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Microbiology
On Call Manual
Updated August, 2005
Table of Contents
Critical Values
Notification
Stat Testing
Documenting Consultations
I have no idea what to do
Requests for
further workup on completed cultures
Requests for
additional susceptibility testing
Stool Testing
Requests for routine culture on unacceptable endotracheal aspirate/sputum
Infection Control Issues
Malaria
Chlamydia/GC testing
PLEASE NOTIFY DR. STEED (14463, cell phone 214-0940) OR
LARRY YOUNGBERG, MICROBIOLOGY LAB MANAGER, (B13434) OF ANY CALLS YOU HANDLE
AS SOON AS POSSIBLE ON DAY SHIFT, MONDAY-FRIDAY.
*************************************************************************************************************
Diagnostic
Microbiology
Technical Coordinators: Anne Panerosa (2-2393)
Intake (specimen processing)
Nancy Wessell
Aerobic/anaerobic bacteriology Weekend team
leaders: Celeste, Eileen, Gloria
Mycobacteriology (AFB)
Mycology
Parasitology
Virology
*************************************************************************************************************
Microbiology
Critical Values notification policy:
The
following laboratory values are considered critical to patient care as they
represent life-threatening infections, or will require immediate infection
control intervention. They must be called immediately to the physician in
charge of the inpatient or outpatient at that time. EXCEPTIONS: STAT TEST;
OR
?PLEASE
PAGE/CALL@
WRITTEN ON THE REQUISITION.
1. Positive Gram stain from blood culture specimen of
bacteria or fungi
2. Positive Gram stain from CSF specimen of bacteria or
fungi
3. Positive Gram stain from sterile body fluid specimen
of bacteria or fungi
4. Positive blood culture of bacteria or fungi if
original smear negative or isolate(s) discrepant from original Gram
stain
5. Positive CSF culture of bacteria or fungi if original
smear negative or isolate(s) discrepant from original Gram stain
6. Positive sterile body fluid culture of bacteria or
fungi if original smear negative or isolate(s) discrepant from original
Gram stain
7. Positive DFA smear or PCR for
Bordetella pertussis
8. Positive AFB smear or culture; positive M.
tuberculosis Gen-Probe
9. Positive fungal smear for hyphae, yeast cells or
spherules suggesting Cryptococcus, Blastomyces,
Coccidioides, Histoplasma, or
Paracoccidioides
10. Positive motile amoebic trophozoite
11. Positive blood smear for parasite
12. Positive viral culture from blood, CSF, sterile body
fluid, tissue, or neonatal urine
13. Pseudomonas species from ophthalmology
locations
Positive PCR results from blood, CSF, sterile body fluid, or tissue will
continue to be called.
*************************************************************************************************************
STAT TESTING
1.
Gram stain
a. 3rd shift in Fast Flow is trained to read Gram stains
on CSF (always a STAT), amniotic fluid (always a STAT), and sterile body
fluids ordered for STAT gram stain. Gram stains performed by 3rd shift
in Fast Flow are reviewed by Microbiology personnel early in the
morning.
b. Gram stains on other specimens are not deemed STAT by
Microbiology.
(1) If a surgeon insists that a stat intraoperative
Gram stain must be performed, have 3rd shift do it.
(2) If a physician insists that a stat Gram stain
must be performed on a non-OR specimen, determine the clinical
relevance and why it cannot wait until 6 am. If physician still
insists, page Larry (B13434).
2.
Cryptococcal antigen test (applies only if testing ordered STAT,
otherwise test performed on day shift)
a. 2nd shift is trained to perform STAT cryptococcal
antigen tests. The answer is positive or negative; positive
cyptococcal antigens tests are titered by day shift. The titer is not
required to initiate appropriate treatment, only to demonstrate response
to therapy and/or assess prognosis.
b. 3rd shift is NOT trained to perform cryptococcal
antigen tests.
*************************************************************************************************************
1.
Consult must include
name & beeper of physician requesting additional testing; this
information must be added to the culture result to document billing
issues.
2. If
request approved, call 2-2393 and ask for Larry, Anne, or Nancy (if a
weekday) or weekend team leader to make arrangements for appropriate
testing.
3. If
request is denied, I will add this information to the culture result to
document the consultation.
