Lab Test

Pinworm Exam

Enterobius vermicularis, enterobiasis, Scotch tape prep, Pinworm Examination

Test Codes

Antrim #40547, EPIC: LAB5520, SOFT: PINWM


Pinworms usually migrate to the anus and lay eggs during the night. Therefore, specimens should be collected when the patient first awakens in the morning, before the patient defecates or bathes.

Specimen Collection Criteria

Collect: Pinworm eggs from the perianal region using the cellophane tape (placed on a glass slide in sterile collection container) or paddle method. Please see Testing for Pinworm Instructions.

Note: A minimum of four to six consecutive negative tape preps are required to rule out the infection.

Physician Office/Draw Specimen Preparation

Maintain specimens at room temperature (20-26°C or 68-78.8°F) prior to transport.

Preparation for Courier Transport

Transport: Slides containing cellophane tape, or pinworm paddle, at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Specimens not collected and processed as indicated.
  • Fecal or other specimens will not be tested without consultation with the Microbiology Medical/Technical Director.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable


Farmington Hills Microbiology Laboratory.
Grosse Pointe sent to Royal Oak Microbiology Laboratory for testing.
Royal Oak Microbiology Laboratory
Troy sent to Royal Oak Microbiology Laboratory for testing.


Monday – Friday, 7:00 am – 3:30 pm.
Results available within 24 hours.

Reference Range

No pinworm eggs detected.

Test Methodology

Microscopic examination, unstained.


Presence of Enterobius vermicularis ("pinworm") eggs indicates infection.

Clinical Utility

This assay aids in the diagnosis of pinworm infection.

Clinical Disease

Pinworm infection is caused by the nematode, Enterobius vermicularis. Pinworm infection (enterobiasis) causes pruritus ani and, rarely, pruritus vulvae. Although pinworms have been found in the lumen of the appendix, most evidence indicates that they are not causally related to acute appendicitis. Many symptoms, such as grinding of the teeth at night and enuresis, have been attributed to pinworm infections, but proof of a relationship has not been established. Vaginitis, salpingitis, and pelvic peritonitis can occur because of aberrant migration of the adult worm from the perineum (1).


Enterobiasis is distributed worldwide and usually occurs in family clusters. There is no sex preference or seasonal variation in disease incidence. In the past, 5% to 15% of the population of the United States was thought to be infected, but the incidence has declined recently. Prevalence rates are higher in preschool-aged and school-aged children, in mothers of infected children, in daycare nurseries, and in institutionalized individuals where up to 50% of the population may be infected (1) (2).

Incubation Period

The time from ingestion of an egg until an adult gravid female migrates to the perianal region is 1 to 2 months or longer (1).


Transmission occurs by multiple routes, the primary of which is fecal-oral, with worm eggs transmitted by fingers and hands and via shared toys, bedding, clothing, toilet seats, and baths. Adult gravid female nematodes usually die after depositing eggs on the perianal skin. Thus, reinfection by autoinfection or exposure to eggs from other individuals is necessary to maintain enterobiasis in an individual. The condition is communicable as long as the gravid female nematodes are discharging eggs on perianal skin. Eggs are infectious in an indoor environment for 2 to 3 weeks. Humans are the only hosts (1).


  1. Chin, J. 2000. Enterobiasis. Control of Communicable Diseases Manual. APHA: Washington, D.C., pp. 186-188.
  2. Sheorey, H., B. Biggs, & P. Traynor. 2011. Nematodes. In: Versalovic, J. et. al. (eds.). Manual of Clinical Microbiology. 10th ed. ASM Press. Washington, D.C.

CPT Codes



Last Updated


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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.