Transcript Physical hazards

Independent Learning…
• Sorry I’m still sick. 
• Please take the time to follow the graphing
instructions on the following slides for the
Risks Survey.
• Actual Risks handouts are up front
• Once done graphing, continue learning from
this PPT until the STOP sign at the end of the
LD50 material. We’ll continue tomorrow.
Survey Data
• If you haven’t already, please AVERAGE your
survey results into the three columns on the
far right of the table.
• Then, combine your data with the rest of your
class in the 3 Google Sheets documents that
I’ve uploaded to the APES Darrow folder.
• The class averages should calculate
automatically—unless someone is absent,
then it might not be correct? I’m not sure?
The Graph
• Your handout says to make two graphs…basically
two scatter graphs with a diagonal line from 0-0
up to the top right corner.
• An alternative would be to make a bar graph (or
two). Keep the same sequence of risk factors so
it’s easy to compare the Actual with the Class
Averages.
• You choose the best way to graph and compare
the data.
Chapter 18
Risk, Toxicology, & Human Health
Key Concepts
•
•
•
•
•
Risk estimation, management, and reduction
Types of hazards people face
Methods of toxicology
Types and measurement of chemical hazards
Types and effects of biological hazards
RISK
• What do we mean by “risk”?
Risks and Hazards
• Risk is the possibility of suffering harm
from a hazard that can cause injury,
disease, economic loss or environmental
damage.
• risk expressed as a probability;
• Risk assessment: process of determining how much harm
a substance can do
• Risk management: process of determining how to bring
toxin to acceptable levels and at what cost.
4 Major Types of Hazards:
• Cultural/lifestyle hazards such as unsafe working
conditions, smoking, poor diet, drugs, drinking, driving,
criminal assault, unsafe sex and poverty;
• Chemical hazards from harmful chemicals in air, water,
soil and food;
• Physical hazards, such as noise, fire, tornadoes,
hurricanes, earthquakes, volcanic eruptions, floods and
ionizing radiation;
• Biological hazards from pathogens, pollen and other
allergens and animals, such as bees and poisonous
snakes.
Risk Assessment & Risk Management
Comparative Risk Analysis
•
•
•
•
Compare risks
Evaluate whether risk is acceptable
Find affordable ways to reduce risk
Communicate risk to public
Proponents contend that risk analysis is
a useful way to…
• Organize and analyze available scientific
information
• Identify significant hazards
• Focus on areas that warrant more research
• Help regulators decide how money for
reducing risks should be allocated,
• Stimulate people to make more informed
decisions about health and environmental
goals and priorities.
Risk Analysis
What are the limitations of risk assessment?
• inaccuracy of models;
• inadequate data;
• bias because of who does the analyses;
Major questions?
• Which risks are worth evaluating?
• How reliable are analyses?
• How much risk is acceptable?
• How much will it cost to reduce each risk?
• How can a risk management plan be communicated?
© Brooks/Cole Publishing Company / ITP
Who do we protect?
• When regulating levels of a toxic substance in
the environment, should the allowed levels be
set to protect the most sensitive (at great
cost) or the average person?
What do you think are the highest
risk hazards in the U.S.?
How well do we perceive risk?
• Risk survey—how well do the perceived risks
compare to the actual risk?
Distorted Perception of Risk
We fear:
• What we can’t control (would rather drive our own car than
fly in a plane)
• What we don’t understand (nuclear power, new
technology)
• What is not voluntary (driving is OK, someone building a
power plant next door is not)
• What is catastrophic/played up by media (Chernobyl,
terrorist attack is more worrisome than death from
smoking)
• What is “unfair.” (Living by a power plant has risk of 1 in
100,000, but can upset people because their risk is higher
than others)
How well do we perceive risks?
• If the chance of death is 1 in 100,000,
people are not likely to be worried or
change behavior.
• Most of us do a poor job of assessing
relative risks from hazards around us.
