EPIDEMIOLOGICAL ENVIRONMENT
Endemic - is a disease that is always present in a certain population or
region. Ex: Malaria, Chicken pox
Epidemic - outbreak of a disease. Ex: Dengue, SARS
Pandemic - are worldwide epidemics. An epidemic (a sudden
outbreak) that becomes very widespread and affects a whole region,
a continent, or the world due to a susceptible population. Ex: AIDS
Factors that Cause disease: Heredity, Age, Nutritional condition,
Personal hygiene , Habits
Classes of diseases:
1.
2.
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Infectious diseases - the most important class of diseases
caused by bacteria, protozoa, worms, fungi and viruses
Pollution diseases – air-related pollution disease
Ex:
a. Emphysema
COPD (chronic obstructive pulmonary disease)
involves gradual damage of lung tissue, specifically thinning
and destruction of the alveoli or air sacs
accompanied by chronic bronchitis, with almost-daily or
daily cough and phlegm.
difficult to breathe
Cigarette smoking
not curable
b. Pneumonia
respiratory infection
is a common lung infection caused by germs, such as
bacteria, viruses, and fungi
complication of the flu
Pneumonia and its symptoms can vary from mild to severe
life-threatening
can be prevented—by getting an annual flu shot
can be spread by coughing, sneezing or even breathing
cough, fever, chills and shortness of breath
c. Bronchitis
is a condition in which the airways that move air to and
from your lungs, also called bronchial tubes, become
inflamed
cough with mucus production
shortness of breath
chest discomfort and fatigue
wheezing
chronic bronchitis N/C
Cigarette smoking is the major cause
exposure to air pollution as well as dust or toxic gases
productive cough (producing mucus) that lasts at least three
months and happens multiple times over the course of at least
two years.
Acute bronchitis
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is a form of lower respiratory tract inflammation affecting
the air tubes (bronchi) of the lungs
caused by a respiratory virus and occasionally by bacterial
infection
Coughing up mucus that may be yellow or green
A physical examination, and possibly an X-ray if you've had
fever
Resting and getting plenty of fluids
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d. Lung cancer
A cough that doesn't go away and gets worse over time
Hoarseness
Constant chest pain
Shortness of breath or wheezing
Frequent lung infections such as bronchitis or pneumonia
Coughing up blood, Weight loss, Loss of appetite
Headaches, Bone pain or fractures, Blood clots
Your medical history, Your symptoms
Findings from your physical exam
e. Liver cancer
is cancer that begins in the cells of your liver.
Losing weight without trying
Loss of appetite
Upper abdominal pain
Nausea and vomiting
General weakness and fatigue
Abdominal swelling
Yellow discoloration of your skin and the whites of your
eyes (jaundice)
White, chalky stools
Chronic infection with HBV or HCV
Cirrhosis
Nonalcoholic fatty liver disease
Excessive alcohol consumption
Certain inherited liver diseases
Stress diseases – related to social environment of man
Ex: Food poisoning
foodborne illness
caused by eating contaminated food. Infectious organisms
— including bacteria, viruses and parasites
nausea
vomiting
diarrhea
Abdominal pain and cramps
Fever
Neurological symptoms such as blurry vision, muscle
weakness and tingling in the arms
a. Red tide
is a common name for a phenomenon known as an algal
bloom, an event in which estuarine, marine, or fresh water
algae accumulate rapidly in the water column, or "bloom"
dinoflagellate - algae, phytoplankton, are microscopic,
single-celled protists, plant-like organisms
fish and shellfish become poisonous for human
consumption due
gastrointestinal issues
diarrhea
nausea
abdominal distress
loss of motor control
ataxia
paresthesia
vertigo
muscle pain
Hepatitis A
is a highly contagious liver infection caused by the hepatitis
A virus.
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usually get it when you eat or drink something that’s been
exposed to poop from someone who has the virus.
Jaundice (yellow eyes and skin, dark urine)
Pain in your belly
Clay-colored bowel movements
Low-grade fever
Loss of appetite
Nausea
Diarrhea
Fatigue
Eat fruits, vegetables, or other foods that were
contaminated during handling
Eat raw shellfish harvested from water that's got the virus
in it
Swallow contaminated ice
Live with or have sex with someone who's infected
Men who have sex with men
People who inject illegal drugs
b. Hepatitis B
is an infection of your liver.
Having chronic hepatitis B increases your risk of developing
liver failure, liver cancer or cirrhosis — a condition that
permanently scars of the liver.
It can cause scarring of the organ, liver failure, and cancer.
It’s spread when people come in contact with the blood,
open sores, or body fluids of someone who has the
hepatitis B virus.