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IF
YOU ARE UNCOMFORTABLE MAKING THESE DECISIONS, your options:
1. Call me (214-0940)
2. Call 2-2393 and ask for Larry, Anne, or Nancy
(weekdays) or the weekend supervisor or the tech working on that type of
culture and ask his/her advice on what to do. Any of them may be able
to tell you enough about the culture to resolve the clinician=s
concern. Then call the clinician back with your answer.
*************************************************************************************************************
REQUEST FOR FURTHER WORK UP on completed culture
Cultures are worked up@
based on (1) specimen source; (2) pathogens expected; (3) number of
potential pathogens isolated; and (4) epidemiological relevancy (e.g.,
methicillin resistant Staph aureus [MRSA] and vancomycin resistant
Enterococci [VRE]).
Any
culture with 3 or more potential pathogens (“Rule of 3”) is not generally
worked up due to lack of clinical relevance. An
?official
dispensation@
may be granted after consultation with beeper 14463. For example, for an
abdominal surgical specimen, infections are usually polymicrobial with
organisms from the gastrointestinal tract. ID and susceptibility testing do
not usually provide information the clinician does not--or should
not--already know. For a different example, IV catheters, foley catheters,
endotracheal tubes, and any other tubing going from within a patient thru
the skin to the outside world becomes colonized with hospital flora
(predominantly Gram negative bacilli like E coli and Pseudomonas
aeruginosa) and/or the patient=s
skin flora within 3 days. Mixed Gram negative and/or Gram positive flora
almost always represents colonization; again, ID and susceptibility testing
do not usually provide clinically relevant information. These cultures are
examined for Staph aureus, which is tested for methicillin
resistance, enterococci, which are tested for vancomycin resistance, and
Pseudomonas aeruginosa (without AST). Otherwise, nothing should be done
with these cultures.
Also, determine the age of the culture. Susceptibility testing has a short
predictive window:
Staph aureus
& MRSA 3-5 days
Coag negative staph 5 days
Most Gram negative bacilli 5 days
Citrobacter,
Enterobacter, Providencia, Proteus vulgaris,
Pseudomonas aeruginosa, Serratia 3 days
If the culture is already beyond that point, do not perform
testing on old specimen; agree with clinician what should be done with the
new specimen. If patient has endocarditis or osteomyelitis, an old specimen
can still be tested since treatment is 6-8 weeks. If specimen cannot be
recollected, use your best judgement once you have the clinical situation
assessed (i.e., infection vs colonization) and you know the clinician
understand the limits of our testing.
You
may want to speak with the tech working on the culture to determine what’s
growing in the culture and their relative proportions. For example, you
might handle differently a culture with 3 Gram negative rods all in light
growth compared with a culture with moderate growth of “E coli”, light
growth of “Klebsiella” and scant growth of “Pseudomonas”.
1. If a physician insists on full identification and
susceptibility testing on surgically obtained specimen or
CT-guided aspirate, ask
?why?@
a.
because my attending wants it@
is insufficient scientific reason and the answer is
?no@
(unless, of course, the attending calls you directly--then do it).
b. to
guide therapy@,
still
?no@
because combination therapy is appropriate for polymicrobial
infections
c. Susceptibility
testing required on Pseudomonas aeruginosa only, approve
test
d. If
the patient has a history of numerous abdominal procedures over
several months with numerous courses of antibiotics, e.g., chronic
pancreatitis, then approve ID and susceptibility testing.
2. If a physician insists on full identification and
susceptibility testing on any other specimen, ask
?why?@
a.
because my attending wants it@
is insufficient scientific reason and the answer is
?no@
(unless, of course, the attending calls you directly--then do it).
b.
“to guide
therapy@,
still
?no@
because combination therapy is appropriate for polymicrobial
infections
c.
Susceptibility
testing required on Pseudomonas aeruginosa only, determine
role of this organism in the patients current disease process and
how susceptibility test will change therapy; if request is
reasonable, approve test
d.
If the patient
has a complicated medical history with numerous courses of
antibiotics, discuss culture with tech working on it first
3. If a physician insists on full identification of a
yeast grown from a bacterial culture:
a.
Yeast isolated
from blood, bone marrow, tissue, bone, sterile body fluid (not
urine) [critical sites] on routine bacterial culture are identified
whether or not a fungal culture is ordered on the same specimen.
b.
