BACTERIAL DISEASES OF THE SKIN (1 STAPHYLOCCAL SKIN INFECTIONS Staphylococcus aureus: Pyogenic (pus producing) Produce: Leukocidins, b-lactamase, Alpha-Delta toxin and TSS toxin (Toxic shock syndrome) PATHOLOGY Cutaneous lesions: ______________________________, Abscess, Folliculitis, Furuncles, Carbuncles Scalded Skin Syndrome: Epidermis becomes necrotic and peels off (desquamation) Exfoliative toxin (phage transduction) ________________________________: Highly contagious skin infection Superficial pustules gcrusted g rupture ginfects adjacent area, spreading (possible entry into bloodstream) Impetigo of the Newborn: Pemphigus neonatorum Systemic Disease: Osteomyelitis, Endocarditis, Pneumonia, Meningitis Treatment: Susceptibility testing (MRSA: Methicillin-Resistant Staph. aureus) STREPTOCOCCAL SKIN INFECTIONS Streptococcus pyogenes : Gm + cocci in chains Beta Hemolytic ; Group A Produce: Streptolysins (Hemolytic), Streptokinase (Fibrinolysin), ____________ protein (Rheumatic Fever Ag) Inhibits phagocytosis Hyaluronidase (Dissolves hyaluronic acid) Protein G (Binds Fc portion of Ab, becomes coated with "self") Proteases (Cleave antibodies protecting mucous membranes) Impetigo: (5-10% of Impetigo) Not life-threatening, but can lead to poststreptococcal glomerulonephritis. ______________________________: (Saint Anthony?s Fire) Effects both the epidermis and underlying dermis. Spreads quickly as bac. travel through lymphatic vessels. Painful reddish, swelling patches. May cause fatal septicemia. Scarlet Fever: Sore throat, fever, nausea and vomiting. "Strawberry tongue" ; bright red rash can cover much of the body. Caused by erythrogenic toxin. ______________________________Fasciitis: Mimics gas gangrene. Destroys sheath covering skeletal muscles, the muscles themselves as well as fat tissue. Exotoxin A: Superantigen (abnormally large quantities of cytokines g damage endothelial cells lining blood vessels g fluid loss and tissue death from lack of oxygen.) Exotoxin B: Cysteine protease (destroys tissues by breaking down proteins) Inflammatory acne Propionibacterium acnes: Gm + Rod. Acne lesions. An inflammatory disorder. Lesions develop when sebum becomes trapped in pores. Bacteria break down sebum producing fatty acids that initiate an inflammatory Pseudomonads Pseudomonas aeruginosa: Gm neg. Motile rods Found in soil, water, plants and flowers. Minimal organic material required for growth. Can use a wide variety of organic compounds: Can grow in: respiratory equipment, catheters, soaps, antiseptics and disinfectants solutions. A major cause of nosocomial infections: Burn patients, immunosuppressive or antibiotic therapy g Fatal infections due to Exotoxin A ___________________________Externa : (Swimmer?s Ear) Infection of the ear external to the eardrum. (2 VIRAL DISEASES OF THE SKIN _____________________________: Papovavirus family (icosahedral DNA) Human Papilloma Virus: (HPV) Common and benign (May be associated with cancer) Transmission: Probably direct contact Smallpox (Variola) : Poxviridae: Lg. Brick shaped DNA virus Patho: 10-14 days g high fever, chills, convulsive seizures in children g vomiting g stupor g coma Last ~3days (feel better) g sore throat and skin lesions (macular g papular g vesicular g pustular) Other symptoms return. Pustules rupture leaving pitted scars (pox) Oct. 26,1979 WHO pronounced smallpox ____________________________. Routine vaccination ended in the U.S. in 1972 Transmission: Respiratory route Chickenpox :Varicella-Zoster Virus (VZV)/ Herpes VZ Herpesviridae: 2 stranded DNA, Icosahedral. Enveloped Patho: Inc. ~2 wks : Fever, Headache, Malaise g Enters bloodstream g localizes in peripheral nerves and skin g Forms vesicles, itch and break open yielding infectious virus laden fluid. Usually self limiting Complications: Reye?s syndrome, Encephalitis, Pneumonia, Damage to blood vessels. (Virus can cross the placenta g congenital abnormalities) (More severe in adults ~30% develop pneumonia; 1in 5 adult cases fatal ) Virus may remain latent in dorsal root ganglion. Yrs. later physical or psychological stress (immunosuppression) activates the virus g ________________________ (Herpes Zoster): Similar to chickenpox but more localized. (Waist, face, upper chest, back) Headache, fever, and pain. Transmission: Respiratory droplets and skin lesions Prevention: Vaccine Treatment: Avoid aspirin in children Measles (_______________________) Lat. Rub= Red (1.5 mill deaths/yr world wide) Paramyxovirus: Morbillivirus: Helical RNA virus Trans and Patho: Contact with respiratory droplets and/or conjunctiva of the eyes (Highly contagious) ~9-11 days Koplik spots (red patches with white centers along the gum line) g characteristic red skin rash (starts at the hairline spreads down) (T-cell Rxn) ~1 wk rash fades g Usually complete recovery. Complications: Middle ear infec., Pneumonia, SSPE (subacute sclerosing panencephalitis) Brain damage may be fatal. (SSPE ~1/1million cases) Prevention: MMR (Measles-Mumps-Rubella) Rubella (________________________Measles) Togavirus: Rubivirus :RNA icosahedral, Enveloped Trans and Patho: Respiratory droplets and nasal secretions g inc. 2-3 wks g often subclinical or rash, and fever. Complications: ____________________________ rubella, virus crosses to fetus g Deafness, Cataracts, Heart defects, Mental retardation, Stillbirth (~15% fatal w/in 1st yr) (3 Cold Sores/Fever Blisters Herpesvirus: _________________________________________ Type I (HSV-1) Icosahedral, Enveloped, DNA Causes episodic infections (Latency) Trans and Patho: Oral contact with saliva (Kissing; utensils) contact with skin lesions, stools, urine, etc. Initial infection: subclinical or lesions on oral mucosa (tongue, gums; inner cheeks), mouth, lips, face g latent in ganglia of facial nerves (life long carrier) gTrauma (UV light, fever, hormonal changes associated with menstrual cycle, emotional strain and upset) Can trigger an outbreak. Herpetic _________________________________: Infections on fingers caused by contact with HSV-1. Fifth Disease Human parvovirus ____________ produces flu-like symptoms and facial rash. Roseola Human herpesvirus 6 causes a high fever and rash, lasting for 1-2 days. MYCOTIC INFECTIONS MYCOTIC INFECTIONS OF THE SKIN (Dermatomycoses) SUPERFICIAL MYCOSES These Fungi occupy outer epidermal surfaces. Infections are not inflammatory or invasive. _________________________: Colored nodules on hair shaft. White Piedra: Trichosporon begigelii Black Piedra: Piedraia hortae Tinea __________________________ caused by Malassezia fur fur Normal inhabitant