Parasitology Proficiency Testing Program
Parasitology PT Program
Parasitology PT Program
GENERAL CRITIQUE FOR 02 OCTOBER 2006
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
| SAMPLE | CORRECT ANSWERS | POINTS |
|---|---|---|
| 07-F | Clonorchis sinensis/Opisthorchis sp. | 20 |
| 07-G | Strongyloides stercoralis | 20 |
| 07-H | NO PARASITES SEEN | 20 |
| 07-I | Giardia lamblia | 20 |
| 07-J | NO PARASITES SEEN | 20 |
TOTAL POSSIBLE POINTS 100
SAMPLE 07-F Report Helminths Only
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| Clonorchis sinensis/Opisthorchis sp. | 144/144 | 100 | 10/10 | Correct |
| Hymenolepis nana | 01 | 0.7 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that Clonorchis sinensis/Opisthorchis sp. was the correct response (100%). Quality control examination of 4% of this sample revealed an average of 20 ova per coverslip. 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
 |
Clonorchis sinensis is a trematode that parasitizes the biliary ducts of humans. Humans become infected when they eat uncooked freshwater fish that contain metacercariae. The metacercariae excyst and travel to the distal bile capillaries where the worms mature. Adult worms deposit eggs in the bile fluid and these are later discharged into the feces. The eggs measure 28-35 microns. They are thick shelled, ovoid, have an operculum with distinct opercular shoulders, and a knob at the abopercular end. |
SAMPLE 07-G Report Helminths Only
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| Strongyloides stercoralis | 143/144 | 99 | 10/10 | Correct |
| Necator americanus/Ancylostoma duodenale | 01 | 0.7 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that Strongyloides stercoralis was the correct response (99 and 100%). Quality control examination of 4% of this sample showed an average of 10 larvae per coverslip. 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
 |
Strongyloides stercoralis is an intestinal nematode with a very complex life cycle. Infection is acquired when filariform larvae in the soil penetrate the skin and are carried in the blood to the lungs. From the lungs they travel up the trachea and are swallowed. Once in the intestine they develop into mature female worms and begin to produce eggs by parthenogenesis. These eggs, which are rarely seen, hatch in the intestine into rhabditiform larvae. The larvae pass in the feces and develop into male and female worms in the soil where they complete their life cycle. The diagnostic stage is the rhabditiform larvae passed in the stool. They measure 180-380 microns, have a short buccal cavity and a prominent genital primordium as indicated by the arrow. |
SAMPLE 07-H Report All Parasites
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| NO PARASITES SEEN | 141/144 | 98 | 10/10 | Correct |
| Blastocystis hominis | 01 | 0.7 | 0 | Incorrect |
| Endolimax nana | 01 | 0.7 | 0 | Incorrect |
| Cryptosporidium sp. | 01 | 0.7 | 0 | Incorrect |
QUALITY CONTROL
Participating and referee laboratories agreed that NO PARASITES SEEN was the correct response (98 and 100%). Quality control examination of 4% of this sample revealed no organisms on wet mount examination. 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 07-I Report Protozoa Only
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| Giardia lamblia | 143/143 | 100 | 10/10 | Correct |
QUALITY CONTROL
Participating and referee laboratories agreed that Giardia lamblia was the correct response (100%). Quality control examination of 4% of this sample showed cysts and trophozoites in every 6-8 100X oil emersion fields.
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 07-J Report All Parasites
RESULTS OF PARTICIPATING LABS
| ORGANISM | NUMBER REPORTED | PERCENT REPORTED | REFEREE RESULTS | STATUS |
| NO PARASITES SEEN | 138/139 | 99 | 10/10 | Correct |
| Plasmodium malariae | 01 | 0.7 | 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 no organisms.
IMMUNOASSAY RESULTS
CRYPTOSPORIDIUM IMMUNOASSAY RESULTS
| METHOD | 07-F | 07-G | 07-H | ||||
| NEGATIVE | POSITIVE | NEGATIVE | POSITIVE | NEGATIVE | POSITIVE | ||
| MCC Para-Tect Crypto/Giardia DFA | 01 | 0 | 01 | 0 | 0 | 01 | |
| Meridian ImmunoCard STAT Crypto/Giardia | 15 | 0 | 15 | 0 | 16 | 0 | |
| Meridian Merifluor Crypto/Giardia | 21 | 0 | 21 | 0 | 21 | 0 | |
| Meridian Premier Cryptosporidium | 02 | 0 | 02 | 0 | 02 | 0 | |
| Remel ProSpecT Crypto EIA | 16 | 0 | 16 | 0 | 17 | 0 | |
| Remel ProSpect Crypto Rapid | 01 | 0 | 01 | 0 | 01 | 0 | |
| Remel Xpect Giardia/Crypto | 02 | 0 | 02 | 0 | 02 | 0 | |
| TechLab/Wampole Test EIA | 05 | 0 | 05 | 0 | 06 | 0 |
GIARDIA IMMUNOASSAY RESULTS
| METHOD | 07-F | 07-G | 07-H | ||||
| NEGATIVE | POSITIVE | NEGATIVE | POSITIVE | NEGATIVE | POSITIVE | ||
| MCC Para-Tect Crypto/Giardia DFA | 01 | 0 | 01 | 0 | 01 | 0 | |
| Meridian ImmunoCard STAT Crypto/Giardia | 16 | 0 | 16 | 0 | 17 | 0 | |
| Meridian Merifluor Crypto/Giardia | 16 | 0 | 16 | 0 | 16 | 0 | |
| Meridian Premier Giardia | 02 | 0 | 02 | 0 | 02 | 0 | |
| Remel ProSpecT Giardia EIA | 25 | 0 | 25 | 0 | 26 | 0 | |
| Remel ProSpecT Giardia EZ | 01 | 0 | 01 | 0 | 01 | 0 | |
| Remel Xpect Giardia | 03 | 0 | 03 | 0 | 03 | 0 | |
| Remel Xpect Giardia/Crypto | 02 | 0 | 02 | 0 | 02 | 0 | |
| TechLab/Wampole Test EIA | 06 | 0 | 06 | 0 | 07 | 0 |
DISTRIBUTION OF SCORES
| SCORE | NO. OF LABS | PERCENT |
| 100 | 143 | 96 |
| 90-99 | 01 | 0.7 |
| 80-89 | 05 | 03 |
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 mailout dates for Parasitology have been changed from the first Monday to the first Tuesday of February, June, and October.
The next Parasitology Proficiency Test is scheduled for February 06, 2007. You are responsible for notifying us before February 13, 2007 if you do not receive your test. Proficiency test results must be postmarked by February 20, 2007 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.
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E-mail: Parasit@wadsworth.org.