Transcript 05. The concept of disease, controlled by the International Health

The concept of disease,
controlled by the
International Health
Regulations
Smallpox Plague
Disease, Prevention, and
Intervention
Progression of Smallpox
Incubation Period
Prodrome Stage
Macules
Papules
Vesicles
Pustules
Scabs
Scars
Smallpox Prodrome
Incubation period 12 days (range 7-17 d)
Prodrome
– abrupt onset of fever >101oF
– malaise, headache, muscle pain, nausea,
vomiting, backache
– lasts 1- 4 days
Smallpox Rash
Enanthem (mucous membrane lesions)
appears ~ 24 hours before skin rash
– Minute red spots on the tongue and
oral/pharyngeal mucosa
– Lesions enlarge and ulcerate quickly
– Become infectious from lesions in mouth
– Virus titers in saliva highest and most
infectious during first week of exanthem
(skin rash)
Smallpox Rash
• Exantham (skin rash) – (21 days)
Stages: macules, papules, vesicles, pustules, scabs
Pustules raised, round, firm - like small beads in the
skin (“shotty”)
Umbilication common
• Begins and most dense on face and extremities
•
•
(centrifugal distribution)
Lesions on palms and soles (>50% of cases)
Lesions in same stage and evolve slowly (1-2
days/stage)
Day 4 of rash
Ordinary Smallpox
Pustular lesions
on palms
Flattened lesions
on soles
Smallpox
Ordinary Type (Discreet lesions)
Smallpox
Ordinary Type (Dense lesions)
Smallpox
Flat-type
Smallpox
Hemorrhagic Type
Varicella
Differential Diagnosis
SMALLPOX
CHICKEN POX
Deep, hard lesions
Superficial
Round, well
circumscribed
Not well circumscribed
Confluent or umbilicated
Lesions at same stage of
development
Confluence and
umbilication uncommon
Lesions at all stages of
development
CHICKENPOX
SMALLPOX
Smallpox
Chickenpox
Smallpox
Varicella
Smallpox Outbreak Control
Activities and Strategies
Surveillance and Containment
(Ring Vaccination)
•
•
Search for cases
Provide a ring of immunity
around each case
-
•
Vaccinate close contacts
Vaccinate close contacts of
contacts
Required to control disease
-
most efficient use of vaccine
minimize adverse reactions
Contacts of Contacts
Contacts of Case(s)
Case(s)
Surveillance
Pre-Event Surveillance
– Identify cases with typical presentation
– Rapid laboratory confirmation
– Confirmation initiates contact vaccination
– Passive with more specificity
Post-Event Surveillance
– Identify all potential cases (typical/atypical)
– Clinical diagnosis can initiate contact
vaccination
– Active with increased sensitivity
Epidemiologic Investigation
Identify source of initial introduction(s)
Identify contacts and other population(s) at risk
Characterize and define outbreak
– Identify unusual/unexpected features
– Scope
Monitor effectiveness of control measures
Communicate information and define public
health recommendations
Contact Tracing
Goal is to find as many contacts as possible
– Contact with patient after onset of fever
– Prioritize based on closeness, length, and date
of exposure
– If too many to find quickly, consider all people in
same room (or possibly facility) with smallpox
case after onset of fever as contacts
Contact Tracing
Examples:
– Highest priority - people who live full-time in
home and other face-to-face contacts after
onset of fever
– Next priority – non face-to-face contacts
exposed in a medical care facility or in home
– Last priority – people in same facility after onset
of fever (other than home or hospital) but
without face-to-face contact
Isolation and Quarantine
Goals of Smallpox Isolation
Protect others from becoming infected
– Healthcare personnel
– Response personnel
– Other patients
Isolate smallpox patient
– Prevent sharing of airspace (respiratory
isolation)
– Prevent direct contact (protective clothing)
– Prevent contact with infectious materials
(decontamination)
Prevent sharing of airspace
with potentially infectious patients
Negative pressure isolation rooms.
Separate facilities for larger groups.
Respirators for unvaccinated careproviders.
Personal Protective Equipment
Use disposable gloves, gowns, and shoe
covers.
Reusable bedding and clothing should be
autoclaved or laundered in hot water with
bleach.
