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Biological Weapons: Essential Information on Category A Agents

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Title: Biological Weapons: Essential Information on Category A Agents


1
Biological Weapons Essential Information on
Category A Agents
  • Felissa R. Lashley, RN, PhD, FAAN, FACMG
  • Professor, College of Nursing, and
  • Interim Director, Nursing Center for Bioterrorism
    and Infectious Disease Preparedness
  • College of Nursing
  • Rutgers, The State University of New Jersey

2
  • This module on the use of biological agents as
    bioweapons covers general material, the
    classification of biological agents as to their
    use in bioterrorism and gives the most important
    information regarding the Category A Agents
    according to the Centers for Disease Control and
    Prevention (CDC) classification. Separate modules
    address Category B and Category C agents. This
    module was supported in part by USDHHS, HRSA
    Grant No. T01HP01407.

3
  • The format and information in this module
  • focuses on the use of the agent or outbreak of
  • disease particularly in regard to bioterrorism
  • including emphasis on management with
  • nursing applications and infection control
  • material. Detailed material on general
  • transmission of disease, infection control and
  • isolation precautions is in a separate module
  • and this should be consulted. Aspects of
  • preparedness are also in a separate module.
  • Note that for the care of persons exposed to
  • any biological agent, the nurse should be sure
  • he/she is adequately protected first.

4
Objectives
  • At the completion of this module, participants
  • will be able to
  • 1. Identify at least 10 factors that make a
    biological agent or biological toxin suitable for
    use as a bioterror agent.
  • 2. List the 3 CDC categories for critical
    biological agents and why they are so
    categorized.
  • 3. Identify and list CDC Category A biological
    agents with potential for use in a bioterrorism
    attack.
  • 4. Describe the signs and symptoms of infection
    with Category A agents.
  • 5. Discuss isolation precautions for each
    Category A agent.

5
Using Biological Agents as Bioweapons
6
Biological Agents and Bioterrorism
  • Includes microorganisms, especially certain
    bacteria and viruses, and biological toxins such
    as botulinum toxin, which act like chemical
    agents.
  • May be directed at humans, plants, animals, and
    be a threat to crops, livestock, food products
    (agroterrorism) during processing, distribution,
    storage and transportation which could cause
    illness and also have severe economic
    consequences such as bovine spongiform
    encephalopathy, and foot and mouth disease.

7
Biological Agents and Bioterrorism-2
  • Biological agents can be used as weapons in
  • Biocrimes
  • Bioterrorism
  • Biowarfare
  • Definition North Atlantic Treaty Organization
    (NATO) defines a biological weapon as the
    provision of any infectious agent or toxin by any
    means of delivery in order to cause harm to
    humans, animals, or plants.

8
Biological Agents and Bioterrorism-3
  • Various definitions for bioterrorism have been
    given. The following may be used the
    intentional use or threat of use of biological
    agents on a population to achieve political,
    social, religious, ethnic, or ideological ends by
    causing illness, death and wide scale panic and
    disruption. The aim may not be maximum damage
    but rather a political statement.

9
Biological Agents and Bioterrorism-4
  • The technology exists to modify existing
    biological agents, or weaponize them, to, for
    example, make it easier to disseminate and/or
    cause greater harm in their dissemination.
  • The use of biological agents for bioterrorism has
    been referred to as the poor mans nuclear
    bomb.
  • All involve the use of biological agents in order
    to obtain an outcome political, social,
    economic, theological, personal.

10
Agents with Potential for USE in BIOTERRORISM
  • Varies according to source
  • NATO handbook lists 39 agents
  • World Health Organization (WHO) has another list
  • CDC lists biological agents in various
    categories, A, B, and C
  • National Institute for Allergy and Infectious
    Diseases (NIAID), National Institutes of Health
    (NIH) also lists categories A, B, and C, but they
    differ somewhat from how CDC categorizes agents
    and lists a greater number of agents
  • Others

11
The Following are Desirable Characteristics for
Biological Agents to be Used for Harmful Intent
  • Generate high levels of panic among population
  • Easy to obtain
  • Inexpensive
  • Easy to produce in mass quantities
  • Can be relatively easily weaponized or altered
    for maximum effect (even with genetic
    manipulation)
  • High infectivity
  • High person-to-person contagion
  • High mortality

12
The Following are Desirable Characteristics for
Biological Agents to be Used for Harmful Intent-2
  • Lack of effective treatment
  • Need for intensive care, straining resources
  • High potential for casualties/morbidity
  • Result in lengthy illness with prolonged care
    needed
  • Non-specific symptoms, especially early, delaying
    recognition
  • Long incubation periods
  • Hard to diagnose
  • Great degree of helplessness from effect

13
Examples of Historical Uses of the Deliberate
Release of Biological Agents
  • Known as early as the 6th century BC
  • Soldiers dropped corpses of those who died of
    plague over city walls during siege of Kaffa to
    start a plague epidemic and force surrender.
  • British soldiers used variola contaminated
    blankets to spread smallpox to American Indians
    during the French and Indian Wars (1754-1767).

14
Examples of Historical Uses of the Deliberate
Release of Biological Agents-2
  • Followers of Bhagwan Shree Rajneesh intentionally
    contaminated salad bars in the The Dalles, Oregon
    with Salmonella. The purpose was to keep people
    from voting in a local election in November,
    1984. More than 750 people were affected.
  • The Aum Shinrikyo group in Japan attempted to
    carry out attacks using aerosolized anthrax
    spores and botulinum toxin before releasing sarin
    in the Tokyo subway in 1995.

15
Examples of Historical Uses of the Deliberate
Release of Biological Agents-3
  • Intentional distribution of anthrax spores mainly
    through the US mail to various people occurred in
    the fall of 2001. In all, there were 22 known
    cases of anthrax 11 were inhalational.
  • Picture from CDC. Inhalational
  • anthrax.

