Flashcards in Chapter 20 Deck (13)
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1
Bacterial Meningitis (29)
-Signs & Symptoms
Sudden high fever; severe meningeal inflammation, and increased white blood cells in the CSF; inflammation causes most signs & symptoms; infection of the brain causes encephalitis; can results in brain changes, coma, and death; can develop rapidly
-Pathogens and Virulence Factors
NEISSERIA MENINGITIS
STREPTOCCUS PNEUMONIAE-MOST COMMON IN ADULTS
HAEMOPHILUS INFLUENZAE _leading cause ***
LISTERIA MONOCYTOGENES- CAN OCCUR IN PREGNAN WOMEN-FETUSES, NEWBORNS, AND ELDERLY AND IMMUNOCOMPROMISED
STREPTOCOCCUS AGALACTIA-CAUSES BACTEREMIA, PNEUMONIA, AND MENINGITIS IN NEWBORNS
Diagnosis, treatment, and prevention
Treated with intravenous antimicrobial drugs, vaccines available
2
Hansen's Disease (Leprosy) 30
-Signs & Symptoms
TUBERCULOID LEPROSY: non aggressive form of disease; strong cell-mediated immune response
LEPROMATOUS Leprosy: More virulent form, weak-cell mediated immune response
-Pathogen & Virulence Factors
MYCOBACTERIUM LEPRAE is the causative agent; distinctive slow growth rate; resistant to antimicrobial drugs
Pathogenesis: best grows in cooler regions of the body; can live inside infected cells for years; may destroy nerve and tissues
Epidemiology: Leprromatous leprosy is becoming rate; transmitted by person to person contact or breaks in the skin
Diagnosis, treatment, & Prevention
confirmed by acid fast vacilli in samples; treated with multiple antimicrobials; may be lifelong treatement; vaccine provides some protection
3
Botulism (31)
Sign & Symptoms
Intoxication with 3 manifestations: Foodborne botulism; Infant botulism (no honey if under 1 yr); Wound botulism
Progressive paralysis on both sides of the body
Pathogen & Virulence Factors
CLOSTRIDIUM BOTULINUM ; Gram positive endospore forming bacillus
Epidemiology
infant botulism most common form in US
Diagnosis, Treatment, and Prevention
3 Approaches to treatment; wash intestinal tract; administration of botulism immune globulin; antimicrobial drugs; prevented by destroying endospores in contaminated food
4
Tetanus (32)
Signs & Symptoms
TIGHTENING OF THE JAW; spasms and contractions may spread to other muscles; irregular heartbeat and blood pressure and profuse sweating may occur
Pathogen & Virulence Factors
CLOSTRIDIUM TETANI is causative agent; found in soil, dust, and the intestines of humans and animals; produce a neurotoxin called tetanospasmin
Pathogenesis:
Can aquire through break in the skin or mucous membrane
-Epidemiology
MORTALITY RATE IS 50% IF UNTREATED; INCIDENCE HAS DECREASED WORDWIDE
Diagnosis & Prevention
Diagnosis based on characteristic of muscle contraction; Vaccine is available against tetanus
5
Viral Meningitis (32)
Signs & Symptoms
Similar to those of bacterial meningitis; usually milder then those of bacterial or fungal meningitis
Pathogens & Virulence Factors
90% caused by RNA viruses in genus ENTEROVIRUS; COXSACKIE A VIRUS, COXSAKIE B VIRUS, ECHOVIRUS
Spread by fecal contamination of food, water, or hands
Pathogenesis
Damage to cells in the meninges triggers meningitis
Epidemiology
More common than bacterial and fungal meningitis; spread via respiratory droplets and feces
Diagnosis, treatment & prevention
Difficult to prevent spread of Enterovirus, no specific treatment available, characteristic signs in the absence of bacteria in CSF
6
Poliomyelitis (34) (Poliovirus)
Epedemics of Polio were common in the past; soon to be eradicated
Signs & Symptoms
ASYMPTOMATIC INFECTIONS: 90% OF CASES
MINOR POLIO; NON SPECIFIC SYMPTOMS 5% OF CASES
NONPARALYTIC POLIO: MUSCLE SPAMS AND BACK PAIN 2% OF CASES
PARALYTIC POLIO: PRODUCES PARALYSIS-LESS THEN 2%
Post polio syndrome can be debilitating
Pathogen & Pathogenesis
Poliovirus is causative Agent; transmitted by drinking water
Epidemiology
Currently exists in Africa & Asia; difficult to control because of high population and poor sanitation, and political/religious tension
Prevention
2 Effective Vaccines available
7
Rabies (35)
Sign & Symptoms
Characteristic neurological virus reaches CNS; Hydrophobia, seizures, hallucination, paralysis
Pathogen & Virulence
Rabies Virus (-ssRNA virus)
Pathogenesis
Transmitted via vite, scratch from infected animal; virus replicates in muscle cells and then moves into neurons
Epidemiology
ZOONOTIC DISEASE
Diagnosis, treatment, & prevention
Postmortem detection of NEGRI BODIES in the brain; diagnosis by unique neurological symptoms; treated with immunoglobulin, vaccine injections, and cleansing infection site; prevented by controlling rabies in domestic animals.
