biologic agent of conasdcern

7/29/2019 Biologic Agent of Conasdcern

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categories A,B and C were created in

order to classifyBiological agent thesebiological agent of concerns.

Agents were ranked based on severalfactors including public health, disease

and mortality rates, dissemination

potential, public perception and the needfor special public health preparations.


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CATEGORY A

The most deadly microbes known to man

Easily disseminated or transmitted from

person to person

Have high mortality rates as well as thepotential for severe public health

consequences including public panic and

social disruption.

Their high infectivity poses a danger not only

to those infected with disease but also to

those with who treating the infected patients.


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CATEGORY A AGENTS

Anthrax (Bacillus anthracis)

Botulinu toxin (Clostridium botulinum) Plague (Yersinia Pestis)

Smallpox (Variola major)

Tularemia (Francisella tularensis) Hemorrhagic fever viruses

- Ebola

- Marburg- Lassa machupo

- Junin

- Guanarito


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CATEGORY B

Second highest priority

Share certain characteristic such as the

potential for moderate morbidity and lower

mortality rate

Moderately easy to disseminate and

require specific diagnostic capabilities

Agents are extremely toxic but are difficult

to disseminate or has lower infectivity

compared to category A


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CATEGORY B AGENTS

Brucellosis

Epsilon toxin of clostridium perfringens Food safety threats (salmonella, shigella, E.

coli, etc.)

Melioidosis

Psittacosis

Q fever

Ricin toxin from castor beans

Staphylococcal enterotoxin B Viral encephalitis

Water safety threats


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CATEGORY C

Emerging agents that is potential futureinfective threats such as Nipah fever

and Hantavirus.


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ANTHRAX

A zoonotic disease found in herbiboresuch as sheep, goats and cattle thatingest spores fro infected soil.

wool sorters disease

Bacillus Anthracis

Occurs in 3 distinct forms

- Cutaneous

- Inhalational

- gastrointestinal


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1.Cutaneous anthrax

- Contact with abraded skin derivedfrom infected herbivores.

2. Inhalational anthrax

- Contacted by inhalation of sporesfrom infected animals

3. Gastrointestinal anthrax

- Rare and is contracted viaconsumption of meat from infected

animals.


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INHALATIONAL ANTHRAXSUBJECTIVE Sx

Cough, chest pain, dyspnea, viral URI(sorethroat, myalgias, mild fever) during

prodrome

Meningeal signs -Hemorrhagic meningitisOBJECTIVE FINDINGS

Lympadenopathy, widened mediastinum on

chestNOTES

S/S are progress to respiratory failure,

sepsis, and hemodynamic collapse in pre


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CUTANEOUS ANTHRAX

SUBJECTIVE SxRaised bump on face, hands or arms,

typically with black painless ulceration.

OBJECTIVE FINDINGSUlcer with black eschar, moderate to

severe localized edema and

lympadenopathyNOTES:

Time course is 1-7 days until appearnce

oof typical ulcer.


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GASTROINTESTINAL ANTHRAX

SUBJECTIVE SxVomiting, diarrhea and abdominal pain

OBJECTIVE FINDINGS

Diarrhoea may be bloody. Acuteabdomen may be present with or

without ascites

NOTES:Fluid volume loss may be severe.


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BIO SAFETYISSUES,

PROTECTION ANDISOLATION


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Biosafety Level II

Precautions are recommended forlaboratory personnel who come incontact with anthrax specimen.

Handling of specimen in a laminarflow hood with protective eyewear,

using gloves pulled over lab coatsand avoiding activities that mayproduce aerosol or droplet dispersal


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BIOSAFETY LEVEL III

Precautions are recommended forpersonnel who worked extensively

with anthrax specimen (research

purposes)

Precautions similar to BSL II,

- respiratory protective equipment

- Controlled access to lab- Decontamination of all waste

- Negative air pressure in the laboratory


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Health care workers who come in

contact with patients in whom anthrax

is suspected should use universal

precautions at all times, including the

use of rubber gloves, disposal of

sharps AND FREQUENTHANDWASHING


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VACCINATION AND POST EXPOSUREPROPHYLAXIS

An anthrax vaccine is available butreserved for laboratory and military

personnel who may come in contact

with disease. AVA Anthrax Vaccine Adsorbed

No currently licensed for use to

civilian populations


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TREATMENT

CUTANEOUS ANTHRAX 60 day oral

course of either ciprofloxacin or

doxycycline.


