darkness: Pathogens may be destroyed by bright light.

• A neutral pH environment and one that provides plentiful oxygen.

  • Tetanus and botulism do not require oxygen to thrive.

The Cycle of Infection and Modes of Transmission

• In order to be transmitted from the reservoir, the pathogen requires a portal of exit.

• Upon exit, it needs a mode of transmission.

  • This is where the sonographer can break the chain with precautions based on these modes.

  • Modes include contact (direct and indirect), droplet, and airborne transmission.

  • Someone who appears to be asymptomatic may be a carrier.

    • Carriers have been colonized but show no signs.

• The pathogen’s portal of entry introduces it into another person.

susceptible host

person whose body cannot repel the pathogen

Stages of Infection

• Stage 1: Incubation—Pathogen enters the body and becomes dormant. Eventually, the person may start to exhibit symptoms of the disease.

• Stage 2: Prodromal—Explicit disease symptoms abound. The disease becomes highly infectious.

• Stage 3: Full disease—Disease reaches full potential with distinct clinical features. However, some diseases may not produce symptoms while still producing damage. The disease remains very infectious.

• Stage 4: Convalescent—Symptoms dissipate. However,some diseases, like herpes and tuberculosis, can go through a dormant period, only to return again to produce symptoms.

Common Communicable Diseases and Modes of Transmissions

• Influenza (flu)- Airborne droplet or direct contact with contaminated object

• Measles (rubeola)- Airborne droplets

• Meningitis- Airborne droplets

• Mononucleosis- Airborne droplets or direct contact with contaminated object containing saliva from host

• Mumps- Airborne droplets or direct contact with contaminated object containing saliva from host

• Rubella (German measles)- Airborne droplets

• Tetanus- Direct contact with spores or infected animal feces

• Varicella (chickenpox)- Direct contact or droplets

Nosocomial infection

• Without proper infection control, patients may contract nosocomial infections.

• These types of infections are preventable and result from these three major contributing factors:

  • Inability or noncompliance of healthcare workers to follow infection control guidelines

  • Increasing number of drug-resistant pathogens

  • Increasing number of immunocompromised patients

Healthcare-associated infections include:

• These types of infections are preventable and result from these three major contributing factors.

  • Central line–associated bloodstream infections

  • Ventilator-associated pneumonia

  • Catheter-associated urinary tract infections

    • The most commonly reported is caused by the use of an indwelling catheter.

    • Always remember to place the urinary catheter bag lower than the urinary bladder in order to prevent the spread of bacteria from the bag back into the urinary bladder.

  • Surgical site infections

Methicillin-Resistant Staphylococcus aureus (MRSA)

• Some strains of staph have become resistant to previously successful treatments.

• Patients prone to these infections include those in nursing homes, on dialysis, in intensive care, and on extended hospital stays.

• One in three people carry staph in their noses; 2 in 100 carry MRSA.

Vancomycin-resistant Enterococcus (VRE)

• This is a normal type of flora that can cause an infection if it enters the blood, urine, or a wound.

• Patients on bed pans can easily spread the bacteria.

• VRE may be resistant to normal hand-washing procedures.

• Special contact precautions will be required.

Clostridium difficile (C. difficile)

• This is a spore-forming bacterium that releases toxins into the bowel.

• It is resistant to disinfectants and can be spread through casual contact.

• Long-term antibiotics destroy normal flora in the colon, increasing patient susceptibility.

Tuberculosis

• This disease can affect the lungs as well as many other parts of the body.

• It can be asymptomatic in the early stage of the disease.

• If left untreated, it can ravage the body.

• Many healthcare facilities require use of special respirators for protection from airborne diseases.

• Sonographers in a patient care setting are required to have routine PPD tests. 

• Some institutions may require you to be fitted for a N95 respirator face mask.

Bloodborne pathogens

• HIV, HBV, and HCV are the three most common bloodborne pathogens that put healthcare workers at risk.

• Typical exposure is via percutaneous injury or direct contact with mucous membranes or nonintact skin.

• Viral hepatitis:

  • Can live within pooled, dried blood for more than a week.

  • Can lead to permanent liver damage.

  • Vaccines are available.

