2.3. Pre-treatment screening for Enterobius infection, anal
itching and enuresis
2.3.1. Collection of anal swabs
For parasitological screening, anal swab was collected
from each child, using an 8 cm 伊 2 cm piece of transparent
adhesive tape (Cellotape, Henkel Consumer Adhesives,
Winsford, UK) held sticky side out, over the end of a glass
microscope slide[26]. The tape was briefly patted on the
perianal area of a subject and then reversed, so that it stuck
to the glass slide, with the sample trapped between the tape
and the glass. All samples were collected between 06:00 and
Iquo B Otu-Bassey et al./Asian Pacific Journal of Tropical Medicine (2011)315-319 317
08:00, just after the children had woken up but before they
had bathed. Each subject was sampled only once due to
poor co-operation of the subjects and/or their parents.
2.3.2. Screening for anal itching and enuresis
After the anal swabs had been obtained, each of the
subjects was interviewed in the presence of at least one
of his or her parents or guardians based on a standard
questionnaire. The ages and gender of the subjects were
recorded before they were asked if they suffered from any
anal itching and/or bedwetting (and if so, for how long).
They were asked also if they had felt the movement of, or
seen worms emerging from their anus. For the purpose of
this work, only subjects who wetted themselves frequently
and night wetters were considered enuretic since about 85%
of enuretics are night wetters[27].
2.4. Detection of ova of E. vermicularis
To each anal swab, 2 drops of xylene were added, between
the slide and the tape, and spread over the entire length of
the slide to dissolve the mucilage in the sample[26]. Each
slide was then carefully examined under a light microscope,
at 10伊 and 40伊, for the characteristic ova of E. vermicularis.
2.5. Treatment of Enterobius egg- and anal itching-positive
subjects
All subjects (enuretic and non-enuretic) found positive
for Enterobius eggs and those reported as having anal
itching in the initial screening, except those who opted
out were administered with a single oral dose of 400 mg of
albendazole[22] (supplied as Zentel and manufactured by
Glaxo Wellcome Nigeria Ltd., Lagos, Nigeria) following
their clinical assessment by the study physician, who also
monitored them for any adverse effects. Anal itchingpositive
but Enterobius egg-negative individuals were
treated to ascertain to what level syndromic management
of helminths infections undermine the determination of the
true prevalence of enterobiasis.
2.6. Post-treatment screening for Enterobius eggs, anal