Alternative Title日本の土壌伝播蠕虫は制圧されているのか？分子生物学的手法を用いた日本の土壌伝播蠕虫感染状況調査結果
Degree grantor/typeNagasaki University (長崎大学)
Note (General)Background: Japan is one of the few countries believed to have eliminated soil-transmitted helminths (STHs). In 1949, the national prevalence of Ascaris lumbricoides was 62.9%, which decreased to 0.6% in 1973 due to improvements in infrastructure, socioeconomic status, and the implementation of national STH control measures. The Parasitosis Prevention Law ended in 1994 and population-level screening ceased in Japan; therefore, current transmission status of STH in Japan is not well characterized. Sporadic cases of STH infections continue to be reported, raising the possibility of a larger-scale recrudescence of STH infections. Given that traditional microscopic detection methods are not sensitive to low-intensity STH infections, we conducted targeted prevalence surveys using sensitive PCR-based assays to evaluate the current STH-transmission status and to describe epidemiological characteristics of areas of Japan believed to have achieved historical elimination of STHs. Methods: Stool samples were collected from 682 preschool- and school-aged children from six localities of Japan with previously high prevalence of STH. Caregivers of participants completed a questionnaire to ascertain access to water, sanitation and hygiene (WASH), and potential exposures to environmental contamination. For fecal testing, multi-parallel real-time PCR assays were used to detect infections of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale and Trichuris trichiura. Results: Among the 682 children, no positive samples were identified, and participants reported high standards of WASH. Conclusions: To our knowledge, this is the first STH-surveillance study in Japan to use sensitive molecular techniques for STH detection. The results suggest that recrudescence of STH infections has not occurred, and that declines in prevalence have been sustained in the sampled areas. These findings suggest that reductions in prevalence below the elimination thresholds, suggestive of transmission interruption, are possible. Additionally, this study provides circumstantial evidence that multi-parallel real-time PCR methods are applicable for evaluating elimination status in areas where STH prevalence is extremely low.
長崎大学学位論文 学位記番号:博(医歯薬)甲第1250号 学位授与年月日:令和2年3月31日
Author: Mitsuko Hasegawa, Nils Pilotte, Mihoko Kikuchi, Arianna R. Means, Marina Papaiakovou, Andrew M. Gonzalez, Jacqueline R. M. A. Maasch, Hiroshi Ikuno, Toshihiko Sunahara, Kristjana H. Asbjornsdottir, Judd L. Walson, Steven A. Williams and Shinjiro Hamano on behalf of the DeWorm3 Project Team
Citation: Parasites & Vectors, 13, art.no.6; 2020
identifier:Nagasaki University (長崎大学), 博士(医学) (2020-03-31)
http://hdl.handle.net/10069/39948
Collection (particular)国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文
Date Accepted (W3CDTF)2020-04-06T03:04:11+09:00
Data Provider (Database)国立国会図書館 : 国立国会図書館デジタルコレクション