Infectious Diseases
Lynn K. Wittwer, MD, MPD
Clark County EMS
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Normal Flora
Pathogens
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Bacterial
☼ Staphylococci
☼ Streptococci
☼ Enterobacteriaceae
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Viral
☼ Rickettsiae
☼ Protozoans
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Opportunistic
Pathogens
Brady; Paramedic Care Principles & Practice
Microorganisms
Microorganisms
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Bacteria
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Common Bacterial Diseases
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Sinusitis
Otitis media
Bacterial pneumonia
Pharyngitis
TB
UTI’s
Bacterial growth
E.coli
Microorganisms
Bacterial Growth (cont.)
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LAG PHASE: Growth is slow at first,
while the "bugs" acclimate to the food
and nutrients in their new habitat.
LOG PHASE: Once the metabolic
machinery is running, they start
multiplying exponentially, doubling in
number every few minutes.
STATIONARY PHASE: As more and
more bugs are competing for dwindling
food and nutrients, booming growth
stops and the number of bacteria
stabilizes.
DEATH PHASE: Toxic waste products
build up, food is depleted and the bugs
begin
to die.
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Staphylococcus aureus
Microorganisms
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Bacteria (cont.)
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Gram Stains
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 Released
from gram
neg. bacteria
 Released during cell
destruction
☼ Gram
positive
☼ Gram negative
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Types of Bacteria
☼ Cocci
(spheres)
☼ Rods
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E. coli
☼ Spirals
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Spirochetes
Endotoxins
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Exotoxins
 Toxic
protein shed by
living bacteria
Microorganisms
Viruses
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Obligate Intracellular
Parasites
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Grow/reproduce w/in
host cell
Virus Replication
Viral Illness
Brady; Paramedic Care Principles & Practice
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Microorganisms
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Other Microorganisms
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Prions
Fungi
Protozoa
Parasites
Pinworms
Hookworms
Trichinosis
Giardia lamblia
Cellsalive.com
Entamoeba histolytica
Water-borne, free-living
parasite, causes amoebic
dysentery and invasive
liver abscesses.
Contraction, Transmission, and
Stages of Disease
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Transmission of Infectious Disease
Interaction of Host, Infectious Agent, and
Environment
 Reservoirs
 Direct vs. Indirect Transmission
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 Routes
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Bloodborne, airborne, sexual, fecal-oral, and foodborne
 Risk
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of Exposure
of Infection
Theoretical vs. measurable
Contraction, Transmission, and
Stages of Disease
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Factors Affecting Disease Transmission
Mode of Entry
 Virulence
 Number of Organisms Transmitted
 Host Resistance
 Other Host Factors
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Contraction, Transmission, and
Stages of Disease
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Phases of the Infectious Process
Latent Period
 Communicable Period
 Incubation Period
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 Seroconversion
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Disease Period
and the window phase
The Body’s Defenses against
Disease
Barriers to Entry
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Intact Skin
Respiratory System
The Immune System
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The Reticuloendothelial System (RES)
Identifies Foreign Material
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Includes antigens of most bacteria and viruses.
An inflammatory response triggers
mechanisms designed to remove foreign
material.
Cellsalive.com
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Viral antigens
The Body’s Defenses against
Disease
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The Immune System (cont.)
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Leukocytes
 Neutrophils
and macrophages
Cell-Mediated Immunity
 Humoral Immunity
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 Results
in the formation of antibodies.
 Memory and specificity.
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Antibodies (Immunoglobulins)
 IgG,
IgM, IgA, IgD, and IgE
 Autoimmunity
•neutrophil, ingesting
Streptococcus
pyogenes
The Body’s Defenses against
Disease
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The Complement System
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The Body’s “Rapid Response” System
 Proteins
that work with antibody formation and
inflammatory reaction to fight infection.
 Recognizes endotoxins of certain bacteria.
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The Lymphatic System
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Structures
 Spleen,
thymus, lymph nodes, and ducts.
 Collects and filters lymph.
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Facilitates Phagocytosis in Lymph Nodes.
The Body’s Defenses against
Disease
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Individual Host Immunity
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Passive Immunity
 Maternal

atibodies
Active Immunity
 Immunization
 Direct
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
exposure
Seroconversion
Titer
Brady; Paramedic Care Principles & Practice
Infection Control in Prehospital
Care
Infection Control in Prehospital
Care
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Phases of Prehospital Infection Control
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Preparation for Response
 Provide
written procedures for infection control.
 Prepare an infection control plan.
 Provide adequate infection control training.
 Ensure easy access to appropriately fitted,
checked, and maintained personal protective
equipment.
 Ensure that all personal wounds are bandaged
and treated before responding to an emergency.
 Use disposable supplies and equipment when
possible.
Infection Control in Prehospital
Care