16
Categories of Critical Biological Agents as
Specified by CDC
  • Three Categories of Agents
  • Category A Agents Pose the greatest threat to
    national security
  • Category B Agents Second highest priority to
    national security.
  • Category C Agents Third highest priority agents
    include emerging pathogens that could be
    engineered for mass dissemination in the future.

17
Category A Agents
  • Pose a threat to national security because they
  • Can be easily disseminated or transmitted
    person-to-person
  • Cause high mortality with potential for major
    public health impact
  • Might cause public panic and social disruption
  • Require special action for public health
    preparedness

18
Category B Agents
  • Second highest priority to national security
  • Are moderately easy to disseminate
  • Cause moderate morbidity and low mortality
  • Require specific enhancements of CDCs diagnostic
    capacity and enhanced disease surveillance

19
Category C Agents
  • Third highest priority agents include emerging
    pathogens that could be engineered for mass
    dissemination in the future because of
  • Availability
  • Ease of production and dissemination
  • Potential for high morbidity and mortality and
    major health impact

20
Category A Agents
  • These agents include the following diseases, with
    the organism in parentheses. Discussion of each
    individual organism listed below follows
  • Anthrax (Bacillus anthracis)
  • Botulism (Clostridium botulinum)
  • Ebola hemorrhagic fever (Ebola virus)
  • Lassa Fever (Lassa virus)
  • Marburg hemorrhagic fever (Marburg virus)
  • Plague (Yersinia pestis)
  • Smallpox (Variola virus)
  • Tularemia (Francisella tularensis)

21
Category A Agents-2
  • Other hemorrhagic fever viruses, such as
  • Junin virus (Argentine hemorrhagic fever)
  • Guanarito virus (Venezuelan hemorrhagic fever)
  • Machupo virus (Bolivian hemorrhagic fever)
  • Sabia virus (Brazilian hemorrhagic fever)

22
Anthrax (Bacillus anthracis)
  • Etiology
  • A gram-positive rod-like bacteria, B. anthracis
  • Capable of aerobic spore formation
  • Spores can last 40 years or more
  • Non-motile
  • Forms capsule

23
Anthrax-2
  • Description has several clinical types
  • Cutaneous (skin) anthrax most common.
  • Gastrointestinal (GI) anthrax
  • Rare in developed countries
  • Results from infected meat that is undercooked or
    raw
  • Can affect oropharynx or esophagus, causing
    ulcers
  • Inhalational (respiratory) anthrax
  • Abrupt respiratory distress
  • No person-to-person transmission
  • Other names
  • Was known as woolsorters or ragpickers disease.

24
Anthrax-3
  • Epidemiology
  • A zoonotic disease, primarily of animals such as
    cattle, sheep, goats, deer and horses.
  • Worldwide there can be up to 100,000 cases per
    year. Most natural cases occur in the Middle
    East, India, Asia, Africa and Latin America.
    Usually rare in the US and western Europe.
  • Until the deliberate release of anthrax spores in
    the US in 2001, inhalational anthrax had not been
    reported in the US for more than 20 years. In
    2001, 22 cases of human anthrax were reported in
    the US, 2 in 2002, none in 2003, 2004, and 2005,
    1 in 2006, and none in 2007.

25
Anthrax-4
  • Transmission
  • Animals become infected through ingestion of
    spores in soil which germinate and produce
    toxins.
  • Humans usually contract anthrax from contact with
    anthrax infected animals or contaminated animal
    hair, hides, flax, wool, excretions, blood and
    products such as bone meal.
  • Direct contact from infected persons skin
    lesions.
  • Inhalational anthrax is acquired by inhaling
    aerosolized spores.
  • Gastrointestinal anthrax results from eating
    undercooked or raw meat or dairy products from
    infected animals.
  • Inhalational and gastrointestinal anthrax are not
    known to be transmitted person-to-person.
  • Humans may also become infected through
    intentional exposure.

26
Anthrax-5
  • Transmission cont.
  • Occupational exposure in humans has been the most
    usual way in which anthrax was acquired.
  • Examples include farm workers, laboratory workers
    or industrial exposure (see below).
  • Cutaneous and inhalational anthrax cases formerly
    occurred during the manufacturing process of
    infected wool, hair and hides. In 2006, one case
    occurred in a man who acquired the disease from
    an infected animal hide he brought back from
    Africa to make drums.

27
Anthrax-6
  • Incubation period
  • Cutaneous anthrax a few hours to 12 days
  • Gastrointestinal anthrax 1 to 7 days
  • Inhalational anthrax Less than 7 days (usually
    4-6 days) but up to 2 months.

28
Anthrax-7
  • Clinical manifestations
  • Cutaneous anthrax
  • Local response is itching followed by small red
    macule progressing to papule formation (3-5 days
    usual), resembling an insect bite.
  • This becomes a vesicle with a painless ulcer
    formation that may enlarge to 1 to 3 cm.
  • Black eschar develops within 7-10 days with
    surrounding edema.
  • Typically seen on arms, hands, head or neck.
  • May also have lymphadenitis and fever, malaise
    and headache.
  • Septicemia can occur.

29
Cutaneous Anthrax(Notice the edema and typical
lesions)Photos from CDC.
Notice the edema and typical lesions
30
Further examples of Cutaneous Anthrax lesions
Photos from CDC.
Black eschar, redness remains
Ulcer and vesicle ring
31
Anthrax-8
  • Clinical manifestations cont.
  • Gastrointestinal anthrax
  • Symptoms initially are nausea, vomiting,
    anorexia, fever, followed by abdominal pain,
    hematemesis and bloody diarrhea.
  • Symptoms depend on site of lesions.
  • If there are lesions in oral pharynx, may swell
    to affect the airway, and there may be dysphagia
    and throat pain.
  • In gastrointestinal anthrax, ascites may develop
    as may septicemia within 5 days after onset.

