en weeks after government scientists discovered that H5N1 bird flu was sickening dairy cattle in the United States, many of the mysteries surrounding what is happening on affected farms remain just that.
Widespread reluctance on the part of farmers to allow scientists — government or otherwise — onto their premises to study spread of the virus among infected cows has created a frustrating lack of understanding of the dynamics of this outbreak. U.S. Department of Agriculture incentives aimed at getting farmers to test their cows and take preventive measures to protect both animals and farmworkers do not seem to have solved the impasse, even as the outbreak has affected 82 herds in nine states.