West Nile figures trickling in

The Centers for Disease Control say that only 35 cases of the West Nile virus have so far been reported in the United States this year, but the season is just getting started: late summer and early fall are the times when most infections occur.

Of the 35 cases, 19 are in the West and 10 of those cases were reported as encephalitis/meningitis. Researchers caution that the high percentage of neuroinvasive disease is often overstated because serious cases are more likely to be reported than mild cases.

In 2008, 1,356 cases were reported nationwide, including 44 fatalities. About half the cases were neuroinvasive. There were 680 cases in the West, with California reporting the highest number (445) and Washington the lowest (3). There were 398 cases of encephalitis/meningitis, with California again having the most: 292. Montana and Wyoming reported no cases of neuroinvasive disease.

The peak of West Nile infection in the U.S. occurred in 2003, when cases totaled nearly 10,000 nationwide and 264 people died of a neuroinvasive strain.