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UNIT 9: DISEASES AND DISORDERS:. An infection occurs when living agents enter tissue, multiply there and damage the tissue. The General causative agents for disease include:. bacteria viruses fungus Rickettsia protozoan arthropods (acting as vectors)

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Unit 9 diseases and disorders

UNIT 9: DISEASES AND DISORDERS:

An infection occurs when living agents enter tissue, multiply there and damage the tissue.


The general causative agents for disease include
The General causative agents for disease include:

  • bacteria

  • viruses

  • fungus

  • Rickettsia

  • protozoan

  • arthropods (acting as vectors)

  • vermiform (various invertebrate worms)


Staphyloccoccal infections bacteria
STAPHYLOCCOCCAL 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 .


  • 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 treatment…treat with penicillin or erythromycin.


  • Staph infections on newborns includes impetigo (vesicles on the skin rupture and crust over), or scalded skinsyndrome ( 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 touched…serious 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)


Scalded skin syndrome
scalded skinsyndrome



Streptoccocal infection including flesh eating bacteria
STREPTOCCOCAL INFECTION: including flesh-eating bacteria could only have been caused by staph

  • 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


Impetigo is one disease caused by strep infections
Impetigo is one disease caused by Strep infections could only have been caused by staph


  • Strep also causes scarlet fever, infections of the throat could only have been caused by staph

  • Steptococcus pneumonia most common cause of bacterial pneumonia…and also the cause of flesh-eating bacteria (necrotizing fasciitis )

  • S. pneumoniais 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 hour…about 1500-2000 cases in USA per year with fatality rate of 30% in otherwise healthy adults.


Necrotizing fasciitis
necrotizing fasciitis could only have been caused by staph


Jim Henson from muppets died of this bacteria in 1990 from a splinter cut on his finger (duration from time of splinter to death—6 weeks)


Pseudomonads bacteria
PSEUDOMONADS ( splinter cut on his finger (duration from time of splinter to death—6 weeks)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


  • Pseudomonas aeruginosa splinter cut on his finger (duration from time of splinter to death—6 weeks) 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)


Warts viral
WARTS: viral splinter cut on his finger (duration from time of splinter to death—6 weeks)

  • 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.


Small pox variola virus
SMALL POX (VARIOLA VIRUS) splinter cut on his finger (duration from time of splinter to death—6 weeks)

  • 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) .


Rameses V (1156B.C.) showed evidence of small pox rash, splinter cut on his finger (duration from time of splinter to death—6 weeks)

Pocahontas (1617) died of small pox



Ali Maow Maalin 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

The last known case of wild smallpox occurred in Somalia in 1977


Herpes simplex virus
HERPES SIMPLEX: (VIRUS) 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

  • 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 virus…initial 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)


  • Between recurrences 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, 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)


  • Herpes simplex 2 for small pox were discontinued in the United States in 1971 when it was deemed that the vaccination posed a greater threat that did contractinghas latent periods and active periods…varying per person…it can cross placental barriers and affect fetus…birth 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.



Measles rubeola virus
MEASLES (RUBEOLA VIRUS Juliet: “ O’er ladies’ lips, who straight on kisses dream/Which oft the angry Mab with blisters plagues,/Because their breaths with sweetmeats tainted are” )

  • 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 school…vaccines being 95% effective.


  • Development and progression of rubeola begins in the upper respiratory system…incubation 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


Koplike patches respiratory system…incubation 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

indicating measles


Scabies arthropod
SCABIES: arthropod respiratory system…incubation 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

  • 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 adults…sometimes 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.


  • 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.


Scabies mites, and first occur 2 to 6 weeks after the initial infection….


Cutaneous mycoses fungal ringworms and athletes foot
CUTANEOUS MYCOSES: (fungal) ringworms and athletes foot mites, and first occur 2 to 6 weeks after the initial infection….

  • 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)


  • 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 athlete’s foot

  • Treatment is of a variety of topical medications including: miconazole, or clotrimazole, or with oral medication such as griseofulvin.


Ring worms well as humans, if ring worms are in the groin region it is called jock itch, if on the feet it is athlete’s foot

Athletes foot


Candidiasis fungi
CANDIDIASIS: Fungi well as humans, if ring worms are in the groin region it is called jock itch, if on the feet it is athlete’s foot

  • 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.


