Micro 4 USMLE Flashcards
this is an enveloped, single stranded RNA virus with a segmented genome, with a vaccine, that commonly causes illness every winter
influenza virus
what 2 antigens does the influenza virus contain?
hemagglutinin and neuraminidase
the influenza virus is responsible for worldwide influenza epidemics. It has rapid genetic changes and puts pts at risk for a fatal ________ superinfection.
bacterial.
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
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
this type of genetic change involves minor changes based on random mutation
genetic drift.
what is more deadly a genetic shift or drift.
mneu: Sudden Shift is more deadly than a graDual Drift
give two Rxs for tx and prophylaxis of influenza A
Amantidine & Rimantadine
Give 2 neuraminidase inhibitors that are useful to tx both influenza A & B
Zanamivir and oseltamivir
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
what are the characteristic cytoplasmic inclusions in neurons infected by the rabies virus
negri bodies
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.
Give 2 arboviruses
flavivirus, togavirus, and bunyavirus
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
flavi=______
yellow
what charicteristic acidophilic inclusions would you expect to see in the liver of a pt with yellow fever
councilman bodies
Name the herpesviruses
CMV
HSV1,2
EBV
VZV
mneu: get herpes in a CHEVrolet
this herpes virus causes gingivostomitis, keratoconjunctivitis, temporal lobe encephalitis, herpes labiales via respiratory secretion and saliva
HSV-1
this herpes virus causes herpes genitalis and neonatal herpes via sexual contact and perinatal transmission
HSV-2
this herpes virus causes shingles, encephalitis, and pneumonia via respiratory secretions
VZV
this herpes virus causes infectious mononucleosis & Burkitt’s lymphoma via respiratory secretions and saliva
EBV
this herpes virus causes congenital infection, mononucleosis (negative monospot), and pneumonia via congenital, transfusion, sexual contact, saliva, urine, or transplant transmission
CMV
this herpes virus causes Kaposi’s aarcoma in HIV pts via sexual contact
HHV-8
18 y/o female presents wtih fever, hepatosplenomegaly, pharyngitis, and posterior auricular lymphadenopaty. What virus and what dz?
EBV (herpes virus)
Mononucleosis
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
T
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
T
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
T
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