32
Anthrax-9
  • Clinical manifestations cont.
  • Inhalational anthrax
  • There are usually two phases.
  • Initial symptoms are nonspecific and consist of
    malaise, low grade fever, nonproductive cough and
    gastrointestinal complaints such as nausea and/or
    vomiting.
  • Sometimes there is improvement for a few days
    followed by a second phase with dry cough,
    dyspnea, high fever, chills, diaphoresis,
    tachypnea and respiratory distress.
  • Bacteria enter the blood causing bacteremia, and
    seeding of the meninges and gastrointestinal
    tract.
  • Abdominal pain, hematemesis, melena, cyanosis,
    confusion and hemorrhagic, purulent meningitis
    develop.

33
Anthrax-10
  • Clinical manifestations cont.
  • Inhalational anthrax cont.
  • Meningitis occurs in about 50.
  • Cardiovascular collapse and death follow if
    untreated.
  • Because early symptoms are non-specific, the
    presence of nausea and vomiting and neurological
    symptoms help to differentiate it from other
    disorders and a widened mediastinum on x-ray is
    suggestive of inhalational anthrax.

34
Inhalational Anthrax
Mediastinal widening and pleural effusion on
Chest X-Ray in inhalational anthrax
35
Anthrax-11
  • Diagnosis
  • For all, blood cultures may be done if organism
    has spread.
  • Lab may do rapid screening followed by
    confirmatory testing.
  • Combine lab testing with clinical findings.

36
Anthrax-12
  • Diagnosis cont.
  • Cutaneous
  • Gram stain, PCR, culture of exudate or eschar
  • Should be done before antibiotic therapy
  • Gastrointestinal
  • Blood cultures
  • Oropharyngeal swabs
  • Inhalational
  • Chest x-ray findings especially widened
    mediastinum, pleural effusions, and pulmonary
    congestion
  • Tissue biopsy
  • Fluid for gram stain, PCR or culture if from
    sterile site

37
Anthrax-13
  • Mortality
  • Cutaneous - if untreated can be 10-20, less
    than 1 with treatment
  • Gastrointestinal - depends on site, 25-60
  • Inhalation - mortality can be 45-97 with
    antibiotic therapy. The case fatality rate may be
    as high as 75.

38
Anthrax-14
  • Treatment
  • Cutaneous anthrax
  • Initial therapy in adults is usually
    ciprofloxacin or doxycycline in children both
    are also used, although care must be taken in
    children as doxycycline may discolor teeth.
  • Therapy may be oral.
  • Inhalational anthrax
  • For adults and children, ciprofloxacin or
    doxycycline are used with one or two additional
    antimicrobials.
  • Initial therapy is IV, switching to oral therapy
    when appropriate.
  • Therapy may be as long as 60 days.
  • Therapy may be combined with a 3 dose regimen of
    anthrax vaccine for prophylaxis.

39
Anthrax-15
  • Treatment cont.
  • Gastrointestinal anthrax
  • May be treated with the same antibiotic regimens
    as inhalation because of potential to spread to
    respiratory tract.
  • Note Post-exposure prophylaxis may be given to
    those exposed to an initial release of anthrax as
    soon as possible after exposure. This is usually
    administered orally for 60 days with
    ciprofloxacin and doxycycline being the most
    desired followed by amoxicillin which is
    preferred for pregnant women. If organism is
    susceptible, children may also be switched to
    amoxicillin.

40
Anthrax-16
  • Nursing considerations
  • Be sure decontamination has taken place.
  • Appropriate isolation precautions.
  • Supportive care as needed for symptoms.
  • If associated with intentional release,
    psychosocial support/therapy is needed.
  • In analysis of survivors of fall 2001 anthrax
    release, a year later survivors had reported
    lower health-related quality of life and greater
    overall psychological distress. Those who had
    inhalation anthrax reported loss of functional
    capacity, and some still had respiratory
    abnormalities.
  • Adherence may be an issue for persons on
    long-term antimicrobial therapy and nurses should
    plan to address this.

41
Anthrax-17
  • Isolation Precautions
  • Cutaneous anthrax Standard and the transmission
    based contact precautions. Avoid any contact with
    skin lesions or drainage.
  • Inhalational anthrax Both standard and contact
    precautions have been recommended in addition to
    respurology N95 mask or PAPR protective
    clothing for environmental aerolized powder on
    person.
  • Gastrointestinal anthrax Standard precautions.

42
Anthrax-18
  • Vaccine
  • Multidose vaccine available but currently used
    for special populations such as the military.
  • Both live cellular and live acellular vaccines
    are available. Recombinant vaccines are in
    development.
  • Other
  • Persons known to be exposed to anthrax spores
    should remove clothing and shoes and leave at
    worksite and wash exposed skin including any
    jewelry and glasses.
  • Removed clothing should be bagged.
  • At home, systematic showering with systematic
    cleaning from hair down should be done if at risk
    for higher contamination.
  • Care needs to be taken when removing outer
    clothing to keep inner clothing from being
    contaminated.
  • Biosafety level 2 handling.

                             
43
Anthrax Special Considerations Re Bioterrorism
  • Anthrax is considered one of the most important
    biological agents with potential for use as a
    bioterror agent.
  • It can be weaponized in an aerosolized stable
    spore form.
  • One deep breath at the site of intentional
    release can result in inhalational anthrax with
    high mortality.
  • Environmental surveillance and assessment is
    needed.
  • Decontamination procedures are needed.

44
Anthrax Special Considerations Re
Bioterrorism-2
  • Anthrax potential for use as bioterror agent
    cont.
  • Pre-exposure immunization available for defined
    population segments.
  • If anthrax is suspected, one part of the patient
    assessment is to assess whether there is an
    epidemiological linkage to a plausible
    environmental exposure such as through the
    persons occupation.
  • Antimicrobial prophylaxis will be used for
    persons potentially exposed to anthrax. In those
    who are demonstrated not to be exposed,
    prophylaxis can be discontinued. For others, this
    will be continued for about 60 days.

