PRINCETON — The Bureau/Putnam County Health Department has received a state grant to help with surveillance work for the coming West Nile Virus (WNV) season.
The local health department will receive $14,236 for Bureau County and $11,362 for Putnam County. The Illinois Department of Public Health awarded the WNV grants totaling $3.4 million to 90 certified local health departments throughout the state. The grants are based on WNV activity surveillance from the previous three years, along with county population.
In announcing the grant, Illinois Department of Public Health Director LaMar Hasbrouck said Illinois experienced its second highest number of human West Nile Virus cases last year, second only to the 2002 outbreak.
“Our local health departments around the state are on the front lines in the fight against West Nile Virus, and it is important they have the resources necessary to monitor mosquito activity, take steps to reduce the mosquito population and investigate human infections,” Hasbrouck said.
For the 2012 season, Illinois reported 290 human cases of West Nile disease and 12 deaths. The state followed a nationwide trend and ranked fourth in the country for the total number of human cases, Hasbrouck said.
Concerning local surveillance plans, Kurt Kuchle, director of health protection for the Bureau/Putnam County Health Department, said Bureau and Putnam counties are each asked to submit five birds per season for testing, with the bird testing running May through October.
Also, the health department sets two traps per county, generally near recreation areas where human exposure is most likely, Kuchle said. The mosquito traps are put out when nighttime temperatures remain at or above 55 degrees. When temperatures are 55 degrees are lower, mosquitoes are not very active. The health department usually sets outs its mosquito traps sometime in June depending on the temperatures.
The testing/surveillance is needed to detect when activity or amplification of the virus is beginning, so public service announcements can get the word out, Kuchle said.
However, not all mosquitoes are carriers of the virus. The wet April weather tends to favor the “inland floodwater mosquito,” which are active biters but not thought to be disease-carriers. As a rule, hot dry conditions favor a higher percentage of “house mosquitoes” which are the carriers of WNV.
“It is difficult to predict if we will have a heavy season for mosquitoes, which can be different than a heavy season for the virus,” Kuchle said. “You can have lots of mosquitoes with low virus activity or few mosquitoes and lots of virus activity.”
Whether or not it’s a mild season for WNV, history has shown that mid-to-late July is when detection of the virus peaks, and mid-to-late August is when illness among humans peaks, Kuchle said.
“Last year was hot and dry with a corresponding higher number of West Nile cases,” Kuchle said. “Most experts believe such weather conditions to be the determining factor for West Nile virus activity/amplification.”
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