Micro 4 USMLE Flashcards by Mani Yavi

this is an enveloped, single stranded RNA virus with a segmented genome, with a vaccine, that commonly causes illness every winter

influenza virus

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what 2 antigens does the influenza virus contain?

hemagglutinin and neuraminidase

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the influenza virus is responsible for worldwide influenza epidemics. It has rapid genetic changes and puts pts at risk for a fatal ________ superinfection.

bacterial.

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this type of viral influenza vaccine is the major mode of protection. It is reformulated yearly and offered in the fall to health care workers and the elderly

killed

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this type of genetic change involves teh reassortment of viral genome (such as when human flu A virus combines with the swine flu A virus)

genetic shift

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this type of genetic change involves minor changes based on random mutation

genetic drift.

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what is more deadly a genetic shift or drift.

mneu: Sudden Shift is more deadly than a graDual Drift

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give two Rxs for tx and prophylaxis of influenza A

Amantidine & Rimantadine

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Give 2 neuraminidase inhibitors that are useful to tx both influenza A & B

Zanamivir and oseltamivir

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pt presents with strange behavior, seizures, and fear of water, 2 mo after being bit by racoon. He dies quickly of fatal encephalitis. What is the bullet shaped virus that travels to the CNS by migrating in a retrograde fashion up nerve axons

rabies

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what are the characteristic cytoplasmic inclusions in neurons infected by the rabies virus

negri bodies

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these viruses are transmitted by arthropods (mosquitoes, ticks). Classic examples are dengue fever (aka break bone fever) & yellow fever. Note: A varient of dengue fever in Southeast Asia is hemorrhagic shock syndrome

Arboviruses

mneu: ARBOvirus - ARthropod-BOrne virus.

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Give 2 arboviruses

flavivirus, togavirus, and bunyavirus

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pt presents with a high fever and juandice. Wife reports he has been vomiting black stuff. His dz is caused by the flavivirus, and arbovirus transmitted by the Aedes mosquito with a monkey or human resevior.

Yellow Fever

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flavi=______

yellow

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what charicteristic acidophilic inclusions would you expect to see in the liver of a pt with yellow fever

councilman bodies

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Name the herpesviruses

CMV
HSV1,2
EBV
VZV

mneu: get herpes in a CHEVrolet

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this herpes virus causes gingivostomitis, keratoconjunctivitis, temporal lobe encephalitis, herpes labiales via respiratory secretion and saliva

HSV-1

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this herpes virus causes herpes genitalis and neonatal herpes via sexual contact and perinatal transmission

HSV-2

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this herpes virus causes shingles, encephalitis, and pneumonia via respiratory secretions

VZV

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this herpes virus causes infectious mononucleosis & Burkitt’s lymphoma via respiratory secretions and saliva

EBV

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this herpes virus causes congenital infection, mononucleosis (negative monospot), and pneumonia via congenital, transfusion, sexual contact, saliva, urine, or transplant transmission

CMV

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this herpes virus causes Kaposi’s aarcoma in HIV pts via sexual contact

HHV-8

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18 y/o female presents wtih fever, hepatosplenomegaly, pharyngitis, and posterior auricular lymphadenopaty. What virus and what dz?

EBV (herpes virus)

Mononucleosis

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what test should you do to detect mononucleosis and what antibody does it detect

Monospot test tests for heterophil antibodies by agglutination of sheep RBCs

what atypical lymphocytes are circulating in the blood of a pt with mononucleosis.

cytotoxic T cells

what viruses does a Tzank test detect

HSV-1,2, & VZV mneu: Tzank heavens I do not have herpes or varicella

In a tzank test you take a smear of an opened skin vesicle to detect this

multiniucleated giant cell.

what hepatitis virus: this RNA picornavirus is transmitted primarily by fecal-oral route. There is a short incubation period (usually 3 weeks) and No carrieres.

Hep A mneu: Hep A-Asymptomatic (usually), Acute, Alone (no carriers; naked ssRNA)

what hepatitis virus: This DNA hepadnavirus is transmitted primarily by parenteral, sexual, and maternal-fetal routs. It has a long incubation (3 mo). There are carriers. Reverse transcription occurs; however, the virion enzyme is a DNA-dependent DNA polymerase

Hep B mneu: hep B is Blood borne

what hepatitis virus: This RNA flavivirus is transmitted primarily via blood and resembles HBV in its course and severity. Carriers. Common cause of IV drug use hepatitis in the US

Hep C mneu: Hep C: Chronic, Cirrhosis, Carcinoma, Carieres

what hepatitis virus: | this delta agent is a defective virus that requires HBsAg as its envelope. Carriers.