• Most people deny the high-risk activities
they voluntarily enjoy
– Motorcycles (1 in 50)
– Smoking (1 in 300 pack-a-day smokers, by 65)
– Hang-gliding (1 in 2,500)
Yet some of these people are terrified of dying from…
• Commercial plane crash (1
in 4.6 million)
• Train crash (1 in 20 mil.)
• Snakebite (1 in 36 mil.)
• Shark attack (1 in 300 mil.)
Each year 99.1% of the people on
Earth do not die.
(don’t think that means you’re immortal, though!)
Average life expectancy continues to
increase.
The Greatest Risks People Face
• Poverty is the greatest risk
by far
• Poverty can lead to
malnutrition, which can
bring down the immunity
and makes a path for other
diseases to come in.
• Also the greatest risks of
premature death are mostly
the result of careless
mistakes.
Risk Analysis
What are the greatest risks to humans in the U.S.?
• poverty poses the greatest risk (shortens lifespan by
7–10 years);
• smoking and being overweight pose the next greatest
risk (each shortens lifespan by 6 years);
• being born male poses a greater risk than being
female (shortens lifespan by 7.5 years);
• being unmarried is associated with risk (shortens
lifespan by 5 years);
• other significant risks in the U.S. include second–hand
smoke, driving, air pollution, alcohol use and drug
abuse.
© Brooks/Cole Publishing Company / ITP
Risk Analysis
© Brooks/Cole Publishing Company / ITP
Hazards
1. Cultural hazards: unsafe working conditions,
smoking, poor diet, drugs, drinking, driving,
criminal assault, unsafe sex, and poverty.
2. Physical Hazards
Earthquakes
are among
various types of
natural physical
hazards. Other
physical
hazards include
volcanoes and
ionizing
radiation.
Fig.17–5
© Brooks/Cole Publishing Company / ITP
Physical Hazards
Ionizing radiation, a form of electromagnetic
radiation, has enough energy to damage body
tissues.
• examples include X rays and ultraviolet radiation, and
various types of radiation emitted by radioactive
isotopes;
Fig. 3–13
© Brooks/Cole Publishing Company / ITP
Physical Hazards
Natural and human
sources of the
average annual
dose of ionizing
radiation received
by the U.S.
population. Most
studies indicate
that there is no
safe dose of
ionizing radiation.
Fig.17–8
© Brooks/Cole Publishing Company / ITP
Physical Hazards
Each year people are exposed to some radiation
from natural or background sources, as well as from
human–caused exposure.
• background sources include about 82% of the
exposure;
• human–caused exposure include medical X rays
(10%), nuclear medicine (4%), and consumer products
(3%);
• harmful effects include burns, miscarriages, eye
cataracts and certain cancers;
• serious accidents, such as at the Chernobyl reactor,
can release large quantities of radiation, far above
background levels.
© Brooks/Cole Publishing Company / ITP
Physical Hazards
Is non-ionizing electromagnetic radiation harmful?
• we don't know;
• concern that electromagnetic fields (EMFs) from
electrical appliances (e.g., microwave ovens, hair
dryers, electric blankets, computer and TV monitors)
may increase risk of some cancers, miscarriages, birth
defects and Alzheimer's disease;
• many respected scientists say that a statistical link has
between established;
• however, the evidence is still not conclusive.
© Brooks/Cole Publishing Company / ITP
Toxicology: is the study of the adverse
effects of chemicals on health.
Toxicity: how harmful something is.
Depends on:
• Dose: the amount of a potentially
harmful substance that is ingested,
inhaled, or absorbed through the skin
• Frequency
• Genetic make up of those exposed
• Health of those exposed
Other factors include:
• Solubility (water or oil/fat)
• Persistence
• Bioaccumulation (small dose build up in individuals over
time)
• Biomagnification (build up as passes through food chain)
• Chemical interactions (antagonistic or synergistic)
Effects/Response:
• Acute effects: immediate/rapid effect of exposure. E.g.
dizziness, rash, death
• Chronic effects: long-lasting effects from one or repeated
exposures E.g. asthma, kidney damage, heart disease
Bioaccumulation and Biomagnification
The pesticide DDT becomes increasingly concentrated high in the
food chain because it is stored in fatty tissue and not easily broken
down or excreted.