Respiratory Protection Smallpox
•Airborne precautions
•Recommendation: fitted NIOSH
N95 or greater respirators for
personnel entering patient room
Properly Fitted – air goes
through mask filter
Isolation Strategies
3 groups to consider
– Confirmed or suspected smallpox cases
– Febrile vaccinated contacts
– Asymptomatic (vaccinated) contacts
under surveillance
Confirmed/Suspected
Smallpox Cases (Few)
Known or presumed
infectious individuals
Hospital isolation room(s)
Rooms under negative
pressure
At least 6 to12 air
changes/hour
Air vented to outside
Air not re-circulated to other
rooms or areas
Confirmed/Suspected
Smallpox Cases (Many)
Designated Facility
for smallpox patients
Aerosol precautions
not needed if only
potential smallpox
cases in facility and
no shared ventilation
system
– All people
admitted/entering
facility vaccinated
Febrile Vaccinated Contacts
Vaccinated contacts with fever (no rash)
–
–
–
–
Two successive temps > 101º F (38ºC)
Less need for medical care
No shared ventilation system
Can be housed in same facility with smallpox
cases or separate facility
– All persons in facility require vaccination
Asymptomatic Vaccinated
Contacts
Not infectious
– Own home or other lodging
– No special ventilation or medical requirements
All other persons staying in home must also be
vaccinated
– Household members with contraindications stay
elsewhere
Fever surveillance for 18 days from last
exposure or 14 days from vaccination
Decontamination
Air:
– UV Light Sensitive
– Exhaust, Good Air Flow
Surfaces:
– Diluted bleach solution (Fresh every
day)
– Hospital disinfectants
Blood, pus contaminated equipment:
– Wash before disinfecting
Decontamination
Laundry:
– Contain separately
– Dissolving laundry bags if available
– Don’t sort first, wash, then sort
– Hot water with detergent and/or bleach
Household:
– Basic cleaning
– Wash all clothing in hot w/ bleach if
possible
– Public health review of home
Plague
Objectives
Identify plague bacterium
Epidemiology
Natural Occurrence
Bio-Terror Threat
Plague can cause large numbers of
cases
Could create panic
Considered for use since 14th century
Clinical Syndromes
Bubonic
Pneumonic
Septicemic
Plague Meningitis
Pharyngeal
“Safety Pin” Y. Pestis in blood
Bubonic Plague
Infected flea bite
Exposure through
break in skin
No person-to-person
Untreated progresses
to pneumonic
Pneumonic Plague
Inhalation of plague
bacteria
Disease progression
– Respiratory failure
– Shock
– Rapid death
Person-to-person
transmission
Septicemic Plague
Primary Form
– Direct inoculation in bloodstream
Secondary Form
– Development of untreated pneumonic or
bubonic plague
Epidemiology
Natural Reservoirs
Bites of infected flea
Blood meal from bacteremic animal
Regurgitates into human/ animal host
Common reservoirs
– Deer mice
– Ground squirrels
Epidemiology
Transmission
Bite of infected flea
Respiratory droplets
Direct contact (1,5-2
m)
Direct skin/mucous
membrane less
common
BT event –
Respiratory droplets
or aerosols
Plague Incidence
Worldwide, 1970 - 1998
All inhabited continents, but Australia
1,500 to 3,000 cases annually
Greatest Concentrations
– Asia, South America
Plague Bioterrorism Scenario
Most dangerous as
aerosol
Outbreak of
pneumonic
Possibly pharyngeal
or ocular
Report all suspect
cases to public
health immediately
Bubonic Plague
Incubation: 2 to 6 days
Symptoms
– Lymphadenopathy, fever
– Buboes at site of inoculation
Disease Progression - Untreated
– Septicemia
– Secondary Pneumonic Plague
– Meningitis (rare)
Bubonic Plague
Bubonic Plague
Bubonic Plague
Pneumonic Plague
Incubation: 2 to 4 days (range 1 to 6 days)
Symptoms
– Acute fever, chills, malaise, myalgias
– Productive cough
– Watery mucoid sputum, may be bloody
– Associated chest pain, increasing dyspnea
Pneumonic Plague
Disease Progression
– Adult Respiratory Distress Syndrome
– Refractory pulmonary edema
– Signs of shock
– Without treatment in less than 24 hours,
almost universally fatal
Pneumonic Plague
Coughing patient can spread
Respiratory precautions
Rapidly expanding infiltrates
Pulmonary parenchymal necrosis and
hemorrhage
Occasional pulmonary abscesses
Enlarged hilar nodes and pleural effusions
Pneumonic Plague
Pneumonic Plague
Pneumonic Plague
Septicemic Plague
Incubation: Most common as complication
of pneumonic or bubonic plague
Symptoms
– Acute fever, chills, prostration, abdominal
pain, nausea, vomiting
Disease Progression
– Purpura
– DIC
– Hypotension and other signs of shock
– Fatal if not treated
Infection Control
Large numbers of plague bacilli
Respiratory droplet spread in close direct
contact
Respiratory droplet precautions with
suspect cases
Contact public health
Bubonic Plague
Differential Diagnosis
Streptococcal or
staphylococcal adenitis
Purulent/ inflamed lesion often distal to
nodes
(Staphylococcal aureus,
Involved nodes more likely to be fluctuant
Staphylococcal pyogenes)
Ascending lymphangitis or cellulitis may
be present
Tularemia
(Francisella tularensis)
Cat scratch disease
(B. henselae)
Ulcer or pustule distal to nodes