Hep D mneu: Hep D: Defective, Dependent on HBV

what hepatitis virus: this RNA calicivirus is transmitted enterically and causes water-borne epidemics. It resembles HAV in course, severity, incubation. There is a high mortality rate in pregnant women

Hep E mneu: Hep E: enteric, expectant mothers, epidemics

Hep ___ & ____ are spread via the fecal-oral route

A & E mneu: the vowels hit your bowels.

Hep ___ & ____ predispose a pt to chronic active hepatitis, cirrhosis, and hepatocellular carcinomai

B & C

Hepatitis serologic markers: | best test to detect active hep A

IgM HAV Ab

Hepatitis serologic markers: continued presence indicates carrier state of hep B

HBsAg (Ag found on surface of HBV)

Hepatitis serologic markers: PROVIDES IMMUNITY to hep B

HBsAb (Ab to HBs Ag)

Hepatitis serologic markers: Ag assoc. w/ core of HBV

HBcAg

Hepatitis serologic markers: positive during WINDOW PERIOD of Hep B infection

HBcAb

Hepatitis serologic markers: A second different antigenic determinant in the HBV core. Important indicator of transmissibility

HBeAg mneu: BEware

Hepatitis serologic markers: Antibody to e antigen. Indicates low transmissibility of hep B

HBeAb

HBsAg will be + if pt is either in ______ or _______ Hepatitis B

acute or chronic (carrier)

HBsAb is + only when pt has _________ from hep B

completely recovered

this test rises about 2 mo after hep B exposure and remains + after complete recovery

HBcAg

HIV has a ______ genome (2 molecules of RNA)

diploid

HIV capsid is made of ______ (a rectangular nucleocapsid protein)

p24

HIV surface has these 2 envelope proteins

gp41 & gp120

image p 159 HIV

1st test given for HIV is this. It is a sensitive test with a high false positive rate and a low threshold (RULE OUT TEST).

ELISA

After pt tests + with the ELISA test dx of HIV is confirmed by this test. This test is more specific, it has a high false - rate and a high threshold (RULE IN TEST)

Western blot assay

these test allows the physician to monitor the effect of drug therapy on viral load.

HIV PCR/ viral load tests

Elisa/Western blot tests look for antibodies to viral proteins. These tests are often falsy negative when?

first 1-2 mo of HIV infections

Elisa/Western blot tests look for antibodies to viral proteins. These tests are often falsy positive when?

babies born to infected mothers (anti-gp120 crosses the placenta0

when is someone considered as having AIDS (3)

1) =/< 200 CD4 count 2) HIV+ w/ indicator conditon (e.g., PCP 3) CD4/CD8 ratio <1.5

1% of caucasions are homozygous for this mutation granting them immunity from HIV virus (20% are heterozygous leading to slower course)

CCR5 mutation

this mutation is associated with a rapid progression to AIDS

CXCR1

image 160-time course of HIV infection

give 3 opportunistic infections or dzs that attack the brain in AIDS

cryptococcal meningitis, toxoplasmosis, CMV encephalopathy, AIDS dementia, PML

PML is associated with what virus

JC virus

give 1 opportunistic infection or dz that attacks the eyes in AIDS

CMV retinitis

give 3 opportunistic infections or dzs that attack the mouth and throat in AIDS

Thrush, HSV, CMV, oral hairy leukoplakia

what organism causes thrush

candida albicans

what virus causes oral hairly leukoplakia

EBV

give 3 opportunistic infections or dzs that attack the lungs in AIDS

pneumocystis carinii pneumonia (PCP), TB, histoplasmosis

give 3 opportunistic infections or dzs that attack the GI system in AIDS

cryptosporidosis, mycobacterium avium-intracellulare complex, CMV colitis, non-hodgkins lymphoma

what virus can cause non-Hodgkin's lymphoma in AIDS

EBV

give 2 opportunistic infections or dzs that attack the skin in AIDS

shingles, kaposi sarcoma

what virus causes shingles

VZV

what virus causes Kaposi's sarcoma

HHV-8

give 3 opportunistic infections or dzs that attack the genitals in AIDS

genital herpes, warts, and cervical cancer

what virus can lead to cervical cancer

HPV

these are infectious agents that do not contain RNA or DNA (consist only of proteins). They are encoded by cellular genes.

