PNUR124
Week 4 Study Guide: Inflammation, Infection & Fever
Infection: the state produced by the establishment of one or more pathogenic agents or
microorganisms (as bacteria, viruses, protozoans, or fungi) in or on the body of a suitable host
• Is a process involving the invasion of body tissues by microorganisms (bacteria, viruses,
fungi, protozoa, and parasites). Infections almost always cause inflammation.
Causes of Infection:
Bacteria – example: Clostridium difficile, Escherichia coli, staphylococcus aureus
Virus – example: COVID-19, Hepatitis, HIV, HINI, Ebola
Fungi – example: Candida albicans, Aspergillus organism
Parasites – example: Cryptosporidium parvum – acute and chronic diarrhea
Protozoan – example: Plasmodium falciparum
Rickettsia & Chlamydia
Mycoplasma - example: walking pneumonia
Infection Control - Why is infection control important in the clinical setting?
• To protect clients from acquiring infections.
• To protect health care providers from becoming
infected.
• To prevent complications in the inpatient/outpatient
client.
• To decrease length of stay in hospital.
• To decrease health care cost.
• To promote a clean and safe healthcare
environment.
• To promote public safety.
Risk Factors for Infection
Age (newborn and the elderly is more susceptible)
Immune status (immunocompromised) and lack of immunization.
Prolonged stress
Poor nutritional status
Broken skin or mucosa
Medications (antineoplastic and corticosteroids)
Obesity (related to ↓ blood flow to skin and underlying tissue)
Smoking
Chronic diseases (pulmonary diseases, diabetes)
Hospitalization
Decreased mobility
Obstructed urine outflow (urinary retention)
Stages of an Infection
,PNUR124
• Incubation: Pathogens actively replicate but does not yet cause manifestations
(symptoms). Based on the microorganism and host factors, this period may last for
hours, days, months, years. (Influenza 1-3 days, chicken pox, 2-3 weeks).
• Prodromal Stage: Interval from the onset of nonspecific signs and symptoms (low-grade
fever, malaise, headache, and fatigue) to when more specific symptoms occur.
Organisms multiply and the individual can spread disease to others.
• Illness Stage: Interval when the individual manifests signs and symptoms specific to the
type of infection. Acute phase when maximal impact of infection is felt (fever and chills,
tachycardic and tachypneic).
• Convalescence: Interval when infection is contained and the body attempts to return to
a state of homeostasis. Affected tissues are repaired and manifestations resolved.
Types of Infection:
Colonization
o Presence of a microorganism on/in a host, with
growth and multiplication of the organism, but
without interaction between host and organism (no
clinical expression, no immune response).
Carrier
o A person with inapparent infection who is capable of
transmitting the pathogen to others. Asymptomatic or
passive or healthy carriers are those who never
experience symptoms despite being infected.
Local infection
o An infection that affects only one body part or organ
o Example: infected wound
Systemic infection
o Affecting the entire body, rather than a single organ or body part
o An infection that is in the bloodstream is also a systemic infection
o Example: high blood pressure or the flu
o Septicemia: When bacteremia results in systemic symptoms (complications of
infection)
o Bacteremia: Blood culture is positive for microorganisms.
Nosocomial infection
o Healthcare-associated infections (HAI), are infection(s) acquired during
the process of receiving health care that was not present during the time
of admission
o Example: UTI, respiratory pneumonia, surgical site wound infections
Diagnostics for Infection
WBC with differentials (increases in acute infection and immunosuppression).
ESR (elevated in acute and chronic infection)
Iron levels (Decreased in chronic infection).
C-reactive protein
, PNUR124
Blood and urine culture
Cultures and Gram stain of wound, sputum, and throat
Culture and Sensitivity
o Culture: laboratory cultivation of bacteria or yeast in a special growth medium,
which allows for positive identification of organisms.
o Different culture media are used for suspected pathogens
o (e.g., liquid medium is used for blood specimens as in blood culture)
o Common pathogens such as Staphylococci, streptococci, and
o enterococci are identified in 48 hours.
o Sensitivity: Used to determine minimal concentration of antibiotics that will
inhibit growth of an organism. Assess resistance to specific antibiotics. Why is
this important?
o Gram Stain: done to identify the presence of bacteria, WBCs and epithelial cells
in the original specimen (↑WBCs indicates infection, ↑epithelial = poor quality
specimen)
Older Adults and Infections
The elderly are at higher risk for infections.
Age-related changes perpetuate susceptibility (impaired immune function, immobility)
May present with atypical symptoms due to altered response to infections.
Common clinical presentation with infection is confusion (delirium) esp. with UTIs.
Elderly clients living in LTC or hospitalized are at increased risk for infections.
The elderly should be assessed for possible infection if:
Changes in ability to perform ADLs
Changes in cognition (CAM tool)
Delirium in Infection
o Delirium is defined as “an acute state of confusion that presents as a sudden,
severe change in a person’s cognition, affecting their awareness, attention,
thinking, perception, and subsequently, their behavior (Pallium Canada, 2013 as
cited in Murray, 2016, p. 133).
o It is not psychological issue or mental health issue.
o Caused by multiple factors (drugs, malnutrition, electrolyte imbalance, infection
(urinary, pneumonia), dehydration).
o Delirium is a common manifestation in the elderly with an UTI.
Chain of Infection
Infectious Agents: includes bacteria, viruses, fungi,
parasite, and protozoa.
These agents will cause disease depending on:
there are sufficient number of organisms.
Increased virulence
The susceptibility of the host
The ability to enter and survive in the host.