45
Botulism(Clostridium botulinum toxin)
  • Etiology
  • Toxin from Clostridium botulism, a spore- forming
    bacillus.
  • Seven known types cause disease.
  • These toxins are potent neurotoxins.
  • Toxin prevents acetylcholine release and blocks
    neuromuscular transmission, presynaptic
    inhibition affecting autonomic and motor
    receptors.
  • Minute quantities of botulinum toxins can cause
    death, as they are extremely poisonous.
  • Infective dose 0.001 micrograms.

46
Botulism-2
  • Types
  • Foodborne most common
  • Wound
  • Infant
  • Inhalational - rare, may be intentional
  • Incubation period For foodborne botulism 18-36
    hours usual but can be 6 hours to 10 days.
  • Incubation period for inhalation botulism is
    24-72 hours after exposure.

47
Botulism-3
  • Epidemiology
  • Most cases of foodborne botulism occur through
    improperly canned or prepared foods especially
    those that are of low acidity such as corn,
    beans, tomato sauce.
  • Improperly heated and stored sauteed onions were
    the cause of one outbreak in Peoria, Illinois.
  • Botulinum toxins have been weaponized to be
    delivered by aerosol means.
  • Wound and infant botulism are not discussed here.

48
Botulism-4
  • Transmission
  • Ingestion, inhalation (in deliberate release
    situation) or absorption.
  • Not transmissable from person-to- person.

49
Botulism-5
  • Clinical manifestations
  • Blurred vision
  • Dilated pupils
  • Diplopia
  • Ptosis
  • Dry mouth, and
  • Photophobia
  • These may be followed by
  • Dysarthria
  • Dysphagia
  • Dysphonia
  • Generalized weakness, and
  • A symmetrical descending progressive paralysis
    leading to respiratory failure.

50
Botulism-6
  • Clinical manifestations cont.
  • Cranial nerve palsies are responsible for
    symptoms, such as difficulty in speaking or
    swallowing.
  • Symptoms such as constipation and urinary
    retention may be seen and nausea and vomiting may
    be present.
  • Patients are usually alert and afebrile.

51
Botulism-7
  • Diagnosis
  • By detection of toxin in serum, stools or gastric
    secretions.

52
Botulism-8
  • Treatment
  • Important to recognize botulism early and
    administer botulism antitoxin as soon as possible
    to neutralize the circulating toxin or
    progression will continue to occur.
  • Antitoxin does not reverse paralysis but limits
    it.
  • In cases of aerosol exposure, the antitoxin is
    effective before clinical symptoms are present
    but if given later will not prevent respiratory
    failure.

53
Botulism-9
  • Treatment cont.
  • Full recovery can take a long timemonths--as
    presynaptic axons regenerate and new synapses are
    formed.
  • In the botulism outbreak in Peoria in the 1980s,
    symptoms such as fatigue, headache, and weakness
    lasted for years.
  • Therapy includes rapid administration of botulism
    antitoxin, monitoring of vital capacity to
    institute rapid ventilatory support when vital
    capacity falls below 12 ml/kg.

54
Botulism-10
  • Nursing considerations
  • Use of standard precautions
  • Isolation room not required
  • Observe for possible respiratory distress which
    can occur rapidly
  • Assist patient with communication if on a
    mechanical ventilator
  • Prevent nosocomial infections through use of good
    hygiene
  • Prevent deep vein thromboses (DVT)
  • Give appropriate bowel and bladder care

55
Botulism-11
  • Nursing considerations cont.
  • May need extensive rehabilitation for swallowing,
    speech, muscle strength and so on.
  • Address psychosocial issues and fears associated
    with the progressive paralysis and loss of
    voluntary movement and speech.
  • CDC recommends decontamination of patients and
    their clothing with soap and water if exposed to
    aerosolized botulism toxins and decontamination
    of exposed surfaces by cleaning with a bleach
    solution.

56
Botulism-12
  • Other
  • In case of use in bioterrorism, resources such as
    ventilatory support (which may be needed in the
    long term) and supportive intensive care services
    would be overwhelmed, as would the availability
    of antitoxin.
  • Prevention
  • Pre-exposure vaccination with toxoid is available
    for military personnel and laboratory workers at
    high risk of exposure.
  • Development of recombinant toxoid vaccines for
    wider use is underway.

57
Ebola Hemorrhagic Fever (Ebola virus)
  • Etiology
  • Ebola virus, a rod-shaped RNA virus in the
    filovirus family.
  • Changes shape rapidly.
  • The filamentous form is associated with high
    infectivity.
  • Has 4 (possibly 5 )subtypes to date
  • Zaire
  • Sudan
  • Reston
  • Cote dIvoire (Ivory Coast)
  • A possible new subtype responsible for the
    outbreak in Uganda in 2007-8
  • Picture from CDC

58
Ebola-2
  • Description
  • Is a viral hemorrhagic fever caused by the Ebola
    virus.
  • Epidemiology
  • Ebola virus occurs naturally in Africa.
  • While subclinical infections have been noted,
    typically Ebola hemorrhagic fever emerges in
    sporadic outbreaks.
  • Outbreaks have been reported in the Democratic
    Republic of the Congo, Gabon, Sudan, the Ivory
    Coast, Uganda and Republic of the Congo.

59
Ebola-3
  • Epidemiology cont.
  • First outbreaks recognized in 1976 in Sudan and
    in Zaire, now part of the Democratic Republic of
    the Congo.
  • It is believed to be a zoonotic virus normally
    maintained by a natural host native to Africa.
  • Photo from CDC.

