Record Number of West Nile Deaths Reported in California This Year

A record number of California residents have died from West Nile virus this year, according to new state data, the Los Angeles Daily News reports.

Details of West Nile Cases

Overall, 512 cases of West Nile virus have been reported in the state so far in 2015, compared with 642 during the same period last year.

However, the number of deaths has increased. According to the data, 32 California residents have died from the illness this year, the most in a year since the California Department of Public Health started recording cases in 2003. In comparison, 31 Californians died from the virus last year.

The average age among those who died from the illness this year was 75, with ages ranging from 50 to 98.

Meanwhile, the number of West Nile virus-related deaths is expected to rise through November, the Daily News reports.

Reasons for Spike in Deaths

According to health officials, it is unclear why there have been more West Nile-related deaths this year.

Gil Chavez, state epidemiologist and deputy director for infectious diseases, said, "At this point, it is difficult to determine the reasons for the higher proportion of fatal cases to date in 2015," adding, "An analysis of the severity of the 2015 West Nile virus season will be done when reporting for the year is complete."

However, the state's ongoing drought could be a factor in the high number of cases, the Daily News reports (Abram, Los Angeles Daily News, 11/6). Gov. Jerry Brown (D) declared a state of emergency over the drought in January 2014.

Deborah Bass, public affairs manager for the Contra Costa Mosquito and Vector Control District, said, "Drought years are worse for [West Nile] and other mosquito-borne diseases than years with more rain because there are fewer watering holes forcing birds and mosquitoes to congregate at the same location" (California Healthline, 9/24).

Meanwhile, Los Angeles County health officials have said that the El Niño effect this year could cause an increase in the number of West Nile virus cases next year. The additional rain and higher temperatures under the weather system could enable mosquitoes -- which carry the disease -- to survive winter more easily and breed more aggressively (California Healthline, 10/30).

As a result, Rachel Civen, medical epidemiologist at the Los Angeles County Department of Public Health, said the agency plans to provide residents with more education about the illness (Los Angeles Daily News, 11/6).