Kagoshima University Research Center for the Pacific Islands Occasional Papers No.39, 107-109, 2003
Section 3, Report 4. The Progress Report of the 2000 and 2001 Survey of the Research Project“Social Homeostasis of Small Islands in an Island-zone”

107

CONTAMINATION OF SOIL WITH PARASITE EGGS IN MADRICH,
YAP ISLANDS, FEDERATED STATES OF MICRONESIANODA Shinichi1) and John GILMATAM2)

Abstract
Soil samples were collected from shady ground of dwelling areas in Madrich. Detection of parasiteeggs from soil samples were carried out. Three species of helminth eggs, Ascaris lumbricoides,Trichuris trichiura and Txocara canis were detected. Among the 10 soil samples examined, A.
lumbricoides eggs were detected in 4 samples, and T. trichiura eggs were in one sample. Txocara canis
eggs were also detected in 6 samples. A. lumbricoides and T. canis eggs contained infective larvae.
Keywords: intestinal parasite, Toxocara canis, soil, Yap Islands, Federated States of Micronesia

Introduction
Parasitism is usually considered as a common condition in rural populations in developing
countries. Although the mortality rate by intestinal helminth infections is low, these infections
are recognized as a serious public problem because of the high prevalence. In our previous survey, of 111 persons examined, 12 (10%) were infected with one or two species of intestinal parasite in Yap Islands. The prevalence of intestinal parasites was relatively high in Rull (26.2%)(N ODA et al. 2001). Eggs of Ascaris lumbricoides and Trichuris trichiura are discharged into
natural environments, and develop to embryonated egg stage under appropriate climate conditions. Embryoneted eggs are ingested by humans with dust or food. The source of parasite egg
contamination to environments is untreated human feces. This study was conducted to recoverparasite eggs from soil samples collected in Madrich, Yap Islands.

Materials and Methods
Soil samples were collected from shady ground of dwelling areas in Madrich. Detection ofparasite eggs from soil samples was carried out according to the method reported by U GA andK ATAOKA (1995). Collected samples were dried overnight in the shade and sifted through a
150-µm mesh sieve. Approximately 2 gm of the powdery sand obtained was placed in a test tubeand suspended in approximately 8 ml of 0.05% Tween 20 solution. After centrifugation of thetest tube at 80 g for 10 minutes, the supernatant was removed and sucrose solution with a specific gravity of 1.200 was added to fill the tube 1 cm from the top. The tube was then filled tothe top with the sucrose solution so that only a small bubble was formed when a cover glass wasplaced on the tube. After a final centrifugation of the tube at 25 g for 5 minutes, the cover glass
was removed from the tube, placed on a slide glass, and examined under a microscope. The sametest tube was then treated repeatedly using three final steps to recover more eggs.
1)
2)

Kagoshima University Research Center for the Pacific Islands. Kagoshima 890-8580, Japan.
Department of Health Services, Yap State Government, P. O. Box 148, Colonia, Yap 96943, FSM.

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NODA Shinichi and John GILM ATAM

Results and Discussion
Three species of helminth eggs, Ascaris lumbricoides, Trichuris trichiura and Txocara
canis were detected (Table 1 and Fig. 1). Among the 10 soil samples examined, A. lumbricoides
eggs were detected in 4 samples, and T. trichiura eggs were in one sample. Txocara canis eggs
were also detected in 6 samples. A. lumbricoides and T. canis eggs contained infective larvae(Fig. 1a, c). T. canis is a parasite that occurs commonly in dogs. Eggs of non-human ascarids
such as T. canis are capable of undergoing a limited development in the human host. Theirparasitological importance to humans involves the occasional symptomatic diseases that result
from a condition known as larva migrans. Visceral larva migrans affects primary children. Thereis hepatomegaly, persistent hypereosinophilia, bronchial asthma and fever.
The results indicate that the surveyed area was contaminated with parasite eggs which were
the source of new infection to villagers. Measures to prevent environmental contamination will
be concerned with the safe disposal of human and animal excreta and the prevention of food contamination by fecal material. Education of the public in personal hygiene will be necessary.
Health education should be based on what the people need to know and what they can do forthemselves.
Table 1. Number of parasite eggs recovered from soil samples
Sample No.
12345678910Ascaris lumbricoides
0200
1001
10

SpeciesTrichuris trichiura
0000000020Toxocara canis
010050162622Fig. 1. Recovered parasite eggs; (a) Ascaris lumbricoides, (b) Trichuris trichiura, (c) Toxocara canis (Bar=50 µm).

CONTAMINATION OF SOIL WITH PARASITE EGGS IN MADRICH, YAP ISLANDS, FEDERATED STATES OF MICRONESIA 109References
N ODA, S., J. G ILMATAM, Y OSHIIE K., and OGINO K. 2001. Medical Survey on Yap Proper:
Intestinal Helminthic Infections, Distribution of Mosquitoes and Health Condition ofInhabitants. Kagoshima University Research Center for the Pacific Islands OccasionalPapers 34: 129–132.
U GA, S. and KATAOKA N. 1995. Measures to Control Toxocara Egg Contamination in Sandpitsof Public Parks. American Journal of Tropical Medicine and Hygiene 52: 21–24.