Yeast isolated
from any other specimen on routine bacterial culture are not
identified as the clinician obviously wasn=t
thinking fungus in the differential diagnosis. Most bacterial
cultures are held only long enough to detect bacteria (24-48 hours)
and yeast usually take 36-72 hours to grow. That=s
why the final report states
?No
growth of bacteria@
at whatever incubation period. Lack of growth of yeast on a routine
bacterial culture does not mean the patient does not have a
fungal infection! Fungal cultures use larger volumes of specimen
and 10-28 days of incubation (depending on the source) to enhance
recovery of yeast and molds. Remind the physician of bacteria &
fungus growth rates and recommend that s/he request fungal culture
when yeast (or mold) is in the differential diagnosis. If the
physician sees yeast on a urinalysis and is concerned about the
yeast, s/he can call the lab the same day the urine is sent for
culture and add a fungal culture (we=ll
still have the specimen). S/he will have a result s/he can believe,
will automatically get a yeast ID, and we=ll
be paid for the extra work.
c.
The techs are
supposed to note in the worksheet if a yeast has
?feet@--yeast
with
?feet@
are presumptive Candida albicans. If a physician insists that
an ID is required, call 2-2393 and ask for Larry, Anne, Nancy, or
weekend team leader. If the yeast has feet, have the report updated
to presumptive C albicans; you can call the physician back
with that information. If the yeast does not have feet, the yeast
will have to be sent to our mycology lab for identification.
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REQUESTS FOR ADDITIONAL SUSCEPTIBILITY TESTING
Antibiotic susceptibility testing batteries have been selected based on (1)
what agents usually kill an organism; (2) what agents are in our formulary;
(3) what agents are on commercially available testing cards or panels; (4)
growth requirements of the organism in question; and (5) number of organisms
isolated from a given site.
Remember: Susceptibility testing has a short predictive window (generally
from the time of collection):
Staph aureus
& MRSA 3-5 days
Coag negative staph 5 days
Most Gram negative bacilli 5 days
Citrobacter,
Enterobacter, Providencia, Proteus vulgaris,
Pseudomonas aeruginosa, Serratia 3 days
If the culture is already beyond that point, do not perform
testing on old specimen; agree with clinician what should be done with the
new specimen. If patient has endocarditis or osteomyelitis, an old specimen
can still be tested since treatment is 6-8 weeks. If specimen cannot be
recollected, use your best judgement once you have the clinical situation
assessed (i.e., infection vs colonization) and you know the clinician
understand the limits of our testing.
Call me or call 2-2393 and ask for Larry, Anne, or Nancy (weekdays) or the
weekend supervisor or the tech working on that type of culture for current
Gram negative and Gram positive susceptibility testing options and methods (MicroScan
MIC panels; disk diffusion or E tests [for determination of MICs by a disk
diffusion-type method]).
1. Requests for Rifampin on Staph aureus
or methicillin resistant Staph aureus [MRSA]:
a. Can be requested only by Infectious
Disease physicians, fellows, or residents or pharmacy staff doing
the ID rotation. Generally the information is required to optimize
therapy for bacteremia/ endocarditis, osteomyelitis, or deep-seated
tissue infection.
b. Rifampin is part of every Staph susceptibility
test, but is never released without approval to avoid inappropriate
usage as a single anti-Staph agent (develops resistance too fast).
Ask Larry, Anne, or weekend team leader to get rifampin results from
Vitek and email it to the requesting individual.
2.
Vancomycin resistant Enterococci (VRE): applies to VRE faecium
or VRE faecalis only
a. Ask requesting individual how many antibacterial
agents are in the report--1 (we looked for vancomycin resistance
only) or 3-4 agents (we did a full susceptibility panel).
Additional testing that can be requested include following:
(1) Linezolid (works against VRE faecium
or VRE faecalis) is on the full susceptibility panel & is
routinely reported on VRE faecium/faecalis.
(2) Daptomycin (works against VRE faecium
or VRE faecalis) requires susceptibility testing
separately because it is not on formulary.
3.
AI
see methicillin susceptibility [or resistance] for Staph aureus ,
but is it susceptible to [insert antibiotic name here]?@
Similarly
AI
see vancomycin susceptibility [or resistance] for Enterococcus,
but is it susceptible to [insert antibiotic name here]?
a. We look for methicillin resistance on Staph
aureus and/or vancomycin resistance on Enterococcus when
there are 3 or more potential pathogens in a given site (refer above
to section REQUEST FOR FURTHER WORK UP on completed culture).
b. For staphylococci or enterococci, call me or call
2-2393 and ask for Larry, Anne, or Nancy (weekdays) or the weekend
supervisor or the tech working on that type of culture. The NCCLS/
CLSI documents will often extrapolate the results of other
antibiotics based on a class drug. Otherwise, the answer is
?can=t
tell without performing that specific susceptibility test at
additional charge to the patient@.
