DO NOT COVER THE STOOL WITH CRESOL 
OR OTHER DISINFECTANT. 
DO NOT CONTAMINATE THE SPECIMEN WITH 
URINE, DIRTY WATER, OR EARTH. 
DO NOT FILL THE EMPTY VIAL MORE 
THAN HALF FULL. 
LABEL EACH VIAL WITH THE PATIENT’S 
NAME AND ADDRESS. 
c. Collection of multiple specimens with and 
without catharsis 
Because of the intermittent passing of para- 
sites from the host, examination of multiple 
specimens is desirable. Ascaris, hookworm, 
and Trichuris eggs appear almost daily in 
feces. Cysts of Entamoeba histolytica and 
eggs of certain of the helminths such as 
Schistosoma species and Diphy Robot hr ium 
latum are passed intermittently. These ir- 
regularities emphasize the need for collec- 
tion of at least three specimens spread over 
10 to 14 days. 
Normally, passed stool specimens spaced 
several days apart are preferable to speci- 
mens obtained by catharsis or sigmoidos- 
copy, since cysts are more likely to be pres- 
ent in passed stool specimens. Purged speci- 
mens increase the possibility of finding 
organisms. A cathartic of sodium sulphate 
or buffered phospho-soda is preferable to 
magnesium sulphate since such cathartics af- 
fect the morphology of the organism less. 
Each bowel movement should be collected 
separately, numbered serially, and delivered 
promptly to the laboratory. Egg, larvae, 
cysts, and trophozoites may be found in such 
specimens. If examination of the specimen 
is to be delayed, add a portion to PVA 
fixative. 
d. Collection of specimens by sigmoidoscopy 
In amebiasis, if stools are negative, material 
may be obtained by sigmoidoscopy immedi- 
ately following a normal bowel movement, 
or if a cathartic is given, after a lapse of 2 to 
3 hours. Collect the specimens with a 
serologic pipette rather than a cotton swab 
by aspirating material from any visible lesion 
and the mucosa. Pathologic areas or the 
mucosa wall may also be gently curetted. 
Examination of sigmoidoscopic specimens 
for diagnosis of amebiasis must be immedi- 
ate, but after the direct examination, PVA 
fixative may be added and the preparation 
dried and stained. 
e. Collection of specimens other than feces 
Sputum specimens as well as stools should 
be collected in suspected cases of paragoni- 
miasis. Pulmonary amebiasis and echinococ- 
cosis may also be diagnosed by sputum 
examination. Urine specimens are used in the 
diagnosis of Trichomonas vaginalis and 
Schistosoma haematobium. The optimum 
urine specimen to be examined for the latter 
is one passed at or shortly after noon. Vagi- 
nal swabs or scrapings are used in diagnosis 
of T. vaginalis.* Anal swabs or cellulose 
tape specimens are the usual means of col- 
lecting the eggs of Enterobius vermicularis, 
as shown in Figure 3. Specimens taken be- 
tween 10 p.m. and 12 midnight, or in the 
early morning before defecation, are best. 
Three consecutive examinations are desir- 
able, and a short delay in examination of 
either the swab or tape specimen makes no 
particular difference, but the specimens 
should be refrigerated if examination is de- 
layed for more than a day. Biopsied material 
for the dagnosis of schistosomiasis may be 
collected from the colon, rectum, or bladder 
and, for amebiasis, from the rectum or liver. 
Biopsy is not recommended for echinococ- 
cosis because of the danger of complications 
resulting from the leaking of hydatid fluid 
into the surrounding tissue. Duodenal drain- 
age often reveals organisms when stool speci- 
mens are negative for Strongyloides ster- 
coralis and Giardia lamblia and should be 
collected when diagnosis cannot be estab- 
lished by fecal examination. 
Biopsy material (human gastrocnemius or 
deltoid muscle) may be collected for diag- 
nosis of trichinosis. The muscle may be 
fixed and sectioned or the fixed tissue may be 
submitted for examination and sectioning 
and staining. Serologic methods are more 
commonly used in the diagnosis of trichinosis 
than direct examination of tissue for the 
larvae. Animal biopsy or autopsy meat or 
other foodstuffs of animal origin suspected 
of harboring T. spiralis larvae should be 
submitted to the laboratory in plastic bags 
and liberally covered with sodium borate 
powder. The specimen should not be frozen. 
The borate preserved meat may then be 
subjected to pepsin-HCl digestion for re- 
covery of larvae. 
* The swabs may be examined as a wet mount or, prefer- 
ably, they may be placed in a suitable culture medium. 
25 