Jaundice. (Your skin or the whites of the eyes turn yellow,
and your pee turns brown or orange.)
Light-colored poop
Fever
Fatigue that persists for weeks or months
Stomach trouble like loss of appetite, nausea, and vomiting
Belly pain
unprotected sex
needles and syringes contaminated with infected blood.
Pregnant women with hepatitis B can pass it to their babies
during childbirth.
c. Hepatitis C
Bleeding easily
Bruising easily
Fatigue
Poor appetite
Yellow discoloration of the skin and eyes (jaundice)
Dark-colored urine
Itchy skin
Fluid buildup in your abdomen (ascites)
Swelling in your legs
Weight loss
Confusion, drowsiness and slurred speech (hepatic
encephalopathy)
Spider-like blood vessels on your skin (spider angiomas)
d. Hepatitis D
hepatitis delta
HDV is the most severe form of hepatitis.
it can lead to liver cancer or liver failure.
Super-infection: You can get sick with hepatitis B first, then
later come down with HDV. This is the most common way
to get hepatitis D.
Inject drugs
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Have a sex partner who has HDV
Yellow skin and eyes (jaundice)
Stomach upset
Pain in your belly
Throwing up
Fatigue
Not feeling hungry
Joint pain
Dark urine
Light-colored stool
From another source:
a.
b.
c.
d.
e.
f.
g.
4.
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Obesity
heart disease
Alzheimer's disease
Diabetes
Depression
gastrointestinal problems
and asthma
Allergies
a. Superficial mycosis
superficial fungal infections
dermatophytosis or ringworm
tinea versicolor
antifungal drugs such as clotrimazole (Canestan) or
terbinafine (Lamisil)
b.
c.
Deep mycosis – deep fungal infection
Dandruff
is a common skin condition that causes white or grey flakes of skin to
appear on the scalp and in the hair.
5.
Developmental anomalies can be caused by
environmental contaminants and unhealthy practice
a. STD
b. AIDS
Categories of Infectious Diseases:
1.
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Two-factor complex – involves a pathogen (a bacterium,
virus, or other microorganism that can cause disease) and
man.
a. Influenza
is a viral infection that attacks your respiratory system —
your nose, throat and lungs.
Flu Common signs and symptoms of the flu include: Fever
over 100.4 F (38 C)
Aching muscles
Chills and sweats
Headache
Dry, persistent cough
Fatigue and weakness
Nasal congestion
Sore throat
People at higher risk of developing flu complications
include:
o Young children under age 5, and especially those
under 2 years
o Adults older than age 65
o Residents of nursing homes and other long-term
care facilities
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Pregnant women and women up to two weeks
postpartum
People with weakened immune systems
People who have chronic illnesses, such as
asthma, heart disease, kidney disease, liver
disease and diabetes
People who are very obese, with a body mass
index (BMI) of 40 or higher
b. Acute Coryza
The common cold is a viral infectious disease that infects
the upper respiratory system.
It is the most common infectious disease in humans and is
mainly caused by coronaviruses or rhinoviruses.
Pneumonia
Three-factor complex- involves a pathogen, vector (vector
is any agent who carries and transmits an infectious
pathogen into another living organism, ex; parasite and
microbe), and a man.
o Malaria
It’s typically transmitted through the bite of an infected
Anopheles mosquito
Infected mosquitoes carry the Plasmodium parasite
mature parasites enter the bloodstream and begin to infect
red blood cells
typically found in tropical and subtropical climates
Common symptoms of malaria include:
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shaking chills that can range
from moderate to severe
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high fever
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profuse sweating
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headache
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nausea
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vomiting
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abdominal pain
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diarrhea
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anemia
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muscle pain
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convulsions
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coma
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bloody stools
 Malaria can cause a number of lifethreatening complications. The
following may occur:
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swelling of the blood vessels
of the brain, or cerebral
malaria
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an accumulation of fluid in the
lungs that causes breathing
problems, or pulmonary
edema
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organ failure of the kidneys,
liver, or spleen
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anemia due to the destruction
of red blood cells
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low blood sugar
o H-fever
infectious diseases that can cause severe, life-threatening
illness
They can damage the walls of tiny blood vessels, making
them leaky.
They can also interfere with the blood's ability to clot.
These diseases most commonly occur in tropical areas of
the world.
