Title: UNIT 9: DISEASES AND DISORDERS:
1UNIT 9 DISEASES AND DISORDERS
- An infection occurs when living agents enter
tissue, multiply there and damage the tissue.
2The General causative agents for disease include
- bacteria
- viruses
- fungus
- Rickettsia
- protozoan
- arthropods (acting as vectors)
- vermiform (various invertebrate worms)
3STAPHYLOCCOCCAL INFECTIONS (bacteria)
- Staphyloccocci are spherical gram positive
bacteria about .5 to 1.5 miccrometers in
diameter. - They tend to form in irregular clusters like
grapes - Staphylococcus aureus is the most pathogenic of
the staphylococci (forms golden yellow colonies,
almost all pathogenic and produces coagulase for
blood clotting) - S. Aureus common problem in hospital s due to
being carried on the skin of patients, visitors
and the danger of infection of surgical wounds or
skin breaks is high .
4- S. aureus is difficult to treat and is very
resistant to many antibiotics..mainly due to
resistance to penicillinase. - S aureous often enters the body via natural
openings in the skin barrier, hair follicles
ect, if through mouth (food poisoning) - Antibiotics do not penetrate abscesses well, thus
making the infection more difficult to treat,
often draining pus from abscess is one of the
first steps of treatmenttreat with penicillin or
erythromycin.
5- Staph infections on newborns includes impetigo
(vesicles on the skin rupture and crust over), or
scalded skin syndrome ( lesions on the nose and
mouth, then bright red area appears, within 48 hr
the skin of palms and soles peels off in sheet
when touchedserious illness) - 30 to 50 health adults carry staph in their nose
and 20 carry staph on their skin.. and the human
immune system is good at combating staph
infections ( most susceptible include infants,
elderly drug users and immune impaired)
6scalded skin syndrome
7- The boils that Job scraped with broken pottery
(Job 27-8) could only have been caused by staph
8STREPTOCCOCAL INFECTION including flesh-eating
bacteria
- Streptococci are gram positive spherical bacteria
with cells growing in chains. - They are facultative anaerobes
- Many are nonpathogenic and occupy the mouth,
gastrointestinal tract and upper respiratory
systems. - Some Streptococci are responsible for skin
infections and secrete several enzymes including
hemolysins (damages RBCs) - Impetigo is one disease caused by Strep
infections (symptoms include superficial skin
infection, isolated pustules( round elevations
full of pus) that become crusted and rupture
9Impetigo is one disease caused by Strep infections
10- Strep also causes scarlet fever, infections of
the throat - Steptococcus pneumonia most common cause of
bacterial pneumoniaand also the cause of
flesh-eating bacteria (necrotizing fasciitis ) - S. pneumonia is highly resistant and emits an
enzyme able to destroy the fascia, or tissue that
binds skin to muscle at a rate of an inch an
hourabout 1500-2000 cases in USA per year with
fatality rate of 30 in otherwise healthy adults.
11necrotizing fasciitis
12- Jim Henson from muppets died of this bacteria in
1990 from a splinter cut on his finger (duration
from time of splinter to death6 weeks)
13PSEUDOMONADS (bacteria)
- Aerobic gram negative rods, widespread in soil
and water, able to survive in any moist
environment. - Cause otitis externa (swimmers ear)
- Pseudomonas dermatitis causes rash outbreaks and
is associated with swimming pools
14- Pseudomonas aeruginosa common and serious
opportunistic pathogen in burn patients (esp 2nd
and 3rd degrees), it is carried on flowers or
plants sent by well-wishers, thus reason
hospitals do not permit these patients to receive
flowers. - Treatment with antibiotics gentamicin and
carbenicillin, (Silver sulfadiazine used in burn
victims)
15WARTS viral
- Caused by Viruses that stimulate an uncontrolled
but benign growth of skin cells, they can be
transmitted from one person to another by
contact. - Medical treatment includes applying extremely
cold liquid nitrogen to them, drying them with
electric current, or burning them off with acid. - Some skin or cervical cancers associated with
this papillomarivius.