Never, ever approve any of the following
drug/bug combinations:
Organism |
Antimicrobial agents that will always
be resistant in vivo regardless of susceptibility test results |
Methicillin-resistant Staph
aureus |
|
Methicillin-resistant coagulase negative Staph |
Zosyn (piperacillin/tazobactam) |
Enterococcus
spp. |
Aminoglycosides (except at synergistic
concentrations)
All cephalosporins
Clindamycin
Trimethoprim-sulfa |
Salmonella
spp., Shigella spp. |
1st & 2nd generation
cephalosporins
Aminoglycosides |
Listeria monocytogenes
|
All cephalosporins |
4. FOR ALTERNATIVE ORGANISM susceptibility
testing--Corynebacterium, Bacillus, anaerobes, etc.
a.
Organisms not on
the NCCLS charts have no standardized susceptibiilty testing method
and no correlation between lab results and patient outcome (i.e., no
idea what results mean or even if they are relevant). If physician
insists, determine what agents are reasonable to test using the
Sanford guide (attached) and the antimicrobial agents available by
Pasco MIC broth panels for Gram negative bacilli and Strep
pneumoniae and E tests.
b.
Anaerobes are
sent to the reference lab for testing. Beta-lactamase generally
tells a physician how to treat the patient.
5. Yeast (Candida) susceptibility testing is a
send out and takes about a week to get results back. The reference lab
that we send these to routinely tests: amphotericin B, 5-flucytosine
(5-FC), fluconazole, itraconazole, ketoconazole, voriconazole.
Beta-lactamase positive
means:
Haemophilus,
N. gonorrhoeae--resistance to penicillin, ampicillin, amoxicillin
Staphylococci and Enterococci--resistance to penicillin, ampicillin,
ticarcillin, piperacillin
Anaerobes—resistance to penicillin, ampicillin
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STOOLS
Stool specimens unlikely to provide clinically relevant information on most
inpatients are rejected using the criteria below.
STOOL REJECTION CRITERIA
(begun January 6, 1997)
|
Acceptable specimen collection
periods |
Routine
stool culture |
Days of admission: 1, 2, 3 |
All
Parasitology testing
(O & P,
Giardia Ag, Cryptosporidium, etc) |
Days of admission: 1, 2, 3, 4 |
C difficile
toxin assay* |
Days of admission: 4, 5, 6, ... |
*
Exception: Stool for C difficile toxin assay submitted on days of
admission 1-3 is acceptable on patients with liquid stool (not semi-solid or
solid stool), patients that have been on antibiotics within the previous 3
weeks, patients that were transferred from another hospital, or patients
with Hirschprung’s disease
or ulcerative colitis.
Routine stool cultures
look for Salmonella, Shigella, Campylobacter only.
E coli
O157:H7, Yersinia, Aeromonas, Vibrio must be ordered
specifically and are included in the rejection policy.
Our
most common parasite is Giardia lamblia and the best test to detect
that parasite is the Giardia EIA antigen test. Second most common
parasite is Cryptosporidium and the best test to detect this parasite
is the EIA antigen (it may or may not be seen on an O & P).
1. Stool specimens unlikely to
provide clinically relevant information on most inpatients are rejected
using the criteria below.
a. Patients eating hospital food are unlikely to
develop diarrhea due to Salmonella, Shigella,
Campylobacter or parasites. Typical incubation periods for
these diseases are 24-48 hours for Salmonella and Shigella,
2-4 days for Campylobacter. Same is true for other stool
pathogens (E coli O157:H7, Yersinia, Aeromonas,
Vibrio).
b. Patients not on prior (within the previous 3
weeks) or current antibiotics are unlikely to develop diarrhea due
to C difficile.
2. As with all rejected specimens, the floor is
notified. Exceptions for individual patient needs can be made by any
physician upon consultation with beeper 14463.
a. Stool culture:
(1) If stool cultures x3 are being collected and
the first 1 or 2 specimens have arrived in Microbiology on the
first 3 days of admission, but the 2nd or 3rd specimen(s) arrive
on or after day 4, accept the specimen(s).
