1999 Fiscal Year Final Research Report Summary
Biased distribution of pathogenic Entamoeba histolytica
| Project/Area Number |
10041202
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
寄生虫学(含医用動物学)
|
|---|
| Research Institution | Nagasaki University |
|---|
Principal Investigator |
KANBARA Hiroji Nagasaki University, Inst. of Trop. Med., Professor, 熱帯医学研究所, 教授 (20029789)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TACHIBANA Hiroshi Tokai University, School of Med., Associate Professor, 医学部, 助教授 (10147168)
YANAGI Tetsuo Nagasaki University, Inst. of Trop. Med., Research Associate, 熱帯医学研究所, 助手 (10174541)
UEMURA Haruki Nagasaki University, Inst. of Trop. Med., Assistant Professor, 熱帯医学研究所, 講師 (60184975)
RIVERA Windell l. Tokai University, School of Med., Postdoctoral Fellow, 医学部, 特別研究員
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Keywords | Entamoeba histolytica / Entamoeba dispar / pathogenic species / transmission mode / Philippines / PCR / cyst / PCR |
|---|
| Research Abstract |
Recently, Entamoeba histolytica has been recognized to consist of a pathogenic species, E. histolytica and a non-pathogenic species, E. dispar. This means that the conventional method using microscopic examination of fecal samples can not determine prevalence of pathogenic E. histolytica that is more important from the viewpoint of public health. Since the PCR method using extracted DNA from cysts has been shown to be useful for differentiation of E. histolytica from E. dispar, it was used in combination with the microscopic method to clarify the difference of the transmission mode between two species at various parts of Luzon in the Philippines. The following results were obtained.
1) The prevalence of two species was not over 15% in all the places examined, although the prevalence of helminthic infection reached nearly 70% in the slum area. This indicated that the transmission mode of Entamoeba is less effective than some helminths.
2) The prevalence of a pathogenic species, E. histolytica was less than a half of that of a non-pathogenic species, E. dispar in all the areas examined.
3) Both species showed a with variety of prevalence according to places. If the condition of public health is similar, the colder climate provides the better condition for transmission of Entamoeba.
4) The distribution of the pathogenic species was more varied than the non-pathogenic. Transmission from a human to a human is inferred to be maintained mainly by intimate contact in a family. Consequently the highest prevalence was found in the slum area.
5) Higher prevalence was found in children aged from 5 to 14 years, and in women than in men. This may be caused by differences of their living habits.
6) High prevalence of E. dispar was found in Japanese monkeys at the Takasaki mountain, Oita prefecture, Japan. This indicated that monkeys are more fitting hosts for E. dispar than humans.
|
Research Products
(6 results)