of the skin Produces scaling which interferes with pigmentation. Results in spotty or mottled appearance. CUTANEOUS MYCOSES Ringworm (________________________) Trichophyton, Microsporum, Epidermiphyton Of the Body: Tinea corporis the Groin (Jock itch): Tinea cruris the Head: Tinea capitis the Foot: (Athlete?s foot) Tinea pedis the Hand: Tinea manuum the Beard: Tinea barbae the Nails: Tinea unguium SUBCUTANEOUS MYCOSES Sporotrichosis (Rose-gardner's Disease) caused by Sporothrix schenckii Common Saprophyte. Found in soil/humus. Introduced by thorns and splinters. Penetration of skin g Fungus grows forming hard nodule. (days-months) gEnlarges to bubo g Becomes necrotic g Breaks through skin and drains g Often progresses along lymphatic channels leaving a chain of lesions. Contained by regional lymph nodes but may persist for several yrs. untreated. Chromoblastomycosis : Fonsecaea pedrosoi Characterized by _____________________________ (Tough, warty) lesions. Generally not painful g many individuals do not seek treatment g disease continues to progress. Mycetoma (Madura Foot) : Madurella, and Actinomyces (4 OPPORTUNISTIC MYCOSES Candidiasis : Candida albicans Infections run from: Superficial skin togFatal systemic. Widespread ________________________, normal flora of: oral cavity, genitalia, and large intestine Increased risk of infection: Age, pregnancy, use of birth control pills, immunodeficiency, antibiotic therapy, and providing a warm moist environment against the skin. ______________________/Oral Candidiasis Common in newborns who pick it up in passage through the vagina. White milk like growth covering the mucus membranes of the oral cavity. Vaginitis : Itching, burning sensation, white ?cheesy? discharge. May become systemic: Meninges and heart tissues involved. Scabies Pediculosis Pediculus humanus capitis (head louse) P. h. corporis (body louse) Feed on blood. Lay eggs (___________________) on hair Trachoma (Inclusion Conjunctivitis: Mild form in infants) Chlamydia trachomatis : A leading cause of _______________________________. Obligate intracellular parasite. Infection causes scar tissue to form on cornea. 2nd infections from dry eyes. Transmission: Fingers/Fomites; Flies _____________________________________________________________________________________________ MICROBIAL DISEASES OF THE NERVOUS SYSTEM Bacteria can grow in the cerebrospinal fluid in the subarachnoid space of the CNS. The blood brain barrier (capillaries) prevents passage of some materials (such as antimicrobial drugs) into the CNS. Meningitis: Inflammation of meninges. Encephalitis: Inflammation of the brain. Fever, headache, stiff neck Followed by nausea and vomiting. May progress to convulsions and coma. _____________________________________________________________________________ Bacterial Meningitis Haemophilus influenzae Meningitis Occurs mostly in children (6 months to 4 years) _____________________________________________________________________________ Neisseria Meningitis (Meningococcal Meningitis) N. meningitidis 10% of people are healthy nasopharyngeal carriers. Begins as throat infection and rash. Vaccine against some serotypes is available. _____________________________________________________________________________ Streptococcus pneumoniae Meningitis 70% of people are healthy nasopharyngeal carriers. Most common in children (1 month to 4 years) Mortality: 30% in children, 80% in elderly. Prevented by vaccination. _____________________________________________________________________________ (5 Listeriosis _____________________________________ monocytogenes: Gm+ rod 1985 epidemic in LA and Orange County CA. ~100 tons of cheese destroyed. 48 deaths: 30 infants/fetuses18 adults) Signs & Symp: Several forms of disease: Meningitis: Headaches, stiff neck, delirium g coma Bacteremia: Increased # of Monocytes Infected Uterus: Flu like symptoms Neonatal and Fetal infections: Disseminated abscesses and granulomas. Typically fetus is aborted or stillborn Transmission: Consumption of animal products: Raw milk, cheese and meat _____________________________________________________________________________ Tetanus Tetanus Clostridium tetani: Common in soil Produces: ____________________________________ (causes sustained muscle contraction, blocks relaxation of antagonistic muscles) Exotoxin: 2nd most potent toxin known. Trans. & Symp. : Spores in wound g ~2 -10 days: muscle stiffness and spasm g muscles of face and neck contract (lockjaw/risus sardonicus) g arching of the back g respiratory failure. Prevention: __________________________ _____________________________________________________________________________________________ Botulism Clostridium botulinum Gm+ obligate anaerobe, endospore forming. Found in soil and fresh water sediments. Pathology: Produces exotoxins (________________________________, a Neurotoxin that blocks the release of acetylocholine and prevents transmission of nerve impulses across the synapses) (1 cup of Botulin is thought to be enough to kill the entire population of the world) Botulinal Toxins Type A: 60-70% mortality rate. Found in CA, WA, CO, OR, NM Type B: 25% mortality rate Europe and eastern U.S. Type E: Found in marine and lake sediments Pacific Northwest, Alaska, Great Lakes area. Transmission : Ingestion of exotoxin in food. Within hours (1-36h) Symptoms occur: Double/Blurred vision, slurred speech, labored breathing, vomiting difficulty swallowing g flaccid paralysis g death due to respiratory and cardiac failure. Infant Botulism Organism may grow in the intestinal tract of infants (approx. 