Thrush
Thrush well as humans, if ring worms are in the groin region it is called jock itch, if on the feet it is athlete’s foot


Contatgious conjunctivitis pinkeye bacteria

Caused by well as humans, if ring worms are in the groin region it is called jock itch, if on the feet it is athlete’s footHemophilus aegytius, and is transmitted by hand contact or by flies.

Treatment topical application of antibiotics (vary)

CONTATGIOUS CONJUNCTIVITIS: pinkeye bacteria


Bacterial mening itis
BACTERIAL MENING well as humans, if ring worms are in the groin region it is called jock itch, if on the feet it is athlete’s footITIS:

  • 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 today…many survivors suffer from various neurological damage.


Meningitis caused by different types of pathogens viruses bacteria fungi protozoan
Meningitis caused by different types of pathogens (viruses, bacteria, fungi, protozoan)

  • There are 3 major types of bacterial meningitis:

  • meningococcal meningitis: caused by Neisseriameningitides mortality rate 27%

  • pneumococcal meningitis caused by Streptococcuspneumonia 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


  • Tetanus bacteria
    TETANUS: bacteria bacteria, fungi, protozoan)

    • 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


    • This neurotoxin blocks the relaxation pathway so that both the muscles contract, resulting in characteristic muscle spasms (if in the jaw…lock 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.


    Tetanus
    Tetanus the muscles contract, resulting in characteristic muscle spasms (if in the jaw…lock jaw)


    Botulism bacteria
    BOTULISM: Bacteria the muscles contract, resulting in characteristic muscle spasms (if in the jaw…lock jaw)

    • 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.


    • 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


    Leprosy bacteria
    LEPROSY: BACTERIA safe)

    • Causitive agent Mycobacterium leprae, an acid-fast rod, with an optimum growth temperature of 30 C

    • first isolated and identified about 1870.

    • Sometimes called Hansen’s disease (avoid term leprosy)


    Two main forms
    Two main forms: safe)

    • 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 body…mucous membrane of nose affected, deformation of hand into clawed form and necrosis of tissue


    • 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


    Poliomyelitis virus
    POLIOMYELITIS: Virus or inanimate objects exposed to lesion discharge

    • 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


    • Occurrence more often in summer months in temperate regions or inanimate objects exposed to lesion discharge

    • 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)


    Polio or inanimate objects exposed to lesion discharge


    Rabies virus
    RABIES: virus or inanimate objects exposed to lesion discharge

    • 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)


    • 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


    • 2 forms of the disease connective tissue then enters the peripheral nerves to the central nervous system where it causes encephalitis

    • 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


    Rabies connective tissue then enters the peripheral nerves to the central nervous system where it causes encephalitis


    African trypanosomiasis protozoan
    AFRICAN TRYPANOSOMIASIS: protozoan connective tissue then enters the peripheral nerves to the central nervous system where it causes encephalitis

    • 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 numbers…making this a difficult condition to treat.


    African sleeping sickness connective tissue then enters the peripheral nerves to the central nervous system where it causes encephalitis


    Naegleria fowleri protozoan amoeba
    NAEGLERIA FOWLERI: protozoan (amoeba) connective tissue then enters the peripheral nerves to the central nervous system where it causes encephalitis

    • 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%


    Anthrax bacteria
    ANTHRAX: Bacteria connective tissue then enters the peripheral nerves to the central nervous system where it causes encephalitis

    • 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


    • 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


    3 types of anthrax
    3 types of Anthrax: insect,

    • 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



    Tapeworms
    TAPEWORMS: insect,

    • 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


    Nematodes
    NEMATODES: insect,

    • Round worm infections including the following:

    • pinworms: Enterobius vermicularis…. Which migrates out anus of human host to lay eggs, causing local itching…treat entire house with pyrantel pamoate, or mebendazole… contraction is oral fecal …generally children putting dirty fingers in mouth.


    hookworms insect, : 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.


    Ascariasis insect, : Ascaris lumbricoides…can 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


    Chinese 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

    CHINESE RESTRANT DISEASE: bacterial


    Tuberculosis bacteria
    TUBERCULOSIS: bacteria burning sensations, and feeling that your face is blowing up like a balloon.