60
Ebola-4
  • Epidemiology cont.
  • The natural reservoir for Ebola virus is not
    known, but it is believed that human outbreaks
    occur when a person is exposed to an infected
    animal. Fruit bats have been suggested as having
    a role.
  • Outbreaks also occur among gorillas and
    chimpanzees.
  • Ebola-Reston occurred in infected monkeys in the
    Phillipines, but is not known if Ebola is also
    native to Asia since there have not been other
    recognized outbreaks there.
  • The most recent reported outbreaks are in The
    Democratic Republic of the Congo (2007) and
    Uganda (2007-2008)
  • The outbreak in Uganda is believed due to a
    previously unknown subtype with a lower mortality
    rate.

61
Ebola-5
  • Transmission
  • Person-to-person spread may occur when a person
    comes into contact with infected blood, tissues,
    secretions, or excretions of another person.
  • Infection may also occur through contact with
    contaminated objects.
  • Infection may further occur in hospitals or
    health care settings through
  • The use of contaminated medical equipment, such
    as reused needles and syringes,
  • Contaminated multivials of medicine, and/or
  • Lack of appropriate infection control.
  • Traditional burial ceremonies involving contact
    with the infected corpse may spread Ebola virus.
  • Handling of infected wild animal carcasses, such
    as chimpanzees, gorillas and duikers, including
    food preparation activities.

62
Ebola-6
  • Incubation period 2 to 21 days.
  • Clinical manifestations
  • Asymptomatic infection may occur.
  • In most cases, the onset of illness is abrupt
    with fever, headache, myalgia, weakness, malaise
    and pharyngitis.
  • These may be followed by nausea, diarrhea and
    vomiting as well as stomach pain.
  • A maculopapular rash may appear around the 5th
    day and desquamation can occur.
  • Conjunctival injection, hiccups, and hemorrhage
    from orifices as well as petechiae and ecchymoses
    may be seen.
  • Blindness can occur.
  • Obtunding may occur.

63
Ebola-7
  • Diagnosis
  • By antigen-capture enzyme-linked immunosorbent
    assay (ELISA), IgM ELISA, polymerase chain
    reaction (PCR), and virus isolation.
  • Mortality
  • The mortality rate is high, usually 25 to 90.

64
Ebola-8
  • Treatment
  • Supportive
  • This may include maintenance of appropriate fluid
    and electrolytes, oxygenation and blood pressure,
    and treating complications promptly.
  • Immune plasma from convalescent patients has been
    used in some instances.
  • Nursing considerations
  • Limit number of staff approaching patient, use
    mask, gown, gloves, goggles, leg coverings, and
    shoe coverings.
  • Be sure health care staff understands the
    infection control procedures in use.
  • Prevent other cases by preventing nosocomial
    transmission, including to health care staff.

65
Ebola-9
  • Nursing considerations cont.
  • Appropriate infection control critical.
  • Should use immediate isolation of suspected case
    with airborne and contact precautions, as well as
    standard precautions and barrier nursing.
  • Because of the severity of the disease, many
    practitioners in the field use double masks,
    gowns, gloves and so on in implementing
    precautions.
  • Individual room with negative air pressure.
  • In places where no negative pressure isolation
    rooms exist, the patient should be put in a
    private room with a HEPA filtration unit.
  • Limit unnecessary blood draws and other
    procedures.
  • Use N95 or higher respirators for aerosol
    generating procedures in settings where AIIRs are
    unavailable.

66
Ebola-10
  • Nursing considerations cont.
  • The patient should remain in their room with
    doors and windows closed.
  • In full service hospitals, an anteroom may be
    used between the private room and the corridor.
  • If there are a large number of patients needing
    care, a designated nursing unit may be created
    with a barrier plan to seal off the existing
    ventilation system from other hospital areas and
    limiting access to the unit.
  • In cases of mass numbers, a whole facility or
    large gym may be dedicated.
  • Prevent cases through education of family and
    community about methods of spread and how to
    avoid them and why these precautions are
    necessary.

67
Ebola-11
  • Nursing considerations cont.
  • Be sure staff fully understand isolation
    precautions.
  • During some Ebola outbreaks, governments outlawed
    traditional ways of preparation of bodies and
    other burial practices.
  • Specific guidelines are available online for
    infection control for viral hemorrhagic fever in
    the African health care setting at
  • http//www.cdc.gov/ncidod/dvrd/spb/mnpages/vhfman
    ual.htm
  • Supportive care depending on manifestations
    including maintaining appropriate fluid and
    electrolytes.

68
Ebola-12
  • Vaccine
  • Experimental vaccine in animals

69
Ebola-13
  • Prevention
  • Prevent other cases by preventing nosocomial
    transmission including to health care staff.
  • Prevent cases through education of the family and
    community about methods of spread and how to
    avoid them.
  • The latter should include information that Ebola
    virus may be transmitted in semen up to 12 weeks
    after infection.

70
Ebola-14
  • Social, behavioral and cultural issues
  • Affected families may be stigmatized and not be
    allowed in other dwellings or schools.
  • Families tend not to seek medical care because
    of
  • Cost,
  • Mistrust of hospitals (nosocomial spread supports
    these fears),
  • Belief in traditional remedies and healers, and
  • Problems of transportation to health care
    facilities especially in rainy season.
  • Traditional burial practices contribute to
    person-to-person spread.
  • Civil unrest and wars can exacerbate outbreaks
    through overcrowding, poor sanitation, and
    economic dispair.

71
Ebola-15
  • Other notes
  • Ebola outbreaks tend to burn out relatively
    quickly because of the high mortality rates.
  • Ebola virus is studied in a level 4 biosafety
    facility.
  • There are great fears that the Ebola virus could
    mutate into a form that is more easily
    transmitted from human-to- human or becomes
    airborne.