30% of cases from _______________________________, 10-13% of honey tested contained C. bot.) Honey should not be fed to infants<1yr old. Transmission : Ingestion of endospores (or viable organisms) in food. _____________________________________________________________________________ (6 Leprosy (_______________________________ Disease) Mycobacterium leprae : acid fast; cannot be grown on artificial media: footpads of mice & armadillo tissues. Pathology: Incubation 2-9yrs 2 Forms: Tuberculoid/Neural Form: Bacteria grow in peripheral nerves (PNS) gRegions of skin lose sensation and are surrounded by a border of nodules. (Rarely contagious) __________________________________/Progressive Form : Infected skin cells g Disfiguring nodules (Lepromas) & Tissue necrosis Transmission: Multiple skin contacts or respiratory droplets. _____________________________________________________________________________________________ VIRAL DISEASES OF THE NERVOUS SYSTEM Poliomyelitis ____________________________________ (3 serotypes) Humans only known natural host. Virus remains infectious outside the body in food or water. Signs & Symp: ~90% Subclinical Polio 4-8% Abortive Polio: Slight fever, malaise, headache, sore throat; vomiting. Nonparalytic: As above with muscle tenderness and spasms. Major Polio (CNS is affected) Paralytic: 5-7 days after fever gloss of superficial and deep reflexes, constipation; urine retention gParalysis: Extent depends on degree of spinal cord damage. Transmission: ________________________ contaminated with feces containing the virus. Pathology: Virus multiplies in the throat & intestines g invades tonsils & lymph nodes g blood (viremia) most cases don?t progress g virus enters CNS (high affinity for motor nerves in the spinal cord (neurotropic) g multiply in nerves g cell death & paralysis Prevention: Vaccine Salk (1954) Contains killed poliovirus. __________________________ (1963) Oral vaccine: Weakened/attenuated live virus. Both are available as trivalent: Types I, II, III Type III may revert to virulence Treatment: Supportive: Physical therapy; Braces etc. _____________________________________________________________________________________________ Rabies Rhabdovirus ?Bullet shaped? Can infect most warm blooded animals. Trans. & Symp.: Virus enters through wound contaminated with saliva. Urine and blood can be infectous through mucous membranes or eye conjunctiva. Incubation: 6 days to 2 years: burning at bite site, fever, malaise etc. 2-10 days after prodromal symptomsg Phase of excitation: Agitation, anxiety, apprehension g ______________________________________ (spasms while trying to swallow,dehydration) g paralysis, vascular collapse gcoma and death. _____________________________________________________________________________ Arboviral Encephalitis Encephalitis (Acute inflam. of the brain) St. Louis (SLE), Western Equine (WEE), Eastern Equine (EEE), California encephalitis (CE) West Nile (WNV) Trans. & Symp.: Mosquito Infects : Birds & Horses g Humans: Chills, headache, feverg mental confusion g coma. EEE most severe: Neurological damage, brain damage, deafness. (7 FUNGAL DISEASES OF THE NERVOUS SYSTEM _______________________________________ Crytococcus neoformans Soil saprophyte. Yeast form only. Symptoms: Lungs gBlood stream gBrain and Meninges (chronic meningitis) Head ache and vomiting gCNS involvement gFatal within 3yrs. Can also cause cutaneous lesions. Transmission: Inhalation of ______________________________ _____________________________________________________________________________________________ THE CARDIOVASCULAR AND LYMPHATIC SYSTEM Bacterial Infections of the Heart ____________________________________ Inflammation of the endocardium. (Inner layer of the heart: Lines the heart muscle itself and covers the heart valves) Subacute bacterial endocarditis Develops slowly over weeks or months. Alpha-hemolytic streptococci from mouth. Acute bacterial endocarditis _____________________________________ from mouth. Pericarditis Inflammation of the sac around the heart. Streptococci. _____________________________________________________________________________________________ Tularemia Fanciscella tularensis Common in: rodents, rabbits, moles g cats and dogs. Trans. & Symp.: Tick bites, direct contact with infected animals, _______________________________, eating infected meat. Tick bite (Deer flies, Rabbit lice): Skin ulcer g ~1 wk lymph nodes enlarge gsepticemia gpneumoniag abscesses throughout the body. Bite: _______________________________ Tularemia Inhalation: Pneumonic Tularemia Contaminated meat: Typhoid Tularemia Eye: Oculoglandular Tularemia _____________________________________________________________________________________________ Brucellosis (_____________________________________ Fever) Brucella abortus Signs & Symp: (Chronic may last years) Fever (undulant : increases in the evening), chills, profuse sweating, headache, hepatosplenomegaly; enlarged lymph nodes. Complications: Meningitis & Encephalitis, Abscesses in: testes, ovaries, kidney or brain. Transmission: Consumption of contaminated dairy products, undercooked meat, cattle secretions or excretions in cuts or eyes. _____________________________________________________________________________________________ (8 Anthrax __________________________________ anthracis Cattle are routinely vaccinated Cutaneous anthrax Endospores enter through minor cut. 20% mortality Gastrointestinal anthrax Ingestion of undercooked food 50% mortality Inhalational anthrax Inhalation of endospores Approaches 100% mortality _____________________________________________________________________________________________ Gangrene Gas Gangrene: (Anaerobic cellulitis (localized) and Myonecrosis) Clostridium perfringens Interrupted blood supply to tissue (______________________________________) g anaerobic environment gClost. grows in deep tissues. Produces: Lecithinase (Breaks down fibers in tendons), Hyaluronidase: Spreading factor, Hemolysin (Destroys RBCs) Also produces large amounts of gas (Rips tissues apart) Symptoms: Intense pain and swelling at wound site, foul order, tissues become red g green g blue-black. ___________________________________________________________________________________________ Bubonic Plague (__________________________________________________________) Yersina pestis: Gm- short rod Sylvatic plague: Rodent pathogen (Zoonosis), Western Ground Squirrels most common reservoirs in the US. Septicemia plague: Septic shock Trans. and Symp. : Vector: Xenopsylla cheopis (________________________ flea) Bacteria enter blood (mult. in monocytes) g lymph nodes (Bubo = swelling) fever & dark purple spots (Hemorrhages) : 60-90% fatal within 10 days. untreated ______________________________________ Plague: Bacteria carried by blood to lungs. (Highly contagious) Human to Human by droplet route. (~100% fatal untreated) Prevention: Rat control, Vaccine available for high risk personnel and military. ___________________________________________________________________________________________ Lyme Disease Trans. & Symp. : _____________________________bite (Ixodes) g sm. red skin lesion at bite site g Expands to a large patch with a bright red border (hot to the touch) Erythema Chronicum Migrans (ECM) g along with flu like symptoms. Complications: 1 wk - 4 months later: Arthritis, neurologic (destruction of myelin sheath) and cardiac involvement. ___________________________________________________________________________________________ Epidemic Typhus Rickettsia prowazekii