More than 1,000 locally acquired West Nile virus cases reported in Europe

Europe has recorded more than 1,000 locally acquired West Nile virus infections since the start of the season, with cases rising sharply in recent weeks. The European Centre for Disease Prevention and Control said 1,086 infections had been registered by Thursday in people who contracted the virus locally rather than while traveling.

At the beginning of August, authorities had recorded 241 cases in seven European countries. The number of affected countries has since risen to 15, although the latest total cited by the report covered cases in seven countries. A total of 144 areas across Europe were affected, including 62 in Italy. The ECDC cautioned that the figures did not provide a complete picture of transmission.

Italy reported the most cases, with 516, followed by Greece with 284, including 11 infections of unknown origin, and Spain with 88. Germany had recorded two cases as of Sept. 3. France, the Netherlands and Austria, all neighbors of Germany, had also reported infections.

The virus mainly spreads through mosquitoes among wild birds, but infected mosquitoes can also transmit it to people. The Robert Koch Institute said about 20 percent of infected people develop a feverish, flu-like illness, while roughly one in every 100 infected people becomes seriously ill.

West Nile fever usually clears without complications. Long-term effects are relatively common among patients who develop severe disease.