Burgess E C, Ossa J, Yuill T M
Avian Dis. 1979 Oct-Dec;23(4):940-9.
Healthy waterfowl were found to be carriers of duck plague (DP) virus. Black ducks (Anas rubripes) and Canada geese (Branta canadensis) surviving a natural outbreak of DP at Coloma, Wisconsin, in 1973 yielded DP virus in cloacal swabs taken four years postinfection. Experimental infection of previously unexposed mallard ducks (Anas platyrhynochos) with the Coloma strain of DP virus CO-WI (73) also produced cloacal virus shedding for up to four years after infection. A second DP virus strain, LA-SD (73) from the Lake Andes, South Dakota, epornitic, was detected from cloacal swabs of pintail ducks (Anas acuta), gadwall ducks (Anas strepera), wood ducks (Aix sponsa), and Canada geese infected experimentally one year before. The frequency of swabs positive for DP virus varied between individuals within each of the tested species. The amount of detectable DP virus shed was about 100 plaqueforming units of virus percloacal swab. Oral erosions were present in all species tested except Canada geese and gadwall ducks. Erosions occurred at the openings of the sublingual salivary gland ducts. DP virus was isolated from erosions. All ducks with lesions proved to shed DP virus, although not necessarily at the time they had the lesion.
健康水禽被发现是鸭瘟（DP）病毒的携带者。1973年在威斯康星州科洛马发生的一次自然鸭瘟疫情中存活下来的黑鸭（绿头鸭）和加拿大鹅，在感染四年后采集的泄殖腔拭子中检测到鸭瘟病毒。用科洛马株DP病毒CO-WI（73）对先前未接触过的绿头鸭进行实验性感染，感染后泄殖腔病毒排出可持续长达四年。从一年前实验感染的针尾鸭、赤膀鸭、林鸳鸯和加拿大鹅的泄殖腔拭子中检测到了来自南达科他州安第斯湖禽病流行的另一种DP病毒株LA-SD（73）。在每个受试物种中，个体之间DP病毒拭子阳性频率各不相同。每个泄殖腔拭子中可检测到的DP病毒排出量约为100个病毒空斑形成单位。除加拿大鹅和赤膀鸭外，所有受试物种均出现口腔糜烂。糜烂发生在舌下唾液腺导管开口处。从糜烂处分离出DP病毒。所有有病变的鸭子都被证明排出DP病毒，尽管不一定在出现病变时排出。
