Preventing Infections & Gerontologic Considerations

• Preventing infections is a top priority in nursing, with hand hygiene being essential when caring for patients.
• This chapter covers microorganism survival and aseptic techniques to reduce or eliminate them.

Gerontologic Considerations

• Pneumonia, influenza, urinary tract, and skin infections, along with tuberculosis (TB), are common in older adults.
• Most TB cases occur in those 65+ in long-term care.
• In 2020, adults 65 years and older had the highest TB incidence rate (3.4 per 100,000)
• Followed by a decrease of 24.3% from 2019 (4.5 per 100,000).
• Pathogens enter vulnerable older adults through devices like urinary catheters, humidifiers, and compromised tissues from equipment for IV fluids or tube feedings.
• Many long-term care residents, older hospitalized clients, and healthcare providers carry antibiotic-resistant bacteria.
• Colonization may occur with minimal and/or no symptoms.
• Hospitals now obtain nasal cultures to identify clients with methicillin-resistant Staphylococcus aureus (MRSA).
• Postmenopausal patients are prone to urinary tract infections due to thinning and decreased vascular supply in the urinary tract, caused by a decline in circulating estrogen.
• Enlarged prostates common in aging males, trap urine in the bladder, leading to urinary tract infections often treated with antibiotics, causing resistant pathogens.
• Older adults and those with comorbidities have increased infection risks.
• Visitors with respiratory infections should wear masks or avoid contact with older adults.
• Frequent hand washing prevents organism transfer.
• Older adults, family, and healthcare staff should get annual flu shots, as influenza spreads via respiratory secretions.
• People 65+ should get an initial pneumococcal vaccine dose.

Microorganisms

• Microorganisms, also called "microbes" or "germs," are living things only visible with a microscope.
• Once microorganisms invade, the body's immune system eliminates them, they reside without causing disease, or they cause an infection.
• Factors influencing infection include microorganism type/number, virulence, and the person's health.

Types of Microorganisms

• Microorganisms are split into two groups: non-pathogens/Microflora (harmless), and pathogens (cause illness).

Nonpathogens

• Nonpathogens thrive in/on the human body, found in areas exposed to the external environment and internal areas like the skin, nose, and intestines.
• They adapt to human defense mechanisms.
• They either benefit the host or cause no harm, inhibiting pathogen growth through competition, ensuring their own habitat.

Pathogens

• Pathogens can cause infectious communicable diseases (contagious and community-acquired infections).
• Examples include measles and sexually transmitted infections.
• Although pathogenic infections can lead to death, the majority only cause short term illness
• They become established when nonpathogen numbers drop, such as with broad-spectrum antibiotics.
• Pathogens also cause infections when the host is immunosuppressed (AIDS, cancer chemotherapy).
• Structures/functions can boost pathogen virulence through promoting attachment, motility, or releasing toxins.
• Some pathogens feature fimbriae (tiny hairs) that aid in host tissue attachment to prevent expulsion.
• Flagella (long tails) promote motility to reach more habitable areas.
• Some may release toxins (harmful chemicals).
• Other pathogens enter the host's cells and deplete their contents to encourage their life cycles.

Pharmacologic Considerations

• Broad-spectrum antibiotics are preferred when antiinfective therapy needs to start before identifying the infectious pathogen, multiple pathogenic organisms are involved, or there is resistance to narrow-spectrum drugs.
• Narrow-spectrum antibiotics target specific bacteria and result in less death of nonpathogenic bacteria or bacterial resistance.
• Nonpathogens and pathogens include bacteria, viruses, fungi, rickettsiae, protozoans, mycoplasmas, helminths, and prions.

Bacteria

• Bacteria are generally single-celled microorganisms.
• They come in a variety of shapes: cocci, bacilli, and spirochetes.
• Aerobic bacteria require oxygen, while anaerobic bacteria do not.

Viruses

• Viruses are the smallest microorganisms that cause infectious diseases.
• They are visible via electron microscope and filterable.
• Viruses require materials from other living species to reproduce.
• Some remain dormant and reactivate sporadically, causing infectious disorder recurrence.
• Viral infections can be minor or serious/fatal.

Fungi

• Includes yeasts and molds.
• Superficial infections affect skin, mucous membranes, hair, and nails.
• Intermediate infections affect subcutaneous tissues.
• Systemic infections infect deep tissues and organs.

Rickettsiae

• Resemble bacteria but cannot survive outside another living species.
• Intermediate life forms, like fleas and ticks, transmit rickettsial diseases to humans.

Protozoans

• Single-celled animals classified by the ability to move.
• Some use amoeboid motion, others use cilia or flagella, and some cannot move at all.

Mycoplasmas

• Mycoplasmas lack cell walls, and they are referred to as pleomorphic because they assume various shapes.
• They infect surface linings of the respiratory, genitourinary, and gastrointestinal tracts.

Helminths

• Infectious worms classified into nematodes, cestodes, and trematodes.
• Some enter the body in the egg stage, while others enter as larvae.
• They mate and reproduce after invading, then excrete.