72
Lassa Fever (Lassa virus)
  • Etiology
  • Lassa virus, a single
  • stranded RNA virus in
  • the arenavirus family.
  • Description
  • Is a viral hemorrhagic
  • fever caused by the
  • Lassa virus.

73
Lassa Fever-2
  • Epidemiology
  • Endemic in West Africa, where it kills thousands
    per year, especially in Sierra Leone.
  • Fewer cases are seen in Nigeria, Guinea and
    Liberia.
  • Subclinical infection commonly occurs in areas of
    rural West Africa where Lassa virus is endemic.
    This is known through the high prevalence of
    antibodies to Lassa virus in the serum in
    seropositivity studies in West Africa.
  • Occasional outbreaks occur, often with high
    mortality rates.
  • In 2004, a case was identified in a New Jersey
    man who had recently returned to the Trenton area
    from Africa, and in 2006 a case was diagnosed in
    a man who returned to Germany from Sierra Leone.

74
Lassa Fever-3
  • Epidemiology cont
  • The natural hosts are rodents of the Mastomys
    genus.
  • These rodents prefer to live in or around human
    dwellings. These rodents are persistently
    infected and shed virus in excreta.

75
Lassa Fever-4
  • Transmission
  • Infection results through
  • Direct contact with infected rodent urine or
    droppings,
  • Through touching objects or eating food
    contaminated by infected excreta,
  • Through breaks in the skin,
  • Through inhalation of infected rodent excreta in
    aerosol form, such as when cleaning a heavily
    contaminated area, and
  • Through food preparation or consumption of
    infected rodents. These rodents are considered a
    delicacy in this part of Africa.

76
Lassa Fever-5
  • Transmission cont.
  • Richmond Baglole (2003) note that Lassa viral
    antibodies occur after a febrile illness in twice
    as many people who eat these rodents than in
    those who do not, and deafness (one of the
    sequelae of Lassa fever) occurs four times more
    frequently.
  • Person-to-person spread may occur when a person
    comes into contact with
  • Infected blood,
  • Tissues,
  • Secretions, or
  • Excretions.

77
Lassa Fever-6
  • Transmission cont.
  • Lassa virus is found in semen up to 3 months
    after infection and in urine a month after
    disease onset.
  • Infection may also occur in hospitals or health
    care settings through use of contaminated medical
    equipment such as needles and syringes that may
    be reused or through overcrowding and poor
    hygiene.
  • Traditional burial ceremonies involving contact
    with the infected corpse may spread Lassa virus
    (see cultural considerations under Ebola).

78
Lassa Fever-7
  • Transmission cont.
  • Lassa virus may be excreted in urine up to 9
    weeks after infection, and excreted in semen up
    to 3 months after infection.
  • Incubation period 5 to 21 days.
  • Clinical manifestations
  • In about 80, affected persons are asymptomatic
    or mildly affected.
  • In 20, symptoms may be severe and may mimic
    other hemorrhagic fevers.

79
Lassa Fever-8
  • Clinical manifestations cont.
  • Richmond Baglole (2003) divide clinical stages
    and symptoms as follows
  • Stage 1 (days 1-3)
  • Symptoms include general weakness and malaise,
    high fever, about 39o C with higher peaks.
  • Stage 2 (days 4-7)
  • Symptoms include sore throat (with white
    exudative patches) headache back, chest, side,
    or abdominal pain conjunctivitis nausea and
    vomiting diarrhea productive cough
    proteinuria low blood pressure (systolic
    mm/Hg) and anemia.
  • Stage 3 (after 7 days)
  • Symptoms include facial edema convulsions
    mucosal bleeding (mouth, nose, eyes) internal
    bleeding and confusion or disorientation.
  • Stage 4 (after 14 days)
  • Symptoms include coma and death.
  • Not all progress through all stages.

80
Lassa Fever-9
  • Diagnosis
  • Reverse transcription polymerase chain reaction
    (PCR) can diagnose close to 100 but takes time.
  • Enzyme linked immunosorbent assays (ELISA) for
    Lassa virus antigen and for virus IgM are more
    than 85 sensitive and specific together.
  • If laboratory tests are not available, clinical
    diagnosis should be suspected in patient with
    fever at or above 38o C or 100.4o F who do not
    respond adequately to antibiotics or antimalarial
    drugs.

81
Lassa Fever-10
  • Complications
  • Includes mucosal bleeding, sensorineural
    deafness, hair loss, loss of coordination,
    spontaneous abortion in women, and both pleural
    and pericardial effusion
  • Treatment
  • Supportive such as fluid replacement.
  • Intravenous ribavirin is effective especially
    when given early.
  • Thus, early diagnosis and clinical suspicion is
    needed.

82
Lassa Fever-11
  • Management
  • Strict standard, contact and droplet isolation of
    suspected cases and maintaining procedures for
    handling body fluids and excreta as well as
    appropriate infection control procedures.
  • Stringent barrier nursing procedures.
  • Limit number of staff approaching patient.
  • Use N95 or higher respirators when performing
    aerosol generating procedures.

83
Lassa Fever-12
  • Management cont.
  • Use mask, face shield, gown, gloves, leg
    coverings, and shoe coverings.
  • Be sure health care staff understands the
    infection control procedures in use.
  • Consult http//www.cdc.gov.mcidod.dhgp/pdf/isolati
    on2007.pdf

84
Lassa Fever-13
  • Management cont.
  • Nurses should provide education to patients and
    families regarding why these precautions and
    procedures are necessary and how to prevent the
    spread of the virus.
  • Specific guidelines are available online for
    infection control for viral hemorrhagic fevers in
    the African health care setting at
    http//www.cdc.gov/ncidod/dvrd/spb/mnpages/vhfmanu
    al.htm

85
Lassa Fever-14
  • Prevention
  • Prevent other cases by preventing nosocomial
    transmission including to health care staff.
  • Prevent cases through education of the family and
    community about methods of spread and how to
    avoid them.
  • Vaccination Experimental
  • Mortality
  • Varies.
  • In general population may be 1 to 2, but in
    those who are hospitalized, is generally
    estimated at up to 25.
  • In Sierra Leone, one study indicated that 25 of
    all maternal deaths were due to Lassa fever
    (Price, Fisher-Hoch, Craven McCormick, 1988).