• Bioaccumulation
results when the
concentration of a
chemical in specific
organs or tissues is
higher than would
normally be expected.
• Biomagnification
involves magnification
of concentrations as
they pass through the
food chains and webs.
Fig.16–4
© Brooks/Cole Publishing Company / ITP
Should we be concerned about trace levels
of toxic chemicals in the environment and
our bodies?
• It depends on the chemical and the
concentration!
• Most chemicals have a safe or threshold level
of exposure below which their harmful effects
are insignificant.
• Our bodies have mechanisms for handing
toxins – liver enzymes, cell repair mechanisms,
cell regrowth
Example: Which are you more likely to
die from?
Determining Toxicity
Three methods of determining toxicity:
1. Case reports (usually to physicians) about health
effects after exposure to a chemical;
2. epidemiology, involving studies of populations exposed
to certain chemicals or diseases
3. laboratory investigations (usually with test animals);
- LD50 is the median lethal dose, the amount of a
chemical received that kills 50% of animals (usually
rats or mice) in a test population (usually 60–200
animals) within a 14–day period;
- a poison is legally defined as a chemical that has an
LD50 of 50 milligrams or less per kilogram of body
weight.
Some example toxins
Nail polish
Shampoo
Perfluorochemicals
to add shine
Perfluorochemicals
and phthalates
Teddy bear
Some stuffed animals
made overseas contain
flame retardants and/or
pesticides
Baby bottle
Clothing
Can contain
perfluorochemicals
Mattress
Flame retardants
in stuffing
Perfume
Phthalates
Carpet
Padding and carpet
fibers contain flame
retardants,
perfluorochemicals,
and pesticides
TV
Wiring and plastic
casing contain
flame retardants
Hairspray
Phthalates
Food
Some food contains
bisphenol-A
Milk
Fat contains dioxins
and flame retardants
Sofa
Foam padding
contains flame
retardants and
perfluorochemicals
Frying pan
Nonstick coating
contains
perfluorochemicals
Tile floor
Contains
perfluorochemicals,
phthalates, and
pesticides
Can contain
bisphenol-A
Fruit
Imported fruit
may contain
pesticides
banned in the
U.S.
Water bottle
Can contain
bisphenol-A
Computer
Flame
retardant
coatings of
plastic casing
and wiring
Toys
Vinyl toys
contain
phthalates
Tennis shoes
Can contain
phthalates
Fig. 17-16, p. 458
Dose–Response Curves
Dose–response curves show the adverse effects of
various doses of a toxic agent on a test population by
plotting harmful effect as a function of dose.
The left dose–
response curve shows
increasing harmful
effects with dose, and
no dose is considered
safe. The right
example has a
threshold, such that
low doses are
considered safe.
© Brooks/Cole Publishing Company / ITP
LD50 Practice Worksheet
3. Chemical Hazards
• toxic chemicals are generally defined as substances that
are fatal to over 50% of test animals (LD50) at given
concentrations.
• hazardous chemicals cause harm by
- being flammable or explosive (e.g., gasoline);
- irritating or damaging the skin or lungs (e.g., strong acids or
alkalines such as oven cleaners);
- interfering with or preventing oxygen uptake and distribution
(e.g., carbon monoxide, CO);
- inducing allergic reactions of the immune system (allergens).
• mutagens are agents, chemicals and radiation, that cause
random mutations, or changes in the DNA;
• teratogens are agents (chemicals, radiation, or viruses)
that cause birth defects;
- e.g., PCBs, steroid hormones, heavy metals;
• carcinogens are agents (chemicals, radiation, or viruses)
that cause cancer;
- over 100 types of cancer (depending on cells involved);
- e.g., cigarette smoke.
teratogens
Thalidomide
• Medication that was initially used in Europe for
morning sickness/nausea during pregnancy because it
was tested for safety in animals and showed no harm.