Trans. & Symp. : Human ____________________________________ (Pediculus) Feces of louse rubbed into bite wound by scratching gHigh prolonged fever (2+ wks) g Rash (subcutaneous hemorrhage) on the trunk; extremities g frightful dreams, hallucinations & delirium. Often fatal untreated. ___________________________________________________________________________________________ Epidemic Murine Typhus Rickettsia typhi Reservoir: Rodents Vector: Xenopsylla cheopsis Rat flea Symptoms similar to epidemic typhus. Less severe: mortality rate <%5 ___________________________________________________________________________________________ (9 Rocky Mountain ____________________________________Fever Rickettsia rickettsii Measles-like rash except that the rash appears on palms and soles of the feet. Trans. & Symp.: Ticks ghigh fever; skin rash (pink spots = Macules) gPapules fuse to form Macropapular rash, these become dark red ( palms, soles of feet; ankles g trunk) fades in ~2 wks. Often (20%) fatal untreated. Prevention: Vaccine available. Protective clothing & Insect repellent. _____________________________________________________________________________________________ VIRAL DISEASE OF THE CARDIOVASCULAR AND LYMPHATIC SYSTEMS Infectious _________________________________________ Epstein-Barr virus (Human herpesvirus 4) Infections mononucleosis: (Kissing Disease) Primarily in 15-25 yr. olds. By mid-life 90-95% sero(+) Transmission: Virus in saliva. Direct contact or contaminated utensils. Fomites and Arthropod vectors???? Pathology and Symptoms: Sore throat, fever, enlarged cervical lymph nodes (lymphadenopathy), Gray/white pharyngeal exudate, skin rash, and enlarged spleen and liver. Leukocytosis: gB-cells, Tsuppressor and Cytotyoxic T-Cells. _______________________________________Potential: Burkitt?s Lymphoma: B-cell malignancy in the jaw area. Nasopharyngeal Carcinoma: Malignancy of epithelial cells. in immunosuppressed individuals, malaria patients and AIDS patients. Lymphatic Tumors: In kidney transplant patients and AIDS related cancers. ___________________________________________________________________________________________ Cytomegalic Inclusion Disease Cytomegalovirus (CMV) (Human herpesvirus 5) The most common cause of congenital infections. __________________________________: Syphilis, Toxoplasmosis, Other, Rubella, Cytomegalovirus, Herpes Simplex Viruses. (Organisms that can infect a developing fetus) Epidemiology & Transmission: Transmitted in: Saliva, respiratory mucus, breast milk, urine, semen, blood, cervical secretions; feces. (Sexual contact, vaginal birth, transplacental, blood transfusions and organ transplants) Pathology: Most adults are asymptomatic. Increased pathology in fetuses, newborns and immunodeficient individuals. ________________________________________ CMV Developmental trauma: Enlarged liver and spleen (Hepatosplenomegaly) Jaundice and capillary bleeding. CNS: Microcephaly, seizures, ocular inflammation g death may follow. Survivors exhibit long-term neurological sequelae (Hearing and vision disorders and mental retardation) Disseminated Cytomegalovirus Opportunist in AIDS patients: Fever, severe diarrhea, hepatitis, arthritis, pneumonia g?high mortality. Heart, kidney and bone marrow transplants: pneumonitis, hepatitis. Increased risk of secondary bacterial and fungal infections. _____________________________________________________________________________________________ (10 Hemorrhagic Fevers Yellow Fever : Arbovirus: ____________________________________ borne (Monkeys natural reservoir) Flavivirus YF (Togavirus family) Trans. & Symp.: Mosquito (Aedes aegypti) Blood g lymph nodes gjaundice (bile pigments in blood) fever, bleeding gums, bloody stools, vomiting blood, delirium. 5-30% fatal. Prevention: Vaccine 17-D Strain (virus cultivated in chicken eggs or mouse brain tissue); mosquito abatement/control. _____________________________________________________________________________________________ Dengue Fever (Virus closely related to YF virus) Trans. & Symp.: ____________________________________ (Aedes aegypti): High fever, sharp pain in muscles and joints (Break Bone Fever) Dengue Hemorrhagic Fever: Hemorrhages in skin and shock. ___________________________________________________________________________________________ Hantavirus Pulmonary Syndrome A family of 8-10 viruses. In the USA causes: Hantavirus Pulmonary Syndrome (______________________Corners Disease) Transmission: Carried by a common deer __________________________________ (Found throughout N. America and every California county) Infected rodents shed live virus in salvia, feces, and urine. Inhalation of particles that contain dried rodent urine or feces. May be transmitted by rodent bites. No evidence of human to human transmission. Symptoms: Incubation 1-2 weeks but up to 6 weeks. gFlu like symptoms, fever, muscle aches, cough and headache gseveral days later respiratory problems worsen rapidly. Lungs fill with fluid g?death from respiratory failure, often within as little as 4 hours. Prevention Rodent control. _____________________________________________________________________________________________ DISEASES OF THE RESPIRATORY SYSTEM Most common form of infection. Continued contact with air/external environment. Respiratory System (2Divisions) Upper Resp. System: Nose and throat and associated structures: Sinuses, nasolacrimal ducts, middle ear, and eustachian tubes. Lower Respiratory System Larynx, trachea, bronchial tubes, and alveoli. Bacterial Diseases of the Upper Respiratory System Streptococcal Sore Throat (Strep. Throat) Streptococcus pyogenes Symptoms: Fever and Pharyngitis, Inflammation of mucus membranes of the throat, tonsillitis. Lymph nodes in the neck enlarge. Complications: Otitis media (middle ear infection) Scarlet Fever: Some Strep. pyogens produce erythrogenic toxin: Damages capillaries g blood leaks into surrounding tissues g red rash on neck and chest g lags and arms. Rheumatic Fever: Arthritis and heart valve damage. Transmission:Respiratory secretions/airborne droplets (11 Diphtheria Corynebacterium diptheriae: Produces potent exotoxin (Corynephage mediated) Diphtheria exotoxin interferes with protein synthesis in epithelial cells gdead cells, mucus and fibrin accumulate over mucus membrane of the upper respiratory tract. (___________________________________________): Grayish green membrane. Diphtheria = leather/membrane May block air passages to lungs g fatal Complications: Myocarditis, neurologic and renal involvement. Transmission: Inhalation of droplets Prevention: