Transcript Etiology - HCC Learning Web

Etiology
The study of the causes. For example, of a
disorder.
The word "etiology" is mainly used in medicine,
where it is the science that deals with the
causes or origin of disease, the factors which
produce or predispose toward a certain disease
or disorder.
Sensorineural Hearing Loss
Hearing loss that associated with the inner
ear or in the auditory nerve or both.
Sensorineural deafness:
Congenital-Present at birth.
Often are delays when etiology is unknown
that has lag time between the hearing loss
and the time of diagnosis (dx).
Sensorineural Hearing Loss
Factors to consider:
1. Family history
2. Medical history
3. Auditory dysfunction
Often times there are several causal
conditions causing hearing loss. Most
causes are unknown. However, evidence
supports genetic factors with 50% of
cases attributed to genetic causes.
Nongenetic Causes of Deafness
a.
b.
c.
d.
e.
f.
g.
h.
i.
Rubella (German Measles)
Cytomegalovirus (CMV)
Other viral causes- Herpes simplex virus,
Human immunodeficiency virus (HIV)
Meningitis (bacterial, viral)
Congenital Toxoplasmosis
Erythroblastosis fetalis
Ototoxic drugs
Prematurity
Noise-induced hearing loss
Rubella (German Measles)

commonly known as German measles or 3-day measles
> is an infection that primarily affects the skin and lymph
nodes by the rubella virus (not the same virus that
causes measles), which is usually transmitted by
droplets from the nose or throat that others breathe in.
> It can also pass through a pregnant woman's
bloodstream to infect her unborn child. As this is a
generally mild disease in children, the primary medical
danger of rubella is the infection of pregnant women,
which may cause congenital rubella syndrome in
developing babies.
Signs and Symptoms
Rubella infection

may begin with 1 or 2 days of mild fever
(99–100° Fahrenheit)

swollen, tender lymph nodes, usually in the back
of the neck or behind the ears

rash then appears that begins on the face and
spreads downward. As it spreads down the
body, it usually clears on the face
> this rash is often the first sign of illness that a
parent notices.
Signs and Symptoms

The rubella rash can look like many other viral rashes. It
appears as either pink or light red spots, which may
merge to form evenly colored patches. The rash can itch
and lasts up to 3 days. As the rash clears, the affected
skin occasionally sheds in very fine flakes.
Rubella/Pregnancy

When rubella occurs in a pregnant woman, it
may cause congenital rubella syndrome, with
potentially devastating consequences for the
developing fetus.
Rubella/Pregnancy
Children who are infected with rubella
before birth are at risk for:
 growth retardation
 mental retardation
 malformations of the heart and eyes
 deafness
 liver, spleen, and bone marrow problems.

Cytomegalovirus (CMV)
Infection with cytomegalovirus (CMV)
 a member of the herpes virus family
 very common
 Between 50% and 85% of people in the
United States have had a CMV infection by
the time they are 40 years old, according
to the Centers for Disease Control and
Prevention (CDC).

CMV is mainly a problem for certain high-risk
groups, including:
 unborn babies whose mothers become infected
with CMV during the pregnancy
 children or adults whose immune systems have
been weakened by disease or drug treatment,
such as organ transplant recipients or people
infected with HIV
 Once a person has had a CMV infection, the
virus usually lies dormant (or inactive) in the
body, but it can be reactivated. The virus is
more likely to be reactivated – and cause serious
illness – in people who have weakened immune
systems due to illness.

Symptoms of CMV Infections

The symptoms of a CMV infection vary depending upon
the age and health of the person who is infected, and
how the infection occurred.
Infants who are infected

before birth usually show no symptoms

CMV infection after they are born can develop
hearing, vision, neurologic, and developmental
problems

In a few cases, there are symptoms at birth,
which can include premature delivery (being
small for gestational age), jaundice, enlarged
liver and spleen, microcephaly (small head),
seizures, rash, and feeding difficulties.