HIV and AIDS:

• There are five phases of symptoms; at Phase 5, the person has a 90% chance to live only 3 more years.

• There is no current vaccine or cure.

Hand Hygiene

• Alcohol-based hand rub is the primary mode of hand hygiene in the healthcare setting.

• For visibly soiled hands or when caring for someone with known infectious diarrhea, the CDC recommends washing with soap and water.

You should consistently consider the need of washing your hands throughout the day, including:

• Before and after every instance of patient contact

• After contact with blood or other body fluids

• After contact with suspected infectious material

• After invasive procedures

• After coughing, sneezing, or blowing your nose

• After using the restroom

• Before going to lunch or break and leaving for the day

• Typically, there are wall-mounted alcohol-based hand rub devices available in patient care settings.

Personal Protective Equipment

• This includes gloves, masks, goggles, face shields, gowns, shoe covers, and respirators.

• The form chosen depends upon the patient interaction.

  • Wear a clean pair of gloves to perform an examination.

  • Follow proper procedure for removing dirty gloves.

  • Wash your hands after removing gloves.

• With an isolation patient, you may need to wear a gown or mask.

• If body fluid spatter is possible, wear gloves, a gown, a mask, and eye protection.

• You should always use standard precautions, such as wearing personal protective equipment, whenever contact with blood or other body fluids is possible.

Gloving

• After washing your hands or using an ABHR, you should always put on a pair of gloves before performing a sonogram even if the patient appears outwardly healthy.

• Gloving is a fundamental step that can be taken to prevent the spread of infection among you and your patients.

• Hospitals and other healthcare institutions should provide disposable, single-use gloves for those who may need to touch or interact with patients who may have communicable diseases.

• After each examination, gloves should be removed, and your hands should be washed or cleaned with an ABHR.

Transmission-Based Precautions

• These are measures used for controlling spread of infection based on known transmission mechanisms.

• It is your duty to know specific contact isolations and what PPE should be worn.

• When you travel for portable sonography, stop and read the patient’s isolation signs.

• There are three precautions:

  • Airborne: Prevent spread of pathogens through the air

  • Droplet: Block spread of pathogens transmitted through respiratory secretions

  • Contact: Prevent spread of pathogens by direct or indirect contact

    • Enteric precaution is a specific form.

Medical Asepsis in the Sonography Department

• These practices render an object or area free of pathogenic microorganisms.

  • Personal hygiene

  • Cleaning equipment

  • Nonsterile probe covers

  • Proper disposal of examination waste items

Personal hygiene:

• Keep fingernails short and cover cracked or broken nails.

• Wear minimal jewelry; avoid dangling jewelry.

• Keep hair short or wear it up.

• Wash your scrubs daily with hot water and detergent; wear them only at work.

  • Specific clothing and shoe requirements differ by employer. 

Cleaning equipment:

• There are three levels of infection control you can conduct on a daily basis:

• Sanitization: Includes use of soap or detergent, warm water, and manual friction

• Disinfection: Includes use of disinfectants such as bleach or hydrogen peroxide

  • Transducers should be routinely disinfected.

• Sterilization: Involves the complete destruction of all microorganisms using an autoclave or a high-level chemical disinfectant

Endocavity transducers

• These must undergo a high-level disinfecting process.

• There are wall units and tabletop units.

• Some units may use hydrogen peroxide.

Nonsterile probe covers:

• These should be used for all endovaginal and endorectal examinations.

• In some cases, they should be used with other examinations during which the transducer could come into contact with body fluids.

• Before use of the cover, ultrasound gel should be placed within it to prevent artifacts caused by the air.

• Use a lubricating gel on the outside of the cover over the end of the transducer before insertion.

• Probe covers have been known to fail.

  • Always disinfect the transducer after the examination.

Proper disposal of examination waste items:

• All waste materials should be placed in an appropriate container for disposal.

• Follow your institution’s guidelines for disposal.

• Typically, items visually contaminated with blood or other body fluids must be placed in biohazard waste bags.

What if you are exposed?

• Be aware of the infection control plan in the clinical setting.

• If you are exposed to an undocumented airborne disease, your employer is obligated to notify you.

• The facility will most likely want to monitor your health.

• If you receive an accidental needlestick, report the occurrence immediately.