DPT Vaccine now DTaP D = Diphtheria toxoid _____________________________________________________________________________________________ Viral Diseases of the Upper Respiratory System Common Cold: A number of different viruses: Coronavirus __________________________________ (most common >100 serotypes) Adenovirus (most severe) Symptoms: Sneezing, excessive nasal secretions and congestion. Transmission: Mucus droplets during coughing, sneezing and talking. Contact with fomites, hand to hand. _____________________________________________________________________________________________ BACTERIAL DISEASES OF THE LOWER RESPIRATORY SYSTEM Pertussis (_______________________________________________) (Endemic world wide) Bordetella pertusis: small Gm neg. coccobacillus, virulent forms often have a capsule, obligate aerobes. Pathology: Attaches to ciliated epithelial cells of trachea and bronchi by means of pili g produces both endo and exotoxin Primarily a childhood disease? Symptoms: Incubation 7-10 days Catarrhal Stage: Symptoms similar to common cold, sneezing, hacking nocturnal cough. Loss of appetite, listlessness. (Highly contagious at this stage) __________________________________ Stage: (~2 weeks later) Bacteria grow in trachea and bronchi g causes production of thick tenacious mucus (impedes ciliary action) g severe, spasmodic & recurrent (Episodic) cough in an attempt to expel this material. (Gasping for air between coughs causes ?whoop? sound) vomiting is common g patient is left exhausted and anoxic (short of oxygen) Convalescent Stage : (May last months) Coughing subsides, even a mild upper respiratory infection may cause relapse. Complications: Physical trauma from violent coughing may cause: conjunctival hemorrhage, detached retina (may result in blindness), rectal prolapse; hernia. Transmission: Direct: Inhalation of droplets Indirect: Contaminated linen and bedding Prevention: DPT P for Pertussis (Heat inactivated whole bacteria) Now DTaP (a = acellular) (12 Tuberculosis (TB ?Nearly one-third of the world's population is infected with Tuberculosis (TB), which kills almost 3 million people per year. TB causes more deaths than any other infectious agent in the world. In the mid-1980s, a resurgence of outbreaks in the United States brought renewed attention to TB. An increase in high risk, immuno-suppressed individuals, particularly those infected with HIV, has lead to an increase in TB cases. Drug-resistant strains of this deadly disease also contribute to the problem. In 1990, the Centers for Disease Control and Prevention (CDC) found that nursing home employees are three times more likely to contract TB than any other group of employed adults of similar age, race, and sex?. ____________________________________tuberculosis: Curved, slender Gm + rods (often moldlike) Obligate aerobes, slow growing, Acid fast, Resistant to sunlight, antiseptics and disinfectants. Survive 6-8 months in dry sputum. Symptoms: Incubation ~4-8 weeks gnonspecific symptoms: fatigue, weakness, weight loss, night sweats, low grade fever g bacteria reach lungs and the body walls off the organisms. (Tubercle) Bacteria may lie dormant in the tubercle for years greactivate and spread. Tubercle may undergo necrosis g Caseous Lesion ?g caseous lesion heals to form ________________________________________ (scar formation and calcification seen on chest X-ray) Caseous lesion may rupture g spread of infection by blood and lymph (Miliary tuberculosis/Consumption) gweight loss, coughing, loss of vigor. Transmission: Droplet route. Prevention: Vaccine (BCG) Bacillus of Calmette and Guerin: Live Myco. bovis (a cattle pathogen) averulent after long cultivation on artificial media. _____________________________________________________________________________________________ Pneumococcal Pneumonia Streptococcus pneumoniae : Gm+ diplococcus, heavy capsule. alpha hemolytic (>83 serotypes) Symp. & Patho.: Fever 102-105oF, shaking chills, chest pain, difficulty breathing, cough with blood tinged sputum. (Both bronchi and alveoli involved) Transmission: Respiratory secretions Prevention: Vaccine Pneumococcal Polysaccharide Vaccine (Pneumovax) ____________________________Streptococcal Pneumonia Streptococcus pyogenes _____________________________________________________________________________________________ Klebsiella Pneumonia Klebsiella pneumoniae 1-3% of bac. pneumonias Gm - encapsulated rod _________________________________________________over 40yrs old most susceptible. Often in malnutrition Mortality untreated >85% Transmission: Respiratory route and nosocomial infections. _____________________________________________________________________________________________ Serratia Pneumonia Serratia marcescens: Gm- rod Operation Seaspray 1951-1952 San Francisco. Increased pneumonia & UTIs at Stanford. Isolated Serratia (13 Legionnaires? Disease (______________________________________) Legionella pneumophila Gm- rod (Previously unknown bac.) (1976) Members of the American Legion meeting in Philadelphia. 182 contracted pneumonia and 29 died. Symp. & Path.: Inc. 2-10 days g nonspecific/prodromal symptoms diarrhea, anorexia, malaise, headache, fever (as high as 105oF) cough g More acute symptoms: vomiting, disorientation (mental confusion), temporary amnesia. Complications: Delirium, arrhythmias, acute resp. failure, renal failure, and fatal shock. Transmission: (Person-to-Person uncommon) Inhalation:Organism found in water (able to live and multiply in waterborne protozoa): Air conditioners, water supplies of hotels and hospitals, well water. Pontiac Fever: Milder form of Legionellosis Pontiac Fever Milder form of Legionellosis Haemophilus Pneumonia Haemophilus influenzae: Gm- coccobacillus 1o pneumonia in children 2-5yrs old 2o pneumonia in patients recovering from viral infection. Complications: Meningitis in children, obstructive epiglottitis (Obstruction of the trachea g tracheotomy required) _____________________________________________________________________________________________ ATYPICAL PNEUMONIA No bacterial agent isolated g viral agent was suspected. ___________________________________ Pneumonia (1o Atypical pneumonia (PAP) Walking Pneumonia Mycoplasma pneumoniae: Smallest free-living cellular organisms, Lack cell walls: allows passage through filters 0.2u in diameter. Symptoms: Fever, fatigue and dry hacking cough. _____________________________________________________________________________________________ Psittacosis (Ornithosis) ____________________________ psittaci: Gm- obligate intracellular