Phases of Prehospital Infection Control (cont.)
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Preparation for response (cont.)
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Ensure personnel have access to facilities for personal
hygiene.
Do not allow infected personnel to deliver patient care.
Monitor EMS personnel for compliance with vaccinations and
diagnostic tests.
Appoint a designated infectious disease control officer.
Identify jobs and processes where the possibility of exposure
exists.
Provide haz-mat education, including MSDS training
regarding chemicals or mixtures and health hazards.
Infection Control in Prehospital
Care
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Response
Obtain as much information as possible from
dispatch.
 Prepare for patient contact.
 Prepare mentally for the call.
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Infection Control in Prehospital
Care
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Patient Contact
Isolate all body substances.
 Wear appropriate PPE.
 Allow only necessary personnel to make
patient contact.
 Use airway adjuncts for assisted ventilation.
 Use disposable items whenever possible.
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Infection Control in Prehospital
Care
Patient Contact
(cont.)
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Properly dispose of
biohazardous waste.
Use extreme caution with
sharp instruments and
dispose of sharps in proper
containers.
Never smoke, eat, or drink in
the patient compartment of
the ambulance.
Do not apply cosmetics or lip
balm or handle contacts
when a possibility of
exposure exists.
Brady; Paramedic Care Principles & Practice
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Infection Control in Prehospital
Care

Recovery
Wash your hands immediately after patient
contact.
 If you sustain a wound and are exposed to
the body fluids of others, wash the wound
with soap and water immediately.
 Dispose of biohazardous wastes in
accordance with local laws and regulations.
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Infection Control in Prehospital
Care
 Recovery
(cont.)
Place potentially infectious wastes in leak
proof biohazard bags. Bag and label soiled
linen.
 Decontaminate contaminated clothing and
reusable equipment.
 Handle uniforms in accordance with agency
policy.
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Infection Control in Prehospital
Care
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Decontamination
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Low-Level Disinfection
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Intermediate-Level Disinfection
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Destroys M. TB and most viruses and fungi not bacterial
spores. (1:10 H2O and bleach)
High-Level Disinfection
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Routine cleaning does not destroy mycobacterium
tuberculosis
Destroys all microorganisms and most bacteria
Sterilization
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Autoclave and some chemical immersion agents. Kills
everything
Infectious Diseases of Immediate
Concern to EMS Providers
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Human Immunodeficiency Virus
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Pathogenesis
Risk to the General Public
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Found in blood, blood products, and body fluids.
Common methods of transmission include sexual contact
and shared needles.
Risk to Health Care Workers
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Transmission to health care workers is actually rare.
Accidental needlesticks are the most common source.
High-risk exposures are those involving a large volume of
blood, deep percutaneous injury, actual intramuscular
injection, or a high antibody-retrovirus titer in the source
Diseases of Immediate Concern to
EMS Providers
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HIV (cont.)
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Clinical Presentation
 Fatigue,
fever, sore throat, lymphadenopathy,
splenomegaly, rash, and diarrhea.
 Kaposi’s sarcoma.
 Secondary (opportunistic) infections and weight
loss.
 Dementia, psychosis, and peripheral neurological
disorders develop as AIDS progresses.
Diseases of Immediate Concern to
EMS Providers

HIV (cont.)
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Postexposure Prophylaxis
 Medical
evaluation
 “Triple Therapy”
 Postexposure counseling
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Summary of HIV
 HIV
rarely presents life-threatening challenges, but
often presents psychosocial challenges.
 Take appropriate infection control precautions.
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Precautions should not be a barrier to professional care
Diseases of Immediate Concern to
EMS Providers
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Hepatitis
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General Signs & Symptoms
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Symptoms are similar regardless of type of infection.
Headache, fever, weakness, joint pain, anorexia, nausea,
vomiting, and URQ abdominal pain.
Jaundice, clay-colored stool, and dark urine develop as the
disease progresses.
Hepatitis A (Infectious or Viral Hepatitis) (HVA)
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Transmitted by fecal-oral route.
Typically is mild; many patients are asymptomatic.
Rarely serious and lasts 2–6 weeks.
Diseases of Immediate Concern to
EMS Providers

Hepatitis (cont.)
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Hepatitis B (Serum Hepatitis) (HBV)
 Virus
is transmitted through direct contact with
infected blood, semen, vaginal fluids, or saliva.
 Risk is significantly higher for EMS providers.
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5-35% of all needlesticks result in infection.
 Vaccination
is available and recommended for all
EMS workers.
 60–80% of infected individuals are asymptomatic.
Diseases of Immediate Concern to
EMS Providers

