E-drug: Essential diagnostics
---------------------------------------------
Dear colleagues.
Previously this year, E-drug hosted a starting debate, regarding the
topic of Essential diagnostics. As a keen reader of E-drug, I felt that
this concept deserves more attention . It is actually an absolutely
necessary prerequisite if we wish to reach any rational use of
essential drugs. In the light of our pandemic of antibiotic
resistance, it would be extra interesting to discuss essential
diagnostic criteria
for/against antibiotic use.
Here in Vietnam, within our RUD-program, we have been looking into
this issue in some limited community-based field-studies. We have
seen that any significantly elevated CRP levels only in a small
minority among all patients with the diagnosis "pneumonia", and who
received antibiotic medication targeted against Pneumococci or
Haemophilus. In this case, the diagnostic assessment method we
applied was to detect if antibiotic prescribed patients actually had
any significant elevation of C-reactive protein in blood !
There is of course much to say about specificity and sensitivity of
the CRP-test. Much of the respiratory tract infection panorama may
indeed be due to infections which cause only moderate elevation of
CRP, such as Mycoplasmal or Chlamydial pneumonias. Not all negative
CRP cases, may be viral, and not all elevated may be bacterial
infection.
Among the patient-cases we looked at, the children who were diagnosed
as having Pneumonia were diagnosed to have pneumonia according to
routine diagnostic procedures in daily primary care - in a district
outside Hanoi (rural district some 50 km west). IMCI training has
been given in this province. Throughout Vietnam IMCI is applied as
an integrated part of our attempts to improve primary care management
of child ARI.
The children in this study were collected consecutively as they
arrived in time to Communal primary care centers, and to district
hospital level. This small study did only cover one District. Among
120 antibiotic prescribed children, ages in the range 2-6 years, with
symptoms of ARI, and with fever, we tested CRP among all those who
had been given the written diagnosis "Pneumonia" and
prescribed Penicillins, cephalosporins, co-trimoxazole. (Covering the
majority of all children prescribed antibiotic drugs, with the
diagnosis Pneumonia). Among these 120 children one had a CRP between
30-40 and one a CRP above 130. The rest were below 25, with <10 %
above 10 !
Still, as you see, we have problems to reach a good precision in the
diagnosis. One reason may be due to fear among the doctors, to miss
treating a child, who they fear may become ill at home, out of reach
from the health-center.
We feel that our results show that there is need for a close look at
the diagnostic step, before we can start concluding anything at all,
about if our use of essential antibiotic drugs is rational or not.
Among these 120 children, only two had a CRP which we consider to be
elevated significantly. One child had a CRP above 30 (I'd consider
that rather borderline) and one had a CRP of 130 (OK, Pneumonia).
These CRP were taken on day 2 - 4 of the illness, while the children
still had a fever. My conclusion is that the majority of cases most
likely had a viral infection, and/ or perhaps a mild atypical
pneumonia - - rather than the feared Pneumococcal or Haemophilus
infection which the selected drugs indicated that the prescribing
physicians were aiming for.
This kind of problem is not at all unique for Vietnam. The problem is
common, and thus very important to discuss. It would be interesting
to see what experiences have been gained elsewhere, and what
diagnostic tools and techniques have been applied. I have a feeling
that much has been done, but not published - both in routine work and
in small "research-oriented"field-studies, where diagnostic
procedures has been evaluated.
So, the point I wanted to make, is that current diagnosis seem to be
a troublesome source of erroneous decision making - regarding
selection of drugs, and regarding if to prescribe or not to prescribe
at all !
Of course we really do not know enough to state what would be most
appropriate at this moment. Perhaps these children more often have
atypical pneumonia than we expect (giving only slight CRP elevation
as compared to Pneumococcal of Haemophilus- disease) and thus perhaps
they would have needed other antibiotic drugs, such as erythromycin ?
Regarding erythromycin, our resistance level among the major bacteria
is however so high, that this drug no longer can be considered.
Perhaps the majority of illness is indeed viral infections, but so
far we must declare that we really do not know. What we think now, is
that we need to work with assessing sensitivity and precision in the
diagnostic step, if we shall reach anywhere with Rational use of
essential antibiotic drugs.
The bottom line is - in a field-setting, in a rural and rather basic
healthcare system, what methods would be most appropriate for this
work? Considering the cost, one can not equip every healthcare
center with CRP kits ! Also, looking at the fact that these
observations have been made in a location where the health-workers
have been given IMCI training, one is worried. Of course we also need
to differentiate between routine work, in daily healthcare and this
kind of small "research-oriented" small tests-runs. . . .
We would therefore very much like to "Open" the discussion about
this topic again. Please tell us, what experiences You have from
assessing precision and sensitivity in essential diagnosis for common
infectious diseases, to rationalize use of essential drugs !
Yours truly // CSI Tornquist
Dr med., Ph.D., Msc pharm.,
Adviser for rational and safe use of drugs
Ministry of Health, Hanoi, Vietnam
E-mail: adpc@netnam.org.vn
--
Send mail for the `E-Drug' conference to `e-drug@usa.healthnet.org'.
Mail administrative requests to `majordomo@usa.healthnet.org'.
For additional assistance, send mail to: `owner-e-drug@usa.healthnet.org'.