Week 4 Study Guide: Inflammation, Infection & Fever
Infection: the state produced by the establishment of one or more pathogenic agents or
microorganisms (as bacteria, viruses, protozoans, or fungi) in or on the body of a suitable host
• Is a process involving the invasion of body tissues by microorganisms (bacteria, viruses,
fungi, protozoa, and parasites). Infections almost always cause inflammation.
Causes of Infection:
Bacteria – example: Clostridium difficile, Escherichia coli, staphylococcus aureus
Virus – example: COVID-19, Hepatitis, HIV, HINI, Ebola
Fungi – example: Candida albicans, Aspergillus organism
Parasites – example: Cryptosporidium parvum – acute and chronic diarrhea
Protozoan – example: Plasmodium falciparum
Rickettsia & Chlamydia
Mycoplasma - example: walking pneumonia
Infection Control - Why is infection control important in the clinical setting?
• To protect clients from acquiring infections.
• To protect health care providers from becoming
infected.
• To prevent complications in the inpatient/outpatient
client.
• To decrease length of stay in hospital.
• To decrease health care cost.
• To promote a clean and safe healthcare
environment.
• To promote public safety.
Risk Factors for Infection
Age (newborn and the elderly is more susceptible)
Immune status (immunocompromised) and lack of immunization.
Prolonged stress
Poor nutritional status
Broken skin or mucosa
Medications (antineoplastic and corticosteroids)
Obesity (related to ↓ blood flow to skin and underlying tissue)
Smoking
Chronic diseases (pulmonary diseases, diabetes)
Hospitalization
Decreased mobility
Obstructed urine outflow (urinary retention)
Stages of an Infection
,PNUR124
• Incubation: Pathogens actively replicate but does not yet cause manifestations
(symptoms). Based on the microorganism and host factors, this period may last for
hours, days, months, years. (Influenza 1-3 days, chicken pox, 2-3 weeks).
• Prodromal Stage: Interval from the onset of nonspecific signs and symptoms (low-grade
fever, malaise, headache, and fatigue) to when more specific symptoms occur.
Organisms multiply and the individual can spread disease to others.
• Illness Stage: Interval when the individual manifests signs and symptoms specific to the
type of infection. Acute phase when maximal impact of infection is felt (fever and chills,
tachycardic and tachypneic).
• Convalescence: Interval when infection is contained and the body attempts to return to
a state of homeostasis. Affected tissues are repaired and manifestations resolved.
Types of Infection:
Colonization
o Presence of a microorganism on/in a host, with
growth and multiplication of the organism, but
without interaction between host and organism (no
clinical expression, no immune response).
Carrier
o A person with inapparent infection who is capable of
transmitting the pathogen to others. Asymptomatic or
passive or healthy carriers are those who never
experience symptoms despite being infected.
Local infection
o An infection that affects only one body part or organ
o Example: infected wound
Systemic infection
o Affecting the entire body, rather than a single organ or body part
o An infection that is in the bloodstream is also a systemic infection
o Example: high blood pressure or the flu
o Septicemia: When bacteremia results in systemic symptoms (complications of
infection)
o Bacteremia: Blood culture is positive for microorganisms.
Nosocomial infection
o Healthcare-associated infections (HAI), are infection(s) acquired during
the process of receiving health care that was not present during the time
of admission
o Example: UTI, respiratory pneumonia, surgical site wound infections
Diagnostics for Infection
WBC with differentials (increases in acute infection and immunosuppression).
ESR (elevated in acute and chronic infection)
Iron levels (Decreased in chronic infection).
C-reactive protein
, PNUR124
Blood and urine culture
Cultures and Gram stain of wound, sputum, and throat
Culture and Sensitivity
o Culture: laboratory cultivation of bacteria or yeast in a special growth medium,
which allows for positive identification of organisms.
o Different culture media are used for suspected pathogens
o (e.g., liquid medium is used for blood specimens as in blood culture)
o Common pathogens such as Staphylococci, streptococci, and
o enterococci are identified in 48 hours.
o Sensitivity: Used to determine minimal concentration of antibiotics that will
inhibit growth of an organism. Assess resistance to specific antibiotics. Why is
this important?
o Gram Stain: done to identify the presence of bacteria, WBCs and epithelial cells
in the original specimen (↑WBCs indicates infection, ↑epithelial = poor quality
specimen)
Older Adults and Infections
The elderly are at higher risk for infections.
Age-related changes perpetuate susceptibility (impaired immune function, immobility)
May present with atypical symptoms due to altered response to infections.
Common clinical presentation with infection is confusion (delirium) esp. with UTIs.
Elderly clients living in LTC or hospitalized are at increased risk for infections.
The elderly should be assessed for possible infection if:
Changes in ability to perform ADLs
Changes in cognition (CAM tool)
Delirium in Infection
o Delirium is defined as “an acute state of confusion that presents as a sudden,
severe change in a person’s cognition, affecting their awareness, attention,
thinking, perception, and subsequently, their behavior (Pallium Canada, 2013 as
cited in Murray, 2016, p. 133).
o It is not psychological issue or mental health issue.
o Caused by multiple factors (drugs, malnutrition, electrolyte imbalance, infection
(urinary, pneumonia), dehydration).
o Delirium is a common manifestation in the elderly with an UTI.
Chain of Infection
Infectious Agents: includes bacteria, viruses, fungi,
parasite, and protozoa.
These agents will cause disease depending on:
there are sufficient number of organisms.
Increased virulence
The susceptibility of the host
The ability to enter and survive in the host.
