Avian paramyxoviruses from migrating and resident ducks in coastal Louisiana.

Cloacal and tracheal swabs were collected from 1,409 hunter-killed ducks in Cameron Parish, Louisiana, during the 1986 and 1987 waterfowl seasons. Thirty avian paramyxoviruses (PMV's) were isolated from 605 blue-winged teal (Anas discors), 75 mottled ducks (A. fulvigula), 375 gadwalls (A. strepera), 334 green-winged teal (A. crecca), and 20 mallards (A. platyrhynchos). Prevalence of PMV decreased (P = 0.042) from September (4%) through November (2%) to December and January (1%). Juveniles had a higher prevalence of PMV (P less than 0.0001) than adults. An isolate from resident mottled ducks documents transmission of PMV's on the coastal wintering areas of Louisiana. The four serotypes isolated, PMV-1, PMV-4, PMV-6, and PMV-8, were typical of PMV's commonly associated with free-living waterfowl.