16SMALL POX (VARIOLA VIRUS)
- During middle ages 80 of population expected to
contract small pox - Two basic forms of this disease variola major
(mortality rate 20), and variola minor
(mortality rate 1) - Transmission and progression is via respiratory
route, the virus infect many internal organs
before eventually moving into the blood
(viremia)this leads to infection of the skin and
the production of more recognizable symptoms (
virus in epidermal layers causes skin lesions
that house the virus) .
17- Rameses V (1156B.C.) showed evidence of small pox
rash, - Pocahontas (1617) died of small pox
18- Last outbreak in the USA was in 1947, routine
vaccinations for small pox were discontinued in
the United States in 1971 when it was deemed that
the vaccination posed a greater threat that did
contracting - Ali Maow Maalin
19Ali Maow Maalin
The last known case of wild smallpox occurred in
Somalia in 1977
20HERPES SIMPLEX (VIRUS)
- Greek meaning to creep
- both types of herpes simplex viruses may spread
to the brain and cause herpes encephalitis, type
2 70 mortality if untreated - About 90 of the population of the United States
has been infected with the herpes simplex
virusinitial infection usually during infancy,
and often subclinical. - About 15 of the cases develop lesions known as
cold sores or fever blisters (usually occurring
in oral or nasal mucous membranes) these lesions
heal and the infection subsides but recur when
the infection strengthens again ( due to
hormonal, emotional stress or drop in immune
system)
21- Between recurrences, herpes simplex type 1
viruses are latent in the trigeminal nerve
ganglia communication between the face and the
central nervous system. - Herpes simplex 2 virus is transmitted via sexual
contact (lesions appear after incubation period
of 1 week and cause a burning sensation, after
which vesicles appear) urination can be painful,
and walking uncomfortable. ( vesicles heal in a
couple of weeks and contain the virus)( location
of vesicles in female external genitals, males
base of penis)
22- Herpes simplex 2 has latent periods and active
periodsvarying per personit can cross placental
barriers and affect fetusbirth is via c section
to prevent spread of disease to baby if the
disease has not spread thru placenta - There is no cure for genital herpes, however
Acyclovir can be administered topically or
orally.
23- Shakespeare wrote of this unsightly curse in
Romeo and Juliet Oer ladies lips, who
straight on kisses dream/Which oft the angry Mab
with blisters plagues,/Because their breaths with
sweetmeats tainted are
24MEASLES (RUBEOLA VIRUS)
- Extremely contagious disease that spread by the
respiratory route. - Person with measles is infectious before symptoms
appear, thus quarantines not effective - Humans are the only reservoir for measles,
although monkeys are also susceptible. - Law requires immunization for schoolvaccines
being 95 effective.
25- Development and progression of rubeola begins in
the upper respiratory systemincubation period of
10-12 days, symptoms develop including sore
throat, headache, and cough, followed by a
papular rash appearing on the skin, lesions of
the oral cavity include Koplik spots ( tiny red
patches with central white specks (helpful for
diagnostics) on the oral mucosa opposite the
molars - Measles is extremely dangerous disease,
especially in very young or elderly. (1 in 3000
cases fatal in infants, complications such as
encephalitis occur, if at all, about a week after
the rash appears) and can cause severe birth
defects if an expecting mother contracts german
measles
26Koplike patches indicating measles
27SCABIES arthropod
- Infection of the human skin caused by the mite
Sarcoptes scabiei, a parasitic arthropod. - The disease is most common among school children
and is also found in adultssometimes occurring
as a nosocomial infection. - The fingers, wrist, and elbows are the most
frequent sites of infection. - The mite burrow into the skin and fill the tunnel
with their eggs and feces. - The eggs hatch, and new mites mature, mate and
lay more eggs, perpetuating the life cycle.
28- Symptoms are the result of hypersensitivity
reactions to the mites, and first occur 2 to 6
weeks after the initial infection. - main symptom is itching especially when the skin
is warm (ex in bed at night), a red raised
lesions (erythematous papules) develop, which may
become infected with bacteria through scratching. - Diagnosis is made by examination of the skin with
a 10X hand lens to id burrows, sometimes the
mites can be picked out with a needle for
microscopic examination. - Treatment is by a topical application of gamma
benzene hexachloride (kwell) , with bedding and
other personal objects sanitized.