PRions

give 3 examples of diseases caused by prions

Creutzfeldt-Jakob dz (CJD) Kuru Scrapie "Mad cow dz"

this dz caused by prions results in rapid progressive dementia

CJD

Prions are associated with this brain damage

spongiform encephalopathy.

normal prions have this type of conformation; pathologic prions (like CJD) are this conformation.

alpha helix | Beta pleated sheets

Give the dominant normal fora for the body location: skin

staphylococcus epidermidis

Give the dominant normal fora for the body location: nose

S. aureus

Give the dominant normal fora for the body location: oropharynx

viridans streptococci

Give the dominant normal fora for the body location: dental plaque

streptococcus mutans

Give the dominant normal fora for the body location: colon

bacteroides fragilis> e. coli

Give the dominant normal fora for the body location: vagina

lactobacillus, colonized by E. coli and group B strep

T or F: Neonates delivered by cesaerean section have no flora but are rapidly colonized after birth

Give the dominant normal fora for the body location: vagina

lactobacillus, colonized by E. coli and group B strep

T or F: Neonates delivered by cesaerean section have no flora but are rapidly colonized after birth

common causes of pneumonia in children 6 wks -18 yrs

viruses (RSV) mycoplasma Chlamydia pneumoniae Streptococcus pneumoniae

common causes of pneumonia in adults (18-40 y/o)

mycoplasma C. pneumoniae S. pneumoniae

common causes of pneumonia in adults (40-65 y/o)

``` S. pneumoniae H. influenzae Anaerobes Viruses Mycoplasma ```

common causes of pneumonia in the elderly

``` S. pneumoniae Viruses Anaerobes H. influenzae gram negative rods ```

common causes of pneumonia in the hospital

Staphylococcus, gram-negative rods

common causes of pneumonia in immunocompromized

staphylococcus, G- rods, fungi, viruses, PCP (HIV)

common causes of pneumonia after aspiration

anaerobes

common causes of pneumonia in alcoholics or IV drug users

S. pneumoniae, Klebsiella, Staphylococcus

common causes of pneumonia in alcoholics or IV drug users

S. pneumoniae, Klebsiella, Staphylococcus

common causes of pneumonia in postviral infections

staphylococcus, H. influenzae

common causes of pneumonia in the neonate

Group B streptococci, E. coli

common causes of atypical pneumonia

mycoplasma, legionella, chlamydia

Common causes of meningitis in the newborn (0-6mo)

GROUP B STREPTOCOCCI E. COLI Listeria

Common causes of meningitis in children (6 mo- 6yrs)

Streptococcus pneumoniae Neisseria meningitidis H. influenzae type B Enteroviruses

Common causes of meningitis in ages 6-60 y/o

N. MENINGITIDIS Enteroviruses S. Pneumoniae HSV

Common causes of meningitis in 60 + y/o

S. PNEUMONIA G - rods Listeria

Common causes of meningitis in HIV

cryptococcus CMV toxoplasmosis (brain abscess) JC virus (PML)

incidence of this type of meningitis has greatly decreased after the introduction of the vaccine within the last 10-15 years

H. influenzae

On LP pt has increased PMNs, increased, protein, and decreased sugar. CSF pressure is increased. What kind of meningitis is this?

bacterial

On LP pt has increased lymphocytes, increased, protein, and decreased sugar. CSF pressure is increased. What kind of meningitis is this?

fungal or TB

On LP pt has increased lymphocytes, normal protein, and normal sugar. CSF pressure is normal. What kind of meningitis is this?

viral

osteomylitis is usually caused by what bug

S. aureus

osteomylitis in sexually active pts is rearely caused by this organism but they may be infected with this bug and have septic arthritis.

N. gonorrheae

osteomylitis usually occurs in this age group

children

osteomylitis in diabetics and drug addics is often due to this bug

pseudomonas aeruginosa

osteomylitis in pts with sickle cell anemia is often due to this bug

salmonella

osteomyelitis in pts with sickle cell often presents with this elevated lab value

ESR

osteomylitis in pts with prosthetic replacement is often due to these bugs

S. aureus & S. epidermis

vertebral osteomylitis (Potts dz) is due to this bug

Mycobacterium tuberculosis

urinary tract infections in ambulatory pts is most often due to this bug

E-coli (50-80%) | Klebsiella (10%)

2nd most common urinary tract infection young ambulatory women after E. Coli

Staphylococcus saphrophyticus

urinary tract infections in hospitalized pts

E. coli, proteus, klebsiella, serratia, pseudomonas

ratio of UTIs: women to men

10:1 (short urethra colonized by fecal flora)

urinary tract infections are usually caused by ascending infections. T or F

male baby presents with UTI what do you suspect

congenital defect

elderly male presents with UTI. what do you suspect

enlarged prostate

symptoms of UTI

dysuria, frequency, urgency, suprapubic pain

pt presents with fever, chills, flank pain, and CVA tenderness. What do you suspect?

pyelonephritis

some strains of this bug that causes UTI result in a red pigment. Often these infections are nosocomial and Rx resistant.