86
Lassa Fever-15
  • Social, behavioral and cultural issues
  • Because Lassa virus is spread through rodents,
    families may wish to continue to eat the sweet
    meat of this rodent and not associate that
    practice with developing Lassa fever since in
    many cases, infection will be asymptomatic or
    mild.
  • Affected families may be stigmatized and not be
    allowed in other dwellings or schools.

87
Lassa Fever-16
  • Social, behavioral and cultural issues cont.
  • Families tend not to seek medical care because
    of
  • Cost,
  • Mistrust of hospitals (nosocomial spread supports
    these fears),
  • Belief in traditional remedies and healers,
  • Non-availability of a quick early diagnostic test
    in the field,
  • Problems of transportation to health care
    facilities especially in rainy season, and
  • Attribution of some complications, such as
    miscarriage, to witchcraft or fault of the
    woman.

88
Lassa Fever-17
  • Social, behavioral and cultural issues cont.
  • Traditional burial practices contribute to
    person-to-person spread.
  • The resulting deafness in some may lead to social
    isolation.
  • Civil unrest and wars can exacerbate outbreaks
    through overcrowding, poor sanitation, and
    economic dispair.

89
Lassa Fever-18
  • Other notes
  • Lassa fever has been diagnosed in travelers
    including relief workers and UN peacekeepers
    returning from West Africa to Europe and North
    America.
  • A case was imported to New Jersey in August 2004.
    The patient was hospitalized and subsequently
    died. No further transmission was identified.
  • Lassa fever is studied in a level 3 biosafety
    facility.

90
Marburg Hemorrhagic Fever (Marburg virus)
  • Etiology
  • Marburg virus, a RNA
  • virus in the filovirus family, the only other
    member of which is Ebola virus.  
  • Description
  • Is a viral hemorrhagic fever caused by the
    Marburg virus.
  • Also called Marburg disease.
  • Image courtesy of Russell Regnery,
  • Ph.D., DVRD, NCID, CDC.

91
Marburg hemorrhagic fever-2
  • Epidemiology
  • Marburg hemorrhagic fever was first recognized in
    1967 among workers in laboratories in Germany and
    was then Yugoslavia.
  • The source of this infection was infected green
    monkeys imported from Africa, specifically
    Uganda.
  • The next reported index case was in 1975 in a
    tourist who apparently acquired the infection in
    Zimbabwe, and who was hospitalized in South
    Africa. He transmitted Marburg virus to his
    travel companion and to a nurse who cared for him.

92
Marburg hemorrhagic fever-3
  • Epidemiology cont.
  • In 1998, an outbreak occurred in the Democratic
    Republic of the Congo, and the index case was
    believed to have acquired infection from a source
    in a gold mine there.
  • In late 2004 and 2005, an outbreak occurred in
    Angola. Of the 175 identified cases as of 4/4/05,
    155 had been fatal. Other outbreaks were
    relatively small. Another small outbreak
    occurred in a mining community in Uganda in 2007.
    In July 2008 a Dutch tourist returned to the
    Netherlands with Marburg fever.
  • The natural host for Marburg virus is unknown.

93
Marburg hemorrhagic fever-4
  • Transmission
  • Person-to-person spread may occur when a person
    comes into contact with infected blood, tissues,
    secretions, or excretions, or has close contact
    with an infected person.
  • Infection may also occur through contact with
    contaminated objects or through droplets of body
    fluids.
  • The virus is still found in seminal fluid months
    after infection, and sexual transmission from a
    male to a female has been documented.

94
Marburg hemorrhagic fever-5
  • Incubation period
  • Typically 3-10 days
  • Clinical manifestations
  • In most cases, the onset of illness is abrupt
    with fever, chills, headache, and myalgia.
  • Nausea, vomiting, chest pain, pharyngitis,
    abdominal pain and severe diarrhea may be seen.
  • A maculopapular rash may appear around the 5th
    day.

95
Marburg hemorrhagic fever-6
  • Clinical manifestations cont.
  • Other severe symptoms such as jaundice
    pancreatitis severe weight loss delirium
    shock liver failure massive hemorrhage through
    vomitus, eyes, skin, and vagina and multiorgan
    dysfunction may be seen.
  • Recovery is prolonged and may include hepatitis,
    transverse myelitis, uvietis, and/or orchitis in
    men as well as prolonged hepatitis.

96
Marburg hemorrhagic fever-7
  • Diagnosis
  • By antigen-capture enzyme-linked immunosorbent
    assay (ELISA), IgM capture ELISA, polymerase
    chain reaction (PCR), and virus isolation.
  • Diagnosis can be difficult because signs and
    symptoms can be similar to diseases such as
    malaria or typhoid fever or be nonspecific,
    especially initially.
  • Diagnosis is particularly difficult when only one
    or a few cases appear.

97
Marburg hemorrhagic fever-8
  • Treatment
  • Supportive, and may include
  • Maintenance of appropriate fluid and
    electrolytes,
  • Oxygenation,
  • Frequent blood pressure checks,
  • Replacement of lost blood and clotting factors,
    and
  • Treating complications promptly.
  • Immune plasma from convalescent patients has been
    used in some instances.

98
Marburg hemorrhagic fever-9
  • Management
  • Strict isolation of suspected cases and
    maintaining procedures for handling body fluids
    and excreta as well as appropriate infection
    control procedures using standard, contact, and
    airborne or droplet precautions.
  • Stringent barrier nursing procedures.
  • Do not wear jewelry.
  • Limit number of staff approaching patient.