Rarely as fulminant as in plague
Systemic toxicity uncommon
History of cat contact/scratch
Indolent clinical course
Primary lesion at site of scratch
No systemic toxicity
Bubonic Plague
Differential Diagnosis
Mycobacterial
infection, including
scrofula (Mycobacterium
tuberculosis and other
Mycobacterium species)
Lymphogranuloma
venereum
(Chlamydia trachomatis)
• Adenitis occurs in cervical region
• Usually painless
• Indolent clinical course
• More likely to occur in immunocompromised
patients
• Adenitis occurs in the inguinal region
• Sexual exposure 10-30 days previously
• Suppuration, fistula tracts common
• Exquisite tenderness usually absent
• Although patients may appear ill (headache,
fever, myalgias), systemic toxicity not present
Bubonic Plague
Differential Diagnosis
Chancroid
(Hemophilus ducreyi)
Adenitis occurs in inguinal region
Ulcerative lesion present
Systemic symptoms uncommon; toxicity
does not occur
Primary genital herpes
Genital area
Adenitis occurs in the inguinal region
Severe systemic toxicity not present
Primary or secondary
syphilis
(Treponema pallidum)
Enlarged lymph nodes in inguinal region
Lymph nodes generally painless
Chancre may be noted
Strangulated inguinal
hernias
Evidence of bowel involvement
Primary Pneumonic Plague
Differential Diagnosis
Inhalational anthrax
(Bacillus anthracis)
Tularemia
(Francisella tularensis)
• Widened mediastinum and pleural
effusions
• Not true pneumonia
• Minimal sputum production
• Hemoptysis uncommon
Not as rapid or fulminant as in pneumonic
plague
Primary Pneumonic Plague
Differential Diagnosis
Community-acquired bacterial
pneumonia
Mycoplasmal pneumonia
(Mycoplasma pneumoniae)
Pneumonia caused by Chlamydia
pneumoniae
Legionnaires' disease (Legionella
pneumophila or other Legionella
species)
Psittacosis (Chlamydia psittaci)
Other bacterial agents (e.g.,
Staphyloccocus aureus, Streptococcus
pneumoniae, Haemophilus influenzae,
Klebsiella pneumoniae, Moraxella
catarrhalis)
Rarely as fulminant
Usually occur in persons with
underlying pulmonary or other
disease or in the elderly
Bird exposure with psittacosis
Gram stain may be useful
Community outbreaks not as
explosive as pneumonic plague
outbreak
S. pneumoniae usually
institutional
Community outbreaks of
Legionnaires' disease often involve
exposure to cooling systems
Primary Pneumonic Plague
Differential Diagnosis
Viral pneumonia
Influenza
Hantavirus
RSV
CMV
Q fever
(Coxiella burnetii)
Influenza generally seasonal
History of recent cruise ship
travel or travel to tropics
Exposure to excrement of mice
with Hantavirus
RSV usually occurs in children
CMV usually occurs in
immunocompromised patients
Exposure to infected parturient
cats, cattle, sheep, goats
Severe pneumonia not
prominent
Laboratory confirmation
Critical for first cases
Collect immediately and before antibiotics
Store appropriately
Presumptive diagnoses
Specimens
Respiratory
Pharyngeal swabs
Tracheal washes or aspirates
Sputum specimens
Trans-thoracic lung aspirates
Pleural fluid collection
Testing – Staining, culture, DNA
amplification
Specimens
Tissues
Lung tissue
Lymph node tissue
Spleen
Liver
Testing – Culture, Gram stain
Specimens
Tissues (Autopsy)
Lung
Liver
Spleen
Lymph nodes
Skin lesions
Kidney
Testing – PCR (Specimens kept fresh
frozen, unpreserved)
Specimens
Blood
Baseline before antibiotics
Convalescent
– Minimum 14 days apart
– 3 to 4 weeks after symptom onset
Two or more sequentially collected
samples preferred
Laboratory Testing
Pneumonic Plague
Collect before initiating
therapy
Sputum, blood, lymph node
aspirate
Gram Stain and culture
– Gram-negative coccobacillus
– Bipolar (safety pin) staining
Acute and convalescent
bloods for public health
Recommended Plague Treatment
Contained Casualty - Adults
Preferred
Streptomycin
1g IM BID
Gentamicin
5 mg/kg IM or IV daily OR
2 mg/kg loading with 1.7 mg/kg
IM or IV TID
Alternative
Doxycycline
100mg IV BID or 200mg IV
Ciprofloxacin
400mg IV BID
Chloramphenicol
25 mg/kg IV QID
Recommended Plague Treatment
Mass Casualty - Adults
Preferred
Doxycycline
100 mg PO BID
Ciprofloxacin
500 mg PO BID
Alternative
Chloramphenicol
25 mg/kg PO QID
Plague Infection Control
Precautions
Bubonic
Standard
Pneumonic
Standard and Respiratory
Septicemic
Standard
Suspect
Respiratory and Isolation
Isolation for 48 hours of antibiotic
treatment or until clinical improvement
Plague Infection Control
Cohort and Droplet precautions if no
isolation available
Isolation of contacts may increase in
importance for outbreak control
Corpses – Standard Precautions
Shipping Biological Specimens
Infectious Substance
UN Hazard Class 6
UN Division 6.2
UN = United Nations
Shipping Biological Specimens
Infectious Substances
Primary Container
– Positive Seal
Absorbent Material
Shipping Biological Specimens
Infectious Substances
Secondary Packaging
Water-tight
Leak proof
Shipping Biological Specimens
Infectious Substances
Must be approved by the United Nations.
Designated as UN Certified Packaging or UN
Specified Packaging.