• produced phocomelia, which is a congenital condition
with abnormalities in the face, limbs, ears, nose,
vessels and many other organs. Thalidomide is used in
non-pregnant humans now for multiple myeloma,
leprosy, wasting syndrome of HIV, and other
conditions, but is under strict control for dispensation
of the drug by the STEPS program
Mutagens
Hormonally active agents (HAAs)
• Estrogen-like chemicals that alter
development (early pubescence, low sperm
counts)
• DDT, PCB’s, pesticides, aluminum, mercury,
BPA, and industrial solvents are known
hormone mimics.
Hormone
Estrogen- like chemical
Antiandrogen chemical
Receptor
Cell
Normal Hormone
Process
Normal Mimic
Hormone Blocker
Fig. 16.7, p. 403
Why Do We Know So Little about the
Harmful Effects of Chemicals?
 Severe limitations estimating toxicity levels and
risks
 Acceptable levels vary between 1/100 and 1/1000
of the estimated harmful levels
 10% of at least 75,000 chemicals in commercial
use have been screened for toxicity
 Only 2% has been tested to determine whether
they are carcinogens, teratogens, or mutagens
 Currently, federal and state governments do not
regulate 99.5% of commercially used chemicals in
the U.S.
Pollution Prevention and the
Precautionary Principle
 Those introducing a new chemical or new technology would have to
follow new strategies
• A new product is considered harmful until it can be proved to be safe
• Existing chemicals and technologies that appear to cause significant
harm must be removed
• Global treaty to phase out 12 most persistent pollutants
detrimental to life:
–DDT
–Dioxin
–Furans
–Other persistent pesticides
• Treaty went into effect in 2004 and is called: Stockholm Convention
on Persistent Organic Pollutants
Research ONE of these toxins for
tomorrow:
Each group of two tables must have a student researching one of these
toxins:
• Botulism
• Ricin
• Lead
• Mercury
• Arsenic
• Anthrax
• Dioxin (Agent Orange)
• DDT
• Include: where the toxins come from/are found, how they affect the
human body, and what the LD50 level is for humans (if possible) or
another mammal
• You will share your findings in small groups in preparation for an open
note quiz
Viruses, bacteria, diseases oh my!
• On average humans touch their face 16 times
per hour
• 1973 observation of 124 adults seated in
crowds for 30 to 50 minutes.
– Even in public, researchers saw 29 episodes of
outright nose-picking and 33 eye rubs.
• 1982 study found flu viruses lived on hard
surfaces for 24 to 48 hours and on soft
materials for eight to 12 hours
4. Biological Hazards
• Biological hazards include both non-transmissible
and transmissible diseases.
• Non-transmissible disease: heart disease, cancer, etc.
• Transmissible: caused by “living” organism
(pathogens), can be spread.
–Bacteria
–Virus
–Protozoans
• Pathogen reproduction: 1 bacteria becomes almost
17,000,000 in 24 hours!
7 Deadliest infectious diseases:
1.
2.
3.
4.
5.
6.
7.
Acute respiratory infections (viral)
HIV/AIDS (viral)
Hepatitis B (viral)
Diarrheal diseases (bacteria & viral)
Tuberculosis (bacterial)
Malaria (parasitic protozoa)
Measles (viral)
Disease transmission
•
•
•

Bodily fluids (influenzas, ebola, HIV)
Airborne (SARS)
Animal (rabies)
The greatest virus health threat to humans is
the emergence of new, very virulent strains of
influenza.
• Few numbers of antiviral drugs exist because
most of the drugs kill not only the virus, they
also kill the cells of its host.