29Scabies
30CUTANEOUS MYCOSES (fungal) ringworms and
athletes foot
- Fungi that colonized the hair, nails and outer
layer of the epidermis are called dermatophytes
and their infection are called dermatomycoses. - Dermatophytes grow on the karatin present in
those locations, causing ringworms ( most being
asymptomatic and removed for cosmetic reasons,
named from Greek time period who believed the
infection to be caused by worms)
31- Dogs and cats are frequently infected with
ringworms, as well as humans, if ring worms are
in the groin region it is called jock itch, if on
the feet it is athletes foot - Treatment is of a variety of topical medications
including miconazole, or clotrimazole, or with
oral medication such as griseofulvin.
32 33CANDIDIASIS Fungi
- The infection of the mouth with the fungi Candida
albicans, which is not affected by antibacterial
drugs, and will sometimes overgrow the mucosal
tissue when normal bacterial flora are
suppressed. - Newborns infants, whose normal flora have not yet
established are often afflicted with candidiasis
of the oral cavity called thrush - Elderly, diabetics, and cancer patients can be
afflicted with candida in the mucosal tissues of
the vaginitis. - Treatment is usually with a topical application
of miconazole, clotrimazole, or nystiatin.
34Thrush
35CONTATGIOUS CONJUNCTIVITIS pinkeye bacteria
- Caused by Hemophilus aegytius, and is transmitted
by hand contact or by flies. - Treatment topical application of antibiotics
(vary)
36BACTERIAL MENINGITIS
- An inflammation of the meninges caused by gram
negative bacteria. - Most patients suffering from any type of
meningitis complain of headache and have symptoms
of nausea and vomiting, convulsions and coma
accompany the infection in many cases. - Mortality rate varies with pathogen but is
generally high for an infectious disease
todaymany survivors suffer from various
neurological damage.
37Meningitis caused by different types of pathogens
(viruses, bacteria, fungi, protozoan)
- There are 3 major types of bacterial meningitis
- meningococcal meningitis caused by Neisseria
meningitides mortality rate 27 - pneumococcal meningitis caused by Streptococcus
pneumonia mortality rate 11 - Hemophilus influenza mortality rate 43 most
common - Diagnosis is via analysis of cerebral spinal
fluid and blood. - Treatment is though a strengic regime of various
antibiotics including Rifampin, penicillin and
ampicillin
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39TETANUS bacteria
- Causitive agent is Clostridium tetani, an
obligate, anaerobic,endospore-forming, gram
positive rod that is common in soil contaminated
with animal feces. - Symptoms are caused by an extremely potent
neurotoxin (tetanospasmin) that is released upon
the dath and lysis of the growing bacteria.(
potent enough that the amount of toxin in the ink
of one . could kill 30 people) - In normal muscle operations, one muscle contracts
and the opposing muscle relaxes
40- This neurotoxin blocks the relaxation pathway so
that both the muscles contract, resulting in
characteristic muscle spasms (if in the jawlock
jaw) - Mode of transmission is improperly cleaned deep
puncture wounds, especially those with little or
no bleeding, immunization is 100 effective and
boosters of every 10 years maintains
immunity..(DPT diphtheria, pertussis, tetanus) - Recovery does not confer immunity, an d about
560,000 babies die each year in Asia and Africa
because their umbilical cords are cut with filthy
instruments or the stump is packed with dirt.
41Tetanus
42BOTULISM Bacteria
- Caused by Clostridium botulinum, an obligately
anaerobic, endospore-forming, gram-positive rod
that is found in soil and many freshwater
sediments. - Ingesting the endospore usually does no harm,
however in anaerobic environments, ex sealed
cans, the microorganisms produces an exotoxin
that is highly potent. - Persons suffering from botulism undergo
progressive flaccid paralysis for 1-10 days and
may die from respiratory and cardiac failure.
43- Symptoms include nausea, but no fever, varying
neurological safe) , difficulty swallowing
,general weakness, blurred Recovery does not
confer immunity - First described 1800s with blood sausage (blood
and ground meat tied in pig stomach and
incubated) - Botulin toxin not formed in foods with acidity
below ph 4.7 ( ex tomatoes - Mortality rate 25 to 40
- Treatment relies heavily on supportive care,
antibiotics of no use because toxin is preformed - Diagnosis by inoculation of mice with samples
from patients serum, stool, or vomitus
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45LEPROSY BACTERIA
- Causitive agent Mycobacterium leprae, an
acid-fast rod, with an optimum growth temperature
of 30 C - first isolated and identified about 1870.