parasite, Elementary bodies: resistant/ dormant form. Symptoms: Fever 103-105oF, headache, chills, nausea and vomiting. In birds: Diarrhea, ruffled feathers, breathing problems ?droopy appearance?. Complications: CNS involvement: Disorientation and delirium, stupor. Extensive pulmonary infection g cyanosis ~20% Fatal untreated < 4% treated Transmission: Inhaling organism in airborne dust (bird droppings) Bite of infec. bird or droplets from infec. human. _____________________________________________________________________________________________ Q Fever (Query) Endemic in CA. ARIZ. Oregon and WASH. Coxiella burnetii: Rickettsia (Obligate intracellular parasite) Symptoms: Inc.18-21 days Headache, fever, dry cough, nausea and vomiting, burning eyes. Complications: Rare: Endocarditis, Meningitis Transmission: Animal to animal by ticks, inhaling contaminated dust (tick or cattle feces), respiratory droplets, unpasteurized milk, tick bite to humans (rare) (14 VIRAL DISEASES OF THE LOWER RESPIRATORY SYSTEM Influenza: Orthomyxoviridae virus RNA: 8 separate segments capable of reassorting during viral assembly. H Spike: (Hemmagglutinin) Binds to host cells. N Spikes: (Neuraminidase) Assist in viral budding and release. _________________________________ Varation: Major outbreaks associated with the development of new strains of the virus. New strains result from mutation and reassortment Type A: Every 2-4 years (Most pandemics) Type B: Every 4-6 years (Geographically limited) Type C: Only sporadic cases Antigenic ________________________: Minor mutations in the genes that code for the H & N spikes. Antigenic Shift: Reassortment of RNA from different strains. Symptoms: Inc. 24-48 hrs g?Sudden onset of chills, fever, headache, malaise and cough Complications: Pneumonia (1o viral or 2o Bacterial) Reye?s Syndrome: High fever, protracted vomiting, liver and brain damageg coma and death. Transmission: Respiratory droplets, indirect contact Prevention: Vaccine (Vaccine complication 1976: Guillain-Barre? Syndrome (GBS) Paralysis g coma g 5% fatal _____________________________________________________________________________________________ FUNGAL DISEASES OF THE LOWER RESPIRATORY SYSTEM Histoplasmosis (______________________________________ Disease) Histoplasma capsulatum: Dimorphic fungus (25oC = mold form, 37oC = yeast form) Yeast form: Phagocytized by WBCs, and found in RES macrophages g Not destroyed but grow in WBCs. _____________________________________________________________________________________________ Coccidioidomycosis (San Joaquin _______________________________Fever, Valley Fever) Coccidioides immatis: _____________________________ Fungus Symptoms: Common cold like g pneumoniag 1% lead to visceral, bone and CNS involvement. Transmission: Inhalation of spores. _____________________________________________________________________________________________ Pneumocystis Pneumonia (___________________) Pneumocystis jiroveci Formerly carinii Multiply in lung alveoli g Fills air spaces g Often fatal in AIDS patients. Transmission: Droplet route/inhalation _____________________________________________________________________________________________ (15 _____________________________________________ Blastomyces dermatitids Dimorphic Fungus Symptoms: Most asymptomatic Chronic skin disease Systemic disease may involve any organ or CNS 30-60 deaths/yr Transmission: Inhalation of spores or through cuts. _____________________________________________________________________________________________ _________________________________________ Aspergillus fumigatus Continues to grow in a mold form within the body. Forms Aspergillomas (Ball of mycelium) in the lungs. Systemic: Blood vessels g Thrombosis g Seizures. Transmission: Inhalation of spores. Symptoms: Flu like: Chest pain, headache, chills Complications: Ulceration of: Tongue, palate and larynx. Meningitis, endo and pericarditis. Progressive disseminated disease: 90% fatal untreated. Transmission: Inhalation of spores. _____________________________________________________________________________________________ MICROBIAL DISEASES OF THE DIGESTIVE SYSTEM Diseases of the digestive system rank 2nd only to respiratory diseases. Most result from ingestion of contaminated food and water. (Microorganism or their products) Many can be controlled by: Handwashing, Sewage treatment, fly (and cockroach) control, disinfecting drinking water, and proper preservation of food. Diseases of the Mouth ________________________________________(Tooth decay) Streptococcus mutans : (S. sanguis, salivarious) Gm+ coccus Adhere to teeth by glucans/dextran g Dental Plaque Strep. mutans : Ferments sugars g Lactic and other acids gDissolves tooth enamel and dentin. Prevention : Brushing, Flossing, Fluoride; Decrease Sucrose intake Periodontal Disease (Inflammation & Degeneration of the gums, and supporting bone) _________________________________________________________________________________________ Acute Necrotizing Ulcerative Gingivitis (ANUG) (_________________________________ Mouth) Prophyromonas gingivalis Bacteroides gingivalis Ulcers & Necrosis of periodontal tissues g Tooth loss Predisposing Factors: Poor oral hygiene, stress, heavy smoking, malnutrition. _________________________________________________________________________________________ DISEASES OF THE LOWER DIGESTIVE SYSTEM Food Intoxication vs. Food ____________________________________________ Food/Bacterial Intoxication: Results from ingesting contaminated food or water containing preformed bacterial toxins. Symptoms occur rapidly 1-36hrs. Food/Bacterial Infection: Disease results from microbial growth in host tissues. Slower onset of symptoms. 