Parasitology Proficiency Testing Program
Parasitology PT Program
Parasitology PT Program
GENERAL CRITIQUE FOR 07 February 2005
The purpose of the New York State Proficiency Testing Program in the category of Parasitology General is to monitor the performance of applicant laboratories in detecting and identifying parasites in fecal emulsions, fecal smears, and blood films.
SAMPLE PREPARATION AND QUALITY CONTROL
All emulsions and slides used in this test were prepared by a commercial source. The emulsions were dispensed into the vials from pools which were continuously mixed during the loading process. Numerous samples of each test specimen were selected at random by the Parasitology Unit of the David Axelrod Institute for Public Health, and were checked to confirm their contents. Extensive quality control tests were also conducted by the supplying vendor and a detailed quality control report was submitted to the New York State Parasitology Laboratory for inspection and verification. Samples were authenticated by 80% of participating laboratories and/or referee laboratories.
GENERAL ANSWER KEY FOR 07 February 2005
| SAMPLE | CORRECT ANSWERS | POINTS |
|---|---|---|
| 05-K | NO PARASITES SEEN | 20 |
| 05-L | Entamoeba coli | 20 |
| 05-M | Hymenolepis diminuta | 20 |
| 05-N | Giardia lamblia | 20 |
| 05-O | NO PARASITES SEEN | 20 |
TOTAL POSSIBLE POINTS 100
SAMPLE 05-K Report All Parasites
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| No Parasites Seen | 157/162 | 97 | 10/10 | Correct |
| Blastocystis hominis | 2 | 01 | 0 | Incorrect |
| Endolimax nana | 2 | 01 | 0 | Incorrect |
| Dientamoeba fragilis | 1 | 0.6 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that No Parasites Seen was the correct response (97% and 100%). Quality control examination of 4% of this sample revealed normal fecal debris including vegetable matter. Other tests performed include Direct Immunofluorescent Assay and ELISA for Giardia lamblia and Cryptosporidium sp. which were negative for both organisms. A modified acid-fast stained smear was also negative.
SAMPLE 05-L Report Protozoa Only
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| Entamoeba coli | 160/162 | 99 | 10/10 | Correct |
| Endolimax nana | 106 | 65 | 8 | No Penalty |
| Giardia lamblia | 1 | 0.6 | 0 | Incorrect |
| Blastocystis hominis | 1 | 0.6 | 0 | Incorrect |
| Cryptosporidium sp. | 1 | 0.6 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that Entamoeba coli was the correct response (99 and 100%). Quality control examination of 4% of this sample revealed cysts in every 10-12 40X fields. Also present is Endolimax nana which was seen in quality control examination and reported by 80% of referee laboratories. Therefore this specimen was graded as no penalty. Other tests performed include Direct Immunofluorescent Assay and ELISA for Giardia lamblia and Cryptosporidium sp. which were negative for both organisms. A modified acid-fast stained smear was also negative.
DIAGNOSTIC CHARACTERISTICS
 |
Entamoeba coli is distributed worldwide and is nonpathogenic. The cysts in this sample measure between 10-35 microns and have eight nuclei. The addition of iodine makes it much easier to visualize the nuclei as shown in the images. These images taken at 100X are of the same cyst before and after the addition of iodine. All eight nuclei can usually be seen by focusing up and down through the plane of focus. |
SAMPLE 05-M Report Helminths Only
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| Hymenolepis diminuta | 160/162 | 99 | 10/10 | Correct |
| Trichuris trichiura | 4 | 2 | 0 | No Penalty |
| Hymenolepis nana | 1 | 0.6 | 0 | Incorrect |
| Taenia sp. | 1 | 0.6 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that Hymenolepis diminuta was the correct response (99 and 100%). Quality control examination of 4% of this sample revealed an average of 5 ova per coverslip. The eggs measure between 75-85 microns. Entamoeba coli cysts are also present but but should not have been reported because "Helminths Only" was requested. Rare Trichuris trichiura were reported in low numbers by both the supplying vendor and the NYS Parasitology Laboratory so no credit was deducted for this response. Other tests performed include Direct Immunofluorescent Assay and ELISA for Giardia lamblia and Cryptosporidium sp. which were negative for both organisms. A modified acid-fast stained smear was also negative.
