I am a MT (ASCP) (I also have a Masters Degree in Microbiology). When I
graduated from the Univ. of Illinois School of Medical Technology in
1967, I was taught to perform a direct saline and iodine prep, a
formalin-ether concentration and a stained smear(hematoxylin) on fecal
specimens received for parasitology work-up. I worked in hospital
microbiology labs for twenty years at four different hospitals in
different cities in Illinois. A few minor changes took place. We
switched from ether to ethyl acetate. We switched to a Trichrome stain
from HE. We added a direct acid-fast stain in the 1980's when we
learned about Cryptosporidia. When I left human medicine in 1990 and
started working in Veterinary microbiology, I learned flotation
concentration techniques for the first time. My laboratory (the
Wisconsin Animal Health Laboratory) switched from sucrose flotations to
ZNSO4 floatations about five years ago. (Our observation was that ZNSO4
was superior to sucrose for Giardia and we occasionally found bovine or
feline lungworm on our ZNSO4 flotations. Yes, I know the Baermann
technique is best for lungworm but it is not part of our routine set-up
unless the submitting veterinarian suspects lungworm and specifically
requests a Baermann).
When I left human medicine in 1990, the most common parasites we found
in the northern Illinois hospital I was working in were Giardia and
Cryptosporidia (about 50-50). I find it surprising that many human
clinical microbiology laboratories do not include a test for
Cryptosporidia as part of the "routine" parasitology workup.
Finally, I think that many inexperienced Medical Technologists who are
asked to perform parasitology exams have trouble recognizing the small
parasites such as Giardia and Cryptosporidia. I found this to be the
case time and time again in hospital laboratories where I worked. Also,
I don't expect expertise to improve as Medical Technologists are being
required to perform as generalists instead of specializing in a
specific area of the laboratory.
Kathleen Strelow, MS,MT(ASCP),SM(AAM)
STRELKM at CAHL.DATCP.STATE.WI.US
Wisconsin Animal Health Laboratory
Madison, WI