1day-2weeks (16 Food/Bacterial Intoxication Staphylococcus Food Poisoning/Intoxication Staphylococcus aureus: Gm+ Cocci Produces: Exotoxins (Enterotoxin A-D) Very heat stable (Withstands boiling for 30min) Signs & Symptoms: Rapid onset 1-6hrs after ingesting contaminated food. (Creamy dishes, salad dressing, custards & meats, especially ham) Nausea, vomiting, diarrhea; cramps. Rarely Fatal. Last about 24hrs. Transmission: Ingesting contaminated food. (Food handlers: 25-30% carriers) Sufficient toxin to cause disease is produced in a few hours (dependent on temperature) Toxin is odorless and tasteless _________________________________________________________________________________________ ____________________________________Dysentery (Shigellosis) Shigella spp. Gm neg. Nonmotile rods. Produce exo & endotoxins (Shiga toxin) Signs & Symp: Inc 1-7 days (Within 6hrs host cells lyse) Shig. sonnei: Most common species in the US. Causes a mild dysentery Shig. dysenterae: (Central Amer. & Tropical countries)Severe dysentery: Ulcerations of the intestinal mucosa, high fever (in children), cramps, diarrhea with bloody-mucoid stools. Can effect CNS (convulsions in children) Transmission: Contaminated food and water. ?Gay Bowel Syndrome? from anal sex. _____________________________________________________________________________________________ Salmonellosis (Food _____________________________________________) Salmonella spp. (typhimurium, eteritidis, newport) Gm neg. motile rods. Produce Endotoxins 2100+ serotypes. All members of Sal. are pathogenic to some degree. Signs & Symptoms: Inc. 12-36hrs (Varies with # of organism ingested) Bacteria multiply and die g endotoxin released g Moderate fever, nausea, cramps; diarrhea. Mortality <1% (4million cases/yr, 500-2000 deaths/yr) Transmission: Ingesting contaminated: Poultry, eggs, egg products (Ice cream, mayonnaise) Raw milk (1983 outbreak in CA) Pet turtles (reptiles in general) FDA prohibited sales of turtles < 4in long in 1975. Prevention: Proper cooking of poultry and eggs, disinfection of cutting surface (Plastic or marble bread boards???) _________________________________________________________________________________________ _______________________________ Fever Salmonella typhi Signs & Symptoms: Inc ~ 2 weeks g Fever, malaise, headache (Last about 1 week) g 2nd week Fever 104oF, chills, delirium, abdominal pain and distention, rash, constipation (diarrhea generally does not occur until late in the disease) g 3rd week, Increased fatigue and persistent fever. Complications: Can leave the GI tract (___________________________________________) and invade other organs (Liver, spleen, gall bladder, lungs, lymph tissue; heart) Transmission: Contaminated food and water. Flies, Food Handlers: ?Typhoid Mary? Mary Mallon. NY cook. (1903 Ithaca NY. 1300 deaths) Prevention: as above. Vaccine (killed salmonella cells) Recommended for travel to: India, Mexico and Mediterranean. DNA probes of food. Cholecystectomy of carriers. _____________________________________________________________________________________________ (17 Cholera Vibrio Cholerae: Motile, curved Gm neg. rods. Produce Exotoxin and Enterotoxin Signs & Symp: Inc. hrs-days: Enterotoxin gIncreased permeability of the intestinal wallgbody fluids and electrolytes are excreted, ?_____________________ water stools? (intestinal epithelial cells, mucus and bacteria) gsudden loss of fluid. (1 liter/hr ~ 3.2 gal/day) g blood thickens. Viscous blood: Organ dysfunction, vomiting, decreased blood to brain g shock, collapse g coma g death. Transmission: Contaminated food and water. Prevention: Vaccine ~ 60% effective for 3-6 months ________________________________________________________________________________________ GASTROENTERITIS Esherichia coli: Gm neg rod (#1 cause of infant mortality 5-15% of children <5 years old in some areas) Enterotoxigenic strains: Produces 2 toxins (a heat labile and a heat stable) Infantile/Epidemic diarrhea (in nurseries), Travelers diarrhea (Turista, Delhi Belly, etc.) 0157:H7 ______________________________________ syndrome Prevention: ?Don?t drink the water? Antibiotic prophylacsis: Doxycycline/Vibramycin. Peptobismol _________________________________________________________________________________________ Campylobacter jejuni: Gm neg rod. Trans: Raw milk, water and meat Clostridium difficile: Pseudomembranous colitis Clostridium perfringens: Gm + Endospore forming, Obligate anaerobe. Transmission: Meats and stews _________________________________________________________________________________________ Vibrio parahaemolyticus Similar to V. cholerae The most common cause of gastroenteritis in Japan and S. E. Asia. Present in Hawaii and both coasts of the US, and Cruise ships. (Sardines, crab, tuna, shrimp, oysters, clams, squid; mackerel) Signs & Symp: 2-48hrs inc: Watery diarrhea, cramps, nausea, vomiting, headache, weakness, chills; fever. Self limiting: Last ~2 days Transmission: Ingesting uncooked or undercooked seafood: shellfish, crab, shrimp, fish, etc. _________________________________________________________________________________________ Helicobacter pylori: Stomach _________________________________ and Stomach cancer _________________________________________________________________________________________ VIRAL DISEASES OF THE DIGESTIVE SYSTEM _________________________________________ (Parotitis) Paramyxovirus: Enveloped helical virus, SSRNA Signs & Symp: Inc 16-18 days Painful swelling of the parotid glands & fever Complications: Orchitis: 20-30% of males past puberty. Sterility now disclaimed. Meningitis, inflammation of the ovaries, pancreatitis, hearing loss and encephalitis. Transmission: Droplets, fomites Pathology: Multiplies in respiratory tract and lymph nodes in the neck ? blood ? salivary glands Prevention: Trivalent Vaccine: (MMR) Measles-Mumps-Rubella _________________________________________________________________________________________ Hepatitis A (Infectious Hepatitis) 50% of US pop. infected by adulthood. Does not cause chronic hepatitis or cirrhosis Vomiting, abdominal pain, diarrhea, fever, jaundice. Most infections resolve within 6-10 weeks Pts become immune (lifelong) Can cause acute liver disease, and in rare cases death. Transmission: Oral-Fecal route Prevention: Vaccine Hepatitis B (Serum Hepatitis) ~300,000 new cases/yr US & 200 deaths of health care workers/yr (6-30% fatal from needle stick unvaccinated) Often progresses to cirrhosis, chronic hepatitis, liver cancer and death. Loss of appetite, nausea and vomiting, fever, fatigue, abdominal pain, dark urine, jaundice. Transmission: IV drug use, needle stick, tattoos or body piercing, sexual contact, dialysis, blood transfusions (before 1972), fomites (survives several days) Prevention: Vaccine now recommended for newborns, infants, teenagers, and health care workers. ____________________________________________________________________________________________ Hepatitis C (Posttransfusion Non A Non B hepatitis) Prevalent and underreported ~170,000/yr US. Chronic hepatitis, cirrhosis and death. Transmission: As for HBV (Transfusions before 1992) ____________________________________________________________________________________________ Hepatitis D (Delta Virus) A _______________________________________ of HBV Chronic hepatitis, cirrhosis and death ____________________________________________________________________________________________ Hepatitis