These infants are also at high risk for developing
hearing, vision, neurologic, and developmental
problems.
Other Viral Causes
Herpes that cause painful blisters and sores.
Types of herpes viruses:
Herpes simplex, causes both cold sores
around the mouth and genital herpes
(herpes around the sexual organs)
Herpes zoster, another kind of herpes,
causes chickenpox and shingles.
Herpes Simplex
Chicken Pox
Genital Herpes
Shingles
How genital herpes spread
Genital herpes is spread easily.
The virus from contact with an infected person can
enter your body through:
a break in your skin or through the skin of your
mouth
penis or vagina
urinary tract opening
cervix or anus
Herpes is most easily spread when blisters or sores
can be seen on the infected person
But it can be spread at any time, even when there
aren't any symptoms.
How genital herpes spread
Genital herpes is spread from one person to
another by having sex, including anal and oral sex.
Herpes can also be spread from one place on your
body to another, such as from your genitals to
your fingers, then to your eyes or to other parts of
your body.
Herpes can also be spread from a mother to
her baby when she gives birth.
Stages of Herpes: Primary stage
usually starts 2 to 8 days after you're infected, but it can
take much longer to begin.
usually, the infection causes groups of small, painful
blisters. The fluid in the blisters may be clear or
cloudy.
The area under the blisters will be red. The blisters
break open so easily that they quickly become open
sores. You may not ever notice the blisters.
While most people have a painful primary stage of
infection, some
don't have any symptoms at all, and may not even know
they're
infected
Stages of Herpes: Primary stage
Besides having tender blisters or sores in your
genital area, it may hurt to urinate.
You may run a fever and have other flu-like
symptoms.
While most people have a painful primary stage of
infection, some don't have any symptoms at all,
and may not even know they're infected
Stages of Herpes
Latent stage
During this stage, there are no blisters,
sores or other symptoms. At this time,
the virus is traveling from your skin
into the nerves near your spine.
Stages of Herpes
Shedding stage
The virus starts multiplying in the nerves.
It can then get into body fluids, such as
saliva, semen or vaginal fluids. This is
called shedding.
There are no symptoms during this stage,
but the virus can be spread during this
time.
Treatment/Cure for Herpes
No, but medicines can help.
The medicine acyclovir (brand name: Zovirax) can speed up
healing and can lessen the pain of herpes for many people.
Acyclovir pills can treat primary or recurrent herpes and can stop
or lessen the number of recurrences. Acyclovir also comes in a
cream to put on sores during the primary stage or during
recurrences.
Famciclovir (brand name: Famvir) and valacyclovir (brand name:
Valtrex) are other medicines used to treat recurrent genital herpes
and for prevention of recurrences.
Meningitis
Meningitis is an inflammation of the meninges
(membranes that cover the brain and spinal cord)
inflammation is caused by bacteria or viruses
(viral meningitis is also called aseptic meningitis)
Less common causes include fungi, protozoa, and
other parasites. Sometimes certain medications,
cancers, or other diseases can inflame the meninges,
although such noninfectious cases of meningitis are
much rarer.
Bacterial Meningitis
Bacterial meningitis is less common than viral meningitis
but is usually much more serious and can be lifethreatening if not treated promptly.
Viral Meningitis

Viral meningitis is relatively common and far less serious
than bacterial meningitis.

It often remains undiagnosed because its symptoms are
similar to those of the common flu.

The frequency of viral meningitis increases slightly in the
summer and fall months because people are more often
exposed to common viral agents during those seasons.

The mumps virus was once a common cause of viral
meningitis, but it is now rare due to the routine use of
the measles, mumps, and rubella (MMR) vaccine.
Signs symptoms of
Meningitis
The symptoms of meningitis vary and depend both on the
age of the child and on which bacterium or virus is causing
the infection.
The first symptoms of meningitis may surface several days
after a child has had a cold and runny nose, diarrhea and
vomiting
Some of the more common symptoms of meningitis include
fever, lethargy (decreased consciousness), or irritability.
Older children may complain of a headache, photophobia
(eye sensitivity to light), and a stiff neck, which is often
noted by the doctor during a physical exam.
Signs symptoms of
Meningitis

Meningitis also can lead to skin rashes, although rashes
caused by bacterial meningitis look different from those
caused by viral meningitis. Seizures occasionally
accompany meningitis as well

Newborns and infants with meningitis may lack the
classical signs described above and simply be extremely
irritable or lethargic.

Normally, infants who are not feeling well will be
comforted when their mothers pick them up. However, a
baby who has meningitis may display something called
paradoxical irritability - when picking up and rocking a child
makes the child more distressed. This can be a sign of
irritated meninges.
Signs symptoms of
Meningitis
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symptoms of meningitis in infants can include:
jaundice (a yellowish tint to the skin)
a stiffness of the body and neck (neck rigidity)
a mild fever, a lower-than-normal temperature
poor feeding, a weak suck, and a high-pitched
cry
Parents may also notice bulging fontanelles on
their baby's head.
Meningitis
Contagiousness
The infectious agents usually spread from
person to person in tiny drops of fluid from the
throat and nose of someone who is infected.
The drops may become airborne when the
person coughs, laughs, talks, or sneezes.
They then can infect others when people
breathe
them in or touch the drops and then touch their
own noses or mouths.
Meningitis
Sharing food, drinking glasses, eating utensils, tissues,
or towels may all transmit the infections as well.
Some infectious organisms can spread through a
person's stool, and someone who comes in contact with
the stool - such as a child in day care - may contract the
infection.
Prevention
Routine immunization of young adolescents
Experts now recommend that kids who are 11 years old
Children who have not had the vaccine and are 15
years old, or entering high school should also get the
vaccine
People who are entering college, and will be living
in a dormitory setting should also get the vaccine.
Congenital Toxoplasmosis
Toxoplasmosis is a parasitic disease caused by a
protozoan, Toxoplasma gondii.
Infections of humans are common, and are usually
asymptomatic.
Improper handling of cat litter or contact of play
sand.
Congenital Toxoplasmosis
Symptoms
The classical triad of Congenital Toxoplasmosis
 Chorioretinitis