- Sometimes called Hansens disease (avoid term
leprosy)
46Two main forms
- tuberculoid (neural) form characterized by
regions of skin that have lost sensation and are
surrounded by a boreer of nodules. Recovery
sometimes spontaneously - lepromatous (progressive) form skin cells are
infected and disfiguring nodules form all over
bodymucous membrane of nose affected,
deformation of hand into clawed form and necrosis
of tissue
47- Both forms are spread by transfer of bacteria
from lesions or inanimate objects exposed to
lesion discharge - Patients can be made noncommunicable within 4-5
days by administration of sulfone drugs - National leprosy hospital in Carville Lousiana
reports about 200 cases a year. - No vaccine for leprosy currently exists
48POLIOMYELITIS Virus
- Causitive agent poliomyelitis virus
- Best known as a cause of paralysis, however, only
about 10 of infected people develop identifiable
symptoms, and the paralytic form probably
affects less that 1 of those infected. - Symptoms often asymptomatic or mild and may
include headache, sore throat, fever and nausea. - Humans only known natural host
- Primary mode of transmission is ingestion of
water that is contaminated with feces containing
virus
49- Occurrence more often in summer months in
temperate regions - Predilection sites tonsils, lymph nodes of neck
and ileum - Diagnosis based on isolation of virus from feces
and throat secretions - Preventives Salk vaccine and Sabin vaccine (more
common in USA, less expensive and oral medication
of orange flavored medicine)
50Polio
51RABIES virus
- An acute infectious disease that usually results
in fatal encephalitis. - Causative agent is rabies virus (rhabdovirus)
with a characteristic bullet shape - Mode of transmission bite of an infected animal,
even the lick of such an animal can transmit the
virus - Bats probably transmit the disease among
themselves via inhalation of virus in guano (
documented cases of aerosol transmission to
human who spelunker)
52- Initially the virus multiplies in skeletal
muscles and connective tissue then enters the
peripheral nerves to the central nervous system
where it causes encephalitis - Symptoms spasms of muscles of mouth and pharynx
when liquid is swallowed, later stages just the
sight of water causes spasms (hydrophobia), final
stages result from extensive damage to the nerve
cells of the brain and spinal cord.Death
inevitable
53- 2 forms of the disease
- furious rabies dogs highly excitable and snap at
anything within reach - Dumb (paralytic) rabies common in cats, only
minimal excitability - Treatment Pasteur treatment (14-21 inoculations)
and more recent human diploid cell vaccine (HDCV)
(5-6 inoculations) - Carriers skunks 46, bats 19, foxes 10,
raccoons 10,domestic animals 6, dogs 6.seldom
in rabbits, squirrels or mice
54Rabies
55AFRICAN TRYPANOSOMIASIS protozoan
- Causes African sleeping sickness..
- Causative agent Trypanosoma brucei gambiense, a
flagellate that is injected by the bite of the
tsetse fly (arthropod vector) - Predilection site blood
- Symptoms decreased physical activity and mental
acuity, if untreated, the host enters a coma and
death is inevitable. - Treatment drugs only affective when central
nervous system is not affected,, drugs kill 99
but the remaining 1 becomes immune and multiply
in the blood, new antibiotics are used and 99
are killed and the 1 become immune and rebuild
the numbersmaking this a difficult condition to
treat.
56African sleeping sickness
57NAEGLERIA FOWLERI protozoan (amoeba)
- A protozoan known to cause neurological disease.