(2)
For a single
stool specimen, unless the patient has been eating food from
outside or a family member having close contact with the patient
has diarrhea (and the family member should not have been allowed
to have any contact with the patient!), there is no logical
reason for any stool culture.
(3)
A routine
stool culture will not tell if a patient has the normal
bacterial constituents of stool. That assessment needs to be
referred directly to me or Larry‑‑on day shift.
(4)
If the
physician insists on the culture and the specimen is in
Cary‑Blair transport media (vial with a green top), tell the
physician I or Larry will have to make the final decision on day
shift and that the specimen will not be adversely affected.
(5)
If the
physician insists on the culture and the specimen is in a
sterile container AND if before 10:30 pm, tell the physician I
or Larry will have to make the final decision on day shift, but
that you'll ask 2nd shift to inoculate the specimen in case the
culture is approved.
b. Ova & Parasites, Giardia antigen,
Cryptosporidium screen: O & Ps are performed at a reference
lab; Giardia and Cryptosporidium antigens are
performed Mon-Fri
(1)
If O & P x3
are being collected and the first 1 or 2 specimens have arrived
in Microbiology on the first 4 days of admission, but the 2nd or
3rd specimen(s) arrive on or after day 5, accept the specimen(s).
O & P specimens should be collected 1 every other day.
(2)
For a single
O & P specimen, unless the patient has been eating food from
outside or a family member having close contact with the patient
has diarrhea (and the family member should not have been allowed
to have any contact with the patient!), there is no logical
reason for any parasitology testing.
(3)
If the
physician insists on the parasitology test(s) and the specimen
is in PVA (vial with a red top), tell the physician I or Larry
will have to make the final decision on day shift and that the
specimen will not be adversely affected.
(4)
If the
physician insists on the parasitology test(s) and the specimen
is in a sterile container AND if before 10:30 pm, tell the
physician I or Larry will have to make the final decision on day
shift, but that you'll ask 2nd shift to add PVA to the container
to try to preserve the quality of the specimen.
c. C. difficile toxin assay (CDT):
testing is performed 7 days a week
(1)
See
exceptions under the Stool Rejection Criteria box on the
previous page.
(2)
Physicians
usually know if a patient received antimicrobial therapy at
another hospital or as an outpatient. Please note the
antimicrobial agent the patient received. If the patient was/is
currently on metronidazole (Flagyl) or po vancomycin, the
patient does not need a CDT as these antibiotics are the drugs
of choice for C difficile disease. Note: IV vancomycin
is not effective against C difficile; a specimen
submitted on a patient receiving IV vancomycin is suitable for
testing.
(3)
Patients
with Hirschprung=s
disease or ulcerative colitis have an increased susceptibility
to C difficile and may be tested without record of
previous antimicrobial use. Please note that the patient has
Hirschprung=s
disease or ulcerative colitis.
Fecal leukocytes/Fecal WBC's.
1. The Infectious Diseases literature says that the
presence of fecal WBC's indicates a patient has diarrhea due to
Salmonella, Shigella, or Campylobacter; absence of
fecal WBC=s
indicates a patient has Vibrio, E coli O157:H7, some
parasites, or enteric viruses. However, the microbiology literature
does not support this conclusion and the test is performed in many large
medical institutions only on trichrome stained smears (as part of an O &
P). As Kathleen Beavis relates,
?An
article from the August 23, 1980 Lancet (pp. 413 - 416) reviews
Mass. General's experience with 2468 stool cultures in 1977. Only 27
stools were examined for fecal leukocytes. There was no association
between the presence or absence of fecal leukocytes and positive
cultures. Of the 13 smears from patients with negative cultures, 4 had
fecal leukocytes; of the 14 smears from patients with positive cultures,
5 had fecal leukocytes.@
2. Testing is performed only on day shift. Specimen
should be submitted in formalin or PVA (latter not widely available
in‑house) to maintain the integrity of the cells. Fresh stool is
acceptable if examined within 60 minutes (obviously available only on
day shift). Stat requests are usually made only by ER physicians.
