Doc, its Ebola

Question 1

Rapid Strep Test

Answer 1

Swab, ELISA technique to detect Group A strep cell wall

Specificity >95%

Sensitivity > 90%

Good technique improves sensitivity

Question 2

Throat pathogens

Answer 2

Streptococci, Gonococci, Meningitides, pertussis, diptherium

Question 3

Throat culture

Answer 3

culture on chocolate agar or strep-specific agar, gram stain and culture is ID’d

usually takes 2 days

Question 4

Negative rapid strep, negative throat culture

Answer 4

if sx persist 3+ weeks, could be acid reflux, or throat cancer. Could also be a fungus- candida albicans, thrush in immunocompromised pts

Question 5

Streptolysis O

Answer 5

Produced by strep pyogens. Its toxic to PMNs, RBCs, platelets, etc. It increases the virulence of strep-pyogens.

Question 6

ASO titer

Answer 6

used to detect recent infection with a group A strep. Rise over several weeks, are highest 3 weeks post infection. Draw an ASO titer when a patient has possible systemic manifestations of a sequelae of group A strep (has rheumatic fever, rash, glomerulonephritis)

Question 7

Mononucleosis

Answer 7

Epsein Barr virus, over 80% of US pop has been exposed. Similar sx to strep throat

Question 8

Rapid Mono

Answer 8

Detects IgM of EBV, usually present by day 6 85% sensitivity, 100% specificity Blood test

Question 9

EBV titer

Answer 9

Do when a rapid mono is not available, if you suspect mono but rapid is negative, or to detect the timing of the infection

Question 10

The most common congenital infection

Answer 10

CMV Cytomegalovirus

Question 11

CMV

Answer 11

TORCH Virus Causes mono-like sx. 60 day incubation period!

Question 12

CMV tests

Answer 12

1. ELISA test 2. Latex-agglutination test you are evaluating the presence of CMV antibodies. Can reactivate after years.

Question 13

The Flu

Answer 13

Fever greater than 100 and Myalgias are key! Caused by strain A or B

Question 14

Rapid Flu test

Answer 14

More than 10 exist. Sometimes strain specific, and rapid do not identify the subtype/exact strain. (type A2). Will do a rapid flu if sx started within 48-72 hrs. contraindicated if outside this window- no treatment and the test itself is not comfortable.

Question 15

Rapid flu disadvantages

Answer 15

only 50-70% sensitivity (higher in children than adults because children shed the virus longer). high rate of false negatives. nasopharyngeal swab

Question 16

Flu Viral culture

Answer 16

The gold standard for flu diagnosis. Identifies which strain of flu. Takes 3-10 days.

Question 17

Flu PCR

Answer 17

High sensitivity, differentiates between sub-types. more costly and time consuming. Only do in the seriously ill and to track flu outbreaks.

Question 18

Sputum cultures

Answer 18

Lung sputum samples (expectorated from patient) can be collected and cultured in lab. gram staining can tell if bacteria, viral or fungal. Fungal can take 6-8 weeks to analyze! This is usually done for bacterial cultures.

Question 19

Pertussis

Answer 19

whooping cough. Bacterial URI caused by bordetella pertussis. Also have an inspiratory whoop, coughing fits and post cough emesis

Question 20

Pertussis test

Answer 20

It is another nasopharyngeal test. DO NOT use cotton or rayon swabs! only us Dacron swab with flexible shaft for sample collection.

Question 21

Bordetella pertussis PCR

Answer 21

High cost Not affected by previous abx use 1-2 days for results

Question 22

Bordetella pertussis Culture

Answer 22

GOLD STANDARD 30-60% sensitive, but 100% specific. Can take 7-10 days.

Question 23

RSV

Answer 23

Respiratory Syncitital Virus Common in children: URI, fever, cough, apnea. Can lead to hospitalizations and even death

Question 24

RSV testing

Answer 24

Nasal secretions analyzed via rapid antigen test (30 minutes, 90% specificity and sensitivity), Culture (4-14 days, too long) or PCR (can assay 33 pathogens in one test!)