- Symptoms flu-like and death within one weak
- Etiology the spore enters a broken mucous
membrane, usually oral or nasal and the
protozoan migrates to the brain where it causes
encephalitis like conditions and death. - Most common victims are children who swim in
ponds or streams. - Only a few cases per year are reported, bur
fatality rate is nearly 100
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59ANTHRAX Bacteria
- Common names include splenic fever, mrrian (
biblical term for anthrax), and charbon to name a
few - Anthrax is an acute infectious febrile disease of
virtually all animals caused by Bacillus
anthracis and is generally septicemia in nature
but may be localized. - Clinically characterized in a very short course
(10-12 hrs) - Generally appears in late spring and summer
- It is an aerobic, encapsulated rod, gram
positive, not acid fast and oxygen is necessary
for sporulation. Vegetative form is easy to kill
with disinfectant, 12oF also kills this bacteria
60- Mode of transmission is ingestion, inhalation,
biting insect, - Incubation period 1-14 days usually 3-6Prognosis
unfavorable - Symptoms increased pulse rate (rapid but weak),
temp 104F, spleen enlarged, edema of lungs, Post
mortal findings rigor mortis is incomplete or
completely absent
613 types of Anthrax
- cutaneous anthrax characterized as pustular
infection of skin, danger of septicemia - Inhalation anthrax endospores are inhaled, high
fever, difficulty breathing and chest pain,
septicemia and high mortality rate - Ingestion anthrax ingest endospores and enters
gastrointestinal tract
62KURU AND MAD COW DISEASE
- Kuru occurs in isolated groups of cannibals who
eat brains.
63TAPEWORMS
- Often asymptomatic
- Includes Taenia saginata beef tapeworm,
infestations begin with the consumption of
undercooked beef, pork, or fish, adult worms can
live in the intestines for up to 25 years and
reach lengths of 6 meters (18 feet) - Symptoms abdominal discomfort, psychological
distress, when several feet pass through anus,
flatulence - Drug of choice to eliminate the infection is
niclosamide
64NEMATODES
- Round worm infections including the following
- pinworms Enterobius vermicularis. Which
migrates out anus of human host to lay eggs,
causing local itchingtreat entire house with
pyrantel pamoate, or mebendazole contraction is
oral fecal generally children putting dirty
fingers in mouth.
65- hookworms Necator americanus. Attaches to
intestinal wall and feeds on blood and tissue,
can lead to anemia, or craving unusual food such
as soil or laundry starch, contact is bare skin
in soil, treat with mebendazole.
66- Ascariasis Ascaris lumbricoidescan grow up to
one foot in length, live in intestinal tract and
often diagnosed when adult worm emerge from
anus, may be coughed up and swallowed allowing
for migration to throat, lungs, or abdominal
cavity. - Effectively treated with mebendazole
67CHINESE RESTRANT DISEASE bacterial
- Aka Monosodium glutamate (MSG) which can cause
chest pain, burning sensations, and feeling that
your face is blowing up like a balloon. - The effects depend on how much MSG and vary from
person to person but is a reminder that MSG is
manufactured by Corynebacterium glutamicum, a
cousin to the diphtheria germ
68TUBERCULOSIS bacteria
- A chronic bacterial disease caused by
Mycrobacterium tuberculosis, characterized
clinically by wasting of the body and
granulomatous tubuncles. - Often called white death, it is referred to in
the BibleIt was the plague of the pharaohs - Mode of transmission picked up by injection,
inhalation, wound contamination
69- Etiology it is a slender, rod shaped obligate
aerobe, stains gram positive, is acid fast,
moderate resistance to heat, may stay alive under
moderate conditions 2-4 years - Symptoms gradual lose of weight , coughing,
apnea, partial loss of appetite, unusual signs or
symptoms depending on where the lesion is
located, if body has enough resistance to the
first tubercle, it may become walled off by scar
tissue and never do any other damage to the body
or spread further ( occurred with Marie Currie) - Prognosis unfavorable Incubation time not
definite time
70- By law cattle must me branded on the left jaw
with a T to indicate TB positive animals and a
reactor tag is placed in left ear ( red tag) - Charles Dickens character David Copperfield died
of tuberculosis. Well known personalities that
suffered from TB included King Tut, Edgar Allan
Poe, Chopin, Robert Louis Stevenson, Adolph
Hitler, Nelson Mandela - Treatment today various drugs are used to treat
TB including streptomycin, isoniazid (INH) and
rifampin
71- Charles Dickens character David Copperfield died
of tuberculosis. - Well known personalities that suffered from TB
included King Tut, Edgar Allan Poe, Chopin,