3. If an ER physician insists that stat fecal WBC's must
be performed: stool must be liquid (best) or semi‑formed (i.e.,
conforms to the interior of the container of its own accord)
a. If before 10:30 pm, have 2nd shift do a Gram
stain of the stool. Put the
?Snotty
Comment@
on the report and have the test repeated on day shift on a properly
submitted specimen.
b. If after 10:30 pm, no one in Fast Flow is
qualified to perform the test. The physician is welcome to come to
the lab to make and read his/her own slide, but Larry will not bring
in a tech to do this test as it is not a medical emergency.
REQUEST FOR routine culture on unacceptable
endotracheal aspirate/sputum
Tracheal aspirates and sputum are sent for routine bacterial culture to diagnose
pneumonia. Because endotracheal and tracheostomy tubes come into contact with
saliva, they become colonized with oral flora as well as hospital flora.
Sputum, of course, is produced thru the mouth. Thus, these specimens should
have bacteria present on a Gram stain of that specimen. If such a specimen
does not show bacteria on a Gram stain, that specimen is rejected and the
ordering physician is notified. An
?official
dispensation@
may be granted after consultation with beeper 14463.
Stress
to the physician that this particular specimen is unlikely to establish
the cause of the pneumonia. A new specimen is unlikely to be better because the
cause of the pneumonia is unlikely to be something that routinely grows on
bacterial media in 48 hours. This means the infection is probably not due to
Staph aureus, Pseudomonas aeruginosa, E coli, Strep
pneumoniae, etc etc. The physician should be thinking legionella,
mycoplasma, fungi, possibly acid fast bacilli, or viruses. The physician should
also get either a pulmonary consult or an Infectious Diseases consult if s/he
has not already done so. Rejecting this specimen for routine bacterial culture
is standard of care for adults in microbiology in most medical centers across
the nation.
To
date, the specimens with no bacteria on the Gram stain that we have continued
with culture have grown either nothing at all, a bit of usual oral flora, or a
colonizing Gram negative bacillus (that the patient had in a previous culture).
If the
physician insists the routine culture be performed, tell him/her the culture
will be performed and a disclaimer will be added to the report. [The disclaimer
basically says Micro didn=t
want to do this culture because it shows no bacteria on the Gram stain, the
physician insisted, and we don=t
know what the significance is of what we grow or don=t
grow.] Immediately call 2-2393 to authorize the culture and have the tech
enter the
?Snotty
Comment@;
the physician=s
name & pager and date and time of your conversation are required to complete
this comment.
*************************************************************************************************************
INFECTION CONTROL issues--pages to you
from Micro lab about Reportable Diseases
These
organisms create situations that require close contact between MUSC infection
control, DHEC epidemiology, and us as they present a potential outbreak
situation or other significant public/nosocomial health issue. Please be sure
to record the name and pager of everyone you speak with as well as the date and
time.
1. Upon receipt of the following
information from the Micro lab staff, consult with the physician caring
for the patient to determine if recovery of these organisms are
reasonable given the patients presentation and medical history:
a.
Bacillus anthracis
(BT)—also call my cell phone immediately
b.
Yersinia pestis
(BT)—also call my cell phone immediately
c.
Francisella tularensis
(BT)—also call my cell phone immediately
d.
Brucella
spp. (BT)—also
call my cell phone immediately
e.
Corynebacterium diphtheriae
f.
Salmonella typhi
g.
Vibrio cholerae
If the organism IS reasonable, have tech report
results and immediately call (843) 219-8470 to report it to DHEC
epidemiology. If the organism is NOT reasonable, have lab confirm
ID by a different method but call DHEC to give them a heads up.
2. Call physician and (843) 219-8470 immediately for the
following (if tech has not already done so):
a.
Gram negative
diplococci consistent with Neisseria meningitidis seen on CSF
Gram stain or grown in CSF or blood culture
b.
Hemophilus influenzae
from CSF or blood
c.
Vancomycin
intermediate Staphylococcus (be sure the lab is doing the
appropriate confirmatory testing)
d.
Vancomycin
resistant Staphylococcus (be sure the lab is doing the
appropriate confirmatory testing)
3. Calls for these organisms are for my personal
interest. Make sure the isolate is frozen at –70°C and DHEC notified.
Record the information and give it to me.
a.
Cyclospora
(don’t freeze this one)
b.
E coli
O157:H7
c.
Group A Strep (Strep
pyogenes) from CSF, blood, or invasive site
d.
Group B Strep (Strep
agalactiae) from newborn to 90 day old child
e.
Plasmodium
spp. (don’t freeze this one)
f.
