West Nile Virus Epizootiology, Central Red River Valley, North Dakota and Minnesota, 2002–2005

摘要

West Nile virus (WNV) epizootiology was monitoredfrom 2002 through 2005 in the area surrounding GrandForks, North Dakota. Mosquitoes were tested for infection,and birds were surveyed for antibodies. In 2003, WNV wasepidemic; in 2004, cool temperatures precluded WNVamplification; and in 2005, immunity in passerinesdecreased, but did not preclude, WNV amplification