| avian influenza viruses in minnesota ducks during 1998-2000. | although wild ducks are known to be a major reservoir for avian influenza viruses (aiv), there are few recent published reports of surveillance directed at this group. predominant aiv hemagglutinin (ha) subtypes reported in previous studies of ducks in north america include h3, h4, and h6, with the h5, h7, and h9 subtypes not well represented in these host populations. the objective of this study was to determine whether these subtype patterns have persisted. each september from 1998 to 2000, cl ... | 2003 | 14575079 |