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| Answers: |
 |
| Question: |
Is meconium drug testing more
sensitive than urine testing? |
| Answer: |
Yes. The evidence is overwhelming that meconium
drug testing has a higher sensitivity for drug detection than
urine testing. |
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| Question: |
What do you think about hair
analysis for drug testing in the newborn infant? |
| Answer: |
Mectest is not used for hair analysis. As
for hair analysis, there are some disadvantages to the procedure,
due to passive contamination of hair and that hair collection
is an invasive procedure.
Also, not all babies are born with ample hair for analysis. |
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| Question: |
Can Mectest be used for enzyme
immunoassay such as Enzyme Multiplied Immunoassay Technique
(EMIT) and Fluorescence Polarization Immunoassay (FPIA)? |
| Answer: |
Yes. The Mectest Processor can be used to
prepare the meconium analyte for analysis by EMIT, FPIA or RIA.
The paper of Dr. Ostrea on mass screening, published in the
Journal of Pediatrics, 1994, used the Mectest Processor to prepare
the meconium samples for analysis by EMIT or FPIA. The Mectest
Processor is the only medical device cleared by the food and
Drug Administration for clinical applications in meconium drug
testing in conjunction with Radioimmunoassay (RIA), Enzyme Multiplied
Immunoassay Technique (EMIT) or Fluorescence Polarization Immunoassay
(FPIA). |
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| Question: |
How should meconium samples
be collected and handled for analysis by Mectest? |
| Answer: |
The meconium can be collected directly from
the infant's diaper. Mix the meconium in the diaper well and
get an aliquot using the built-in spoon (cap with scoop of feces
container) from the Mectest processor. Cap the processor, label
and send the sample to the laboratory where it should be vortexed
to achieve an even dispersion of the meconium in the solvent.
Once meconium is dispersed in the solvent, there is no need
to refrigerate the sample, if analysis is to be done within
72 hours. |
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| Question: |
What may contribute to a false
negative result (e.g., mother admits to drug use, yet meconium
drug test is negative? |
| Answer: |
A false negative reading is often due to
a problem from meconium sampling. There should always be enough
meconium to fill a heaping of the collecting spoon. If there
is not enough meconium scooped out, the results may be negative
due to insufficient material analyzed. Similarly, a higher positive
yield can be achieved by collecting meconium from two diapers.
The samples can be mixed into one, and then test samples obtained
from this mixture. |
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| Question: |
If meconium cannot be immediately
processed and analyzed, how should the sample be stored? |
| Answer: |
Meconium should be collected in a plastic
container and kept in a freezer until the time of analysis.
Meconium analysis can be done on batched samples. |
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| Question: |
How does meconium testing by
radioimmunoassy (Mectest) compare with EMIT or FPIA? |
| Answer: |
Testing by radioimmunoassay is the most sensitive
method of analyzing meconium for drugs. However, for practical
purposes, the cut off sensitivity level used by EMIT or FPIA
will suffice for clinical purposes. |
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| Question: |
Can confirmation of Mectest
positive results be done by EMIT or FPIA? |
| Answer: |
Strictly speaking, confirmation of positive
results must be done using other diagnostic methods. Since radioimmunoassay,
EMIT or FPIA are immunoassays, the suggested confirmation method
is either thin layer chromatography or GC/MS. |
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| Question: |
How long does analysis by Mectest
take before results are known?
|
| Answer: |
Once meconium is analyzed using Mectest,
the results can be obtained within 4-5 hours. The most common
cause of delay in meconium analysis is the batch testing of
multiple samples. If this occurs, the hospital need not delay
the discharge of infants who are awaiting the results of the
meconium drug test. Once the results of the test are obtained,
a CD 3200 is filed with the Child Protective Services, on those
who had a positive drug test, so that the home situation of
the infant can be investigated appropriately. |
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| Question: |
Is meconium testing accepted
in Court? |
| Answer: |
Yes, More and more, the public and physicians
are aware that the meconium drug test is a far more sensitive
and specific test, than urine testing, to detect illicit intrauterine
drug exposure of newborn infants. |
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| Question: |
Can Mectest be used for other
illicit drugs, such as valium? |
| Answer: |
The Mectest has been cleared by the FDA only
for the detection of cocaine, opiate and cannabinoid. Future
developments of Mectest will include the other drugs of abuse. |
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| Question: |
How sensitive is Mectest? |
| Answer: |
Mectest is 85% sensitive. (Note: Sensitivity
applies to the positive reading. Hence, if the analytical result
using Mectest is positive, there is an 85% chance that the result
is positive.) |
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| Question: |
What is the specificity of Mectest? |
| Answer: |
The specificity of Mectest is 99 to 100%.
(Note: Specificity of Mectest applies to a negative reading.
Hence if the analytical result using Mectest is negative, 99
to 100% of the time, the reading is in fact negative.) |
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| Question: |
What advantages does meconium
drug analysis using Mectest offer over urine analysis? |
| Answer: |
Urine analysis is not a practical method
to use to determine the exposure of newborn infants to drugs
in utero. Considering the very low specificity of urine analysis
the test is no more that 50% accurate. A negative reading does
not necessarily mean the infant was not exposed to drugs in
utero. Additionally, timing in urine collection is critical.
Urine analysis may not detect the presence of drugs if the mother
stopped taking the drug weeks before the urine collection. Drug
metabolite in meconium, on the other hand, may be detected from
the 12th week of gestation. The risk of contamination during
and following the collection of urine is greater than with meconium.
The stability of meconium once collected is ideal for serial
or batch testing. Meconium if left in the feces container with
the Mectest solvent can be analyzed within 72 hours without
refrigeration. Meconium, as is, can be frozen indefinitely. |
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| Question: |
What is the cost of meconium
drug testing using Mectest? |
| Answer: |
Meconium drug testing using the Mectest Processor
translates to about $4.30 - $6.45 per test, per drug plus the
cost of the EMIT, FPIA or the RIA kits, depending on what method
is employed. Needless to say, there is the added benefit of
enabling hospitals to run the test within the confines of their
laboratories. More than just the convenience of doing meconium
drug testing in hospital laboratories, the Mectest kit allows
hospital facilities to establish adequate control procedures
and therefore, minimize the risk of contamination, loss or mixing
of samples. |
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| Question: |
What are the cut-off concentrations
of Mectest? (Lower limit, i.e., the least amount of drug that
can be detected from meconium using Mectest.) |
| Answer: |
The cut-off concentrations of Mectest for the following drugs
are as follows:
- Cocaine 7.62 ng/ml
- Opiate 27.82 ng/ml
- Cannabinoid 6.54 ng/ml
|
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| Question: |
Can Mectest be used to detect
Methamphetamines? |
| Answer: |
Mectest has been cleared by the US FDA for
the analysis of cocaine, opiate and cannabinoid only. However,
Dr. Enrique M. Ostrea, Jr., the leading authority on meconium
drug testing has done numerous drug screens to detect methamphetamines
in meconium using the Mectest Processor. Should you wish more
information of this subject, we strongly suggest that you contact
Dr. Ostrea at Hutzel Hospital, Department of Pediatrics in Detroit,
Michigan. |
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