Changes in DeCS 2009 tree codes. February 20, 2009.
Descritor	Deleted tree codes	Added tree codes
Acquired Immunodeficiency Syndrome		SP4.001.012.148.179
Avalanches		G01.311.340.111
		G01.595.340.111
Cyclones		G16.500.240.135.500
Droughts		G16.500.240.135.781
		G16.500.750.775.154
Genetic Phenomena	G13	G05
HIV	SP4.001.012.148.204
Infant Nutrition	SP4.011.102.133.219
Infectology		H02.403.776.409.480
(Replaced in 2009 by Infectious Disease Medicine)
Landslide		G01.311.340.674
(Replaced in 2009 by Landslides)		G01.595.340.674
Meteorology		H01.671.547
Natural Disasters	G03.230.100.200
Nutrition, Public Health		SP4.001.002.033
Pharmaceutical Care	SP2.016.152	SP2.016.152.010
Pharmaceutical Services		SP2.016.152
Physiologic Processes	G07	G07.700
(Replaced in 2009 by Physiological Processes)		N06.850.780.800
Secondary Prevention		N02.421.726.825
		N06.850.780.750
Tertiary Prevention		N02.421.726.860
Volatile Organic Compounds		D26.530