V. parahemolyticus
or V. vulnificus
MALARIA
(requires consultation with beeper 14463 prior to collection)
Malaria
smears are performed for 3 reasons
a. Diagnose acute malaria--Plasmodium falciparum
malaria is a medical emergency--continue below
b. Follow parasitemia in a known malaria-infected
patient--not an emergency and performed only on day shift.
c. Requirement to move to another
country (e.g., Saudi Arabia)--not an emergency and performed only on day
shift Monday-Friday.
Questions to ask requesting physician about patient:
1. Where has the patient been and when was
the patient there (arrival and departure)?
|
See attached Table for countries with endemic
malaria. If the patient has not been to one of these areas,
ask question #5. |
2. Did the patient take prophylaxis while
in a malaria-endemic country? What drug, what regimen, and
when did the patient stop taking prophylaxis? |
Quinine, chloroquine,
hydroxychloroquine, amodia-quine, and Fansidar (pyrimethamine
& sulfadoxine) are used for prophylaxis. Prophylaxis must
be continued for 4-6 wks after return from endemic area(s). |
3. Has the patient previously had or been
treated for malaria? Was the diagnosis made by a laboratory
or treatment administered based on symptoms? What species
of malaria was it? |
Often malaria is treated based on symptoms,
not lab diagnosis.
If a patient was previously with malaria
other than P falciparum, the patient may have
malaria, but is unlikely to die during the night. Ask the
physician to contact the micro lab on day shift to arrange
for malaria smears to be performed. |
4. Has the patient ever received a blood
transfusion? Is there a possibility of other needle
transmission (e.g., drug user)? |
Transmission via blood transfusions in the US
are extremely rare; more common in other countries.
|
5. Where does the patient live and what
does the patient do for a living? |
If patient does not live near or work at an
international airport (called
?airport
malaria@),
the request is denied. |
1. If malaria is likely and the specimen needs to be
processed after 5 pm,
a.
Determine if the patient has established a fever pattern. Optimum time
to draw blood is midway between chills, but this timing may be
unreasonable. Blood may be collected every 6 hours; if possible, draw
times should be arranged with me or Larry on day shift. The best
specimen is a needlestick, not a lavender top tube.
b. If malaria smears must be performed immediately,
contact Larry (B13434) to have a parasitology technologist brought in to
make and read the smears.
c. Call the floor back to tell them when to draw a
lavender top (EDTA) tube. Blood must be processed within 1 hour to
retain parasite morphology.
2.
If malaria is unlikely, deny the request.
If blood cultures are negative after 18 hours and malaria
is still high on the differential diagnosis, recommend the physician contact
me or Larry on day shift to arrange for malaria smears to be performed. The
best specimen is a fingerstick, not a lavender top tube.
*************************************************************************************************************
Chlamydia/GC testing
As is
clearly stated in the Reference Values and Specimen Collection handbook, these
are the only specimens acceptable for DNA probe testing:
NO EXCEPTIONS‑‑FDA approval is for these sites only
Chlamydia trachomatis:
urethra, endocervix, “dirty catch” urine
Neisseria gonorrhoeae:
urethra, endocervix, “dirty catch” urine
As
James Snyder of the Univ. of Louisville has said,
If
the test was performed, you could not legally bill for it. Furthermore, if the
case was litigated, and the lawyer for the defense knew that the test had been
performed (lab records subpoenaed) with a method not approved, they would use
that against the prosecution as well as you if you were called to testify. Your
only recourse would be to perform the test and report "for research purposes
only, not for diagnostic purposes". Stay with the culture only approach.
Specimens on sexual assault patients (remember that Lab Medicine does not accept
chain of custody specimens):
a.
pediatric patients: cultures for legal purposes; DNA probes are often
performed for treatment as the results are available sooner
b.
adult patients: cultures may or may not be performed for legal purposes;
DNA probes are almost always performed for treatment
Specimens from other sources must be cultured on appropriate media (GC) or cell
culture (Chlamydia). A direct specimen C trachomatis stain (e.g.,
DFA) can be performed at a reference lab. The fluorescent stain that we use for
Chlamydia culture confirmation cannot be used for direct specimen
examination (manufacturer's package insert states this specifically).
Note:
vaginal specimens for C trachomatis cultures are acceptable for patients
of elementary school age; vaginal specimens are unacceptable for patients older
than that and should be rejected.
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