Question 25

Tuberculosis

Answer 25

spread through the air Cough, fever, weight loss, night sweats, fatigue, skeletal, GI and GU

Question 26

TB skin test

Answer 26

also known as: Tuberculosis skin test, Purified protein derivative, Mantoux test, Tuberculin test, Tubersol

Question 27

TB test, how it works

Answer 27

Inactivated TB culture is injected subdermally. The inactive culture contains mycobacterial PPD antigens, which causes a delayed hypersensitivity reaction by the T lymphocytes in its who have been exposed to TB whether it is active or dormant

Question 28

TB test procedure

Answer 28

0.1mL TB PPD injected. 48-72 hrs later the skin is read. Test cannot determine if infection is active or dormant. Results will be positive 6-8 weeks after TB infection. TB will be positive for life- don't test a known positive. Read from bump edges, not red edges.

Question 29

TB Negative

Answer 29

less than 5 mm

Question 30

TB \> 5mm

Answer 30

TB positive in HIV, close contact with +, immunocompromised, CXR of old TB

Question 31

TB\>10mm

Answer 31

Positive in children under 4, foreigners of high risk country, IV drug users, people who work in high risk setting, economically disadvantaged, Cancer, diabetes, dialysis

Question 32

TB\>15

Answer 32

Positive in healthy, low risk, over the age of 4

Question 33

Things that will result in a false negative TB

Answer 33

infection less than 8 weeks ago, immunosuppressed pt, or someone with waning natural immunity, MMR vaccine in past 4-6 weeks.

Question 34

Things that will result in a false positive TB

Answer 34

Infection with non-TB mycobacterium or a BCG vaccination

Question 35

IGRA test

Answer 35

TB test to use if you suspect a latent TB infection. Can be used regardless of BCG vaccination status. More specific. Cannot differentiate between latent and active, but can be used for latent. More expensive than normal TB. QFT-GIT and T-spot are the two available tests. Blood draw. Still uses an ELISA technique.

Question 36

When to use IGRA test

Answer 36

if your patient comes from a country that administers BCG vaccines if your patient is not compliant in their TB reads.

Question 37

H. pylori serologic test

Answer 37

least expensive, most commonly used. results in 2-3 days. Least sensitive. tests IgG, positive 2 months post infection.

Question 38

H.pyelori bacterial culture

Answer 38

gastric mucus specimen is cultures on enriched medium. Takes at least 5-7 days.

Question 39

H pyelori rapid urease test

Answer 39

biopsied gastric mucosa + urea on pH indicator. results in 3 hours, but can only be done on pts undergoing endoscopy.

Question 40

H. pyelori stool specimen

Answer 40

ELISA technique, using fresh stool. very accurate. Usually used to test if H.pyelori has been eradicated.

Question 41

H. pyelori urea breath test

Answer 41

orally administer radioactive carbon urea. positive result will have radioactive CO2 exhaled. Expensive, but generally non-invasive and reliable.

Question 42

H. pyelori produces

Answer 42

increased urease

Question 43

Pathogenic poop

Answer 43

Salmonella Shigella Yersinia Campylobacter E. coli pathogenic C.diff Staphylococcus pathogenic SSYC

Question 44

Normal in your poop

Answer 44

Enterococcus Bacteroides Proteus Pseudomonas Escherichia coli Clostridium Staphylococcus aureus Candida albicans

Question 45

stool culture staining

Answer 45

not gram stain stain with methylene blue can sometimes see leukocytes- shigella and salmonella

Question 46

standard stool culture

Answer 46

salmonella shigella campylobacter (may need to request yersinia and enterohemorrhagic e. coli)

Question 47

C. diff testing

Answer 47

ordered separately from standard stool culture! can only be performed on loose/watery stools. Tests for toxins A and B

Question 48

C diff PCR

Answer 48

Result in 1 hour, good Specificity and sensitivity.

Question 49

c diff EIA test

Answer 49

75% sensitivity, 99% specificity Can have false negative and you need more toxin to be present to detect.

Question 50

c. diff cell culture assay

Answer 50

GOLD STANDARD for c.diff toxin diagnosis Can take 2 days and is labor intensive

Question 51

OVA and parasites in stool- who to check?

Answer 51

recent travel daycare workers AIDS pts community outbreaks

Question 52

parasites commonly found in stool

Answer 52

hookwork tapeworm giardia cryptosporidium in AIDS pts

Question 53

Hemoccult test

Answer 53

aka fecal occult blood test (FOBT) or stool guaiac checks for occult bleeding from GI or to evaluate colorectal cancer, IBD, and hemorrhoids False positives with red foods False negatives with Vitamin C Low sensitivity and low specificity

Question 54

Normal blood in GI tract

Answer 54

2-2.5 mL daily these tests detect 5mL, so if it is positive (blue stain) there could potentially be abnormal bleeding. usually do over a 3 day span.