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TREATMENT

Ciprofloxacin or doxycycline plus

additional antimicrobials and adjunctive

therapies for inhalational anthrax.

INHALATIONAL ANTHRAX 60 days of

IV course of cipro or doxy plus one or

two additional microbials to which

anthrax has historically been sensitive

such as AMINOGLYCOSIDES OR

CLINDAMYCIN


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Anthrax has been traditionally

resistant to CEPHALOSPORIN such

as CEFTRIAXONE.

Accumulation of haemorrhagic pleural

effusion - CHEST TUBE DRAINAGE


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It is a food borne illness caused by

Clostridium botulinum .

Most poisonous substance known to

mankind less than 1 mcg is a fatal dose

for an adult.

4 types of botulism

1. Foodborne botulism

2. Infantile botulism

3. Wound botulism

4. Intestinal botulism


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CLASSIFICATION AND ETIOLOGY

TYPE A AND B

Associated with the consumption ofhome canned vegetables, fruits , and

meat productsTYPE E

Seen with marine products

INFANTILE BOTULISM involves theingestion of botulism spores which iscommonly found in honey.


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CLINICAL MANIFESTATIONS ANDDIAGNOSIS

Nausea, vomiting and diarrhea

(initial neurologic symptoms)

Constipation becomes prominent in later

stage. INFANTILE BOTULISM

- Constipation is often the main symptom

- Flaccidity characteristic (floppy baby)- Poor suck reflex

- Poor feeding

- Poor head control


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Pitfalls in the diagnosis of botulism

include failure to recognize the

symptoms and to institute adequate

ventilatory support.

Underdiagnosed and Mistaken for a

number of neuromuscular andneurologic disorders.

- Diptheria

- Encephalitis- Poliomyelitis

- Guillain -Barre syndrome

- congenital neuropathies and myopathies


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Ushroom (muscarinic) poisoning are

diagnoses potentially similar in

presentation to botulism

Laboratory test includes:

- F/A- gastric samples of aspirate or food

samples

- C.Botulinum cultures can also beobtained


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LABORATORY ISSUES , PROTECTIONAND ISOLATION

Extremely poisonous to humans, Coats ,face, gloves, face shield and

protective cabinets are recommendedfor handling botulism specimen.

Ideally lab personnel should bevaccinated with C.botulinum antitoxin

Universal precaution should be used

when caring for patients suspected ofbotulism.

Isolation is not necessary but droplet

precaution should be instituted.


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PUBLIC HEALTH IMPLICATION

every case of foodborne botulismshould be treated as public health

emergency.

Every effort should be made toeliminate toxin containing food items

still available for public consumption

to avoid mortality and morbidity.

Cases that happened in geographical

areas should be rapidly investigated.


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VACCINATION AND POST EXPOSURE

PROPHYLAXIS

Botulinum toxoid an investigational

agent intended for lab worker who

work regularly with botulinum toxin.

Post exposure prophylaxis is not

recommended at this time for

asymptomatic patient


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TREATMENT

Ventilatory support

Administration of botulinum antitoxin

trivalent equine antitoxin provides

antibodies to botulinum toxin TypesA,B and E

Cathartics and enemas

Antibiotics are not recommendedexcept for tx of secondary infectious

complication such as pneumonia.


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HISTORY

Most feared infectious disease in thehistory of humankind.

Yersinia Pestis the bacterium

responsible for plague Black death of the middle ages plague


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EPIDEMIOLOGY

Plague is still present worldwide.

The introduction of the disease to

human populations occurs when

plague infected fleas , which

typically infest rodent host, cause

the death of these rodents in large

numbers.

Fleas then move fro their naturalhosts to human, causing outbreaks

of plague.


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Transmission to human is typically

through the bite of an infected flea.

Droplet spread from patients withpneumonic plague is another route of

infection.