99
Marburg hemorrhagic fever-10
  • Management cont.
  • Use mask, fluid-proof long-sleeved gown, gloves,
    goggles, leg coverings and shoe coverings that
    are at least ankle high and fluid proof (may need
    to be higher if floor is visibly soiled).
  • Use double disposable gloves if handling any
    sharp device, and be sure gloves cover cuff of
    gown.
  • Use hair covering and disposable face shields if
    needed.

100
Marburg hemorrhagic fever-11
  • Management cont.
  • Disposable N-95 respirators should be worn when
    entering room.
  • Remove shoe covers and gloves as well as gowns
    before exiting.
  • Wash hands immediately on leaving room with
    antimicrobial agent.
  • Use disposable equipment when possible or
    dedicated equipment such as stethoscopes to be
    kept in patients room.

101
Marburg hemorrhagic fever-12
  • Management cont.
  • Be sure health care staff understands the
    infection control procedures in use.
  • Prevent other cases by preventing nosocomial
    transmission including to health care staff.
  • Specific guidelines are available online for
    infection control in the African health care
    setting at http//www.cdc.gov/ncidod/dvrd/spb/mnpa
    ges/vhfmanual.htm
  • Also see information in module discussing
    infection control, and at http//www.cdc.gov/ncido
    d/dhgp/pdf/isolation2007.pdf

102
Marburg hemorrhagic fever-13
  • Prevention
  • Prevent other cases by preventing nosocomial
    transmission including to health care staff.
  • Prevent cases through education of the family and
    community about methods of spread and how to
    avoid them.
  • Should include information that Marburg virus may
    be transmitted in semen as long as 3 months after
    infection.

103
Marburg hemorrhagic fever-14
  • Mortality
  • The mortality rate is high, usually 23 to 25 or
    more.
  • Vaccine
  • Experimental vaccine is being looked at in
    animals.
  • Other notes
  • Marburg virus is studied in a level 4 biosafety
    facility.
  • Knowledge of Marburg hemorrhagic fever and
    Marburg virus is somewhat limited due to the few
    number of cases known.

104
Plague (Yersinia pestis)
  • Plague is considered a Category A agent for
    bioterrorism because
  • Plague bacteria are not difficult to obtain,
  • Aerosolized plague bacteria are easily
    transmitted,
  • There is a high attack rate,
  • Clinical disease is severe, and
  • The word plague has a high psychological
    impact.
  • A sudden outbreak of disease due to an
    intentional release might present as severe
    pneumonia and sepsis.

105
Plague-2Picture from CDC
106
Plague-3
  • Etiology
  • Yersinia pestis, a small gram-negative rod-like
    bacilli.
  • Description
  • Was known as the Black death in the bubonic form
    in the middle ages when it killed 20-30 million
    in Europe.
  • In the mid 1800s, it killed 12 million in China.

107
Plague-4
  • Epidemiology
  • Plague is considered a zoonosis.
  • Y. pestis is transmitted from infected rodents
    such as rats, mice, gerbils, chipmunks, and
    prairie dogs to humans via infected fleas.
  • Picture from CDC

108
Plague-5
  • Epidemiology cont.
  • Cats and dogs, also may become infected by eating
    infected rodents.
  • Plague occurs worldwide.
  • In the US there are generally 10 to 15 reported
    cases of plague each year, most commonly in rural
    areas of New Mexico, Colorado, Arizona,
    California, Oregon and Nevada.
  • Worldwide there are 1,000-3,000 cases reported
    each year.

109
Plague-6
  • Epidemiology cont.
  • In the fall of 2002, a hospital in New York City
    admitted a couple who were found to have plague
    acquired in their home state of New Mexico before
    traveling to New York.
  • Most cases occur in summer.
  • About 30 of cases occur in southwestern US.
  • Suspicion should be raised if it occurs in other
    geographic areas.

110
Plague-7
  • Clinical types
  • Bubonic infected lymph nodes leading to
    development of buboes. Most common.
  • Septicemic organisms are blood-borne, primary
    through dried inoculation or secondary from
    bubonic or pneumonic plague.
  • Pneumonic is transmissible by aerosol. Rarest,
    high mortality.

111
Plague-8
  • Transmission
  • Via bite of infected fleas,
  • Through contact with infected animals or their
    fluids, and
  • In pneumonic plague, animal-to-person, or
    person-to-person via droplets.
  • In bioterrorism, organisms would most likely be
    transmitted through aerosol dispersion.
  • Incubation period
  • Bubonic 2 to 8 days after exposure
  • Pneumonic 1 to 4 days after exposure

112
Plague-9
  • Clinical manifestations
  • Y. pestis produces an endotoxin that can lead to
    shock, sepsis, disseminated intravascular
    coagulation (DIC), and multiorgan failure.
  • Bubonic
  • May experience abrupt onset of flu-like symptoms
    such as fever, chills, headache, and malaise
    shortly before or at the same time as the bubo
    which is a swollen, warm, reddened (often around
    the edges), very tender lymph node(s) usually in
    the inguinal, axillary or cervical region.

113
Plague-10
  • Clinical manifestations cont.
  • Bubonic cont.
  • Patients may become prostrated with episodes of
    agitation and restlessness.
  • Secondary septicemia may result and this can lead
    to secondary pneumonic plague.
  • Picture from CDC

114
Plague-11
  • Clinical manifestations cont.
  • Pneumonic (primary)
  • Presentation is severe, fulminant, rapidly
    progressing pneumonia.
  • Signs and symptoms include fever, dyspnea, and
    cough with hemoptysis, and chest pain.
  • May also have nausea, vomiting, diarrhea,
    purpura, and abdominal pain.

115
Plague-12
  • Clinical manifestation
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