1.Three types of anal swabs for the diagnosis of Enterobius vermicularis infection were studied: (i) The NIH cellophane swab as described by Hall (ii) the wet pestle swab as described by Schüffner and Swellengrebel and (iii) the transparent adhesive cellulose tape as suggested by Graham, but used in the manner first described by Jacobs, and prepared for microscopic examination in a manner described as new in this paper, the essential feature of the new modification being the use of toluene to clear the preparation.
2.On a small series of transparent adhesive tape specimens it was found that using a drop of toluene between the slide and the tape to clear the preparation increased the positive findings by an average of 24 per cent and decreased the time necessary for examination by an average of 40 per cent.
3.Of 236 positive specimens obtained by simultaneous use of the NIH and wet pestle swabs, 91.5 per cent were diagnosed by wet pestle as compared with 75 per cent by NIH swab. Respectively, the pestle and NIH preparations averaged 88 and 52 eggs per preparation.
4.Of 160 positive specimens obtained by simultaneous use of the wet pestle and transparent tape, 76.3 per cent were diagnosed by wet pestle and 95.6 per cent by transparent tape. Respectively, the pestle and tape preparations averaged approximately 50 and 1,000 eggs.
5.The greater efficiency of the tape technic was found to be due in part to the ease with which the novice can be taught to use it properly. Some of the physicians, nurses, medical students, parents, and matrons made frequent serious technical errors in the use of the others but all were about equally efficient in taking specimens with the transparent adhesive tape.