Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants |
|Research Institution||International Medical Center of Japan |
KANO Sigeyuki International Medical Center of Japan, Research Institute, Director, 部長 (60233912)
KAWAZU Shin-ichiro International Medical Center of Japan, Research Institute, Chief, 室長 (60312295)
SUZUKI Mamoru Gunma University, Graduate School of Medicine, Professor, 大学院・医学系研究科, 教授 (60056033)
|Project Period (FY)
2001 – 2003
Completed (Fiscal Year 2003)
|Budget Amount *help
¥12,600,000 (Direct Cost: ¥12,600,000)
Fiscal Year 2003: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2001: ¥5,800,000 (Direct Cost: ¥5,800,000)
|Keywords||malaria / Drugresistance / epidemiology / International Collaboration Research / Thailand : Philippines, Laos / タイ:フィリピン:ミャンマー:ベトナム|
To develop appropriate diagnostic and therapeutic methods for the treatment of drug resistant malaria in Asian countries, the following evidence is to be adduced.
1.Evidence from in vitro drug susceptibility test
(1)The test was conducted in Hospital for Tropical Diseases Mahidol University, Bangkok, and its field station near Myanmar border. It was revealed that those isolates are 100% resistant against chloroquine and around 50% resistant to mefloquine.
(2)Distribution of chloroquine resistant parasites were first recognized by the test in Mindanao island, the Philippines.
(3)A small pilot study in southeast part (Saravan District) of Laos showed 4 chloroquine resistant isolates out of 9. These 9 isolates were all susceptible to mefloquine.
2.Evidence from the drug administration to patients.
Clinical trials using combination therapy (CT), namely, Artesunate+Mefloquine, Artesunate+Lumefantrine, dihydroartemisinin-napthoquine-trimethoprim (DNP^<【○!R】>), artemether-lumefantrine (Coartem^<【○!
R】>) were successfully conducted in Hospital for Tropical Diseases Mahidol University, concluding that CT is very effective against drug resistant malaria.
3.Evidence from the DNA analysis of the parasite genome
(1)Thirty-two isolates from Mindanao island were subjected to DNA extraction and determination of its sequences on pfcrt and pfmdr, drug resistant markers. Not less than 80% of them showed drug resistant gene whose characteristics were quite different from those from Thailand.
(2)Another survey in the Philippines revealed the island-specific SNPs patterns. That is, a SNP in pfcrt of isolates from Palawan island was similar to that in Asian Continent, and the other SNP observed in Mindanao was similar to Papua New Guinea type.
We concluded from the evidence obtained through our studies that drug resistant malaria in Asian countries are very different from each other according to their distributed areas. We believe that we have successfully showed the way we closely look at the evidence on the epidemiology of drug resistant malaria. Less