DIAGNOSTIC CHARACTERISTICS
 |
Hymenolepis diminuta is an intestinal cestode that rarely infects humans but is commonly found in rats. Infection occurs when the obligatory arthropod intermediate host is accidentally ingested. Diagnosis is usually made from the eggs passed in feces. The eggs measure approximately 70-80 microns, are thin shelled and contain a six-hooked oncosphere. There is a clear space between the membrane surrounding the oncosphere and the outer shell. No polar filaments are observed. |
SAMPLE 05-N Report Protozoa Only
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| Giardia lamblia | 160/160 | 100 | 10/10 | Correct |
QUALITY CONTROL
Participating and referee laboratories agreed that Giardia lamblia was the correct response (100 and 100%). Quality control examination of 4% of this sample revealed cysts in every 1-4 100X oil emersion fields. Some trophozoites are also present.
DIAGNOSTIC CHARACTERISTICS
 |
Giardia lamblia is the most commonly diagnosed flagellate in humans. It has a worldwide distribution and is more prevalent in children than in adults. Trophozoites are pear shaped and measure 10-20 microns. They have 2 nuclei, 4 pair of flagella, 2 axonemes and 2 median bodies. The infective cysts are oval and measure 11-15 microns. They contain 4 nuclei usually located at one end, filaments and median bodies. |
SAMPLE 05-O Report All Parasites
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| No Parasites Seen | 155/157 | 99 | 10/10 | Correct |
| Babesia sp. | 2 | 01 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that No Parasites Seen was the correct response (99 and 100%). Quality control examination of 4% of this sample revealed red blood cells that are normal in size and shape. Other normal blood elements are present and occasional Howell-Jolly bodies were noted.
February 2005 DISTRIBUTION OF SCORES
| SCORE | NO. OF LABS | PERCENT |
| 100 | 157 | 93 |
| 90-99 | 02 | 01 |
| 80-89 | 09 | 05 |
| 0 | 01 | 0.5 |
GRADING
The answer key was derived from the response of all participating laboratories as per CLIA Regulations,Part 493, Subpart I, Section 493.917. These regulations can be viewed at www.phppo.cdc.gov These regulations state that 80% or more of participating laboratories or referee laboratories must identify the parasite for it to be correct. Similarly, less than 20% of the participating laboratories or referees finding parasites or ova is an incorrect response. Organisms reported by 20-80% of the participating laboratories or referees are "Unauthenticated", and are not considered for grading.
Each sample has a maximum value of 20 points. Credit is given according to the formula:
|
Number of correct responses by lab
# Correct Parasites Present + # Lab's Incorrect Answers |
X 100 |
IMPORTANT REMINDERS
The next Parasitology Proficiency Test is scheduled for June 06, 2005. You are responsible for notifying us before June 13, 2005 if you do not receive your test. Proficiency test results must be postmarked by June 20, 2005 or you will receive a zero. These requirements are clearly stated in your NYS Proficiency Testing Handbook provided by the NYS Clinical Laboratory Evaluation Program or can be accessed via the internet at www.wadsworth.org/labcert/clep/ProgramGuide/WebGuide.pdf.
NEWS AND NOTES
Policy changes made by the Clinical Laboratory Evaluation Program now allow for the CQ holder for a particular category to sign the attestation statement instead of the Laboratory Director. Starting with the February 05, 2001 test event we will now accept Director's and/or CQ holder's signatures on the attestation statement.
The Clinical Parasitology Lab of the NYSDOH offers two mailing kits for the submission of specimens. One kit contains vials of PVA and Formalin and the other does not. These kits can be ordered by calling 518-474-4175 and requesting kit DOH-2117. Please be sure to specify whether you need preservatives or not. Remember that the NYS Parasitology Lab only accepts specimens preserved in appropriate fixatives for the test requested.
A Malaria Workshop is scheduled for April 28, 2005 at Weill Medical College of Cornell University, NY, NY. Registration forms were sent to all permitted laboratories. Registration deadline April 18, 2005. For further information or additional registration forms call 800-536-NLTN or visit NLTN web site.
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E-mail: Parasit@wadsworth.org.