8
Arboviral Encephalitis (36)
ARTHROPOD-BORNE VIRUSES; transmitted by blood sucking arthropods; mosquitos*
Signs & Symptoms
Arbovirus usually cause mild, coldlike symtoms; can cause encephalitis if it crosses the blood brain barrier; can infect many different animals; 6 arboviruses cause most of the viral encephalitis in Americans; WEST NILE VIRUS IS THE MOST SIGNIFICANT IN THE US BY THE CULEX MOSQUITO
Diagnosis, Treatment, Prevention
Diagnosis based on symptoms, confirmed by arbovirus-specific antibodies in CSF; treatment is supportive; prevention involves limiting contact with mosquitos; vaccines only for horses
9
Cryptococcal Meningitis (37) (Fungal)
Signs & Symptoms
Similar to those of bacterial meningitis; loss of vision & coma may occur in later states
Pathogen & Virulence Factors
CRYPTOCOCCUS NEFORMANS is causative agent; two varients of YEAST found worldwide; RESISTS PHAGOCYTOSIS BY DEFENSIVE CELLS
Pathogenesis & Virulence Factors
Infections follow inhalation of spores or dried yest cells; occurs in terminal AIDS patients and in transplant recipients
Diagnosis, treatment, prevention
Diagnosed by detection of fungal antigen in CSF, treated with intravenous antifungal drugs; hospital try to prevent entry with air filtration
10
African Sleeping Sickness (38) (protozoan)
Signs & Symptoms
3 clinical stages; site of bite becomes lesion; parasites in the blood create fever, lymph nodes swelling, and headache; protozoa invade CNS, causing meningoencephalitis; characterized by cyclic waves of parasitemia
Pathogen & Virulence Factors
Caused by TRYPANOSOMA BRUCEI; evades immune system by changing surface glycoproteins
Diagnosis, treatment, and prevention
Diagnosed by microscopic observation of trypanosomes in blood, lymph, spinal fluid, or tissue biopsy
Treatment based on disease stage; must begin soon after infection to be successful; insecticide application can help reduce occurrence
11
Primary Amebic Meningoencephalopathy (protozoan)
Signs & Symptoms
Same as those of meningitis and encephalitis caused by other microbes
Pathogen, pathogenesis, & epidimiology
Caused by ACANTHAMOEBA AND NAEGLERIA; enter hose through abrasions on the skin or the eyelid or by inhalation of contaminated water; rare but almost always fatel
Diagnosis, treatment, and prevention
Detect amoebae in sample from the eye or brain, or in CSF, drugs have limited success; prevented by avoiding contaminated water supplies
12
Spongiform encephalopathies (40) (Prion)
Includes SCRAPIE AND "MAD COW" disease; leaves the brains of victims full of holes; can occur spontaneously in the elderly; humans can contract by eating meat from infected cattle
VARIANT CREUTZFELDT-JAKOB DISEASE
Signs & Symptoms
Insomnia, weight loss, memory failure; progressive worsening of muscle control
Pathogen, pathogenesis, and epidimiology
Caused by a abnormal form of prion protein; turn normal prions into abnormal; medical procedures can spread the disease, prions may remain dormant for years
Diagnosis, treatment, and prevention
Diagnosed by characteristic signs & symptoms; can be confused with other forms of dementia in elderly; no treatment is available; destruction of prions outside of body is difficult; prevent by avoiding prion contaminated meat
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