Prions

• Infectious agents containing no nucleic acid.
• Mutated prions can alter normal prion proteins into mutant copies, causing transmissible spongiform encephalopathies.
• Researchers are trying to link prions to neurological disorders.

Survival of Microorganisms

• Each microorganism species is unique, but all need a favorable environment to survive.
• Conditions include: warmth, darkness, oxygen, water, and nourishment.
• Pathogens have mutated to adapt to hostile environments.
• Spores are temporarily inactive microbial life forms and withstand heat, chemicals, and dryness.
• Spores are more difficult to destroy and are able to reactivate and reproduce.

Antibiotic Drug Resistance Causes

• Prescribing antibiotics for minor infections
• Administering antibiotics prophylactically.
• Not finishing treatment.
• Taking someone else's antibiotic.
• Prescribing antibiotics for viral infections.
• Dispersing antibiotic solutions into environment.
• Leaving partially empty IV bags.
• Releasing droplets while purging IV tubing.
• Expelling air before injecting.
• Administering antibiotics to livestock.
• Spreading via unwashed hands.

Chain of Infection

• Interfering with microorganism transmission helps prevent infectious diseases.
• 6 components must be in place to transmit pathogens
• An infectious agent
• A reservoir
• An exit route
• A means of transmission
• A portal of entry
• A susceptible host

Infectious Agents

• Some microorganisms pose less danger.
• Normal microflora can maintain healthy function symbiotically.
• Controlled normal flora remain unless the host weakens and can cause opportunistic infections.

Reservoirs

• Reservoirs provide haven for survival via growing and reproducing.
• They include tissues, wounds, blood, digestive tract, and stagnant water.
• Clients/animals that harbor pathogens are carriers.
• Nonliving reservoirs are fomites.

Exit Routes

• Microorganisms escape from the original reservoir by handling/touching, or releasing blood, fluids, secretions, and excretions.
• Flooding and soil erosion provide escape mechanisms.

Means of Transmission

• How infectious agents move to other locations.
• 5 routes: contact, droplet, airborne, vehicle, and vector.

Portal of Entry

• Where microorganisms enter a new host.
• This often includes opening in the skin/mucous membrane, or being inhaled.
• Biologic defense mechanisms often prevent infection.
• Mechanical defense mechanisms are physical barriers or actions.
• Chemical defense mechanisms destroy microorganisms through natural substances.

Susceptible Host

• Humans become susceptible to infections when their defense mechanisms are impaired.
• Ill clients are prime targets.
• Particularly susceptible clients are older adults, burn victims, those who require invasive procedures, or are infected with HIV.

Asepsis

• Health care institutions are reservoirs of microorganisms, making infection control critical.
• Asepsis decreases or eliminates infectious agents, their reservoirs, and transmission vehicles, which is the major method of preventing and controlling infection.
• Healthcare providers use medical and surgical asepsis.

Medical Asepsis

• Also called clean technique, confines/reduces the number of microorganisms by interfering with the chain of infection.
• Microorganisms exist everywhere.
• Frequent hand hygiene and intact skin reduces transmission.
• Blood, body fluids, cells, and tissues are considered reservoirs.
• Personal protective equipment serve as barriers.
• Clean environment reduces microorganisms.
• Some areas like the floor are more contaminated.
• Cleaning should progress in order from cleaner to dirtier.

Antimicrobial Agents

• Chemicals that destroy or suppress growth of infectious microorganisms.
• Some clean equipment/surfaces, while others are applied to the skin or internally.

Antiseptics

• Also known as bacteriostatic agents, inhibit growth.
• Applied to the skin or mucous membranes.

Disinfectants

• Destroy active microorganisms, but not spores.
• Rarely applied to the skin, used to kill/remove microorganisms from equipment/surfaces.

Hand Hygiene

• Hand hygiene removes surface contaminants via washing or antisepsis.
• Hand washing is preferred when hands are visibly dirty.
• Washing removes resident and transient microorganisms using friction.
• Wash over 20 seconds
• Without hand washing, transient microorganisms become residents and can increase risk of infection.
• Alcohol-based hand rubs remove microorganisms better and are faster.

Antibacterial Soap Vs. Antimicrobial Soap

• Antibacterial soaps include added chemicals to kill bacteria.
• Antimicrobial soaps kill bacteria.

Hand Washing Guidelines

• Use soap and water before, during, and after preparing food.
• Use soap and water before eating, after caring for someone who is sick, and treating a cut or wound.
• Use soap and water after using the bathroom and touching animals or garbage.
• Use soap and water if hands are visibly dirty.

Surgical Hand Antisepsis

• Removes transient microorganisms more extensively prior to surgical procedures.
• Fingernails should be short, and artificial nails are prohibited.
• Remove all rings, watches, and jewelry.

Proper PPE

• Health care providers must wear PPE to prevent microorganism transfer.

Infection Risks

• Inadequate nutrition
• Poor hygiene practices
• Suppressed immune system
• Chronic illness
• Insufficient white blood cells
• Prematurity
• Advanced age
• Compromised skin integrity
• Weakened cough reflex
• Diminished blood circulation