472 Hazards Q2

who is involved in a community wide response

• public health

• medical community

• law enforcement

• emergency management

absenteeism

the practice of staying home from school, work or public outings when ill, when caring for those who are ill, or because of self induced social distancing

presenteeism

the practice of going to school/work despite illness

disease scale

baseline → endemic → outbreak → epidemic → pandemic

baseline

the incidence and prevalence of disease that is expected at any given time in a community

endemic

a disease or agent that is present in a community at all times but at a relatively low frequency

outbreak

sudden rise in incidence of a disease, such as when two or more people who were exposed to a common source are experiencing a similar illness

epidemic

an outbreak that spreads quickly to many people within a population resulting in more cases of a disease than would be expected in a community or region during a given time period

pandemic

an epidemic that becomes very widespread and affects an entire region, a continent, or the world

what leads to a pandemic

• high number of susceptible people (very few people have protective immunity)

• highly transmissible agent

• varying global disease surveillance and control capabilities

• interconnected global economy

biological agent

a microorganism or toxin derived from living organisms

biological incident

any harmful occurrence, regardless of magnitude, that involves a biological agent

naturally occurring biological incident

• occurs as a result of natural forces, with no human cause or intervention

• typically occur in a predictable season or an expected location

• more likely to be of diminished virulence if the biological agent has been endemic in a population for some time

virulence

the relative potential of a pathogen to overcome the body’s defenses and cause harm

• case fatality rates and lethal dose rates are indicators of this

accidental biological incident

• results from human error or human technology; though they are unintentional, unforeseen, or unanticipated, they are the result of some human involvement

• potentially occur in an unexpected season or location

• may result in the same consequences as an intentional biological incident, and it can be difficult to differentiate an accidental incident from an intentional one

• more likely to be more virulent

intentional biological incident

• occurs when a biological agent is purposefully released into a population with the intent to cause deliberate harm

  • EX: biocrime, biowarfare, bioterrorism, agroterrorism

• can occur in multiple locations simultaneously

biocrime

unlawful act in which an individual or group uses biological agents intentionally to cause illness or death in a target for personal reasons (such as revenge or financial gain) and lacks and ideological objective

biowarfare

a specialized type of warfare conducted by a government using biological agents against an adversary with the intention of overwhelming a military force

bioterrorism

the intentional release of biological agents to cause illness or death when the attacker has political, religious, environmental, or ideological motives

• conducted with the intent to intimidate or coerce a government or elicit fear in the civilian population to further political or social objectives

terrorism

unlawful use of force or violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives

agroterrorism

the intentional use of biological agents against agricultural food supply industries

who helps in the detection of a biological agent

• private sector

• food regulatory

• law enforcement

• medical community

• public health

syndromic surveillance

when medical professionals are able to notice an increase of patients with similar symptoms presenting for care and are able to notify authorities of a potential disease outbreak

factors influencing effective response

• route of exposure

• disease transmission

• agent characteristics

routes of exposure

• ingestion

• injection

• absorption

• inhalation

ingenstion

• enters when host eats, drinks, or puts contaminated fingers or other objects in mouth

• fecal-oral spread can occur when individuals do not properly wash their hands

• individuals can swallow droplets of an agent that they have inhaled nasally or orally

injection

enters host through the skin via

• insect or animal bite

• hypodermic needle

• sharp object

• defects in skin surface

most often occurs when a sharp object contaminated with a biological agent penetrates the skin

• intact skin provides a good barrier to organism penetration

absorption

• enters through host’s mucosal surfaces, such as eyes, nose, or throat, or rarely, through intact skin

• can occur directly, or it can occur indirectly by transfer of infectious agents from contaminated objects (such as doorknobs or cooking utensils) through the hands to the mucosal surfaces

• can also be absorbed through injuries from shrapnel, dry skin ,scrapes, cuts, or other skin defects that are invisible to the naked eye

