The Moscow Region is the largest administrative territorial entity that comprises 39 districts, 72 towns, 110 urban settlements, and above 6,000 inhabited localities. This is the most populated region of Russia with the average density of 334.5 persons per square kilometers, which is almost 40 times greater than that of the whole country's population. The malaria situation in the Moscow Region was stable till 2001, then drastically aggravated: in the past 50 years there has been intensive local malaria transmission through malaria mosquitoes in the Moscow Region for the first time. In 2001, there were a total of 98 cases of malaria, of them there were 40 cases of infection; in 2002 there were 103 cases, including 49 cases caused via local transmission. Due to the increased antimalaria measures, the situation gradually improved and in 2007 the malaria cases notified in the region decreased to 20, of them there were 6 locally transmitted cases. Larvicidal treatments of water reservoirs in 2006 were performed in 27 administrative areas, by covering 497 water reservoirs of an area of 296 ha. In 2007, water reservoirs were treated in 23 administrative areas, by covering 684 water reservoirs, the area of which was 369 ha.