Table 2. Stratification Scheme of Malaria Endemic Areas in the Philippines, 2010.

Stratum	Definition	No. of Provinces	No. of Cities
1. Stable Risk	With at least 1 barangay that has a continuous presence of at least one indigenous malaria case in a month for 6 months or more at any time during the past three years	29	8
1.1 high	w/> 1000 aver. malaria cases from 2007-2009	(5)	(2)
1.2 moderate	w/ 100 to <1000 average malaria cases from 2007-2009	(18)	(3)
1.3 low	with < 100 average malaria cases from 2007-2009	(6)	(3)
2. Unstable Risk	With at least 1 barangay that has a continuous presence of at least one indigenous malaria case in a month for less than 6 months at any time during the past three years	10	1
3. Epidemic Risk or Sporadic risk	With at least 1 barangay that has a presence of at least one indigenous malaria case at any time in the past 5 years	18	2
4. Malaria Free	Absence of indigenous malaria case for 5 past years even in the presence of malaria vector	23	-
Total		80	11

Source: [7]

Note: Figures in parentheses represent the number of provinces/cities that fall under the stable risk stratum.