• According to WHO and UNICEF, every year in
developing countries at least 2 million children
under 5 die of preventable infectious diseases
• 80% of all illnesses in developing countries are
caused by waterborne infectious diseases
(diarrhea, hepatitis, typhoid, cholera, etc)
• Antibiotics can be used to treat bacterial
infections
Careful use of antibiotics
• Pathogens are becoming resistant
– Exposure to antibiotics provides selective pressure,
which makes the surviving bacteria more likely to be
resistant.
– Genetic mutation
– Plasmid transfer.
• Over-prescribed
• 75% in US are used to boost livestock production
• Anti-bacterial soap causing “stronger” bacteria??
Staph infections
• 1 out of every 4 healthy people, the staph
germ lives on the skin or in the nasal passages
• infection can be minor and local (for example,
a pimple), or more serious (involving the
heart, lungs, blood, or bone).
• Serious staph infections are more common in
people with a weak immune system.
MRSA
• Methicillin resistant staphylococcus aureus
• 2 out of every 100 people carry a strain of staph that is
resistant to these antibiotics
• Common in hospitals, post surgery
• Other infections have occurred among athletes who
share equipment or personal items (such as towels or
razors) and children in day care facilities.
• Members of the military
and those who get tattoos
are also at risk.
Tuberculosis
• contagious bacterial
infection that attacks the
lungs
• spread usually from person
to person by breathing
infected air during close
contact.
• Scar tissue builds up in
lungs – looks like marbles
• take many different pills at
different times of the day
for 6 months or longer.
• 8 million new cases of TB occur each year
worldwide.
• 10-15 million people are infected with the TB
bacteria, and 22,000 new cases of TB occur
each year in the U.S.
MDR-TB & XDR-TB
• (MDR-TB) resistant to at least two of the first-line drugs,
INH and Rifampin.
• XDR –TB resistant to three or more of the second-line
treatment drugs.
• XDR-TB is seen throughout the world but is most frequently
seen in the countries of the former Soviet Union and Asia.
• Preventing XDR-TB from spreading is essential. The World
Health Organization (WHO) recommends improving basic
TB care to prevent emergence of resistance and the
development of proper laboratories for detection of
resistant cases. When drug-resistant cases are found,
prompt, appropriate treatment is required. This will
prevent further transmission. Collaboration of HIV and TB
care will also help limit the spread of tuberculosis, both
sensitive and resistant strains.
AIDS & TB
• TB could have been eliminated by effective treatment,
vaccinations, and public-health measures by the year
2000. However, the emergence of HIV changed the
whole picture. Because of HIV, a tremendous increase
in the frequency (incidence) of TB occurred in the '80s
and throughout the '90s. This increase in TB happened
because suppression of the body's immune (defense)
system by HIV allowed TB to occur as a so-called
opportunistic infection. With the increasing HIV
epidemic in Africa, serious concerns are being raised
about the development of MDR-TB and XDR-TB in this
population.
Tuberculosis
http://www.youtube.com/watch?v=IpkckkI5KFw
Book plug
Malaria
• parasitic disease that involves high fevers, shaking
chills, flu-like symptoms, and anemia
• Parasite (Plasmodium falciparum) is passed from
one human to another by the bite of infected
Anopheles mosquitoes
• Parasites travel to liver to mature and then enter
the bloodstream and infect RBCs
• Multiply inside the red blood cells, which then
break open within 48 to 72 hours, infecting more
red blood cells.
Malaria Life cycle
Fig. 16.11, p. 409
Anopheles mosquito (vector)
in aquatic breeding area
eggs
larva
pupa
adult
1. Female
mosquito bites
infected human,
ingesting blood
that contains
Plasmodium
gametocytes
4. Parasite invades
blood cells, causing
malaria and making
infected person
a new reservoir
2. Plasmodium
develops in
mosquito
3. Mosquito injects Plasmodium
sporozoites into human host
Malaria
• Symptoms: severe anemia (due to destruction
of RBCs), fever, chills, flu-like symptoms, coma,
death.