Ex: Dengue
Symptoms:
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High fever
Fatigue
Dizziness
Muscle, bone or joint aches
Weakness
Septic shock
Nervous system malfunctions
Coma
Delirium
Kidney failure
Respiratory failure
Liver failure
o Yellow fever
is a viral infection spread by a particular type of mosquito
most common in areas of Africa and South America
Once the infection enters the acute phase, you may
experience signs and symptoms including:
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Fever
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Headache
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Muscle aches, particularly in
your back and knees
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Sensitivity to light
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Nausea, vomiting or both
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Loss of appetite
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Dizziness
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Red eyes, face or tongue
 Toxic phase
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Yellowing of your skin and the
whites of your eyes (jaundice)
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Abdominal pain and vomiting,
sometimes of blood
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Decreased urination
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Bleeding from your nose,
mouth and eyes
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Slow heart rate (bradycardia)
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Liver and kidney failure
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Brain dysfunction, including
delirium, seizures and coma
Four-factor complex – involves an intermediate host,
vector, bacteria and man.
o Plague
is a serious bacterial infection that's transmitted primarily
by fleas.
Black Death
Yersinia pestis, lives in small rodents found most commonly
in rural and semirural areas of Africa, Asia and the United
States. The organism is transmitted to humans who are
bitten by fleas that have fed on infected rodents or by
humans handling infected animals.
Bubonic plague
It's named after the swollen lymph nodes (buboes)
Situated in the groin, armpit or neck
About the size of a chicken egg
Tender and firm to the touch
Sudden onset of fever and chills
Headache
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Fatigue or malaise
Muscle aches
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Septicemic plague
occurs when plague bacteria multiply in your bloodstream.
Fever and chills
Extreme weakness
Abdominal pain, diarrhea and vomiting
Bleeding from your mouth, nose or rectum, or under your
skin
Shock
Blackening and death of tissue (gangrene) in your
extremities, most commonly your fingers, toes and nose
Cause: The plague bacteria, Yersinia pestis, is transmitted to
humans through the bites of fleas that have previously fed
on infected animals, such as:
o Rats
o Mice
o Squirrels
o Rabbits
o Prairie dogs
o Chipmunks
Death. Most people who receive prompt antibiotic
treatment survive bubonic plague. Untreated plague has a
high fatality rate.
Gangrene. Blood clots in the tiny blood vessels of your
fingers and toes can disrupt blood flow and cause that
tissue to die. The portions of your fingers and toes that
have died may need to be removed (amputated).
Meningitis. Rarely, plague may cause inflammation of the
membranes surrounding your brain and spinal cord
(meningitis).
o Typhus
Typhus is a disease caused by rickettsia or orientiabacteria.
You can get it from infected mites, fleas, or lice.
Insects and other parasites spread murine and epidemic
typhus when they bite you and leave bacteria-laden feces
on your skin.
When you scratch the itching bug bite, you can spread the
infested feces into the open bite wound or other cuts on
your skin’s surface. That deposits typhus bacteria into your
bloodstream.
You can get scrub typhus if a mite infected with the
bacterium bites you, even if you don’t scratch the bite.
Symptoms:
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with any kind of typhus, you’ll start to feel ill about 10 days
to 2 weeks after the typhus bacteria get into your body.
At first, you’ll feel chills, run a fever, and develop a severe
headache. You may start to breathe fast and get full-body
muscle aches like what you’d have with the flu. Stomach
pain and vomiting are common, too.
A few days later, you might notice a spotted rash on your
chest and midsection, which often spreads to other parts of
your body. With scrub typhus, you might see a dark scab on
the area where the chigger bit you.
Complications from untreated typhus can include
conditions such as pneumonia, meningitis, or septic shock.
Q-fever
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is an infection caused by the bacterium Coxiella burnetii.
Q fever is usually a mild disease with flu-like symptoms.
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is transmitted to humans by animals, most commonly
sheep, goats and cattle.
When you inhale barnyard dust particles contaminated by
infected animals, you may become infected.
Signs and symptoms may include:
o High fever, up to 105 F (41 C)
o Severe headache
o Fatigue
o Chills
o Cough
o Nausea
o Vomiting
o Diarrhea
o Sensitivity to light
Complications:
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Endocarditis. An inflammation of the membrane inside your
heart, endocarditis can severely damage your heart valves.
Endocarditis is the most deadly of Q fever's complications.
Lung issues. Some people who have Q fever develop
pneumonia. This can lead to acute respiratory distress, a
medical emergency in which you're not getting enough
oxygen.
Pregnancy problems. Chronic Q fever increases the risk of
miscarriage, low birth weight, premature birth and stillbirth.
Liver damage. Some people who have Q fever develop
hepatitis, an inflammation of the liver that interferes with
its function.
Meningitis. Q fever can cause meningitis, an inflammation
of the membrane surrounding your brain and spinal cord.