Robert Louis Stevenson, Adolph Hitler, Nelson
Mandela
72YELLOW FEVER arthropod borne virus
- Historically important because it was the first
such virus discovered and provide the first
conformation that an insect could transmit a
virus. - The virus is injected into the skin by the
mosquito ( Aedes aegypti is the vector) - Symptoms fever, chills, headache, backache,
nausea, jaundice - Treatment none
- Incubation period 4-18 days
- Vaccine good for 6 years
73DENGI virus
- Acute but rarely fatal viral disease transmitted
by the mosquito Aedes aegypti. - Sometimes called breakbone fever, characterized
by acutely high fever ,followed by a rash 2-4
days later (mainly on trunk, never on palms of
hands or soles of feet) - Generally will occur between Sept and November
- No specific treatment against the virus
74HOT VIRUS
- ONE THAT SPREADS EASILY, KILLS QUICKLY, WITH HIGH
MORTALITY RATE, AND HAS NOT CURE OR PREVENTIVE
VACCINE
75VIRAL HEMORRAGIC FEVERS (MARBURG/EBOLA
76Marburg (city in Germany)
- 1967 3 factory workers became nauseated and began
to vomit. - Diarrhea set in eyes became severely bloodshot
and a painful rash occurred ( due to blood
clotting in thousands of capillaries), their
throats became so raw they could not swallow and
had to be fed intravenously - within 10 days they began vomiting and defecating
bloodblood and Marburg virus gush in all
directions - If the virus lands on another human, the horrid
cycle of infection begins again, killing about
25 of the people infected - very lethal virus (only 3 documented outbreaks
1967,1976,1990
77- The virus looked like a short piece of yarn (
thus called filovirus) unlike the spherical shape
of most viruses. - Many scientist believe that this was an emerging
virus ( one that had jumped into a new animal
species. - reason it was uncommonly deadly and the new host
has never been exposed to the virus, and the
hosts immune system has no defense against the
virus. - both Marburg,and Ebola are Biosafety level 4
agents, kept under constant negative air pressure
to ensure no escape of the virus as compared to
HIV with is only a level 2 virus
78Ebola (river in Zaire)
- First appearance 1976 (325 of 358 dead),
- kills 90 of its victims,
- it can attack and amplify itself in virtually
any body tissue except bone and perhaps skeletal
muscle. - Characterized by seering headache, fever and
muscle pain, then the bleeding starts (internal
hemorrhaging and the bodys clotting factors
begin, organs such as liver and spleen are
transformed into hardened masses of coagulated
blood and tissue, kidneys become so clogged with
blood that they cease to function, blood flows
into lungs, stomach and intestines death soon
follows often from shock , heart failure or lung
congestion - Ebola does in 10 days what it takes AIDs ten
years to do - it is a filovirus( shaped like a question mark),
transmitted by air, but luckily not easily
transmitted from human to human through casual
contacthospitals where greatest miniepidemics
occur.
79- Antibodies have been collected and used to treat
victims of hot virus diseases. - The blood of one nun, a survivor of Ebola, was
repeatedly tapped for its Ebola antibodieswhen
injected into a person during the early stages of
Ebola fever, it sometimes proved beneficial
80CHAGAS protozoan
- A protozoan disease of the cardiovascular system
- Causitive agent is Trypanosoma cruzi , a
flagellated protozoan - Affects 40 to 50 of population in rural areas of
S. America - Reservoir include rodents, opossums, and
armadillos
81- Arthropod vector is the reduviid bug (kissing
bug)that bites humans or animals around the lips
the wound is scratched and the trypanosome enters
the would - Most damage is due to inflammation around the
wound but the nervous system can be affected (
loss of involuntary muscle contraction in
esophagus and gastrointestinal tract - Treatment is difficult in chronic progressive
stage Nifurtimix drug of choice for treatmentno
cure
82- Some believe that Charles Darwin contracted
chagas on his voyage on the H.M.S. beagle - He was known to have been bitten by the kissing
bug
83MALARIA protozoan
- Characterized by chills, fever and often vomiting
and severe headache Causitive agent is
Plasmodium falciparum, carried by the mosquito
vector Anopheles - The sporozoite enters the bloodstream of bitten
human within 30 minutes of bite, reproducing and
moving to the bloodstream where it causes RBCs to
rupture and the release of the mature
merozoites.fever reaches 104F, sweating begins,
fever subsides and patient feels normal until
cycle begins again ( if 1 RBC infected then over
100,000,000,000 parasites in circula
84- Treatment is with quinine, or quinine derived
antibioticsno effective control of malaria in
