濟州道 住民의 痢疾아메바 (entamoeba histolytica) 感染에 關한 疫學的硏究

Abstract

[한글]

[영문]

The prevalence of E.histolytica in Korea has been reported by several investigators. Choi (1926) found 1.5% of prevalence on single examination by direct smear method from 2,000 examinees in Seoul area, whereas 30.2% were found on 6 repeated examinations.

Soh and his associates(1951) reported 4.3% of E.histolytica carriers out of 10,320 examined and found no special age or monthly differences among them, but Cheung et al.(1959) reported that Clinical cases were predominant throughout the summer months.

There have been no researches concerning the mode of amoebic infestation in Korea. According to the previous reports, water pollution due to the unsanitary disposal of human night-soil and parathenic carriers such as flies may be considered as possible transmitters of E.histolytica.

Soh(1959) examined the roadside soils in Seoul area and found cysts of E.histolytica and other protozoa from 19 surface soil samples. The high rate of amoeba detection was found wherever there was a poorly controlled polluted area.

The present paper describes the protozoan incidence at 6 villages and environmental studies in chejudo during 1965∼1966.

Materials and methods:

Six villages were sampled; among of them Sinwom-Ri is located on the coastal area and the inhabitans utilize drinking water from the public well. Yongheung-Ri and Chochon-Ri are located two miles from the coast and he people rely on pools of rain water for drinking or laundry. Stools were examined within 24 hours by iodined direct fecal smear method. If the first slide was negative, then a second examination was done with the same fecal sample. Pig-feces, materials from manure heap(compost), garden soil, dusts from floor, house flies and fingernail dirt of the villagers were collected to examine for E.histolytica cysts. Except with drinking water, the zinc sulfate floatation method was applied in general for the detection of E. histolytica cyst.

Drinking water was taken from the bottom of the jar where the sediments and debris were mixed. The intestinal contents of house rats(Ratus norvegicus) were sampled, and examined by the zinc sulfte floatation method. All the samples were examined under microscope by staining with iodine solution.

Results :

prevalance

53.9% out of 865 examined were positive for intestinal protozoa : E.histolytica 24.4%, E. coli 28.6%, Endolimax nana 19.9%, Giardia lamblia 7.2%, Iodamoeba butschlii 5.5% and Chilomastix mesnili 4.5%. A single infection of protozoa was the highest(44.7%), and double, triple, 4 and 5 species of infestation were experienced in decreasing order.

Age distribution :

The prevalence of E. histolytica infestation was the lowest (15.7%) in the below 5 years age group, and the highest (34.8%) was in the group aging 41-50. In general, the protozoan incidence increased after 6 years of age and continued to old age, although giardial infestation showed a peak at the age group of 6-10.

Sex distribution :

Females showed a higher incidence (32.6%) than males (24.8%) E. coli also showed the same tendency.

Incidence according to households;

173 households were sampled from 3 villages, and 104 families (60.1%) had been infested with E. histolytica. The people from 65 households(78.5%) were found to be positive. In general, two or three persons in positive household were most common.

E. histolytica cysts were found in 24.8% of 177 hog feces, 6.8% from the drinking water, 4.1% from house rats, and 6.2% from compost. These facts indicate that fecal pollution is a serious means of the transmission of amoebiasis in this area.

Although very few or no E. histolytica cysts were found from the house fly, dust, and fingernail dirt, they are still recognized as guilty because other fecal borne parasites were found from the same samples.

Summary :

The incidence of Entamoeba histolytica infestation in Cheju island was examined during the summer seasons of 1965 and 1966. The total number of stools examined was 865. Factors of transmission were also studied.

1. The incidence of intestinal protozoa was 53.9% and E. histolytica was 24.4%.

2. The incidence in adult groups was higher than in groups of younger ages.

3. The households which bad more than three positive members in a family were 56.3% in Sinwom-Ri, 34.6% in Yongheung-Ri.

4. Sources of infection by E. histolytica in Cheju-do were possible hog-feces, compost, and drinking water.