Photo by Wendy Langhans for KHTS

The bird- and bat-counters have been busy this past week, discovering another 15 dead birds infected with West Nile Virus (WNV) and five more rabid bats in Los Angeles County.

Two of those bats were found in the Santa Clarita Valley. One was found dead in a Saugus swimming pool and another was found alive beneath a car in Valencia.  The other three were found in Chatsworth, Sierra Madre and Glendale.

As of today, a total 39 rabid bats have been found in Los Angeles County, which is the highest number detected here in a single year since testing of bats began in 1961. The prior record was set last year, when 38 rabid bats were detected.  During most years, an average of  8-10 rabid bats are found.  Eight people and 10 pets have had potential exposure to these rabid bats. The cause for the increase in findings is unknown.

To date there have been 49 WNV- positive dead birds and squirrels recovered, primarily in the western part of the county. This is a lower number than were detected last year.  Another difference is that last year most of the birds were found in the eastern part of the county. The season for WNV is well underway. The public should continue to be vigilant and check property at least weekly for any standing water (where mosquitoes may breed), and to take precautions to avoid mosquito bites.

Asian tiger mosquito

Cases of WNV infection in birds and people tend to be highest in the late summer, but may be happen at other times.  Thus far in 2012, 43 states have reported West Nile virus infections in people, birds, or mosquitoes. A total of 693 cases of West Nile virus in people, including 26 deaths, have been reported to Centers for Disease Control and Prevention. Of these, 406 (59%) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 287 (41%) were classified as non-neuroinvasive disease.

The 693 cases reported thus far in 2012 is the highest number of West Nile virus disease cases reported to CDC through the second week in August since West Nile virus was first detected in the United States in 1999. Over 80 percent of the cases have been reported from six states (Texas, Mississippi, Louisiana, Oklahoma, South Dakota, and California) and almost half of all cases have been reported from Texas.

In California, there were 23 reported human cases of West Nile virus and one fatality, an 88-year old Kern County woman who died last month. In Texas, where they have undertaken an aerial assault against mosquitoes (and prompted public controversy over the safety of the chemicals), there are 336 reported human cases of the virus and 14 deaths.

The symptoms of West Nile virus can include fever, headache, muscle weakness, nausea, vomiting, swollen lymph glands and rash on the chest, back or stomach. If the disease develops into encephalitis, symptoms can include high fever, severe headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. The milder illness symptoms may disappear after several weeks, but the neurological affectations are usually permanent.

To avoid rabies, make sure that pets are vaccinated and be aware of strange animals in and around your immediate area. If a bat is found during the day, chances are it is sick. Do not handle the bat; cover it with a bucket and call Animal Care and Control for pickup.