The Mississippi State Department of Health says someone who had earlier been infected with West Nile virus in Madison County has died, bringing the state's 2012 death total to five.
The state also reported 14 new cases Monday, pushing the year's total to 200.
That's the largest number of cases ever confirmed by laboratories. In 2011, Mississippi had 52 cases and five deaths.
Dr. Thomas Dobbs, the state epidemiologist, says a warm winter, followed by wet spells, has created perfect breeding conditions for mosquitoes that carry the virus. That's especially true in central and southern parts of the state.
Metropolitan Jackson counties of Hinds, Madison and Rankin have reported 43 percent of cases statewide, though they only have 16 percent of the population.