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3 FORMS

1. BUBONIC

Most common form of plague,

responsible for the European

pandemics

Presents with painful, swollen lymph

nodes the bubo of bubonic plague

Axilla, groin, neck

Following by generalized bacteremia


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3 FORMS

2. SEPTICEMIC

The infected fleabite vector is the

same but rather than develop

buboes, patient develop sepsis

followed by multiple organ failure.

Usually develop gangrene and

necrosis of fingers and toes


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3 FORMS

3. PNEUMONIC PLAGUE

Spread by droplet dispersal from

infected patients and severe

pulmonary involvement is the

cardinal sign.

The most deadly form of plague,

when Y. pestis infects the lungs

causing :

severe hemorrhagic , necrotizing

bronchopneumonia


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This process can either occur by

hematogenous spread of thebacterium (secondary pneumonic

plague)

Droplet spread from infected person

directly to the patient via inhalation

(primary pneumonic plague)


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CLINICAL MANIFESTATIONS

Nausea and vomiting and cough

productive of bloody sputum are

also seen

Chest pain, dyspnea and hemoptysis

are later symptoms are later

symptoms typical of pneumonic

plague


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A history of contact with infected

rodents or fleas is important to elicit.

Ground squirrels, pairie dogs and

rats are reported plague vectors.


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BIOSAFETY ISSUES, PROTECTION AND

ISOLATION

Strict isolation should be

maintained for all patients

suspected of Y. pestis infection.

Gowns, gloves, masks and eye

protection should be worn for at

least the 1st 48 hours of treatment.



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PROPHYLAXIS

Vaccines available protected only an

individual from bubonic plague but notwith pneumonic plague.

Administered only for military and

laboratory personnel working inplague endemic areas researchersworking with plague infected animalsor fleas.

Antibiotic prophylaxis isrecommended for contacts of patientwith plague as well as close

surveillance of contacts refusing


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Doxycycline and Ciprofloxacin are

recommended post exposure

prophylaxis to adult, children and

pregnant women.

Tetracyclines, sulfonamides and

chlorampenicol are also effective as

post exposure prophylaxis against thedisease.


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TREATMENT

Streptomycin antibiotic of choice for

the treatment of plague.

Gentamicin another preferred

antibiotic

Patients with pneumonic plague may

also require advance medical

supportive therapy in addition to

antibiotics.


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HISTORY

Tularemia is a highly infectious

zoonotic disease caused by the

bacterium Francisella tularensis.

First described in Tulare, Country,

California

Tularemia can cause fever, skin or

mucous membrane ulceration,

lympadenopathy and occasionallylife threatening pneumonia


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Its major threat comes from its

extreme infectivity, inhalation orinoculation of as few as 10 organisms

is enough to cause disease.

If untreated can produce severe

disease and death .


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EPIDEMIOLOGY

Primarily a rural disease

Males tend to be more often infected

than females

It may be related to the specificoutdoor activities that may

predispose individuals to contracting

tularemia such as farming, hunting,

trapping and butchering


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Tularemia is caused by gram (-)

aerobic bacterium. It can present clinically in several

forms:

- Ulceroglandular- Glandular

- Oculoglandular

- Oropharyngeal- Pneumonic

- Typhoidal

- Septic forms


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It is typically found in animals such asrabbits and rodents

Can be transmitted to humans inseveral ways.

- Contact with infected animal carcasses

- Ingestion of contaminated meat, soil orwater

- Inhalation of the bacterium(laboratoryworkers)

- Inoculation of the bacterium via cuts orabrasion

- Via bites of infected arthropods such as

ticks


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CLINICAL MANIFESTATIONS AND DIAGNOSIS

Ulceroglandular and typhoidal forms

make up the majority of tularemia

patients

Initially presents with abrupt onset of

- high fever

- Headache

- Rigors- Coryza

- Sorethroat


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Dry cough, sweats, fever and chills

occur as the disease continues.

Ulceroglandularform presents with

skin and mucous membrane ulcers ,

lympadenopathy or both.

A cutaneous chancre like ulcer is the

most common finding.


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Typhoidal form has less significant

lymph node involvement and skinlesion are absent.

Pulmonary involvement is prominent

The differential diagnosis of tularemiaalso includes otherdiseases with

prominent skin manifestations orpulmonary findings such as plague,diphtheria, psittacosis, Q fever andother tick-borne diseases.


