Why do certain regions and populations differ in transmission of the same species of human and non-human primate malaria parasites?

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H04411
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 80010:Area studies-related
• Research Institution: Nagasaki University
• Principal Investigator: Maeno Yoshimasa 長崎大学, 熱帯医学・グローバルヘルス研究科, 客員教授 (70131191)
• Co-Investigator(Kenkyū-buntansha): 益田 岳 東京女子医科大学, 医学部, 助教 (00455916) ; 高木 秀和 愛知医科大学, 医学部, 准教授 (90288522)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: マラリア / サルマラリア / 人獣共通感染 / 疫学調査 / 分子生物学的解析

Outline of Final Research Achievements

The spread of COVID-19 and the situation in the partner countries restricted travel and survey activities for many periods, making field surveys impossible. As a result, surveys were conducted and analyzed to the extent possible, albeit incompletely. Analysis of the infection situation was conducted in the Ranau district of Sabah, Malaysia, where the survey was conducted. The Ranau district is located inland at an altitude of 1,000 m and has a population of approximately 100,000, most of whom are farmers. Interviews and sample analysis were conducted. (1) According to the health center, the number of people infected with monkey malaria is increasing every year. (2) Most of the infected patients were adult male farmers. (3) Based on patients' testimonies, forested areas were suspected to be infected areas. (4) Although there were no human malaria cases and only non-human primate malaria cases, we decided to continue the investigation.

Free Research Field

寄生虫学

Academic Significance and Societal Importance of the Research Achievements

マラリアは、蚊帳の配布や新規開発抗マラリア薬の配布などという有効な対策によって減少傾向が見られる。東南アジアの都市部においても同様な対策により減少傾向が見られる。しかし、東南アジアに広くみられる「森林マラリア」は、マラリア原虫を媒介する蚊がヒトの居住地に現れることなく森林に潜んでいることにより、前述の対策と同様な対策を実施しても効果が希薄となっている。このことが東南アジアにおいてマラリアが根絶できない主要な要因となっている。このため地域に即したマラリア対策の基盤資料の提案を行い、地域における各種健康被害の抑制をはじめ、医療経済を含めた各種損失の抑制に寄与する。