Intracranial calcification

Hydrocephalus
But even the subclinical infection can lead to lateonset problems, most common in the eyes.
Erythroblastosis fetalis
Refers to two potentially disabling/fatal blood
disorders in infants:
Rh incompatibility disease
 ABO incompatibility disease. (Blood typing)

either disease may be apparent before birth
and can cause fetal death in some cases
Erythroblastosis fetalis
The disorder is caused by incompatibility between
a mother's blood and her unborn baby's blood.
Because of the incompatibility, the mother's
immune system may launch an immune response
against the baby's red blood cells. As a result, the
baby's blood cells are destroyed, and the baby
may suffer severe anemia (deficiency in red blood
cells), brain damage, or death.
Erythroblastosis fetalis
Treatment
two techniques that are used to deliver a blood
transfusion to a baby before birth.
a needle is inserted through the mother's
abdomen and uterus, and into the baby's
abdomen. Red blood cells injected into the baby's
abdominal cavity are absorbed into its
bloodstream.
Cordocentesis is performed.
Ototoxic Drugs
A common cause of hearing loss
An ototoxic hearing loss happens when someone
takes or is given a drug that causes loss of hearing
as one of its side effects.
(Sometimes the drugs are needed to save lives,
and hearing loss is the price paid for being able to
live)
Sometimes the drug-induced hearing loss is
temporary and can be reversed or stopped. Other
times it is permanent.
Ototoxic antibiotics should be avoided in
pregnancy.
The elderly and people with preexisting
hearing loss should not be treated with
ototoxic drugs if other effective drugs are
available.
Prematurity
A baby born before 37 weeks of pregnancy
is considered premature, that is, born before
complete maturity.
Slightly fewer than 12 percent of all babies
are premature.
Noise Induced Hearing Loss
Every day, we experience sound in our environment,
such as the sounds from television and radio, household
appliances, and traffic.
Normally, we hear these sounds at safe levels that do
not affect our hearing.
However, when we are exposed to harmful noise—
sounds that are too loud or loud sounds that last a long
time—sensitive structures in our inner ear can be
damaged, causing noise-induced hearing loss (NIHL).
NIHL
These sensitive structures, called hair cells,
are small sensory cells in the inner ear that
convert sound energy into electrical signals
that travel to the brain. Once damaged, our
hair cells cannot grow back.
 Scientists once believed that the pure force
of vibrations from loud sounds caused the
damage to hair cells. Instead, recent studies
have shown that exposure to harmful noise
triggers the formation of molecules inside the
ear that can damage or kill hair cells

What sounds cause NIHL
caused by a one-time exposure to an intense “impulse”
sound, such as an explosion, or by continuous exposure
to loud sounds over an extended period of time, such as
noise generated in a woodworking shop.
Although being aware of decibel levels is an important
factor in protecting one’s hearing, distance from the
source of the sound and duration of exposure to the
sound are equally important. A good rule of thumb is to
avoid noises that are “too loud” and “too close” or that
last “too long.”
What are the effects of
NIHL
Exposure to harmful sounds causes damage to the hair
cells as well as the auditory, or hearing, nerve
Impulse sound can result in immediate hearing loss that
may be permanent. This kind of hearing loss may be
accompanied by tinnitus—a ringing, buzzing, or roaring
in the ears or head—which may subside over time.
Hearing loss and tinnitus may be experienced in one or
both ears, and tinnitus may continue constantly or
occasionally throughout a lifetime.
What are the effects of
NIHL
Continuous exposure to loud noise also can
damage the structure of hair cells, resulting in
hearing loss and tinnitus, although the process
occurs more gradually than for impulse noise.
 Exposure to impulse and continuous noise may
cause only a temporary hearing loss.
 temporary threshold shift largely disappears 16
to 48 hours after exposure to loud noise.

What are the symptoms of
NIHL
When a person is exposed to loud noise over a
long period of time, symptoms of NIHL will
increase gradually. Over time, the sounds a person
hears may become distorted or muffled, and it
may be difficult for the person to understand
speech. Someone with NIHL may not even be
aware of the loss, but it can be detected with a
hearing test.