  • some skin infections follow prolonged exposure to a moist environment, such as standing in water or wearing damp shoes

inhalation

• enters when host breathes

• optimal particle size: 1-5 microns

• agent establishes itself in lungs

• causes disease or enters bloodstream

• can also spread from person to person through respiratory droplets created when a person sneezes, coughs, or talks in close proximity (normally three to six feet)

routes of tranmisssion

• contact

• droplet transmission

• airborne transmission

contact transmission

• absorption and ingestion

• touching an infected person or their belongings, bedding, or other contaminated surfaces, and then touching your eyes, nose, or mouth

droplet transmission

• absorption, ingestion, and inhalation

• inhaling or touching large, disease causing droplets that an infected person discharges when sneezing, coughing, or talking

airborne transmission

• inhalation

• breathing in small, disease causing droplets that move from an infected person through the air

infectious diseases

caused by microorganisms such as bacteria, viruses or fungi

contagious diseases

illnesses that result from the infection, presence and growth of pathogenic biologic agents in an individual human or other animal host

types of biological agents

• bacteria

• viruses

• toxins

bacteria

• can reproduce on their own

• complete, single-celled organisms

• able to treat with antibiotics (target the agent’s ability to repair itself, metabolize, or reproduce)

  • some vaccines available

• pathogens cause disease in humans, animals, and plants

• EX. anthrax and plague

viruses

• require host cells to reproduce and survive

• not complete organisms

• antibiotics not effective

• some antivirals and vaccines available

• EX. smallpox, influenza, and COVID

toxins

• not alive and do not replicate or grow

• toxic chemicals produced by living organisms

• antibiotics and antivirals are not effective

• when exposed, a victim should be removed from the source of exposure and decontaminated

• EX. botulinum toxin and ricin from castor beans

incubation period

period during which a pathogenic BACTERIAL agent multiples and establishes itself in the body before any symptoms appear in the host

latency period

period during which a pathogenic VIRAL agent multiples and establishes itself in the body before any symptoms appear in the host

natural history

the factors that affect the course of the disease

• incubation period

• length and severity of the disease

• amount of time required for survivors to recover or for fatalities to occur

• signs and symptoms of the host when suffering from the disease, such as rashes or other symptoms

biological agents as weapons: advantages for terrorists

• some may be readily available

• can tie up community resources

• some are easy to produce

• produce terror

• definitive ID may be difficult

• many casualties possible

• delayed effects

• may be used covertly

• difficult for community to prepare for

• some are easy to disseminate

biological agents as weapons: disadvantages for terrorists

• dangerous to produce and deploy

• can injure the wrong people

morbidity

the rate at which a disease occurs in a group of individuals

mortality

the number of deaths in a given time or place

biological agent production

• fermenters

• centrifuges

• blenders

• growth media

• biosafety hoods and other personal protection items

aerosol agents

• easy to disseminate

• highly infectious via inhalation

• high quality powders are difficult to produce

  • particle size of 1-5 microns

  • free-flowing

  • hydrophobic

aerosolization - potential disseminators

• backpack sprayer

• rose duster

• paint sprayer

• trailer sprayer

• two gallon garden sprayer

effective aerosol dissemination

• particle size

• concentration of agent

• dispersal device

• agent state (liquid or powder)

• environmental conditions such as wind speed, and direction, UV light, and temperature inversions

temperature inversion

occurs when a layer of warm air is trapped under a layer of colder air and is prevented from rising, causing the ambient air temperature to rise with altitude instead of fall

point source delivery

• single source of dissemination

• depends on wind direction and speed

• most likely to be used on small, discrete targets

  • like a terrorist approaching a building and spraying an agent into an outdoor component of the air handling system

line source delivery

• product sprayed perpendicularly to the wind

• the target can be many kilometers downwind

• line source delivery can be used on much larger targets

biological attack indicators

• unusual time of year or locale for a particular disease

• unusual number of sick or dying people or animals

• unscheduled or unusual dissemination of sprayed material, such as mosquito sprayers or crop dusters

• abandoned spray or dispersion device

chemical attack

immediate signs and symptoms (like nerve agents)

biological attack

most have delayed effects (hours, days, or weeks) due to the need for the microorganism to increase in numbers within the host and overcome the host’s immune response

initial clinical symptoms of incident

• low grade fever

• muscle aches

• fatigue

• sore throat

• headache

• nausea