Serratia marcescens

this is the leading cause of UTI. Colonies show a metalic sheen on EMB agar

E. coli.

This UTI bug is often nosocomial and drug resistant

Enterobacter cloacae

this bug that causes UTIs has a large mucoid capsule and viscous colonies

Klebsiella pneumoniae

this bug that causes UTIs has motility and causes "swarming" on agar. It produces urease and is associated with struvite stones

Proteus mirabilis

this bug that causes UTIs produces a blue green pigment and a fruity odor. It is usually nosocomial and drug resistant

Pseudomonas aeruginosa

If the nitrite test is postitive what kind of bacteria are you looking at

G-

if the leukocyte esterase test is + what type of bug are you looking at

bactreial

UTI bugs can be memorized by the mneumonic--SSEEK PP

``` Serratia marcescens Staphylococcus Escherichia coli Enterobacter cloacae Klebsiella pneumoniae Proteus mirabilis Pseudomonas aeruginosa ```

pt presents with urethritis, cervicitis, PID, prostitis, epididymitis, arthritis, and a creamy purulent discharge. What is the dz and the organism?

Gonorrhea | Neisseria gonorrheae

Pt presents with a painless chancre. What is the dz and the organism?

Treponema pallidum | primary syphilis

pt presents with fever, lymphadenopathy, skin rashes, condylomata lata. What is the dz and the organism?

treponema pallidum | secondary syphilis

pt presents with gummas, tabes dorsalis, general paresis, aortitis, and argyll robertson pupil. What is the dz and the organism?

treponema pallidum | tertiary syphilis

pt presents with painful penile, vulvar or cervical ulcer. What is the dz and the organism?

genital herpes | HSV-2

Pt presents with urethritis, cervicitis, conjunctivitis, Reiter's syndrome, PIDWhat is the dz and the organism?

``` Chlamydia trachomatis (D-K) chlamydia ```

pt presents with ulcers, lymphadenopathy and rectal strictures What is the dz and the organism?

lymphogranuloma venerium | C. trachomatis (L1-L3)

Pt presnts with vaginitis and strawberry colored mucosa. What is the dz and the organism?

trichomoniasis | trichomonas vaginalis

pt presents with opportunistic infections, Kaposi's sarcoma, lymphoma. What is the dz and the organism?

AIDS | HIV

Pt presents with genital warts and koiocytes. What is the dz and the organism?

condylomata acuminata | HPV 6 & 11

Pt presents with juandice What could the STD be and the organism?

HBV | hepatitis B

pt presents with a painful genital ulcer and inguinal adenopathy. What is the dz and the organism?

Haemophilis ducreyi | Chancroid

Pt preents with a noninflammatory, malodorous discharge; positive whiff test, and clue cells. What is the dz and the organism?

bacterial vaginosis | gardnerella vaginalis

this organism is most likely to cause a subacute undiagnosed pelvic inflammatory dz

chlamydia trachomatis

this bug can often causes an acute high fever PID

Neisseria gonorrhea

this cause of PID is the most common STD in the US (3-4 million cases per year).

C. trachomatis

pt presents with cervical motion tenderness (chandelier sign) purulent cervical discharge. Pt may have salpingitis, endometritis, hydrosalpinx, and tubo-ovarian abscess

PID

salpingitis is a risk factor for the following (give 2)

ectopic pregnancy, infertility, chronic pelvic pain, and adhesions

see clue cells on a prep what STD do you think

Gardnerella

see motile on wet prep what STD do you think

Trichomonas

2 most common nosocomial infections are: UTI due to ______ Wound infection due to ______

E.coli | S.aureus

most common pathogens causing nosocomial infections in the newborn nursery are (2)

CMV & RSV

most common pathogens causing nosocomial infections in urinary catheterization are

E. coli, Proteus mirabilis

most common pathogen causing nosocomial infections in respiratory therapy equiptment is?

pseudomonas aeruginosa mneu: presume pseudomonas AIruginosa when AIR or burns are involved

most common pathogens causing nosocomial infections in renal dialysis unit

HBV

most common pathogens causing nosocomial infections in hyperalimentation

candida albicans

most common pathogens causing nosocomial infections in water aerosols

legionella mneu: legionella when water source is involved

Infections dangerous in pregnancy--ToRCHeS

``` Toxoplasma Rubella, CMV HSV/HIV Syphilis ```

If all else fails think this if dealing with pus, empyema, or an absess

S. aureus

If all else fails think this if dealing with a pediatric infection

H. influenzae

If all else fails think this if dealing with pneumonia in CF or a burn infection

pseudomonas aeruginosa

If all else fails think this if dealing with branching rods in oral infection

actinomyces israelii

If all else fails think this if dealing with a traumatic open wound

Clostridium perfringes

If all else fails think this if dealing with a surgical wound

S. aureus

If all else fails think this if dealing with dog or cat bite

pasteurella muticocida

If all else fails think this if dealing with currant jelly sputum

klebsiella

If all else fails think this if dealing with spesis/meningitis in newborn

group B strep