The worst West Nile virus outbreak in years has claimed another 13 lives. In the past week, more than 400 new cases were identified, and the death toll rose from 134 to 147 people, according to a new report from the Centers for Disease Control and Prevention. Federal health officials say there have been 3,545 cases reported so far in 2012, but that the rate of infection appears to be slowing. Roughly 38 percent of the cases were reported in Texas. Mississippi, Michigan, South Dakota, Louisiana, Oklahoma, and California have also seen a large number of patients with the virus.