sight
85LYME DISEASE spirochete
- Named after location identified (Lyme
Connecticut) - Number 1 tic-borne disease in USACausitive agent
is the spirochete Borrelia burgdorferi and the
vector being a tic Ixodes pacificus
86- Symptoms usually a rash appearing near bite site
that expands out to about 15 cm ( bullseye
appearance) followed by flu like symptoms.if
untreated the heart can become affected (possible
requiring a pacemaker) and neurological symptoms
can occur (face paralysis, meningitis,
encephalitis) other symptoms include chills,
headache, and muscle pain - Treat with antibiotics but the later diagnosed
the more difficult the treatment
87Bulls eye rash
Lyme disease
88ROCKY MOUNTAIN SPOTTED FEVER rickettsia
- The number 2 tic-borne disease in USA
- This rickettsia is a parasitic Tick borne disease
that is passed form one generation of ticks to
another through their eggs (transovarian passage) - Causitive agent is Rickettsia rickettsia , major
tic vectors are Dermacentor andersoni (west) and
D. variabilis (east)
89- Symptoms About one week after bite a rash
appears (often on palms and soles...which does
not occur with viral rashes) resulting in leakage
of blood into surrounding tissues, fever and
headache follow,, death in about 3 cases - Treat with Antibiotics such as testracycline and
chloramphenicol very effective
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92TICK PARALYSIS
- Called ascending flaccid paralysis
- Possibly due to a toxin in the tic saliva,
usually affects children - Incubation period is 4-7 days, most cases in May
and June - Host wakes up paralyzed removal of tic results
in full recoverylike a miracle - Severity of case is according to how close to the
brain the tic isdeath is rare - Causitve agent Dermacentor andersoni
93WHOOPING COUGH bacteria
- Causitive agent Bordetella pertussis, a small,
nonmotile, gram negative coccobacillus, it is an
obligate aerobe. - The organisms does not invade tissues, but rather
attaches to the cilia in the trachea and impedes
their action, allowing mucus to accumulate. - It primarily affects children and is quite severe
94- Symptoms initial stage (catarrhal stage) similar
to common cold, the paraoxysmal stage is
characterized with persistent coughs so violent
that it can break ribs, gasping for air between
coughs causes a whooping sound, and occurs
several times a day for 1-6 weeks. - The Covalescence stage may last for months.
- This is a very long duration for a respiratory
infection, symptoms include high white blood cell
count with diagnosis made from cultured throat
swabs.
95- Transmission is by inhaling pathogens expelled by
coughing of infected patientMild case requires
no specific treatment - Severe cases are treated with Tetracyclines and
chloramphenicol..but only render the patient
uncontagious - Vaccines exist but have considerable safety
concerns (3.2 in 1 million result in neurological
damage)
96INFLUENZA virus
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98- Caused one of the worst plagues ever to afflict
humankind in 1918 (Spanish flu also called Swine
flu 40 million dead within months).It is
pandemic - So desperate the situation that Chicago police
arrested people for sneezing in public and San
Francisco required people to wear surgical masks
over their mouths and noses in pubic violators
were arrested
99- 1957 and 1968 had milder epidemics but
Virologist are scared that before long another
superflu will emerge saying we are already
overdue - Influenza does keep reemerging (reason for flu
shot each year)( only AIDS virus mutates faster
that the Influenza virusboth being classified as
RNA viruses)
100- If the same flu strain appeared each year we
would develop an immunity to it - thus it mutates by changing its viral coat ever
so slightly under a microscope it looks like a
pasta salad with twists of macaroni entwined with
one another ( 8 twisted segments in all)
101- Mutation is due to its ability to enter humans,
pigs and ducks ( thriving in the digestive tract
and allowing a mixing and blending of different
strains.what emerges is a new strain each year)
- If the recombinant strain that is made is capable
of infecting and causing illness in humans, a new
pandemic looms over the horizon
102- Solution keep ducks and pigs and humans away
from one another as much as possible If
different strains are not given the opportunity
to co-infect a host, no superflu can emerge - However in Asian countries hens are hung in
cages above pigs, which feed on the hen
droppings, the pig feces are used to fertilize
fish ponds where ducks swim drink and release
their waste the last few flu strains have been
Hong Kong flu, Shanghai flu and Singapore flu
Luckily there has been no epidemic strain since
1968.