• Usually treated with chloroquine and outlook
is good
• Anti-malarial meds for travelers (expensive)
• In 2010 an estimated 216 million cases of
malaria occurred worldwide and 655,000
people died, most (91%) in the African Region.
Malaria
• Malaria on the rise again because mosquitos
are becoming resistant to many insecticides and
the protozoa are becoming resistant to major
treatment drugs (chloroquine)
http://www.youtube.com/watch?v=8ugW
y2OB-So
Climate Change and Health
http://www.youtube.com/watch?v=Rfxx3Bsuj_Q
•
•
•
•
Vector-borne diseases:
Dengue (virus from mosquitos)
Malaria (parasite from mosquitos)
Leishmaniasis (parasite from sand
flieswoodrats)
• West Nile Virus (virus from mosquitos)
• Lyme Disease (bacteria from ticks)
• Climate constrains the range of vectors, but that
range is changing
Ebola Virus Disease (EVD)
• Formerly known as Ebola hemorrhagic fever
• Transmitted to people from wild animals (bats)
and spreads through human-to-human
transmission
• First appeared in 1976
• Case fatality rate: 50%
– Usually expressed as the percentage of persons
diagnosed as having a specified disease who die as a
result of that illness within a given period
• No Ebola vaccines currently, but 2 potential
candidates are undergoing evaluation
Epidemic Proportions
• Epidemic: The occurrence in a community or region of
cases of an illness (or an outbreak) with a frequency clearly
in excess of normal expectancy.
• The 2014 Ebola epidemic is the largest in Ebola history,
affecting multiple countries in West Africa. There were a
small number of cases reported in Nigeria and a single case
reported in Senegal; however, these cases were contained,
with no further spread in these countries.
• Two imported cases, including one death, and two locally
acquired cases in healthcare workers were reported in the
US.
• A Reflection of Growing Inequality
Cases in the US
• Oct. 23, 2014 – Medical aid worker from Doctros
without Borders identified in New York City (from
Guinea) – recovered and released on Nov. 11
• Oct. 10 &15, 2014 – two healthcare workers in
Dallas – recovered and released on Oct. 24 & 28
 had traveled to Cleveland and back by air, but
no passengers caught it
• Sept. 30, 2014 – first case in US (traveled from
Liberia to Dallas) Passed away on Oct. 8.
Worldwide Locations Affected by Ebola
Graph 1: Cumulative reported cases of Ebola virus
disease in Guinea, Liberia, and Sierra Leone, March
25, 2014 – January 18, 2015, by date of WHO Situation
Report, n=21689
Total Cases and Deaths from Mar.
25,2014-Jan. 18, 2014
Where did Ebola come from?
• It is thought that fruit bats of the Pteropodidae family are natural Ebola
virus hosts.
• Introduced into the human population through close contact with the
blood, secretions, organs or other bodily fluids of infected animals such as
chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines
found ill or dead or in the rainforest.
• Ebola then spreads through human-to-human transmission via direct
contact (through broken skin or mucous membranes) with the blood,
secretions, organs or other bodily fluids of infected people, and with
surfaces and materials (e.g. bedding, clothing) contaminated with these
fluids.
• Burial ceremonies in which mourners have direct contact with the body of
the deceased person can also play a role in the transmission of Ebola.
• People remain infectious as long as their blood and body fluids, including
semen and breast milk, contain the virus.
• Men who have recovered from the disease can still transmit the virus
through their semen for up to 7 weeks after recovery from illness.
How do you get the Ebola virus?
Direct contact with
1. Body fluids of a person who is sick with or
has died from Ebola. (Blood, vomit, pee,
poop, sweat, semen, spit, or other fluids)
2. Objects contaminated with the virus
(needles, medical equipment)
3. Infected fruit bats or primates (apes and
monkeys)
Patient Zero
• 2 year old toddler named Emile Ouamouno in
a small village in Guinea.
• Died on Dec. 6, 2013
• Not sure how he contracted the virus –
thought that potentially through a fruit bat
• Outbreak thought to be caused by a single
introduction of the virus as there is great
genetic similarity between cases.
