| norway rat population in baltimore, maryland, 2004. | norway rats are reservoirs for several zoonotic agents, including hantaviruses, and are implicated in the transmission of pathogens to humans in urban environments. the rat population of baltimore, maryland was estimated from surveys in 1949 and again in 1952, but has not been evaluated for more than 50 years. previously identified sociodemographic risk factors for rat infestation, including median income, human density, and percentage of rental properties, were used to categorize census block g ... | 2005 | 16187901 |