103HANTAVIRUS
- 1950s It was known as Korean hemorrhagic fever,
later renamed hemorrhagic fever with renal
syndrome - Was first discovered in the lung tissue of its
natural host, the striped field mouse, in which
it causes no illness - Kidney involvement seemed to be a hallmark of the
disease. - When rats were tested in Baltimore, Philadelphia,
New Orleans, New York and San Francisco the Seoul
Korea
104- Hantavirus turned up everywhere (1980 due to
importing goods) - The American variety of hantavirus is a more
deadly and silent killer, taking its toll
unnoticed until late 1980s. - It has been confirmed in cases of hypertension
and chronic kidney failure at a frequency 5X
greater than the general public.
105- 1993 a hot hantavirus struck a Navajo
reservation in New Mexico a Navajo Indian passed
away 5 days after his bride to be died both
suffered mild flulike symptoms, then suffered
severe respiratory distressOver a dozen more
cases followed. - One patient sat up in bed in the morning talking
and eating breakfast was on a respirator by
afternoon and was dead that night.
106- Prevention Control of rodent population, wear
mask when doing spring cleaning in garages or
attics if mouse droppings are present.birds
possible are carriers of hanta as well - Treatment poor but a vaccine against certain
strains does exist
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108PLAGUE BACTERIAL
- Also called Black Death due to the characteristic
blackish areas of skin caused by hemorrhages
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112- 14th century ¼ total population in Europe died of
Plague - Causitive agent is Yersinia pestis, a gram
negative rod shaped bacteria transmitted from one
rat to another by the rat flea Xenopsylla cheopis
- Is endemic in wild rodents especially ground
squirrels, prairie dogs and chipmunks with the
number of plague cases reported in the USA
increasing - If the host dies, the rat flea seeks a
replacementanother rodent or a human
113- Virulence is due to the ability of the bacteria
to survive and proliferate inside phagocytic
cells rather than being destroyed. - Symptoms lymph nodes in groin and armpit become
enlarged (swellings called buboes reason for name
bubonic plague), fever develops mortality rate
50-75 if untreated death within one week
114- Particular danger is if the bacteria enters the
blood and lungs (pneumonic plague) mortality
rate 100, even today this disease can rarely be
controlled if not identified within 12-15 hours
of onset of fever.death usually within 3 days
high likelihood of airborne infections from
infected person - Diagnosis is by a fluorescent-antibody testno
vaccines are available except for persons likely
to come in contact with infected fleas
Prevention control rat-based population via
sanitation
115IN CONCLUSION
- A wise man should consider that health is the
greatest of human blessings, and learn how by his
own thought to derive benefit from his illness
Hippocrates
116- Fifty million people drink unfiltered water in
America. - Not surprisingly, waterborne microbes such as
rotavirus, the worlds leading cause of diarrhea
continue to infect, sicken and kill. - Each year thousands of people die in the USA from
infections by the familiar foodborne bacteria,
salmonella and shigella. - Tuberculosis and AIDs are also on the rise in the
USA, Canada and Europe.
117- Jet travel has brought the human population(all 6
million ) together. - It creates a melting pot for pathogens and for
disease transmission. - The extremely virulent viruses emerging from the
rain forests (Ebola, Marburg, Lassa) are no
longer isolated from the population. - The resurgence of tuberculosis has reminded us
that diseases once vanquished can return with a
vengeance
118- To this point we have been blessed.
- The most common yet potentially dangerous
bacterial infections (Step and Staph)remain
susceptible to at least one antibiotic
(vancomycin) and the most virulent or most lethal
infections (Ebola, AIDS, and Marburg) are not
easily transmitted.
119But what if common pathogens become resistant to
all antibiotics?
120What if AIDS or Ebola become airborne and easily
spread as the flue or common cold?
121Given the conditions that exist today, it is a
scary thought.
- There is little doubt that the fourth
horsemanpestilencehas saddled up and is
charging at us.
122The fight against pathogens is never over.
- To quote one epidemiologist We are all in it
together
123AND THE BATTLE CONTINUES!!!!!!