• Transmission mainly through healthcare
workers
• Traveled to Sierra Leone by a traditional
healer
• Why is this outbreak so bad?
– Traditionally Ebola has been a disease
primarily found in the villages through bush
meat
– First time it has reached major urban
centers
– Combined with lack of healthcare, poverty,
and recent conflicts (in Liberia, 51 doctors
were left to care for a country of 4 million
after the war)
– On August 8, 2014 the WHO DirectorGeneral declared this outbreak a Public
Health Emergency of International Concern.
– Paul Farmer on Ebola
Symptoms
• Incubation Period: the time interval from infection
with the virus to onset of symptoms (2 to 21 days for
Ebola).
• Humans are not infectious until they develop
symptoms.
• First symptoms are the sudden onset of fever fatigue,
muscle pain, headache and sore throat.
• This is followed by vomiting, diarrhea, rash, symptoms
of impaired kidney and liver function, and in some
cases, both internal and external bleeding (e.g. oozing
from the gums, blood in the stools).
Issues with Diagnosis
• It can be difficult to distinguish EVD from other infectious diseases
such as malaria, typhoid fever and meningitis. Confirmation that
symptoms are caused by Ebola virus infection are made using the
following investigations:
–
–
–
–
–
–
antibody-capture enzyme-linked immunosorbent assay (ELISA)
antigen-capture detection tests
serum neutralization test
reverse transcriptase polymerase chain reaction (RT-PCR) assay
electron microscopy
virus isolation by cell culture.
• Samples from patients are an extreme biohazard risk; laboratory
testing on non-inactivated samples should be conducted under
maximum biological containment conditions.
Prevention and Control
• Case management, surveillance, safe burials
• Community engagement
• Raising awareness of risk factors for Ebola infection to
reduce human transmission
– Reduce wildlife-to-human transmission from contact with
infected fruit bats or monkeys and the consumption of
their raw meat
– Reduce human-to-human transmission from direct or close
contact with people with Ebola (hand washing, gloves,
etc.)
– Outbreak containment measures: prompt and safe burial
of the dead, monitoring during incubation period (21
days), quarantine, etc.
Community Response
Ebola’s Legacy
Outbreak Update
• On January 18, 2015, Malian authorities and the
WHO announced the end of the outbreak of
Ebola in Mali. Forty-two days have elapsed since
the last Ebola case tested negative in laboratory
tests on December 6, 2014.
• Currently in Liberia only 5 people are being
treated for Ebola
• On Monday (01/26) Senegal has reopened its
land border with Guinea which has been closed
since August 2014
Largely eradicated diseases in U.S.
•
•
•
•
•
•
•
•
•
Pertussis (Whooping cough)
Tuberculosis
Measles
Mumps
Smallpox
Cholera
Typhoid
Etc.
Due to: vaccines, better health care, clean water,
sanitation, etc.
• Typhoid: bacterial, affects about 21.5 million
persons each year.
• Cholera: water-borne bacteria. In 2009, 45
countries reported 221,226 cholera cases and
4,946 cholera deaths (case-fatality rate 2.24%)
to the WHO.
Smallpox
• Only truly eradicated disease: Smallpox
• Virus with flu-like symptoms, vaccine as early as 1796, but
not produced in large quantities until 1954
• 1966 a resolution sponsored by many countries made
ending smallpox in 10 years their goal
• Focused on the poorest countries using a vaccine
• last naturally-occurring case of smallpox in the world was
contracted in October, 1977 by a young man in Merka
Town, Somalia
• ironically, in 1978 two more cases popped up in
Birmingham, England, from smallpox virus escaped from a
research lab. One of the patients died. The director of the
laboratory committed suicide.
Smallpox
• In 1979 smallpox was declared eradicated
• Since 1972 U.S. has no longer vaccinated
against small pox
• Concern for possible Bioterrorism