    • 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 Bible…It was the “plague of the pharaoh’s”

    • Mode of transmission: picked up by injection, inhalation, wound contamination


    • Etiology: burning sensations, and feeling that your face is blowing up like a balloon. 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


    • 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


    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


    Yellow fever arthropod borne virus
    YELLOW FEVER: arthropod borne virus tuberculosis….

    • 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


    Dengi virus
    DENGI: virus tuberculosis….

    • 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 againstthe virus


    Hot virus

    HOT VIRUS; tuberculosis….

    ONE THAT SPREADS EASILY, KILLS QUICKLY, WITH HIGH MORTALITY RATE, AND HAS NOT CURE OR PREVENTIVE VACCINE



    Marburg city in germany
    Marburg (city in Germany): tuberculosis….

    • 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 blood…blood 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


    • 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


    Ebola river in zaire
    Ebola (river in Zaire) filovirus) unlike the spherical shape of most viruses.

    • 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 body’s 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 contact…hospitals where greatest miniepidemics occur.



    Chagas protozoan
    CHAGAS: protozoan hot virus diseases.

    • 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


    • 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 treatment…no cure


    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


    Malaria protozoan
    MALARIA: protozoan voyage on the H.M.S. beagle

    • 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


    Treatment is with quinine, or quinine derived antibiotics…no effective control of malaria in sight


    Lyme disease spirochete
    LYME DISEASE: spirochete antibiotics…no effective control of malaria in sight

    • 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


    • Symptoms antibiotics…no effective control of malaria in sightusually 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


    Bulls eye rash antibiotics…no effective control of malaria in sight

    Lyme disease


    Rocky mountain spotted fever rickettsia
    ROCKY MOUNTAIN SPOTTED FEVER: rickettsia antibiotics…no effective control of malaria in sight

    • 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)


    • Symptoms: antibiotics…no effective control of malaria in sight 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


    Tick paralysis
    TICK PARALYSIS antibiotics…no effective control of malaria in sight

    • 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 recovery…like a miracle

    • Severity of case is according to how close to the brain the tic is…death is rare

    • Causitve agent: Dermacentor andersoni


    Whooping cough bacteria
    WHOOPING COUGH: bacteria antibiotics…no effective control of malaria in sight

    • 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


    • Symptoms: antibiotics…no effective control of malaria in sightinitial 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.


    • Transmission antibiotics…no effective control of malaria in sightis by inhaling pathogens expelled by coughing of infected patient…Mild 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)


    Influenza virus
    INFLUENZA: virus antibiotics…no effective control of malaria in sight


    • 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


    • 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 virus…both being classified as RNA viruses)



    • 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


    • Solution: ducks ( thriving in the digestive tract and allowing a mixing and blending of different strains….what emerges is a new strain each year) 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.


    Hantavirus
    HANTAVIRUS: ducks ( thriving in the digestive tract and allowing a mixing and blending of different strains….what emerges is a new strain each year)

    • 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


    • 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.


    • 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 distress…Over 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.


    • Prevention: Mexico… 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 aswell

    • Treatment: poor but a vaccine against certain strains does exist


    Plague bacterial
    PLAGUE: BACTERIAL Mexico…

    • Also called Black Death due to the characteristic blackish areas of skin caused by hemorrhages


    • 14th century ¼ total population in Europe died of Plague Mexico…

    • 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 replacement…another rodent or a human


    • 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


    • 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 test…no vaccines are available except for persons likely to come in contact with infected fleas Prevention: control rat-based population via sanitation


    In conclusion

    IN CONCLUSION: 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

    “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


    • Fifty million people drink unfiltered water in America. 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

    • Not surprisingly, waterborne microbes such as rotavirus, the world’s 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.


    • 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


    • To this point we have been blessed. together.

    • 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.




    Given the conditions that exist today it is a scary thought

    Given the conditions that exist today, it is a scary thought.

    There is little doubt that the fourth horseman—pestilence—has saddled up and is charging at us.


    The fight against pathogens is never over

    The fight against pathogens is never over. thought.

    To quote one epidemiologist “ We are all in it together”



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