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Definitive diagnosis of tularemia is by

culture typically from sputum.

ELISA, bacterial agglutination and

immunofluorescent are also available.

BIOSAFETY ISSUES PROTECTION


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BIOSAFETY ISSUES, PROTECTION

AND ISOLATION

Extremely infectious in aerosol form Biosafety precaution II should be

used for initial evaluation then

specimen should be forwarded to aBSL 3 laboratory for further testing.

Human to human transmission of

tularemia is not at risk , isolation isnot needed.

Universal precautions are

recommended.


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TREATMENT

As the for the treatment of plague ,

streptomycin and gentamicin are theDOC.

Doxycycline and chloramphenicol havealso been used but more treatmentfailures have been reported with theseregimens.

Ciprofloxacin is another alternative

therapy. For the first line regimens aswell as ciprofloxacin, a 10 day course ofIV antibiotics is recommended.

For second line therapies , 14 days are

recommended.


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EPIDEMIOLOGY

Smallpox occurs in two forms:

- Variola major(the most dangerous

and formerly widespread form of

disease)

- Variola minor

Person to person transmission of

the disease occurs by droplet

spread from infected persons or by

contact with contaminated clothing

or bedding


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Viral hemorrhagic fevers are group

of febrile illnesses caused by RNA

viruses from several viral families.

Fiviruses (Ebola and marburg)

Arenaviruses (Lassa and NewWorld arenaviruses)

Bunyaviruses (rift valley river)

Flaviviruses (yellow fever, amongothers)


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These leads to potentially lethal

syndrome characterized by:

- Malaise

- fever

- vomiting

- mucosal and GI bleeding

- edema

- hypotension.

Th t t i b f thi


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The most notorious member of this

group is EBOLA outbreaks which

have been associated with casefatality rates.

These disease are generally

contracted via an infected animal or

arthropod vector.

Bats are considered to be the natural

reservoir for Ebola .

Mastomys rodent - natural reservoir

for Lassa virus.

American arenaviruses are also

spread by rodent contact typically


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Infected mosquito rift valley fever

and yellow fever

Tick bite of flavivirus carrying

anthropods- omsk hemorrhagic

fever and kyasanur forest disease.

PATHOGENESIS


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PATHOGENESIS

The primary defect in patients with

VHF is that of increased vascular

permeability.

H. fever viruses have an affinity for

the vascular system , leading tomucous membrane hemorrhage

with accompanying hypotension

and shock. All of the viruses can also lead to

thrombocytopenia and depletion of

clotting factors



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Incubation period --- 2-21 days

Non specific early symptoms

include :

- High fever , head ache, myalgias,

arhralgias, fatigue, flushing and

abdominal pain.

Patients with Ebola infection oftendemonstrate a petechial rash by

Day 5.

Jaundice is common in patients

BIOSAFETY ISSUES, PROTECTION AND


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,

ISOLATION

BSL 4 precautions are necessary

when handling specimens from

patient suspected of VHF infection.

All medical personnel who have

had close contact with patient

suspected of VHF infection before

the safeguards were institutedshould be placed under medical

surveillance.

SPECIFIC RECOMMENDATION FOR PATIENT


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SUSPECTED OF HAVING VHF INFXN:

Strict hand washing

Double gloving Impermeable gowns

N-95 masks or powered air purifying respiratorsand negative pressure isolation rooms

Leg and shoe coverings

Face shields and goggles

restricted access to patient rooms

Environmental disinfection If multiple patient are present, they should be

cared for in one area of the hospital to minimizeexposure to other patients and health care

personnel.



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PROPHYLAXIS

No approved vaccines exists forany f the VHF infections other than

yellow fever.

Ribavirin a nucleoside analog isrecommended for post exposure

prophylaxis forLassa and other

arenaviruses.

But has no efficacy against

filovirus or flavivirus.

TREATMENT


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TREATMENT

Supportive, IVF and electrolyte

replacement

Hemodialysis, invasive monitoring,

and vasopressor therapy may also

be needed.

IM injection, use of aspirin and

other NSAID and anticoagulants

should be put into consideration.


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biologic agent of conasdcern

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