Chúng tôi không thể bản đồ không đặc hiệu "cao nguyên" hoặc "đồng bằng" mô tả. Nếu các nguồn ITHG cung cấp hạn chế xung đột, chúng tôi sử dụng ngưỡng độ cao cao hơn. Cuối cùng, các ITHGs báo cáo 70 thành phố như bệnh sốt rét. Đây là những tham chiếu địa lý bằng cách sử dụng cơ sở dữ liệu địa lý điện tử | THE GLOBAL SPATIAL LIMITS OF MALARIA TRANSMISSION 161 used to implement national altitudinal transmission limits reported in the ITHGs in metres above sea level. We could not map nonspecific highland or lowland descriptions. If the ITHG sources provided conflicting limits we used the higher altitude threshold. Finally the ITHGs reported 70 cities as malaria free. These were georeferenced using electronic geographic databases Microsoft Corporation 2005 The Getty Research Institute 2005 University of California 2005 co-located to their urban extents as defined by the Global Rural-Urban Mapping Project GRUMP CIESIN IFPRI WB CIAT 2004 and then excluded. Of the 107 countries reporting some degree of malaria risk we mapped 104 according to our ITHG exclusion criteria Table 2 . Uzbekistan reported only sporadic cases and was not mapped as a malaria endemic country MEC in this paper. For Algeria no corresponding administrative data could be obtained and for North Korea there was insufficient detail in the sub-national description of risk. Despite the ITHGs being independent documents there was relatively little complementary information of a potential 318 entries 106 MECs X 3 . risk information defined by administrative boundaries altitude or urbanisation there were only 121 unique reports with IAMAT-WMRC the most comprehensive and WHO-ITH the least Table 1 . 3. THE BIOLOGICAL LIMITS OF TRANSMISSION . Altitudinal Mask Temperature is inversely related to altitude dropping by approximately C for every 100-metre increase above absolute sea level Henderson-Sellers and Robinson 1991 . Mosquitoes and malaria transmission are thus sensitive to altitude Cox et al. 1999 . Altitudinal limits from the ITHGs were available for 42 countries. The majority of the countries 44 62 for which no information was available were in Africa and we assumed no altitudinal limits for most of these see Section . For the 18 remaining non-African MECs we defined limits by those of .