Hepatitis (cont.)
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Hepatitis C (HCV)
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Hepatitis D (HDV)
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Primarily transmitted by IV drug abuse and sexual contact.
Chronic infection that can cause active disease years later.
May cause cirrhosis and end-stage liver disease.
Exists only concurrently with HBV.
Hepatitis E (HEV)
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Is similar to HAV but primarily associated with contaminated
drinking water.
Diseases of Immediate Concern to
EMS Providers
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Tuberculosis
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General Info
 Most
common preventable infectious disease
 Drug-resistant TB
Skin Testing
 Pathogenesis
 Clinical Presentation
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 Chills,
fever, fatigue, chronic cough, weight loss
 Night sweats
 Hemoptysis
Diseases of Immediate Concern to
EMS Providers

Tuberculosis (cont.)
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EMS Response
 Index
of suspicion
 N95 and HEPA respirators
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Postexposure Identification and Management
Diseases of Immediate Concern to
EMS Providers
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Pneumonia
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General
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Differentiating pneumonia from CHF
Source pathogens
At-risk patient populations
History and Assessment
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Community-acquired pneumonia.
Signs include acute onset of chills, fever, dyspnea, pleuritic
chest pain, cough, adventitious breath sounds.
In geriatric patients, the primary sign may be an altered
mental state.
Diseases of Immediate Concern to
EMS Providers

Pneumonia
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Patient Management and PPE
 Management
should support oxygenation and
ventilation.
 Consider the possibility of TB.
 Consider placing a mask on yourself or the patient.
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Immunization and Postexposure Management
 Routine
vaccination is not necessary.
 Antimicrobial agents and multidrug-resistant
strains.
Diseases of Immediate Concern to
EMS Providers

Chickenpox
Varicella Zoster Virus (VCV)
 Clinical Presentation
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 Respiratory
symptoms, malaise, and low-grade
fever followed by a rash.
 Rash may be the first sign of illness and may be
limited or widespread; often prolific on the trunk.
 Transmission is through airborne droplets and
direct contact with lesions.
 Can be lethal in adult immunocompromised
patients.
Diseases of Immediate Concern to
EMS Providers

Chickenpox (cont.)
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Assessing Immunity
 Past
history of chickenpox is sufficient.
Immunization
 EMS Response and Postexposure

 Observe
universal (standard) precautions.
 Get postexposure vaccination.
Diseases of Immediate Concern to
EMS Providers

Meningitis

Inflammation of the Meninges
 Caused

by a variety of pathogens.
Transmission Factors
 Host
resistance factors, weather
 Contact with oral secretions
 Crowding, close contact, smoking
Diseases of Immediate Concern to
EMS Providers

Meningitis (cont.)
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Clinical Presentation
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Incubation period of 4–10 days
Fever, chills, headache, nuchal rigidity, arthralgia, lethargy,
malaise, altered mental status, vomiting, and seizures
Brudzinski’s and Kernig’s signs
Immunization
EMS Response and Postexposure
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Observe universal (standard) precautions.
Perform postexposure prophylaxis within 24 hours.
Other Job-Related
Airborne Diseases
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Influenza and the Common Cold
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Viral Infection
 Mutation
and virulence
 Epidemics
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Symptoms
 Fever,
chills, malaise, muscle aches, nasal
discharge, mild cough
 Secondary infections
Management
 Immunization
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Other Job-Related
Airborne Diseases
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Measles
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Viral Infection
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Symptoms
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Highly communicable, with lifelong immunity after disease.
Transmitted by airborne droplets and direct contact.
Presents similar to severe cold with fever, conjunctivitis,
photophobia, cough, and congestion.
Rash.
Management
Immunization
Other Job-Related
Airborne Diseases
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Mumps
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Viral Infection
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Symptoms
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Transmitted by airborne droplets and direct contact with
saliva of infected patient.
Occurs primarily in 5- to 15-year-old patients.
Painful enlargement of salivary glands
Symptoms of cold with earache, difficulty chewing, and
swallowing
Management
Immunization
Other Job-Related
Airborne Diseases
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Rubella
Systemic Viral Infection
 Symptoms
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 Sore
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throat, low-grade fever, and fine pink rash
Management and Immunization
Respiratory Syncytial Virus (RSV)
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Viral Infection
 Common
cause of pneumonias and bronchiolitis
 Commonly associated with lower respiratory
infections during the winter
Other Job-Related
Airborne Diseases
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RSV (cont.)
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Symptoms
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Runny nose and congestion, followed by wheezing,
tachypnea, and signs of respiratory distress
Management
Pertussis (Whooping Cough)
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Bacterial Infection
Symptoms
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Catarrhal, paroxysmal, and convalescent phases
Management and Immunization
Protocol for Prehospital
Exposure
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Known or suspected exposure
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Notify appropriate agency personnel (agency SOP)
Upon arrival notify team leader of exposure
Prophylaxis/treatment as per infection control
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May require admission to fas trac
Unknown exposure
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Personnel contacted by SWMC upon confirmation
Prophylaxis/treatment as per infection control
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May require admission to fas trac