E (Enteric Non A Non B Hepatitis) Rare in the US 10% Mortality rate in pregnant females. Acute infection. Not chronic Transmission: Contaminated water _____________________________________________________________________________________________ _______________________________________: Norwalk Agents: Probably cause 1/3 of all gastroenteritis outbreaks. Infect mostly older children and adults Rotavirus: Causes sever infantile diarrhea. The most common cause of viral enteric disease worldwide. _________________________________________________________________________________________ MYCOTOXINS (Toxins produced by ____________________________________) Poisonous Mushrooms Amanita phalloides (Death Cap) Amanita virosa (Destroying Angel) Potent toxins: Phalloidin and Amanitin: 8Hrs before onset of symptoms (stomach pains and violent vomiting, intense thirst, cyanosis of extremities, renal and liver failure: 50% fatal. _________________________________________________________________________________________ _____________________________Poisoning: Claviceps purpurea Grows on grains (rye) Causes hallucinations, constriction of capillaries ggangrene of the extremities. _________________________________________________________________________________________ Aflatoxin: Aspergillus flavus: Grows in various grains/cereals; corn. Found in animal feed; peanut butter. Carcinogen. Known to cause cancer (liver and colon) _________________________________________________________________________________________ DISEASES OF THE GENTIAL AND URINARY SYSTEM Urinary System: Kidneys, Ureters, Urinary bladder, and Urethra. Genital System: Reproductive organs, and organs that support and nourish the developing fetus. Bacterial Diseases of the Genital and Urinary System Urinary Tract Infections (UTI) ~10X more common in females Urethritis: Infection of the urethra Cystitis: Infection of the bladder Prostatitis: Infection of the prostate Pylonephritis: Infection of the kidney Various Gram neg. _______________________________________ Bacteria: Eschericha coli, Klebsiella, Proteus, Enterobacter, Pseudomonas, Serratia Signs and Symptoms: Frequency & Urgency of urination ________________________________________: Difficulty or pain in urinating (Burning feeling) Nocturia: (Incontinence) Involuntary voiding of urine at night. Bladder cramps and spasms. _____________________________________________________________________________________________ Leptospirosis Leptospira interrogans Reservoir: ________________________________________________ Transmitted by skin/mucosal contact from urine-contaminated water. Weil?s disease: kidneys and liver become infected. Kidney failure: may be fatal _____________________________________________________________________________________________ Gonorrhea Neisseria gonorrhoeae: Gm- ?coffee bean? shaped diplococci, pili for attachment, aerobic and fastidious: Doesn?t survive well outside the body. 1-2Hrs No immunity: Neisseria produces a protease that inactivates IgA, and frequently alters its antigens. Transmission: ________________________________ Signs and Sym: Inc. 2-7 days. Females: Bac. invade epithelium of cervix & urethra: burning on urination, abdominal pain; vaginal discharge. Untreated 20-50% progress to PID. Males: Pain & burning on urination, whitish/yellowish discharge g1-2% disseminated: Epididymis (may cause sterility), Arthritis, Myocarditis, Meningitis. Gonococcal pharyngitis Gonococcal proctitis (infection of the rectum) Opthalmia neonatorum (can result in blindness _________________________________________________________________________________________ Chlamydial Urethritis (NGU) _______________________________________urethritis Chlamydia trachomatis: Obligate intracellular parasite. Transmission: STD Signs and Sym: Inc. ~1-3wks: Females: burning sensation during urination, inflammation of the cervix (The 1o site of infection), slight vaginal discharge g C. tract. may spread to: Fallopian tubes (Blockage/Salpingitis) PID: Pelvic Inflammatory Disease (Any extensive bacterial infection of pelvic organs) Males: Painful urination and watery discharge g inflammation of the epididmymis (Epididymitis) may cause sterility. Chlamydial Opthalmia (Inclusion Conjunctivitis): Acquired by newborns burning passage through an infected birth canal. _________________________________________________________________________________________ ________________________________________ Treponema pallidum: Spirochete Transmission: STD Signs and Sym: Inc. ~3wks. Primary Syphilis: Chancre (Painless ulcer at site of entry: often a genital organ) Disappears after ~2-6 wks. Several weeks pass g2o syphilis: fever, swollen lymph nodes, skin rash, loss of hair; jaundice. Symptoms may clear at this point)g 3o syphilis: ________________________________(Soft, granular lesion): Gummas of skin and bone (bone deformity) Gummas of CNS (Neurosyphilis), eyes, heart:g insanity, blindness; death. Congenital Syphilis : Lesions; Poor bone formation. Hutchinson?s triad: Deafness, Impaired vision and Notched peg-shaped teeth. (20 VIRAL INFECT. OF THE URINARY & GENITAL SYSTEMS Gential Herpes (HSV-2) Herpes Simplex Virus Type _______ Transmission: STD Signs and Sym: Inc. 2-14 days g Mult. lesions in genital area (males: external genitals, females: cervix), fever, malaise, headache, muscle pain. HSV2 shed from lesions. ~12 days a dry crust formsgHealing complete within ~3 weeks. HSV2 remains latent in dorsal _____________________________________ ganglia. At least 60% of infected individuals with HSV2 have recurrent genital herpes (4-5 episodes/yr) Last only 10-14 days, milder than primary infection. Neonatal Herpes: Females with active genital herpes have ~40% chance of infecting their infant (during passage through the birth canal) Cesarean section recommended. Skin lesions on newborn (at birth or up to 3 wks later) gcan disseminate to CNS, encephalitis (75% fatal untreated) Trans Placental: Rare: Microcephaly and Micropthalmia Hepetic Whitlow: Health care workers. Extremely painful and itchy lesions. Usually on one finger. ~2-3 wks to heal. _________________________________________________________________________________________ Gential Warts: Papilloma Virus (5 Types: 6, 11, 16, 18; 31) Now regarded as the most common STD Signs and Sym: Invades external and internal genital membranes (particularly areas prone to friction) Warts range from small flat to giant, branching, cauliflower-like masses (Condylomata Acuminata) Associated with cancer of cervix and penis.
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